Luciana Giardino - Academia.edu (original) (raw)
Papers by Luciana Giardino
Alzheimer's & Dementia, 2009
European Journal of Pharmacology, 1998
Stress-related behaviors are accompanied by modification of a large number of neurotransmitters i... more Stress-related behaviors are accompanied by modification of a large number of neurotransmitters in the brain. Moreover, the binding to GABA(A) receptors does not account for all the effects of benzodiazepines. In this study we investigated the effect of repeated restraint stress and alprazolam treatment (1 mg/day os) on dopamine receptors (Bmax and Kd) in the striatum of adult rats by means of quantitative receptor autoradiography. After chronic restraint stress dopamine D1 receptors (Bmax value) decreased in the accumbens nucleus, whereas dopamine D2 receptors were not modified in any investigated area. After alprazolam treatment, a considerable increase in both dopamine D1 and D2 receptors in the striatum was observed. Chronic immobilization stress together with alprazolam treatment re-established dopamine D1 receptor density to control values in the accumbens nucleus and olfactory tubercle, whereas it resulted in an increase in dopamine D2 receptors comparable to that elicited by alprazolam treatment alone.
Regulatory Peptides, 1990
Most of the biochemical, physiological and behavioural events in living organisms show diurnal fl... more Most of the biochemical, physiological and behavioural events in living organisms show diurnal fluctuations, normally synchronized with 24-h environmental rhythms, such as the light-dark cycle. The suprachiasmatic nucleus (SCN) of the hypothalamus is considered to be a pacemaker of the circadian rhythms in several mammals. The light-dark cycle is the primary synchronizing agent for many of the circadian rhythms which are regulated by the SCN. The photic information reaches the SCN also through a neuropeptide Y(NPY)-like immunoreactive pathway from the ventro-lateral geniculate nucleus. We found that in 12-h-dark and 12-h-light housed rats the NPY-like immunoreactive innervation of the ventro-lateral part of the SCN shows a 24 h rhythm with values rising gradually during the light phase and falling during the dark phase. Besides this rhythm, we found two peaks corresponding to the switching on and switching off of the light. The average level of NPY-like immunoreactivity, as assessed by means of semiquantitative immunocytochemistry and expressed in 'arbitrary units', is reduced in rats housed in total darkness for 2 weeks. These results confirm the physiological role of NPY in the timing of the circadian activity of the SCN.
Proceedings of The National Academy of Sciences, 2004
Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degenerati... more Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degeneration, which follow remyelination failure. Due to the presence of numerous oligodendrocyte precursors inside demyelination plaques, one reason for demyelination failure could be the inability of oligodendrocyte precursor cells to turn into myelinating oligodendrocytes. In this study, we show that thyroid hormone enhances and accelerates remyelination in an experimental model of chronic demyelination, i.e., experimental allergic encephalomyelitis in congenic female Dark Agouti rats immunized with complete guinea pig spinal cord. Thyroid hormone, when administered during the acute phase of the disease, increases expression of platelet-derived growth factor ␣ receptor, restores normal levels of myelin basic protein mRNA and protein, and allows an early and morphologically competent reassembly of myelin sheaths. Moreover, thyroid hormone exerts a neuroprotective effect with respect to axonal pathology.
Brain Research, 1997
We studied modifications in [3H]MK801-binding sites in the rat brain after chronic clozapine. We ... more We studied modifications in [3H]MK801-binding sites in the rat brain after chronic clozapine. We found a 20-30% reduction of [3H]MK801-binding sites in the anterior cingulate, frontoparietal motor and frontoparietal somatosensory cortices on the left side but none on the right. We also demonstrated a 20% bilateral increase of N-methyl-D-aspartate (NMDA) receptors in the dentate gyrus of the hippocampus. No changes were found in the prefrontal cortex, caudate-putamen, nucleus accumbens, hippocampus or olfactory tubercle.
Endocrinology, 1989
The aim of the present study was to evaluate the possible presence of immunoreactive neuropeptide... more The aim of the present study was to evaluate the possible presence of immunoreactive neuropeptide-gamma (irNPY) in human placenta. Acidic extracts of human placental tissue collected at term pregnancy contained high irNPY concentrations. The extracted irNPY eluted from HPLC with the same retention time as synthetic NPY. The presence of the peptide in placental cells was confirmed by immunohistochemical findings showing numerous cells of the cytotrophoblast layer positively staining for NPY. Further supporting local production of the peptide, primary cultures of human placental cells released irNPY into the culture medium and the addition of high K+ concentrations increased the release of the peptide. The finding of irNPY in human placenta stimulated the characterization of binding sites of NPY in the same tissue. Using autoradiographic techniques we showed specific binding of [125I]NPY in human placental tissue. The binding of [125I]NPY to the placental receptors was saturable and widely distributed within the placental tissue. Finally, the addition of NPY to the medium of cultured placental cells increased the release of immunoreactive CRF, suggesting a possible role of NPY in placental hormone production. The effect of NPY was dose related and augmented by the addition of norepinephrine (10 nM). These results showed that human placenta produces and secretes irNPY and that NPY receptors are present in placental tissue. Moreover, the evidence that NPY stimulated the release of immunoreactive CRF from cultured placental cells suggests an action of NPY in placental hormonogenesis.
