francesco crespi - Academia.edu (original) (raw)
Papers by francesco crespi
Biomedical Journal of Scientific and Technical Research, May 10, 2022
Nicotine induces neurochemical and behavioral changes similar to those induced by the commonly ab... more Nicotine induces neurochemical and behavioral changes similar to those induced by the commonly abused drugs and the mesolimbic dopamine pathway, specifically originating from the Ventral Tegmental Area (VTA) and projecting to the Nucleus Accumbens may be an important component in the neural circuitry of reward. Various classes of amine carrier blockers have been studied for potential therapeutic application in drug addiction. One of these compounds, i.e. bupropion, has been shown to be effective for smoking cessation via its effect upon dopaminergic activities. Such effects are mediated via its metabolites and in particular (+)hydroxybupropion. In rat, bupropion has a different metabolism with no formation of (+)OH-bupropion metabolite making it a good species for comparing the effect of exogenous (+)OHbupropion versus exogenous bupropion itself. Therefore, we have examined the acute effect of these two compounds upon the DA system via concomitant Differential Pulse Voltammetric measurements of DA levels and electrophysiological recordings of the firing rates within the VTA.
Journal of analytical & bioanalytical techniques, Sep 8, 2014
Neuroscience and Neurological Surgery, 2021
Sigma receptors are widespread in the central nervous system and are differentiated in two subtyp... more Sigma receptors are widespread in the central nervous system and are differentiated in two subtypes, sigma1 and sigma2. In particular, the sigma1 receptor subtype appears to be able to influence biological mechanisms connected with neuro-degeneration. Furthermore, several studies are implicating sigma1 receptor agonists within antidepressant activity. Evidence of prefrontal cortex abnormalities in clinically depressed subjects have been reported by several works and that monoamines such as serotonin and cathecolamines can be involved in such malfunctions. Up to now the most of the preclinical work performed to analyze the influence of sigma1 receptor agonists upon catecholaminergic and serotoninergic activities in brain areas has been done by means of in vitro as well as ex vivo methodologies. Here, SA-4503, a selective sigma1 receptor agonist with potential antidepressant activity has been tested in vivo upon dopamine (DA), noradrenaline (NA) and serotonin (5-HT) levels detected by...
Biology, Engineering and Medicine, 2018
Biomedical Journal of Scientific & Technical Research, 2020
Nitric Oxide (NO) is a free radicalinvolved in diverse cellular functions, it also mediates cellu... more Nitric Oxide (NO) is a free radicalinvolved in diverse cellular functions, it also mediates cellular damage through direct reaction with cell proteins or through generation of a number of chemical products such as peroxynitrite ONOO-A number of works suggest a role of NO in psychiatric illness such as schizophrenia and anxiety disorders and that SSRI such as paroxetine act as NOS inhibitor. Our hypothesis is that the increase in nNOS observed after stressful conditions may be followed by intracellular NO increase. This increase could lead to a major production of ONOO-and then to the α-tubulin nitrotyrosination which is irreversible and result in the block of the tyrosination/ detyrosination cycle and to the microtubular dysfunction that may be responsible for the observed neuronal plasticity failure (atrophy, cell death and neurogenesis decrease) in response to stress and depression.The present Research Proposal aims to verify such hypothesis that could lead to potential new therapeutic indication for SSRI i.e. the modulation of NOS activities and therefore modulation of NO levels within abnormal conditions in which the increase of NO activity would influence negatively cell functions in particular at the level of cytoskeleton.
A titrimetric technique has been successfully employed to measure esterase activities in differen... more A titrimetric technique has been successfully employed to measure esterase activities in different tissues. We have applied this tech nique to investigate the distribution of the esterase enzymes in spinal cord and five different brain areas of the rat (telencephalon, mesencephalon, diencephalon, cerebellum and medulla oblongata). The presence of non-specific esterase activity has been determined using alpha-napthyl acetate, a widely employed substrate for these en zymes, whereby the possible existence of “heroin-esterases” has been tested. Our results suggest that the activity of cerebral esterase’s on heroin can be studied selectively at pH 8.5, showing quantitative differences in the distribution of these so-called “ heroin-es terases” in spinal cord and in the five brain areas studied. In parallel, the efficacy of such “heroin-esterases” has been verified using voltammetric analysis of the influence of the brain enzymes upon the substrate heroin resulting in the evidence of an o...
