Francesca Capone - Academia.edu (original) (raw)

Papers by Francesca Capone

Research paper thumbnail of Behavioral responses of 129/Sv, C57BL/6J and DBA/2J mice to a non-predator aversive olfactory stimulus

Acta neurobiologiae experimentalis, 2005

We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) expos... more We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) exposed to an object soaked with the chemical component of the aversive scent (toluquinone odor) emitted by a myriapod species (Ommatoiulus sabulosus) in the presence of a predator. Subjects were exposed to the odor for three consecutive days. Behavioral responses to the toluquinone odor were characterized both by an approach phase of risk assessment and by a repeated series of approach-avoid episodes. Results indicate that toluquinone exposure reduced completely, and in a strain independent fashion, selected behaviors such as crouching, catching and eating object. Other responses were strain-dependent: the DBA (DBA/2J) strain displayed defensive burying at high levels, C57 (C57BL/6J) mice performed high levels of withdrawal while the 129/Sv (129/SvPasIco) strain showed also high levels of stretch attend posture. Compared to other tasks, this test is ethological, simple, cheap and is not affe...

Research paper thumbnail of Maternal deprivation and early handling affect density of calcium binding protein-containing neurons in selected brain regions and emotional behavior in periadolescent rats

Neuroscience, 2007

Adverse early life experiences can induce neurochemical changes that may underlie modifications i... more Adverse early life experiences can induce neurochemical changes that may underlie modifications in hypothalamic-pituitary-adrenal axis responsiveness, emotionality and cognition. Here, we investigated the expression of the calcium binding proteins (CBPs) calretinin, calbindin and parvalbumin, which identify subpopulations of GABAergic neurons and serve important functional roles by buffering intracellular calcium levels, following brief (early handling) and long (maternal deprivation) periods of maternal separation, as compared with non-handled controls. CBP-expressing neurons were analyzed in brain regions related to stress and anxiety. Emotionality was assessed in parallel using the social interaction test. Analyses were carried out at periadolescence, an important phase for the development of brain areas involved in stress responses. Our results indicate that density of CBPimmunoreactive neurons decreases in the paraventricular region of deprived rats but increases in the hippocampus and lateral amygdala of both earlyhandled and deprived rats when compared with controls. Emotionality is reduced in both early-handled and deprived animals. In conclusion, early handling and deprivation led to neurochemical and behavioral changes linked to stress-sensitive brain regions. These data suggest that the effects of early experiences on CBP containing neurons might contribute to the functional changes of neuronal circuits involved in emotional response.

Research paper thumbnail of Shuttle-Box Avoidance Learning in Mice: Improvement by Glucose Combined with Stimulant Drugs

Neurobiology of Learning and Memory, 2000

Glucose was tested alone or in combination with two stimulant drugs, amphetamine and nicotine, in... more Glucose was tested alone or in combination with two stimulant drugs, amphetamine and nicotine, in mice of the CD-1 strain subjected to five daily shuttle-box training sessions. Pretraining intraperitoneal administration of glucose (50 or 100 mg/kg) had no effect, while amphetamine and nicotine, given alone, significantly improved avoidance acquisition at a dose of 0.5 mg/kg, but not 0.025 mg/kg. Significant improvement of avoidance learning was also produced by a combination of glucose with the lower dose of amphetamine or nicotine. This enhancing action, produced by a combination of glucose and stimulant drugs, at doses ineffective by themselves, might be due to a concomitant cholinergic and dopaminergic activation, induced by glucose and stimulant drugs, respectively.

Research paper thumbnail of Studies on a new series of THA analogues: Effects of the aromatic residues that line the gorge of AChE

FEBS Letters, 1997

A series of N‐monoalkylsubstituted 1,2,3,4‐tetrahydro‐9‐aminoacridines have been prepared after m... more A series of N‐monoalkylsubstituted 1,2,3,4‐tetrahydro‐9‐aminoacridines have been prepared after modelling simulation of the AChE–inhibitor complex. Molecular modelling has predicted a number of hydrophobic residues to be involved in the catalytic mechanism of this interaction between the binding sites of AChE and this series of aminoacridines. In these compounds the acridine moiety becomes sandwiched between the rings of PHE330 and TRP84. In particular, the alkyl chain shows the important role of aromatic groups as binding sites. Their in vitro inhibitory properties (enzyme from Electrophorus electricus) confirm the aromatic groups as a general and significant characteristic of the mechanism of AChE inhibition.

Research paper thumbnail of Cerebellar Purkinje Cell Loss in Heterozygousrora+/−mice: A Longitudinal Study

Journal of Neurogenetics, 2006

The staggerer (sg/sg) mutation is a spontaneous deletion in the Rora gene that prevents the trans... more The staggerer (sg/sg) mutation is a spontaneous deletion in the Rora gene that prevents the translation of the ligand-binding domain (LBD), leading to the loss of RORα activity. The homozygous Rora sg/sg mutant mouse, whose most obvious phenotype is ataxia associated with cerebellar degeneration, also displays a variety of other phenotypes. The heterozygous Rora +/sg is able to develop a cerebellum which is qualitatively normal but with advancing age suffers a significant loss of cerebellar neuronal cells. A truncated protein synthesized by the mutated allele may play a role, both in Rora sg/sg and Rora +/sg. To determine the effects during life span of true haplo-insufficiency of the RORα protein, derived from the invalidation of the gene, we compared the evolution of Purkinje cell numbers in heterozygous Rora knockout males (Rora +/-) and in their wildtype counterparts from 1 to 24 months of age. We also compared the evolution of Purkinje cell numbers in Rora +/and Rora +/sg males from 1 to 9 months. The main finding is that in Rora +/mice, when only a half dose of protein is synthesized, the deficit was already established at 1 month and did not change during life span. Thus, the effects of aging on PC number were apparent much earlier in Rora +/than in Rora +/sg , although at 24 months of age the deficit was similar.