Journal of Neurochemistry, 2005
Galanin is a neuropeptide involved in a variety of biological functions, including having a stron... more Galanin is a neuropeptide involved in a variety of biological functions, including having a strong anticonvulsant activity. To assess a possible role of galanin in modulation of glutamatergic synapses and excitotoxicity, we studied effects of a galanin receptor 2(3) agonist (AR-M1896) on several molecular events induced by glutamate administration in primary neural hippocampal cells. Exposure of cells, after 5 days in vitro, to glutamate 0.5 mm for 10 min caused morphological alterations, including disaggregation of β-tubulin and MAP-2 cytoskeletal protein assembly, loss of neurites and cell shrinkage. When present in culture medium together with glutamate, 1 and 10 nm of AR-M1896 reduced these alterations. Moreover, AR-M1896 counteracted glutamate-induced c-fos mRNA and c-Fos protein up-regulation after 30–150 min, and 24 h, respectively. Massive nuclear alterations (Hoechst 33258 staining), observed 24 h after glutamate exposure, were also antagonized by AR-M1896 (0.1–100 nm) in a dose-dependent manner. These findings indicate that galanin, probably mainly through its type 2 receptor, interferes with events associated with glutamate toxicity.
Proceedings of The National Academy of Sciences, 1997
In this paper we report a time-course study of development of experimental allergic encephalomyel... more In this paper we report a time-course study of development of experimental allergic encephalomyelitis in Lewis rats, by monitoring neuroendocrine regulation of the hypothalamus-pituitary-adrenal axis through corticotropinreleasing hormone mRNA expression, inf lammatory cellular infiltrate, macrophagic and neuronal nitric oxide synthase, nerve growth factor (NGF), and NGF p75 and trkA receptors in the brain and spinal cord. We analyzed animals during 20 days after immunization, a time interval that corresponds to the acute immunological phase. We have described a severe, early fall of corticotropin-releasing hormone mRNA expression, which could account for the decreased response of the hypothalamus-pituitary-adrenal axis to inf lammatory stress. During this period, an increase of neuronal nitric oxide synthase was observed in the cerebral cortex and spinal cord, and macrophagic nitric oxide synthase positive cells were found in the inf lammatory cellular infiltrate, which was abundant in perivascular and submeningeal areas 20 days after immunization. Concomitantly, we found a dramatic up-regulation of NGF receptors on the wall of blood vessels and adjacent neurons in perivascular areas. NGF content also had increased in some brain areas, such as the thalamus, while it had decreased in others, like the spinal cord and medulla oblongata, at time points in which the most serious cellular infiltrate was found.
Neuroreport, 1993
Nitric oxide synthesizing (NOS) enzyme has been localized in distinct neural populations, includi... more Nitric oxide synthesizing (NOS) enzyme has been localized in distinct neural populations, including the hypothalamic paraventricular nucleus (PVN). Using in situ hybridization, we have investigated possible changes in NOS mRNA in the PVN of young and old rats after 2 h of immobilization stress. In old rats a 3-fold increase in NOS mRNA was observed in the PVN immediately after the stressor, whereas in young rats the increase reached significance when animals were killed 3 h after the end of the stress procedure. The present results suggest that nitric oxide in the PVN may be involved in the stress response. The differences observed in NOS mRNA between young and old rats could be related to an age-dependent different responsiveness to stressful stimuli.
Neuroscience, 1998
This study investigated the effects of stress on brain dopamine receptor densities in two inbred ... more This study investigated the effects of stress on brain dopamine receptor densities in two inbred strains of mice. Analysis of [ 3 H]SCH23390 binding by quantitative autoradiography revealed that repeated restraint stress significantly increases D 1 -like receptor density in the nucleus accumbens of mice of the DBA/2 strain whist reducing it in the caudate-putamen of C57BL/6 mice. No significant changes in D 2 -like receptor quantified by [ 3 H]( )-sulpiride binding were observed in caudate, substantia nigra and accumbens of stressed C57BL/6 mice. Instead, in DBA/2 mice, stress significantly increased D 2 -like receptor density in the nucleus accumbens whilst reducing it in the substantia nigra. Finally, stress significantly increased D 2 -like receptor density within the ventral tegmental area of C57BL/6 mice whilst significantly reducing it in mice of the DBA/2 strain.