Medical and Clinical Archives, 2018
Biology, Engineering and Medicine, 2019
Brain and Nerves
The present work proposes an original approach to study the effectiveness of antisense interventi... more The present work proposes an original approach to study the effectiveness of antisense intervention in the brain via the association of molecular biological applications and In vivo neuro-pharmacological analysis. In particular, direct influence of specific antisense oligonucleotide of GABAA receptors upon physiological parameters such as sleep duration as well as presynaptic and post synaptic activities via In vivo and in real time electrochemical analysis of neurotransmitters and cell firing in discrete rat brain areas have been monitored.
Serotonin or 5-hydroxytryptamine (5HT) is a monoamine neurotransmitter. Biochemically derived fro... more Serotonin or 5-hydroxytryptamine (5HT) is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system (CNS) of animals, including humans. Discovered and crystallized over sixty years ago, serotonin operates as a short-range neurotransmitter as well as a long-range signalling modulator, with multiple effects on whole organism functions via plasma, platelet and neuroendocrine, gut, adrenal and other peripheral systems across many species. All of the important functions of serotonin in the brain and body were identified over the ensuing years by neurochemical, physiological and pharmacological investigations. Mainly, all these investigations have been performed via invasive methodologies, particularly in the CNS studies. Here we present a rapid overview of such methodological approaches focussing on voltammetry, one of the most recent technical approaches for serotonin anal...
Psychology, 2010
Behavioral observations combined with electrochemical analysis have been performed in Wistar or S... more Behavioral observations combined with electrochemical analysis have been performed in Wistar or Sprague-Dawley CD rats in the attempt to clarify earlier controversial behavioral reports. In particular, these rats were submitted to FST and to repeated Forced Swimming (rFS, during 4 days). In parallel, voltammetric in vivo analysis of serotonin (5-HT) levels in platelet-rich plasma (PRP) collected daily from these animals was also performed as it is known that peripheral 5-HT levels monitored in rat PRP mirror cerebral 5-HT contents. Thus, combined behavioral-voltammetric studies allow deducing changes of central 5-HT levels that could be correlated to FST or rFS, with the advantage of non invasive analysis of central neurotransmitter activities in intact behaving animals. In particular, combined behavioral-voltammetric results suggest that "behavioral despair" is the process interesting Wistar rats when submitted to FST or rFS while "learning to be immobile" is the process involving Sprague-Dawley CD rats.
In order to support the effectiveness of Near Infrared Spectroscopy (NIRS) to enhance the WELFARE... more In order to support the effectiveness of Near Infrared Spectroscopy (NIRS) to enhance the WELFARE of laboratory animals comparative studies have been performed. In particular NIRS has been coupled with MRI as these are two major in vivo non invasive methodologies more and more applied in research. Furthermore NIRS has been coupled with Standard Liquid chromatography-mass spectrometry (LCMSMS) analysis that allow determination of pharmacokinetic-pharmacodinamic (PK-PD) values of chemicals i.e. in brain. This in order to verify the possibility that changes of hemoglobin oxygenation in rat brain as measured by NIRS might be a useful index of brain penetration of chemical entities.
Current opinion in investigational drugs (London, England : 2000), 2002
Nefiracetam (DM-9384) is a cerebral metabolic product under development by Daiichi for the potent... more Nefiracetam (DM-9384) is a cerebral metabolic product under development by Daiichi for the potential treatment of the after-effects of cerebrovascular disorders. By September 1999, nefiracetam was In phase II trials in the US for the treatment of mental symptoms associated with sequelae of stroke and Alzheimer's type dementia. By August 2000, clinical trials in China had been completed in preparation for an NDA filing In November 2000, the companypredicted a launch in 2002. Modified phase III trials of the compound were being repeated in Japan in preparation for re-filing of an NDA. The protocol for the initial Japanese phase III retrial in patients with sequelae of cerebral infarction was approved at the end of July 1999, with completion of the trial expected by the end of 2000. However, in February 2002 Daiichi withdrew its Japanese NDA due to insufficient efficacy in the revised trial. In December 2001, analysts at Morgan Stanley predicted that nefiracetam would be submitted ...