Research paper thumbnail of Methods in the Analysis of Maternal Behavior in the Rodent

Current Protocols in Toxicology, 2005

The aim of this unit is to provide a set of fundamental protocols to assess maternal behavior in ... more The aim of this unit is to provide a set of fundamental protocols to assess maternal behavior in rats and mice. Parental behavior in rodents is characterized by a rather complex set of behavioral items, which are described in great detail. A special emphasis has been placed on listing the many intervening variables that can bias the correct assessment of maternal behavior and the modifications to that behavior resulting from exposure to drugs or toxic compounds. Because changes in maternal behavior can be very subtle, the accuracy of the protocols can enhance the likelihood of detecting minor differences in behavior resulting from the experimental procedures. In addition, some suggestions are given on the most appropriate methods of data collection and their statistical analysis.

Research paper thumbnail of Differential in vitro neurotoxicity of the flame retardant PBDE-99 and of the PCB Aroclor 1254 in human astrocytoma cells

Toxicology Letters, 2004

Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Because of the... more Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Because of their presence in maternal milk and their structural similarity to polychlorinated biphenyls (PCBs), concern has been raised on their possible developmental neurotoxicity. Aim of the present study was to investigate the in vitro effects of PBDE-99 (2,2', 4,4', 5-pentabromodiphenyl ether) on astroglial cells (human 132-1N1 astrocytoma cells) and comparing it with those of the PCB mixture Aroclor 1254. Both PBDE-99 and Aroclor 1254 caused a concentration-dependent inhibition of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) reduction, however, only the latter increased lactate dehydrogenase (LDH) release or cell death, assessed by the trypan blue assay. PBDE-99 caused translocation of the three protein kinase C (PKC) isozymes (alpha, epsilon, zeta) present in 132-1N1 astrocytoma cells, while Aroclor 1254 affected only PKCalpha and epsilon translocation. However, pre-incubation with the PKC inhibitor GF109203X or PKC down-regulation by the phorbol ester PMA, had minimal or no effect on PBDE-99 or Aroclor 1254-induced cytotoxicity. Similarly, the calcium chelator BAPTA-AM, the tyrosine kinase inhibitor genistein, and the MEK (mitogen activated protein kinase kinase) inhibitor PD98059 had no effect on PBDE-99 and Aroclor 1254 cytoxicity. On the other hand, the phosphatidylinositol 3 kinase (PI-3K) inhibitor LY290042 enhanced PBDE-99 toxicity, but did not affect Aroclor 1254. Because of the involvement of PI-3K in apoptotic cell death, the ability of PBDE-99 and Aroclor 1254 to induce apoptosis in astrocytoma cells was investigated. PBDE-99, but not Aroclor 1254, caused apoptotic cell death in astrocytoma cells, assessed by the TUNEL method and by Hoechst 33258 staining, via a p53 dependent mechanism. These results suggest that PBDE-99 and Aroclor 1254 exert differential cytotoxic effects on human astroglial cells.

Research paper thumbnail of Autoantibodies against opioid or glutamate receptors are associated with changes in morphine reward and physical dependence in mice

Psychopharmacology, 2008

Possible interactions between nervous and immune systems during opioid addiction remain elusive. ... more Possible interactions between nervous and immune systems during opioid addiction remain elusive. Recombinant mu-delta opioid receptors (MDOR) and the glutamate receptor 1 (GluR1) subunit of amino-3-hydroxy-5-methyl-4-isoxazole propionic acid glutamate receptors are involved in acute and chronic effects of morphine. Elevated levels of autoantibodies (aAbs) to these receptors were demonstrated in heroin human addicts and in animal models. This study characterized the role of aAbs to these receptors in behavioral modulations recruited during opioid tolerance and sensitization. Male CD-1 mice, immunized with either MDOR or GluR1 peptide fragments (80 microg intraperitoneal (i.p.)), were examined for spontaneous behavior and response to morphine (5 mg/kg i.p.). Spontaneous home-cage activity, novelty-induced self-grooming and morphine-induced hyperactivity were higher in GluR1 mice compared to Vehicle subjects, whereas MDOR immunization was associated with an increased morphine-induced conditioned place preference. In response to escalating doses of morphine (from 10 to 60 mg/kg i.p., twice daily) and naloxone-precipitated withdrawal (1 mg/kg subcutaneous), GluR1 mice exhibited a more marked stereotyped sniffing behavior and less body tremors compared to Vehicle subjects, whereas less sniffing and teeth chattering were found in MDOR mice. The expected downregulation of mu receptor binding sites, induced by chronic morphine in vehicle subjects, was completely absent following MDOR immunization. These findings indicate an altered response to morphine-related reinforcing and aversive effects in MDOR mice and altered coping with the environment in GluR1 mice. Circulating aAbs to specific neuroreceptors may alter the response to opiates and play a role as determinants of vulnerability to opiate addiction.