Brain Research, 2000
The role of nitric oxide NO in inflammatoryrdemyelinating diseases is undergoing extensive invest... more The role of nitric oxide NO in inflammatoryrdemyelinating diseases is undergoing extensive investigation as a potential target for therapeutic intervention. However, interference with NO production has resulted in contrasting effects on the development of Ž . Ž . experimental allergic encephalomyelitis EAE , the most widely used experimental model for multiple sclerosis MS . Purpose of this paper was both the analysis of the individual clinical evolution of EAE induced in Lewis female rats by active immunisation and the Ž . evaluation of the effect of treatment with aminoguanidine, a selective inhibitor for the inducible isoform of nitric oxide synthase iNOS . In our experimental model, relapse occurred in 66% of animals. Aminoguanidine treatment, started 3 days before immunisation, guaranteed a complete recovery from the acute phase and a delayed, milder relapse. Moreover, 79 days after immunisation inflammatory cellular infiltrates in the spinal cord were reduced. These data further support the involvement of NO in EAE evolution. q
Proceedings of The National Academy of Sciences, 2002
Remyelination in the adult central nervous system has been demonstrated in different experimental... more Remyelination in the adult central nervous system has been demonstrated in different experimental models of demyelinating diseases. However, there is no clear evidence that remyelination occurs in multiple sclerosis, the most diffuse demyelinating disease. In this article, we explore the possibility of promoting myelination in experimental allergic encephalomyelitis, a widely used experimental model of multiple sclerosis, by recruiting progenitors and channeling them into oligodendroglial lineage through administration of thyroid hor-
Molecular Brain Research, 1996
Using in-situ hybridizationhistochemistrywe investigatedthe distributionof CRH receptor 1 (CRH-R1... more Using in-situ hybridizationhistochemistrywe investigatedthe distributionof CRH receptor 1 (CRH-R1)mRNA in the cortex of C57BL/6 (C57) and DBA/2 (DBA) strains and its regulationafter repeatedrestraint stress. We showthat DBA mice have a higher concentrationof CRH-R1mRNAthan C57 mice. Repeatedrestraintstressproducedan increasein CRH-R1mRNAexpressionof C57 mice, whereasit was ineffective in DBA mice.
Neuroendocrinology, 1992
Using in situ hybridization histochemistry, we have investigated the effect of thyroid hormone on... more Using in situ hybridization histochemistry, we have investigated the effect of thyroid hormone on the expression of several peptide mRNAs in the hypothalamic paraventricular nucleus (PVN) of adult male rats. Hypothyroidism was induced by surgical ablation of the thyroid gland. The animals (control sham-operated, thyroidectomized, thyroidectomized+T4 replaced rats) were studied 28 and 50 days after surgery. Sections of the PVN were hybridized using synthetic oligonucleotide probes complementary to mRNA for thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), galanin (GAL), enkephalin (ENK), neurotensin (NT), vasoactive intestinal polypeptide (VIP) and vasopressin (VP). GAL mRNA was also analyzed in the anterior paraventricular, arcuate, and dorsomedial nuclei of the hypothalamus. At the PVN level, a feedback effect of thyroid hormone on TRH synthesis was demonstrated by the TRH mRNA increase in hypothyroidism and by its decrease in hyperthyroidism. Hypothyroidism caused a dramatic decrease in GAL mRNA in parvo- and magnocellular PVN neurons both 28 and 50 days after thyroid ablation, whereas no effect was seen in VP mRNA, the main peptide hormone coexisting with GAL. The T4 replacement prevented the GAL mRNA impairment. Hypothyroidism did not influence GAL mRNA in the anterior PVN, perifornical area or in the arcuate nucleus, whereas a decrease in GAL mRNA was observed in the dorsomedial nucleus. VIP mRNA, which is undetectable in the PVN of normal animals, was present in several PVN neurons after thyroidectomy. CRH mRNA was decreased after thyroidectomy, whereas the T4 restitution caused an upregulation. The levels of ENK or NT mRNA were not significantly affected by the thyroid status. The present results show that, in addition to TRH mRNA, other hypothalamic peptide mRNAs are affected by thyroid hormone levels.
Human Molecular Genetics, 1996
The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proli... more The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proliferation, acting as a transducer molecule for developmental processes, including segmentation and neuroblast specification. We have isolated and characterized cDNA clones from two different human dsh-homologous genes, designated as DVL-1 and DVL-3. DVL-1 and DVL-3 putative protein products show 64% amino acid identity. The DVL-1 product is 50% identical to dsh and 92% to a murine dsh homologue (Dvl-1). Both human DVL genes are widely expressed in fetal and adult tissues, including brain, lung, kidney, skeletal muscle and heart. DVL-1 locus maps to chromosome 1p36 and DVL-3 to chromosome 3q27. DVL-1 locus on chromosome 1 corresponds to the murine syntenic region where Dvl-1 is located. DVL-1 and DVL-3 are members of a human dsh-like gene family, which is probably involved in human development. Although the precise role of these genes in embryogenesis is only conjectural at present, the structural and evolutionary characteristics suggest that mutations at their loci may be involved in neural and heart developmental defects.
Experimental Neurology, 1997
Several lines of data from human and animal studies have suggested a role of thyroid hormone in t... more Several lines of data from human and animal studies have suggested a role of thyroid hormone in the regulation of cholinergic neurons in the adult brain. In this study we have investigated the content of nerve growth factor (NGF) and the expression of NGF low affinity receptor (p75(LNGFR)) in the basal forebrain of adult hypothyroid rats. We describe an increase of both NGF and p75(LNGFR) expression in the basal forebrain of adult hypothyroid rats. The administration of colchicine up-regulates p75(LNGFR) expression in both hypo- and control rats, whereas it fails to down-regulate choline acetyl transferase mRNA expression during hypothyroidism. These data offer a possible neurobiological explanation to cognitive defects observed during adult hypothyroidism in humans.
Molecular Brain Research, 1994
A role of thyroid hormone in the regulation of neuropeptide synthesis has been demonstrated in di... more A role of thyroid hormone in the regulation of neuropeptide synthesis has been demonstrated in different tissues. In this paper we investigated the vasoactive intestinal peptide (VIP) mRNA expression by means of in situ hybridization in several brain areas of hypo-and hyperthyroid adult rats. Neither hypo-nor hyperthyroidism modified the VIP mRNA levels in the thalamus and in the hypothalamic suprachiasmatic nucleus. In contrast, in the anterior cingulate and frontoparietal motor cortex of hypothyroid rats there was a marked increase in the signal for VIP mRNA per cell, but the number of VIP expressing neurons did not change. These data indicate that also central VIP synthesis can be influenced by the levels of circulating thyroid hormone, but that this effect is confined to specific areas and cell populations of the brain.
Brain Research, 1991
The peripheral territories of sheep trigeminal neurons which send their central process to the br... more The peripheral territories of sheep trigeminal neurons which send their central process to the brainstem through the oculomotor nerve were investigated by the use of fluorescent tracers in double-labeling experiments. For this purpose Diamidino yellow (DY) injection into the oculomotor nerve was combined with Fast blue (FB) injection either into the extraocular muscles (EOMs), or the cornea, or the superior eyelid. Double-labeled DY+FB cells were found in the ophthalmic region of the trigeminal ganglion in addition to single-labeled DY or FB cells. The DY and DY+FB-labeled trigeminal cells were analysed immunocytochemically for their content of substance P (SP)-, calcitonin gene-related peptide (CGRP)-, and cholecystokinin-8 (CCK-8)-like. All single-labeled DY cells showed SP-, CGRP-or CCK-8-1ike immunoreactivity. Double-labeled DY+FB neurons innervating the EOMs were immunoreactive for each of the three peptides, whereas double-labeled neurons supplying the cornea were only CGRP-Iike positive. The findings suggest that, in the sheep, trigeminal neurons which send their process centrally through the oculomotor nerve supply the EOMs, the cornea, and the superior eyelid and contain neuropeptides which are usually associated with pain sensation.
European Journal of Neuroscience, 1996
Thyroid hormone plays a key role in trophic events during development of the central nervous syst... more Thyroid hormone plays a key role in trophic events during development of the central nervous system. In spite of neurological and psychiatric symptoms associated with adult hypothyroidism, the role of thyroid hormone in mature brain function is less clear. In this paper we investigated the effect of thyroid status on kainic acid-induced up-regulation of mRNAs for members of the nerve growth factor family and related receptors in adult male rats by means of in situ hybridization. We found that in hypothyroid rats there is a dramatic attenuation of the kainic acid-induced up-regulation of mRNA levels for nerve growth factor, brain-derived neurotrophic factor and tyrosine kinase trkB in euthyroid rats. A trend to reduced c-fos mRNA up-regulation, which did not reach significance, was also found, whereas the increase in c-jun mRNA after kainic acid was similar in eu-, hypo- and hyperthyroid rats. These data indicate a severe impairment of the regulation of neurotrophin synthesis after excitotoxin administration in the hippocampus during adult hypothyroidism. Possible roles of thyroid hormone in molecular, biochemical and metabolic mechanisms of this defect are discussed.
Journal of Investigative Dermatology, 1993
Substance P has been detected in human skin and has been implicated in the pathogenesis of certai... more Substance P has been detected in human skin and has been implicated in the pathogenesis of certain inflammatory cutaneous disorders. However, little is known about the number and distribution of substance P binding sites in the skin. Receptor autoradiography was employed to detect and quantitate substance P receptors in normal as well as psoriatic skin. Substance P binding sites were distributed in the epidermis and dermis both in normal and psoriatic skin. In the dermis, the highest densities of SP binding sites were found in the areas corresponding to the dermal papillae and the adnexal structures. Quantitative analysis revealed that saturable binding was obtained both in the epidermis and in the labeled dermal areas. Rosenthal plot values were consistent with a single population of binding sites. No difference in the binding measurements was observed between normal and psoriatic skin. The presence of substance P receptors in the epidermis and in the dermal papillae raises interesting issues on the possible targets of this peptide in human skin both under physiologic and pathologic conditions.