Research paper thumbnail of Response of CD-1 mice to the chemical defence of a common arthropod (Ommatoiulus sabulosus)

Physiology & Behavior, 2001

In order to set up a novel and ethologically relevant methodology that could be applied to the st... more In order to set up a novel and ethologically relevant methodology that could be applied to the study of olfactory capabilities in transgenic mice, we analysed the behavioural responses of sexually mature male and female CD-1 mice individually exposed to a striped millipede, Ommatoiulus sabulosus (L.), a very common myriapod species that secretes a repulsive and persistent odour in the presence of a predator. As control, we exposed mice to a larva of the lepidopteran Greater wax moth, Galleria mellonella (L.), which closely resembles the millipede in shape and dimensions but which does not secrete a repulsive odour in defence. We recorded and analysed a wide spectrum of behavioural responses including both those of avoidance and nonavoidance such as attempts to eat the arthropod. Behavioural responses were measured for 10 min upon first exposure to the millipede or wax moth. The procedure was repeated for 3 consecutive days. Upon exposure to a millipede, mice of both sexes showed a dramatic increase in the avoidance behaviour of digging. Moreover, millipedes were repulsive to mice and though they were sniffed frequently and sometimes caught, they were never eaten. In comparison, mice exposed to a wax moth almost always ate it. Sex differences emerged only for locomotion with female appearing to be more active. These results suggest that mice are able to discriminate between ethologically relevant odours and that the behavioural responses they display in this more natural context differ from those observed in response to odours of predators.

Research paper thumbnail of Prolonged perinatal AZT administration and early maternal separation: effects on social and emotional behaviour of periadolescent mice

Pharmacology Biochemistry and Behavior, 2003

Zidovudine (AZT) is an effective treatment in preventing perinatal transmission of HIV-1; however... more Zidovudine (AZT) is an effective treatment in preventing perinatal transmission of HIV-1; however, a continuous re-evaluation of the risk-benefit ratio of human exposure to this drug is suggested by both clinical and animal studies. The objective of this study was to assess the medium and long-term effects of pre-postnatal AZT treatment on mouse social and emotional behaviour and the possible interactions between AZT exposure and disruptions in the mother-infant relationship. Pregnant CD-1 mice were administered per os with AZT (160 mg/kg) from pregnancy day 10, throughout delivery, to lactation day 10. In half of the litters, the offspring was separated from the mother for 3 h from postnatal days 2 (PND2) to PND14. On PND35, a 30-min social interaction test was performed and corticosterone levels were measured at the end of the session. On PND80, long-term effects of AZT on emotionality were assess by means of an elevated plus-maze. Results indicate that, on PND35, previous AZT exposure affected social behaviour of the experimental subjects, reducing aggressive interactions in males, while decreasing investigative behaviours in females. At adulthood, AZT inhibited exploratory behaviour in the plus-maze while increasing the frequency of risk-assessment postures in male mice. As for maternal deprivation, this early manipulation exerted a pro-aggressive effect in adolescent male mice, deprived subjects being overall characterised by higher activity levels and a deficit in habituation, an effect also observed in the plus-maze. A significant interaction between AZT and maternal deprivation was found for affiliative behaviours. As for corticosterone levels, no AZT effect was found, while maternal deprivation tended to reduce elevations of this hormone in response to stressful stimuli. Overall results from this study indicate that both AZT exposure and maternal deprivation induced gender-dependent changes in social and emotional behaviour both during adolescence and at adulthood.

Research paper thumbnail of Early Developmental Exposure to BDE 99 or Aroclor 1254 Affects Neurobehavioural Profile: Interference from the Administration Route

NeuroToxicology, 2005

Among the most persistent and bio-accumulative environmental pollutants are the polybrominated di... more Among the most persistent and bio-accumulative environmental pollutants are the polybrominated diphenyl ethers (PBDEs), a class of chemicals widely used as flame retardants in plastics and textile coating, and the polychlorinated biphenyls (PCBs), previously used as coolants and lubricants in electrical equipment. Monitoring programs revealed high levels of both these classes of compounds in human breast milk, raising concerns for their potential noxious effects on infants. The aim of the present study was to investigate the neurotoxic effects of 2,2 0 ,4,4 0 ,5-penta BDE (BDE 99: 18 mg/ kg/day) or Aroclor 1254 (A1254, a PCB mixture: 10 mg/kg/day) administration, from gestational day (GD) 6 to postnatal day (PND) 21, on neurobehavioral development in the CD-1 Swiss mouse. In addition, we investigated whether the administration route affects the emergence or the magnitude of the toxic effects of BDE 99 or A1254. In particular, we compared self-administration, consisting in letting the mouse drink spontaneously the compound dissolved in oil from a syringe, with gavage, consisting in force-feeding a substance by a tube inserted in the mouth and then into the stomach, a procedure reported to be stress-inducing. Both compounds induced hyperactivity, though BDE 99 affected activity profile only during adolescence and A1254 mainly at adulthood. Levels of total circulating thyroxine were decreased by both BDE 99 and A1254 administration, though only in the latter group the decrease was statistically significant. These findings suggest a different neurotoxic action exerted by PBDEs and PCBs. An effect of the administration route, independent from the compound administered, was found on thigmotactic behavior and gavage administration affected pup body weight gain only in the A1254 group, suggesting that the stress induced by gavage procedure may either affect results per se or modulate the detrimental action of selected compounds.

Research paper thumbnail of Polybrominated Diphenyl Ethers: Neurobehavioral Effects Following Developmental Exposure

NeuroToxicology, 2003

Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are becoming wid... more Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are becoming widespread environmental pollutants, as indicated by studies on sentinel animal species, as well as humans. Of particular concern are the reported increasingly high levels of PBDEs in human milk, as should be given that almost no information is available on their potential effects on developing organisms. In order to address this issue, studies have been conducted in mice and rats to assess the potential neurotoxic effects of perinatal exposure to PBDEs (congeners 47, 99, 153 and the penta-BDE mixture DE-71). Characteristic endpoints of PBDE neurotoxicity are, among others, endocrine disruption (e.g. decreased thyroid hormone levels), alteration in cholinergic system activity (behavioral hyporesponsivity to nicotine challenge), as well as alterations of several behavioral parameters. In particular, the main hallmark of PBDE neurotoxicity is a marked hyperactivity at adulthood. Furthermore, a deficit in learning and memory processes has been found at adulthood in neonatally exposed animals. Some of neurotoxic effects of PBDEs are comparable to those of polychlorinated biphenyls (PCBs), though the latter class of compounds seems to exert a stronger toxic effect. Available information on PBDE neurotoxicity obtained from animal studies and the possibility of neonatal exposure to PBDEs via the mother's milk suggest that these compounds may represent a potential risk for neurobehavioral development in humans.