Alzheimer's & Dementia, 2009
European Journal of Pharmacology, 1998
Stress-related behaviors are accompanied by modification of a large number of neurotransmitters i... more Stress-related behaviors are accompanied by modification of a large number of neurotransmitters in the brain. Moreover, the binding to GABA(A) receptors does not account for all the effects of benzodiazepines. In this study we investigated the effect of repeated restraint stress and alprazolam treatment (1 mg/day os) on dopamine receptors (Bmax and Kd) in the striatum of adult rats by means of quantitative receptor autoradiography. After chronic restraint stress dopamine D1 receptors (Bmax value) decreased in the accumbens nucleus, whereas dopamine D2 receptors were not modified in any investigated area. After alprazolam treatment, a considerable increase in both dopamine D1 and D2 receptors in the striatum was observed. Chronic immobilization stress together with alprazolam treatment re-established dopamine D1 receptor density to control values in the accumbens nucleus and olfactory tubercle, whereas it resulted in an increase in dopamine D2 receptors comparable to that elicited by alprazolam treatment alone.
Regulatory Peptides, 1990
Most of the biochemical, physiological and behavioural events in living organisms show diurnal fl... more Most of the biochemical, physiological and behavioural events in living organisms show diurnal fluctuations, normally synchronized with 24-h environmental rhythms, such as the light-dark cycle. The suprachiasmatic nucleus (SCN) of the hypothalamus is considered to be a pacemaker of the circadian rhythms in several mammals. The light-dark cycle is the primary synchronizing agent for many of the circadian rhythms which are regulated by the SCN. The photic information reaches the SCN also through a neuropeptide Y(NPY)-like immunoreactive pathway from the ventro-lateral geniculate nucleus. We found that in 12-h-dark and 12-h-light housed rats the NPY-like immunoreactive innervation of the ventro-lateral part of the SCN shows a 24 h rhythm with values rising gradually during the light phase and falling during the dark phase. Besides this rhythm, we found two peaks corresponding to the switching on and switching off of the light. The average level of NPY-like immunoreactivity, as assessed by means of semiquantitative immunocytochemistry and expressed in 'arbitrary units', is reduced in rats housed in total darkness for 2 weeks. These results confirm the physiological role of NPY in the timing of the circadian activity of the SCN.
Proceedings of The National Academy of Sciences, 2004
Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degenerati... more Chronic disabilities in multiple sclerosis are believed to be due to neuron damage and degeneration, which follow remyelination failure. Due to the presence of numerous oligodendrocyte precursors inside demyelination plaques, one reason for demyelination failure could be the inability of oligodendrocyte precursor cells to turn into myelinating oligodendrocytes. In this study, we show that thyroid hormone enhances and accelerates remyelination in an experimental model of chronic demyelination, i.e., experimental allergic encephalomyelitis in congenic female Dark Agouti rats immunized with complete guinea pig spinal cord. Thyroid hormone, when administered during the acute phase of the disease, increases expression of platelet-derived growth factor ␣ receptor, restores normal levels of myelin basic protein mRNA and protein, and allows an early and morphologically competent reassembly of myelin sheaths. Moreover, thyroid hormone exerts a neuroprotective effect with respect to axonal pathology.
Brain Research, 1997
We studied modifications in [3H]MK801-binding sites in the rat brain after chronic clozapine. We ... more We studied modifications in [3H]MK801-binding sites in the rat brain after chronic clozapine. We found a 20-30% reduction of [3H]MK801-binding sites in the anterior cingulate, frontoparietal motor and frontoparietal somatosensory cortices on the left side but none on the right. We also demonstrated a 20% bilateral increase of N-methyl-D-aspartate (NMDA) receptors in the dentate gyrus of the hippocampus. No changes were found in the prefrontal cortex, caudate-putamen, nucleus accumbens, hippocampus or olfactory tubercle.
Endocrinology, 1989
The aim of the present study was to evaluate the possible presence of immunoreactive neuropeptide... more The aim of the present study was to evaluate the possible presence of immunoreactive neuropeptide-gamma (irNPY) in human placenta. Acidic extracts of human placental tissue collected at term pregnancy contained high irNPY concentrations. The extracted irNPY eluted from HPLC with the same retention time as synthetic NPY. The presence of the peptide in placental cells was confirmed by immunohistochemical findings showing numerous cells of the cytotrophoblast layer positively staining for NPY. Further supporting local production of the peptide, primary cultures of human placental cells released irNPY into the culture medium and the addition of high K+ concentrations increased the release of the peptide. The finding of irNPY in human placenta stimulated the characterization of binding sites of NPY in the same tissue. Using autoradiographic techniques we showed specific binding of [125I]NPY in human placental tissue. The binding of [125I]NPY to the placental receptors was saturable and widely distributed within the placental tissue. Finally, the addition of NPY to the medium of cultured placental cells increased the release of immunoreactive CRF, suggesting a possible role of NPY in placental hormone production. The effect of NPY was dose related and augmented by the addition of norepinephrine (10 nM). These results showed that human placenta produces and secretes irNPY and that NPY receptors are present in placental tissue. Moreover, the evidence that NPY stimulated the release of immunoreactive CRF from cultured placental cells suggests an action of NPY in placental hormonogenesis.
Journal of Neurochemistry, 2005
Galanin is a neuropeptide involved in a variety of biological functions, including having a stron... more Galanin is a neuropeptide involved in a variety of biological functions, including having a strong anticonvulsant activity. To assess a possible role of galanin in modulation of glutamatergic synapses and excitotoxicity, we studied effects of a galanin receptor 2(3) agonist (AR-M1896) on several molecular events induced by glutamate administration in primary neural hippocampal cells. Exposure of cells, after 5 days in vitro, to glutamate 0.5 mm for 10 min caused morphological alterations, including disaggregation of β-tubulin and MAP-2 cytoskeletal protein assembly, loss of neurites and cell shrinkage. When present in culture medium together with glutamate, 1 and 10 nm of AR-M1896 reduced these alterations. Moreover, AR-M1896 counteracted glutamate-induced c-fos mRNA and c-Fos protein up-regulation after 30–150 min, and 24 h, respectively. Massive nuclear alterations (Hoechst 33258 staining), observed 24 h after glutamate exposure, were also antagonized by AR-M1896 (0.1–100 nm) in a dose-dependent manner. These findings indicate that galanin, probably mainly through its type 2 receptor, interferes with events associated with glutamate toxicity.
Proceedings of The National Academy of Sciences, 1997
In this paper we report a time-course study of development of experimental allergic encephalomyel... more In this paper we report a time-course study of development of experimental allergic encephalomyelitis in Lewis rats, by monitoring neuroendocrine regulation of the hypothalamus-pituitary-adrenal axis through corticotropinreleasing hormone mRNA expression, inf lammatory cellular infiltrate, macrophagic and neuronal nitric oxide synthase, nerve growth factor (NGF), and NGF p75 and trkA receptors in the brain and spinal cord. We analyzed animals during 20 days after immunization, a time interval that corresponds to the acute immunological phase. We have described a severe, early fall of corticotropin-releasing hormone mRNA expression, which could account for the decreased response of the hypothalamus-pituitary-adrenal axis to inf lammatory stress. During this period, an increase of neuronal nitric oxide synthase was observed in the cerebral cortex and spinal cord, and macrophagic nitric oxide synthase positive cells were found in the inf lammatory cellular infiltrate, which was abundant in perivascular and submeningeal areas 20 days after immunization. Concomitantly, we found a dramatic up-regulation of NGF receptors on the wall of blood vessels and adjacent neurons in perivascular areas. NGF content also had increased in some brain areas, such as the thalamus, while it had decreased in others, like the spinal cord and medulla oblongata, at time points in which the most serious cellular infiltrate was found.
Neuroreport, 1993
Nitric oxide synthesizing (NOS) enzyme has been localized in distinct neural populations, includi... more Nitric oxide synthesizing (NOS) enzyme has been localized in distinct neural populations, including the hypothalamic paraventricular nucleus (PVN). Using in situ hybridization, we have investigated possible changes in NOS mRNA in the PVN of young and old rats after 2 h of immobilization stress. In old rats a 3-fold increase in NOS mRNA was observed in the PVN immediately after the stressor, whereas in young rats the increase reached significance when animals were killed 3 h after the end of the stress procedure. The present results suggest that nitric oxide in the PVN may be involved in the stress response. The differences observed in NOS mRNA between young and old rats could be related to an age-dependent different responsiveness to stressful stimuli.
Neuroscience, 1998
This study investigated the effects of stress on brain dopamine receptor densities in two inbred ... more This study investigated the effects of stress on brain dopamine receptor densities in two inbred strains of mice. Analysis of [ 3 H]SCH23390 binding by quantitative autoradiography revealed that repeated restraint stress significantly increases D 1 -like receptor density in the nucleus accumbens of mice of the DBA/2 strain whist reducing it in the caudate-putamen of C57BL/6 mice. No significant changes in D 2 -like receptor quantified by [ 3 H]( )-sulpiride binding were observed in caudate, substantia nigra and accumbens of stressed C57BL/6 mice. Instead, in DBA/2 mice, stress significantly increased D 2 -like receptor density in the nucleus accumbens whilst reducing it in the substantia nigra. Finally, stress significantly increased D 2 -like receptor density within the ventral tegmental area of C57BL/6 mice whilst significantly reducing it in mice of the DBA/2 strain.