Research paper thumbnail of Early life influences on emotional reactivity: Evidence that social enrichment has greater effects than handling on anxiety-like behaviors, neuroendocrine responses to stress and central BDNF levels

Neuroscience & Biobehavioral Reviews, 2010

During the early post-natal phases the brain is experience-seeking and provided by a considerable... more During the early post-natal phases the brain is experience-seeking and provided by a considerable plasticity which allows a fine tuning between the external environment and the developing organism. Since the early work of Seymour Levine, an impressive amount of research has clearly shown that stressful experiences exert powerful effects on the brain and body development. These effects can last throughout the entire life span influencing brain function and increasing the risk for depression and anxiety disorders. The mechanisms underlying the effects of early stress on the developing organism have been widely studied in rodents through experimental manipulations of the post-natal environment, such as handling, which have been shown to exert important effects on the emotional phenotype and the response to stress. In the present paper we review the relevant literature and present some original data indicating that, compared to handling, which imposes an external manipulation on the mother-infant relationship, social enrichment, in the form of communal rearing, in mice has very profound effects on animal's emotionality and the response to stress. These effects are also accompanied by important changes in central levels of brain-derived neurotrophic factor. The present data indicate that communal rearing has more pervasive effects than handling, strengthening previous data suggesting that it is a good animal model of reduced susceptibility to depression-like behavior. Overall, the availability of ever more sophisticated animal models represents a fundamental tool to translate basic research data into appropriate interventions for humans raised under traumatic or impoverished situations.

Research paper thumbnail of Effects of postnatal manipulation on nociception and morphine sensitivity in adult mice

Developmental Brain Research, 1999

Research paper thumbnail of Oxotremorine-induced modifications of the behavioral and neuroendocrine responses to formalin pain in male rats

Brain Research, 1999

In the present investigation, the antinociceptive effects of the muscarinic cholinergic agonist, ... more In the present investigation, the antinociceptive effects of the muscarinic cholinergic agonist, oxotremorine, were evaluated in rats Ž. Ž using the formalin test. In Expt. 1, two oxotremorine concentrations 0.1 and 0.2 mgrkg and two administration times 15 and 1 min. before formalin injection were chosen. All spontaneous and formalin-evoked behavioral responses were considered. In Expt. 2, only the Ž. higher concentration of oxotremorine 0.2 mgrkg was administered 15 or 1 min before the formalin test. The animals were killed 15, 30 or 60 min after formalin treatment. Blood was collected from the trunk to determine corticosterone plasma levels. Some brain areas Ž. hypothalamus, septum and periaqueductal gray matter were dissected for determination of the b-endorphin content. Oxotremorine induced a dose-and time-dependent reduction of all formalin-evoked responses: licking was decreased during both the first and second phases of the formalin test, flexing was decreased during the second phase by the higher concentration only and paw-jerk was decreased during the first phase by both concentrations. Rearing and line-crossing were significantly decreased by oxotremorine while exploratory activity was only partially reduced; self-grooming was increased. These effects on exploratory activity and self-grooming were abolished by formalin treatment. b-endorphin content in the septum was increased by oxotremorine administered 15 min, but not 1 min, before formalin-treatment. b-endorphin in the hypothalamus increased in all formalin-treated groups independently of oxotremorine administration. These results confirm, and extend to tonic pain, the analgesic effect exerted by oxotremorine on phasic responses. Because of the different effects on each formalin-induced response, they also indicate both spinal and supraspinal CNS sites of action.

Research paper thumbnail of Conjunctivally administered NGF antibody reduces pain sensitivity and anxiety-like behavioral responses in aged female mice

Behavioural Brain Research, 2010

Research paper thumbnail of A comparative study of Purkinje cells in two RORα gene mutant mice: staggerer and RORα−/−

Developmental Brain Research, 2001

The staggerer (Rorasg/sg) mutation is a deletion in the RORα gene, one member of a family of nucl... more The staggerer (Rorasg/sg) mutation is a deletion in the RORα gene, one member of a family of nuclear receptor genes related to the retinoic acid receptor. Recently Steinmayr et al. (Proc. Natl. Acad. Sci. USA 95 (1998) 3960) generated a RORα null-mutant mouse (Rora−/−) by using a targeting vector in which a β-Gal gene replaces the second finger of the

Research paper thumbnail of Refinement of pain evaluation techniques. The formalin test

Annali dell'Istituto superiore di sanità, 2004

The formalin test is an important means of assessing pain evoked-behaviours induced by moderately... more The formalin test is an important means of assessing pain evoked-behaviours induced by moderately intense and long-lasting noxious stimuli, yet the procedures for performing the test have not been standardised, hindering comparisons of data. In rodents, the level of sensitivity to the test and the evoked response have been observed to change depending on a number of variables. Among them, gender is the most important, although many other variables can influence the behavioural response (e.g., the animal species, the strain of mice and rats, housing conditions, and early social experience). In the present work, we provide information on the procedures used to perform the formalin test and the effects of both these procedures and the conditions and manipulation prior to the test on the animal and its behaviour, with the ultimate goal of improving these procedures and conditions and decreasing the variability among laboratories.