Brain Research, 2000
The role of nitric oxide NO in inflammatoryrdemyelinating diseases is undergoing extensive invest... more The role of nitric oxide NO in inflammatoryrdemyelinating diseases is undergoing extensive investigation as a potential target for therapeutic intervention. However, interference with NO production has resulted in contrasting effects on the development of Ž . Ž . experimental allergic encephalomyelitis EAE , the most widely used experimental model for multiple sclerosis MS . Purpose of this paper was both the analysis of the individual clinical evolution of EAE induced in Lewis female rats by active immunisation and the Ž . evaluation of the effect of treatment with aminoguanidine, a selective inhibitor for the inducible isoform of nitric oxide synthase iNOS . In our experimental model, relapse occurred in 66% of animals. Aminoguanidine treatment, started 3 days before immunisation, guaranteed a complete recovery from the acute phase and a delayed, milder relapse. Moreover, 79 days after immunisation inflammatory cellular infiltrates in the spinal cord were reduced. These data further support the involvement of NO in EAE evolution. q
Proceedings of The National Academy of Sciences, 2002
Remyelination in the adult central nervous system has been demonstrated in different experimental... more Remyelination in the adult central nervous system has been demonstrated in different experimental models of demyelinating diseases. However, there is no clear evidence that remyelination occurs in multiple sclerosis, the most diffuse demyelinating disease. In this article, we explore the possibility of promoting myelination in experimental allergic encephalomyelitis, a widely used experimental model of multiple sclerosis, by recruiting progenitors and channeling them into oligodendroglial lineage through administration of thyroid hor-
Molecular Brain Research, 1996
Using in-situ hybridizationhistochemistrywe investigatedthe distributionof CRH receptor 1 (CRH-R1... more Using in-situ hybridizationhistochemistrywe investigatedthe distributionof CRH receptor 1 (CRH-R1)mRNA in the cortex of C57BL/6 (C57) and DBA/2 (DBA) strains and its regulationafter repeatedrestraint stress. We showthat DBA mice have a higher concentrationof CRH-R1mRNAthan C57 mice. Repeatedrestraintstressproducedan increasein CRH-R1mRNAexpressionof C57 mice, whereasit was ineffective in DBA mice.
Neuroendocrinology, 1992
Using in situ hybridization histochemistry, we have investigated the effect of thyroid hormone on... more Using in situ hybridization histochemistry, we have investigated the effect of thyroid hormone on the expression of several peptide mRNAs in the hypothalamic paraventricular nucleus (PVN) of adult male rats. Hypothyroidism was induced by surgical ablation of the thyroid gland. The animals (control sham-operated, thyroidectomized, thyroidectomized+T4 replaced rats) were studied 28 and 50 days after surgery. Sections of the PVN were hybridized using synthetic oligonucleotide probes complementary to mRNA for thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), galanin (GAL), enkephalin (ENK), neurotensin (NT), vasoactive intestinal polypeptide (VIP) and vasopressin (VP). GAL mRNA was also analyzed in the anterior paraventricular, arcuate, and dorsomedial nuclei of the hypothalamus. At the PVN level, a feedback effect of thyroid hormone on TRH synthesis was demonstrated by the TRH mRNA increase in hypothyroidism and by its decrease in hyperthyroidism. Hypothyroidism caused a dramatic decrease in GAL mRNA in parvo- and magnocellular PVN neurons both 28 and 50 days after thyroid ablation, whereas no effect was seen in VP mRNA, the main peptide hormone coexisting with GAL. The T4 replacement prevented the GAL mRNA impairment. Hypothyroidism did not influence GAL mRNA in the anterior PVN, perifornical area or in the arcuate nucleus, whereas a decrease in GAL mRNA was observed in the dorsomedial nucleus. VIP mRNA, which is undetectable in the PVN of normal animals, was present in several PVN neurons after thyroidectomy. CRH mRNA was decreased after thyroidectomy, whereas the T4 restitution caused an upregulation. The levels of ENK or NT mRNA were not significantly affected by the thyroid status. The present results show that, in addition to TRH mRNA, other hypothalamic peptide mRNAs are affected by thyroid hormone levels.
Human Molecular Genetics, 1996
The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proli... more The Drosophila dishevelled gene (dsh) encodes a secreted glycoprotein, which regulates cell proliferation, acting as a transducer molecule for developmental processes, including segmentation and neuroblast specification. We have isolated and characterized cDNA clones from two different human dsh-homologous genes, designated as DVL-1 and DVL-3. DVL-1 and DVL-3 putative protein products show 64% amino acid identity. The DVL-1 product is 50% identical to dsh and 92% to a murine dsh homologue (Dvl-1). Both human DVL genes are widely expressed in fetal and adult tissues, including brain, lung, kidney, skeletal muscle and heart. DVL-1 locus maps to chromosome 1p36 and DVL-3 to chromosome 3q27. DVL-1 locus on chromosome 1 corresponds to the murine syntenic region where Dvl-1 is located. DVL-1 and DVL-3 are members of a human dsh-like gene family, which is probably involved in human development. Although the precise role of these genes in embryogenesis is only conjectural at present, the structural and evolutionary characteristics suggest that mutations at their loci may be involved in neural and heart developmental defects.
Experimental Neurology, 1997
Several lines of data from human and animal studies have suggested a role of thyroid hormone in t... more Several lines of data from human and animal studies have suggested a role of thyroid hormone in the regulation of cholinergic neurons in the adult brain. In this study we have investigated the content of nerve growth factor (NGF) and the expression of NGF low affinity receptor (p75(LNGFR)) in the basal forebrain of adult hypothyroid rats. We describe an increase of both NGF and p75(LNGFR) expression in the basal forebrain of adult hypothyroid rats. The administration of colchicine up-regulates p75(LNGFR) expression in both hypo- and control rats, whereas it fails to down-regulate choline acetyl transferase mRNA expression during hypothyroidism. These data offer a possible neurobiological explanation to cognitive defects observed during adult hypothyroidism in humans.
Molecular Brain Research, 1994
A role of thyroid hormone in the regulation of neuropeptide synthesis has been demonstrated in di... more A role of thyroid hormone in the regulation of neuropeptide synthesis has been demonstrated in different tissues. In this paper we investigated the vasoactive intestinal peptide (VIP) mRNA expression by means of in situ hybridization in several brain areas of hypo-and hyperthyroid adult rats. Neither hypo-nor hyperthyroidism modified the VIP mRNA levels in the thalamus and in the hypothalamic suprachiasmatic nucleus. In contrast, in the anterior cingulate and frontoparietal motor cortex of hypothyroid rats there was a marked increase in the signal for VIP mRNA per cell, but the number of VIP expressing neurons did not change. These data indicate that also central VIP synthesis can be influenced by the levels of circulating thyroid hormone, but that this effect is confined to specific areas and cell populations of the brain.
Brain Research, 1991
The peripheral territories of sheep trigeminal neurons which send their central process to the br... more The peripheral territories of sheep trigeminal neurons which send their central process to the brainstem through the oculomotor nerve were investigated by the use of fluorescent tracers in double-labeling experiments. For this purpose Diamidino yellow (DY) injection into the oculomotor nerve was combined with Fast blue (FB) injection either into the extraocular muscles (EOMs), or the cornea, or the superior eyelid. Double-labeled DY+FB cells were found in the ophthalmic region of the trigeminal ganglion in addition to single-labeled DY or FB cells. The DY and DY+FB-labeled trigeminal cells were analysed immunocytochemically for their content of substance P (SP)-, calcitonin gene-related peptide (CGRP)-, and cholecystokinin-8 (CCK-8)-like. All single-labeled DY cells showed SP-, CGRP-or CCK-8-1ike immunoreactivity. Double-labeled DY+FB neurons innervating the EOMs were immunoreactive for each of the three peptides, whereas double-labeled neurons supplying the cornea were only CGRP-Iike positive. The findings suggest that, in the sheep, trigeminal neurons which send their process centrally through the oculomotor nerve supply the EOMs, the cornea, and the superior eyelid and contain neuropeptides which are usually associated with pain sensation.
European Journal of Neuroscience, 1996
Thyroid hormone plays a key role in trophic events during development of the central nervous syst... more Thyroid hormone plays a key role in trophic events during development of the central nervous system. In spite of neurological and psychiatric symptoms associated with adult hypothyroidism, the role of thyroid hormone in mature brain function is less clear. In this paper we investigated the effect of thyroid status on kainic acid-induced up-regulation of mRNAs for members of the nerve growth factor family and related receptors in adult male rats by means of in situ hybridization. We found that in hypothyroid rats there is a dramatic attenuation of the kainic acid-induced up-regulation of mRNA levels for nerve growth factor, brain-derived neurotrophic factor and tyrosine kinase trkB in euthyroid rats. A trend to reduced c-fos mRNA up-regulation, which did not reach significance, was also found, whereas the increase in c-jun mRNA after kainic acid was similar in eu-, hypo- and hyperthyroid rats. These data indicate a severe impairment of the regulation of neurotrophin synthesis after excitotoxin administration in the hippocampus during adult hypothyroidism. Possible roles of thyroid hormone in molecular, biochemical and metabolic mechanisms of this defect are discussed.
Journal of Investigative Dermatology, 1993
Substance P has been detected in human skin and has been implicated in the pathogenesis of certai... more Substance P has been detected in human skin and has been implicated in the pathogenesis of certain inflammatory cutaneous disorders. However, little is known about the number and distribution of substance P binding sites in the skin. Receptor autoradiography was employed to detect and quantitate substance P receptors in normal as well as psoriatic skin. Substance P binding sites were distributed in the epidermis and dermis both in normal and psoriatic skin. In the dermis, the highest densities of SP binding sites were found in the areas corresponding to the dermal papillae and the adnexal structures. Quantitative analysis revealed that saturable binding was obtained both in the epidermis and in the labeled dermal areas. Rosenthal plot values were consistent with a single population of binding sites. No difference in the binding measurements was observed between normal and psoriatic skin. The presence of substance P receptors in the epidermis and in the dermal papillae raises interesting issues on the possible targets of this peptide in human skin both under physiologic and pathologic conditions.