Research paper thumbnail of Behavioral responses of 129/Sv, C57BL/6J and DBA/2J mice to a non-predator aversive olfactory stimulus

Acta neurobiologiae experimentalis, 2005

We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) expos... more We examined the behavior of three inbred mouse strains (129/SvPasIco, C57BL/6J, and DBA/2J) exposed to an object soaked with the chemical component of the aversive scent (toluquinone odor) emitted by a myriapod species (Ommatoiulus sabulosus) in the presence of a predator. Subjects were exposed to the odor for three consecutive days. Behavioral responses to the toluquinone odor were characterized both by an approach phase of risk assessment and by a repeated series of approach-avoid episodes. Results indicate that toluquinone exposure reduced completely, and in a strain independent fashion, selected behaviors such as crouching, catching and eating object. Other responses were strain-dependent: the DBA (DBA/2J) strain displayed defensive burying at high levels, C57 (C57BL/6J) mice performed high levels of withdrawal while the 129/Sv (129/SvPasIco) strain showed also high levels of stretch attend posture. Compared to other tasks, this test is ethological, simple, cheap and is not affe...

Research paper thumbnail of Maternal deprivation and early handling affect density of calcium binding protein-containing neurons in selected brain regions and emotional behavior in periadolescent rats

Neuroscience, 2007

Adverse early life experiences can induce neurochemical changes that may underlie modifications i... more Adverse early life experiences can induce neurochemical changes that may underlie modifications in hypothalamic-pituitary-adrenal axis responsiveness, emotionality and cognition. Here, we investigated the expression of the calcium binding proteins (CBPs) calretinin, calbindin and parvalbumin, which identify subpopulations of GABAergic neurons and serve important functional roles by buffering intracellular calcium levels, following brief (early handling) and long (maternal deprivation) periods of maternal separation, as compared with non-handled controls. CBP-expressing neurons were analyzed in brain regions related to stress and anxiety. Emotionality was assessed in parallel using the social interaction test. Analyses were carried out at periadolescence, an important phase for the development of brain areas involved in stress responses. Our results indicate that density of CBPimmunoreactive neurons decreases in the paraventricular region of deprived rats but increases in the hippocampus and lateral amygdala of both earlyhandled and deprived rats when compared with controls. Emotionality is reduced in both early-handled and deprived animals. In conclusion, early handling and deprivation led to neurochemical and behavioral changes linked to stress-sensitive brain regions. These data suggest that the effects of early experiences on CBP containing neurons might contribute to the functional changes of neuronal circuits involved in emotional response.

Research paper thumbnail of Shuttle-Box Avoidance Learning in Mice: Improvement by Glucose Combined with Stimulant Drugs

Neurobiology of Learning and Memory, 2000

Glucose was tested alone or in combination with two stimulant drugs, amphetamine and nicotine, in... more Glucose was tested alone or in combination with two stimulant drugs, amphetamine and nicotine, in mice of the CD-1 strain subjected to five daily shuttle-box training sessions. Pretraining intraperitoneal administration of glucose (50 or 100 mg/kg) had no effect, while amphetamine and nicotine, given alone, significantly improved avoidance acquisition at a dose of 0.5 mg/kg, but not 0.025 mg/kg. Significant improvement of avoidance learning was also produced by a combination of glucose with the lower dose of amphetamine or nicotine. This enhancing action, produced by a combination of glucose and stimulant drugs, at doses ineffective by themselves, might be due to a concomitant cholinergic and dopaminergic activation, induced by glucose and stimulant drugs, respectively.

Research paper thumbnail of Studies on a new series of THA analogues: Effects of the aromatic residues that line the gorge of AChE

FEBS Letters, 1997

A series of N‐monoalkylsubstituted 1,2,3,4‐tetrahydro‐9‐aminoacridines have been prepared after m... more A series of N‐monoalkylsubstituted 1,2,3,4‐tetrahydro‐9‐aminoacridines have been prepared after modelling simulation of the AChE–inhibitor complex. Molecular modelling has predicted a number of hydrophobic residues to be involved in the catalytic mechanism of this interaction between the binding sites of AChE and this series of aminoacridines. In these compounds the acridine moiety becomes sandwiched between the rings of PHE330 and TRP84. In particular, the alkyl chain shows the important role of aromatic groups as binding sites. Their in vitro inhibitory properties (enzyme from Electrophorus electricus) confirm the aromatic groups as a general and significant characteristic of the mechanism of AChE inhibition.

Research paper thumbnail of Cerebellar Purkinje Cell Loss in Heterozygousrora+/−mice: A Longitudinal Study

Journal of Neurogenetics, 2006

The staggerer (sg/sg) mutation is a spontaneous deletion in the Rora gene that prevents the trans... more The staggerer (sg/sg) mutation is a spontaneous deletion in the Rora gene that prevents the translation of the ligand-binding domain (LBD), leading to the loss of RORα activity. The homozygous Rora sg/sg mutant mouse, whose most obvious phenotype is ataxia associated with cerebellar degeneration, also displays a variety of other phenotypes. The heterozygous Rora +/sg is able to develop a cerebellum which is qualitatively normal but with advancing age suffers a significant loss of cerebellar neuronal cells. A truncated protein synthesized by the mutated allele may play a role, both in Rora sg/sg and Rora +/sg. To determine the effects during life span of true haplo-insufficiency of the RORα protein, derived from the invalidation of the gene, we compared the evolution of Purkinje cell numbers in heterozygous Rora knockout males (Rora +/-) and in their wildtype counterparts from 1 to 24 months of age. We also compared the evolution of Purkinje cell numbers in Rora +/and Rora +/sg males from 1 to 9 months. The main finding is that in Rora +/mice, when only a half dose of protein is synthesized, the deficit was already established at 1 month and did not change during life span. Thus, the effects of aging on PC number were apparent much earlier in Rora +/than in Rora +/sg , although at 24 months of age the deficit was similar.

Research paper thumbnail of Methods in the Analysis of Maternal Behavior in the Rodent

Current Protocols in Toxicology, 2005

The aim of this unit is to provide a set of fundamental protocols to assess maternal behavior in ... more The aim of this unit is to provide a set of fundamental protocols to assess maternal behavior in rats and mice. Parental behavior in rodents is characterized by a rather complex set of behavioral items, which are described in great detail. A special emphasis has been placed on listing the many intervening variables that can bias the correct assessment of maternal behavior and the modifications to that behavior resulting from exposure to drugs or toxic compounds. Because changes in maternal behavior can be very subtle, the accuracy of the protocols can enhance the likelihood of detecting minor differences in behavior resulting from the experimental procedures. In addition, some suggestions are given on the most appropriate methods of data collection and their statistical analysis.

Research paper thumbnail of Differential in vitro neurotoxicity of the flame retardant PBDE-99 and of the PCB Aroclor 1254 in human astrocytoma cells

Toxicology Letters, 2004

Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Because of the... more Polybrominated diphenyl ethers (PBDEs) are an important class of flame retardants. Because of their presence in maternal milk and their structural similarity to polychlorinated biphenyls (PCBs), concern has been raised on their possible developmental neurotoxicity. Aim of the present study was to investigate the in vitro effects of PBDE-99 (2,2', 4,4', 5-pentabromodiphenyl ether) on astroglial cells (human 132-1N1 astrocytoma cells) and comparing it with those of the PCB mixture Aroclor 1254. Both PBDE-99 and Aroclor 1254 caused a concentration-dependent inhibition of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) reduction, however, only the latter increased lactate dehydrogenase (LDH) release or cell death, assessed by the trypan blue assay. PBDE-99 caused translocation of the three protein kinase C (PKC) isozymes (alpha, epsilon, zeta) present in 132-1N1 astrocytoma cells, while Aroclor 1254 affected only PKCalpha and epsilon translocation. However, pre-incubation with the PKC inhibitor GF109203X or PKC down-regulation by the phorbol ester PMA, had minimal or no effect on PBDE-99 or Aroclor 1254-induced cytotoxicity. Similarly, the calcium chelator BAPTA-AM, the tyrosine kinase inhibitor genistein, and the MEK (mitogen activated protein kinase kinase) inhibitor PD98059 had no effect on PBDE-99 and Aroclor 1254 cytoxicity. On the other hand, the phosphatidylinositol 3 kinase (PI-3K) inhibitor LY290042 enhanced PBDE-99 toxicity, but did not affect Aroclor 1254. Because of the involvement of PI-3K in apoptotic cell death, the ability of PBDE-99 and Aroclor 1254 to induce apoptosis in astrocytoma cells was investigated. PBDE-99, but not Aroclor 1254, caused apoptotic cell death in astrocytoma cells, assessed by the TUNEL method and by Hoechst 33258 staining, via a p53 dependent mechanism. These results suggest that PBDE-99 and Aroclor 1254 exert differential cytotoxic effects on human astroglial cells.

Research paper thumbnail of Autoantibodies against opioid or glutamate receptors are associated with changes in morphine reward and physical dependence in mice

Psychopharmacology, 2008

Possible interactions between nervous and immune systems during opioid addiction remain elusive. ... more Possible interactions between nervous and immune systems during opioid addiction remain elusive. Recombinant mu-delta opioid receptors (MDOR) and the glutamate receptor 1 (GluR1) subunit of amino-3-hydroxy-5-methyl-4-isoxazole propionic acid glutamate receptors are involved in acute and chronic effects of morphine. Elevated levels of autoantibodies (aAbs) to these receptors were demonstrated in heroin human addicts and in animal models. This study characterized the role of aAbs to these receptors in behavioral modulations recruited during opioid tolerance and sensitization. Male CD-1 mice, immunized with either MDOR or GluR1 peptide fragments (80 microg intraperitoneal (i.p.)), were examined for spontaneous behavior and response to morphine (5 mg/kg i.p.). Spontaneous home-cage activity, novelty-induced self-grooming and morphine-induced hyperactivity were higher in GluR1 mice compared to Vehicle subjects, whereas MDOR immunization was associated with an increased morphine-induced conditioned place preference. In response to escalating doses of morphine (from 10 to 60 mg/kg i.p., twice daily) and naloxone-precipitated withdrawal (1 mg/kg subcutaneous), GluR1 mice exhibited a more marked stereotyped sniffing behavior and less body tremors compared to Vehicle subjects, whereas less sniffing and teeth chattering were found in MDOR mice. The expected downregulation of mu receptor binding sites, induced by chronic morphine in vehicle subjects, was completely absent following MDOR immunization. These findings indicate an altered response to morphine-related reinforcing and aversive effects in MDOR mice and altered coping with the environment in GluR1 mice. Circulating aAbs to specific neuroreceptors may alter the response to opiates and play a role as determinants of vulnerability to opiate addiction.

Research paper thumbnail of Response of CD-1 mice to the chemical defence of a common arthropod (Ommatoiulus sabulosus)

Physiology & Behavior, 2001

In order to set up a novel and ethologically relevant methodology that could be applied to the st... more In order to set up a novel and ethologically relevant methodology that could be applied to the study of olfactory capabilities in transgenic mice, we analysed the behavioural responses of sexually mature male and female CD-1 mice individually exposed to a striped millipede, Ommatoiulus sabulosus (L.), a very common myriapod species that secretes a repulsive and persistent odour in the presence of a predator. As control, we exposed mice to a larva of the lepidopteran Greater wax moth, Galleria mellonella (L.), which closely resembles the millipede in shape and dimensions but which does not secrete a repulsive odour in defence. We recorded and analysed a wide spectrum of behavioural responses including both those of avoidance and nonavoidance such as attempts to eat the arthropod. Behavioural responses were measured for 10 min upon first exposure to the millipede or wax moth. The procedure was repeated for 3 consecutive days. Upon exposure to a millipede, mice of both sexes showed a dramatic increase in the avoidance behaviour of digging. Moreover, millipedes were repulsive to mice and though they were sniffed frequently and sometimes caught, they were never eaten. In comparison, mice exposed to a wax moth almost always ate it. Sex differences emerged only for locomotion with female appearing to be more active. These results suggest that mice are able to discriminate between ethologically relevant odours and that the behavioural responses they display in this more natural context differ from those observed in response to odours of predators.

Research paper thumbnail of Prolonged perinatal AZT administration and early maternal separation: effects on social and emotional behaviour of periadolescent mice

Pharmacology Biochemistry and Behavior, 2003

Zidovudine (AZT) is an effective treatment in preventing perinatal transmission of HIV-1; however... more Zidovudine (AZT) is an effective treatment in preventing perinatal transmission of HIV-1; however, a continuous re-evaluation of the risk-benefit ratio of human exposure to this drug is suggested by both clinical and animal studies. The objective of this study was to assess the medium and long-term effects of pre-postnatal AZT treatment on mouse social and emotional behaviour and the possible interactions between AZT exposure and disruptions in the mother-infant relationship. Pregnant CD-1 mice were administered per os with AZT (160 mg/kg) from pregnancy day 10, throughout delivery, to lactation day 10. In half of the litters, the offspring was separated from the mother for 3 h from postnatal days 2 (PND2) to PND14. On PND35, a 30-min social interaction test was performed and corticosterone levels were measured at the end of the session. On PND80, long-term effects of AZT on emotionality were assess by means of an elevated plus-maze. Results indicate that, on PND35, previous AZT exposure affected social behaviour of the experimental subjects, reducing aggressive interactions in males, while decreasing investigative behaviours in females. At adulthood, AZT inhibited exploratory behaviour in the plus-maze while increasing the frequency of risk-assessment postures in male mice. As for maternal deprivation, this early manipulation exerted a pro-aggressive effect in adolescent male mice, deprived subjects being overall characterised by higher activity levels and a deficit in habituation, an effect also observed in the plus-maze. A significant interaction between AZT and maternal deprivation was found for affiliative behaviours. As for corticosterone levels, no AZT effect was found, while maternal deprivation tended to reduce elevations of this hormone in response to stressful stimuli. Overall results from this study indicate that both AZT exposure and maternal deprivation induced gender-dependent changes in social and emotional behaviour both during adolescence and at adulthood.

Research paper thumbnail of Early Developmental Exposure to BDE 99 or Aroclor 1254 Affects Neurobehavioural Profile: Interference from the Administration Route

NeuroToxicology, 2005

Among the most persistent and bio-accumulative environmental pollutants are the polybrominated di... more Among the most persistent and bio-accumulative environmental pollutants are the polybrominated diphenyl ethers (PBDEs), a class of chemicals widely used as flame retardants in plastics and textile coating, and the polychlorinated biphenyls (PCBs), previously used as coolants and lubricants in electrical equipment. Monitoring programs revealed high levels of both these classes of compounds in human breast milk, raising concerns for their potential noxious effects on infants. The aim of the present study was to investigate the neurotoxic effects of 2,2 0 ,4,4 0 ,5-penta BDE (BDE 99: 18 mg/ kg/day) or Aroclor 1254 (A1254, a PCB mixture: 10 mg/kg/day) administration, from gestational day (GD) 6 to postnatal day (PND) 21, on neurobehavioral development in the CD-1 Swiss mouse. In addition, we investigated whether the administration route affects the emergence or the magnitude of the toxic effects of BDE 99 or A1254. In particular, we compared self-administration, consisting in letting the mouse drink spontaneously the compound dissolved in oil from a syringe, with gavage, consisting in force-feeding a substance by a tube inserted in the mouth and then into the stomach, a procedure reported to be stress-inducing. Both compounds induced hyperactivity, though BDE 99 affected activity profile only during adolescence and A1254 mainly at adulthood. Levels of total circulating thyroxine were decreased by both BDE 99 and A1254 administration, though only in the latter group the decrease was statistically significant. These findings suggest a different neurotoxic action exerted by PBDEs and PCBs. An effect of the administration route, independent from the compound administered, was found on thigmotactic behavior and gavage administration affected pup body weight gain only in the A1254 group, suggesting that the stress induced by gavage procedure may either affect results per se or modulate the detrimental action of selected compounds.

Research paper thumbnail of Polybrominated Diphenyl Ethers: Neurobehavioral Effects Following Developmental Exposure

NeuroToxicology, 2003

Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are becoming wid... more Polybrominated diphenyl ethers (PBDEs), a class of widely used flame retardants, are becoming widespread environmental pollutants, as indicated by studies on sentinel animal species, as well as humans. Of particular concern are the reported increasingly high levels of PBDEs in human milk, as should be given that almost no information is available on their potential effects on developing organisms. In order to address this issue, studies have been conducted in mice and rats to assess the potential neurotoxic effects of perinatal exposure to PBDEs (congeners 47, 99, 153 and the penta-BDE mixture DE-71). Characteristic endpoints of PBDE neurotoxicity are, among others, endocrine disruption (e.g. decreased thyroid hormone levels), alteration in cholinergic system activity (behavioral hyporesponsivity to nicotine challenge), as well as alterations of several behavioral parameters. In particular, the main hallmark of PBDE neurotoxicity is a marked hyperactivity at adulthood. Furthermore, a deficit in learning and memory processes has been found at adulthood in neonatally exposed animals. Some of neurotoxic effects of PBDEs are comparable to those of polychlorinated biphenyls (PCBs), though the latter class of compounds seems to exert a stronger toxic effect. Available information on PBDE neurotoxicity obtained from animal studies and the possibility of neonatal exposure to PBDEs via the mother's milk suggest that these compounds may represent a potential risk for neurobehavioral development in humans.

Research paper thumbnail of Early life influences on emotional reactivity: Evidence that social enrichment has greater effects than handling on anxiety-like behaviors, neuroendocrine responses to stress and central BDNF levels

Neuroscience & Biobehavioral Reviews, 2010

During the early post-natal phases the brain is experience-seeking and provided by a considerable... more During the early post-natal phases the brain is experience-seeking and provided by a considerable plasticity which allows a fine tuning between the external environment and the developing organism. Since the early work of Seymour Levine, an impressive amount of research has clearly shown that stressful experiences exert powerful effects on the brain and body development. These effects can last throughout the entire life span influencing brain function and increasing the risk for depression and anxiety disorders. The mechanisms underlying the effects of early stress on the developing organism have been widely studied in rodents through experimental manipulations of the post-natal environment, such as handling, which have been shown to exert important effects on the emotional phenotype and the response to stress. In the present paper we review the relevant literature and present some original data indicating that, compared to handling, which imposes an external manipulation on the mother-infant relationship, social enrichment, in the form of communal rearing, in mice has very profound effects on animal's emotionality and the response to stress. These effects are also accompanied by important changes in central levels of brain-derived neurotrophic factor. The present data indicate that communal rearing has more pervasive effects than handling, strengthening previous data suggesting that it is a good animal model of reduced susceptibility to depression-like behavior. Overall, the availability of ever more sophisticated animal models represents a fundamental tool to translate basic research data into appropriate interventions for humans raised under traumatic or impoverished situations.

Research paper thumbnail of Effects of postnatal manipulation on nociception and morphine sensitivity in adult mice

Developmental Brain Research, 1999

Research paper thumbnail of Oxotremorine-induced modifications of the behavioral and neuroendocrine responses to formalin pain in male rats

Brain Research, 1999

In the present investigation, the antinociceptive effects of the muscarinic cholinergic agonist, ... more In the present investigation, the antinociceptive effects of the muscarinic cholinergic agonist, oxotremorine, were evaluated in rats Ž. Ž using the formalin test. In Expt. 1, two oxotremorine concentrations 0.1 and 0.2 mgrkg and two administration times 15 and 1 min. before formalin injection were chosen. All spontaneous and formalin-evoked behavioral responses were considered. In Expt. 2, only the Ž. higher concentration of oxotremorine 0.2 mgrkg was administered 15 or 1 min before the formalin test. The animals were killed 15, 30 or 60 min after formalin treatment. Blood was collected from the trunk to determine corticosterone plasma levels. Some brain areas Ž. hypothalamus, septum and periaqueductal gray matter were dissected for determination of the b-endorphin content. Oxotremorine induced a dose-and time-dependent reduction of all formalin-evoked responses: licking was decreased during both the first and second phases of the formalin test, flexing was decreased during the second phase by the higher concentration only and paw-jerk was decreased during the first phase by both concentrations. Rearing and line-crossing were significantly decreased by oxotremorine while exploratory activity was only partially reduced; self-grooming was increased. These effects on exploratory activity and self-grooming were abolished by formalin treatment. b-endorphin content in the septum was increased by oxotremorine administered 15 min, but not 1 min, before formalin-treatment. b-endorphin in the hypothalamus increased in all formalin-treated groups independently of oxotremorine administration. These results confirm, and extend to tonic pain, the analgesic effect exerted by oxotremorine on phasic responses. Because of the different effects on each formalin-induced response, they also indicate both spinal and supraspinal CNS sites of action.

Research paper thumbnail of Conjunctivally administered NGF antibody reduces pain sensitivity and anxiety-like behavioral responses in aged female mice

Behavioural Brain Research, 2010

Research paper thumbnail of A comparative study of Purkinje cells in two RORα gene mutant mice: staggerer and RORα−/−

Developmental Brain Research, 2001

The staggerer (Rorasg/sg) mutation is a deletion in the RORα gene, one member of a family of nucl... more The staggerer (Rorasg/sg) mutation is a deletion in the RORα gene, one member of a family of nuclear receptor genes related to the retinoic acid receptor. Recently Steinmayr et al. (Proc. Natl. Acad. Sci. USA 95 (1998) 3960) generated a RORα null-mutant mouse (Rora−/−) by using a targeting vector in which a β-Gal gene replaces the second finger of the

Research paper thumbnail of Refinement of pain evaluation techniques. The formalin test

Annali dell'Istituto superiore di sanità, 2004

The formalin test is an important means of assessing pain evoked-behaviours induced by moderately... more The formalin test is an important means of assessing pain evoked-behaviours induced by moderately intense and long-lasting noxious stimuli, yet the procedures for performing the test have not been standardised, hindering comparisons of data. In rodents, the level of sensitivity to the test and the evoked response have been observed to change depending on a number of variables. Among them, gender is the most important, although many other variables can influence the behavioural response (e.g., the animal species, the strain of mice and rats, housing conditions, and early social experience). In the present work, we provide information on the procedures used to perform the formalin test and the effects of both these procedures and the conditions and manipulation prior to the test on the animal and its behaviour, with the ultimate goal of improving these procedures and conditions and decreasing the variability among laboratories.