Toxicologic Pathology, 2004
The present study investigated the anti-atherosclerotic activity of lacidipine, a calcium antagon... more The present study investigated the anti-atherosclerotic activity of lacidipine, a calcium antagonist with antioxidant properties in apoE-deficient mice. These mice show widespread vascular lesions which closely resemble the inflammatory-fibrous plaques seen in humans in atherosclerosis. Mice were fed a Western-type diet (WTD), and treated for 8 weeks with either vehicle or lacidipine at 3 or 10 mg/kg/day. In parallel with histological studies of atherosclerotic lesions in the aorta, functional studies on vascular acetylcholine (ACh) reactivity and analysis of voltammetric levels of nitric oxide (NO) were performed. Recent work has suggested that dihydropyridines (DHPs) modulate vascular relaxation via an increase in the release of NO. Lacidipine treatment had no effect on the plasma lipid profile. However, a significant (p < 0.01) dose-related reduction of 36.4% and 43.3% of the aortic lesion area in respect to methocel-treated mice was observed. Moreover, the aortic ring from control apoE-deficient mice fed a WTD for 8 weeks showed a lower relaxation in response to ACh in comparison to wild-type C57BL/6J mice; on the contrary, lacidipine-treated apoE-deficient mice lacidipine-treated displayed a response similar to that of wildtype C57BL/6J mice. Voltammetric analyses demonstrated a significant decrease of NO release in apoE-deficient mice, while lacidipine-treated mice showed enhanced activity of the NO system. We conclude that lacidipine reduced the extent of atherosclerotic area in hypercholesterolemic apoE-deficient mice, and this reduction may be associated with the capacity of the drug to maintain endothelial NO levels at concentrations useful to protect against vascular damage.
Brain Research, 2012
Melatonin, an indoleamine hormone synthesized in the pinealocytes, has been implicated as influen... more Melatonin, an indoleamine hormone synthesized in the pinealocytes, has been implicated as influencing the intake of alcohol in rats. It has been shown that this hormone is voltammetrically electroactive at the surface of pretreated carbon fiber microelectrodes in vitro and in vivo, in rat cerebral melatonergic regions such the pineal gland. The aim of this work consisted in the study of the influence of melatonin on spontaneously ethanol drinking or ethanol avoiding rats selected throughout a free choice two bottle test. It appeared that only the water preferring rats were affected by treatment with the hormone and that in vivo voltammetric related levels of melatonin were higher in the pineal gland of ethanol drinking rats versus water preferring rats. In addition, when treated with the melatonin antagonist GR128107 ethanol drinking rats significantly reduced the spontaneous consumption of alcohol.
Journal of New Developments in Chemistry
International Physiology Journal
The pineal gland constitutes a major neuroendocrine organ in the brain. By mean of its neurohormo... more The pineal gland constitutes a major neuroendocrine organ in the brain. By mean of its neurohormone melatonin it transduces exogenous signals such as circadian and seasonal variations of light and temperature into proper hormonal changes which adjust and adapt internal endocrine functions. Alteration of circadian rhythms has been associated with affective disorders, psychosomatic diseases and cancer. It has been observed that light deprivation, which stimulates (the enzymes responsible for) melatonin production in the pineal, enhances the animal's ethanol preference. Similarly, administration of the pineal hormone to rats maintained under normal conditions of constant photoperiod also induced ethanol drinking. Our hypothesis is that in normal conditions melatonin might be acting as a cerebral "pacemaker", sensitive to endogenous as well as exogenous stimuli in the attempt to maintain an equilibrate circadian interaction between the cerebral activities of endogenous ami...
![Research paper thumbnail of Central [CNS] and Peripheral [Gastric Tissue] Selective Monitoring of Somatostatin (SRIF) with Micro-Sensor and Voltammetry in Rats: Influence of Growth Factors (GH, EGF)](https://attachments.academia-assets.com/66617431/thumbnails/1.jpg)
](Biosensors
Somatostatin (SRIF) is widely distributed throughout the body, and regulates the endocrine system... more Somatostatin (SRIF) is widely distributed throughout the body, and regulates the endocrine system via interactions with various hormones, including the pituitary growth hormone, the thyroid stimulating hormone and the majority of the hormones of the gastrointestinal tract. SRIF is present in the central nervous system (CNS), where it affects rates of neurotransmission, and is also reported to be active in the intestinal tract, with evidence that stressed rats present a significant decrease in antral somatostatin-like immunoreactivity (SLI). Analysis of SRIF has mainly been carried out by means of radioimmunoassay methods. Here, we propose the use of an electrochemical method, such as voltammetry, applied with carbon-based sensors and, in particular, the combination of differential pulse voltammetry with treated carbon fiber micro electrodes (DPV-µCFE) to facilitate the analysis of such peptidergic electro active hormones in the rat striatum and gastric tissue; the effect of growth hormone (GH) and epidermal growth factor (EGF), in particular, upon the SRIF signal has been studied in such tissues. a cyto-protective activity on gastric mucosa and, taken together with the evidence that EGF treatment determines levels of antral SLI significantly higher than that in control rats, proposes a role for EGF in preventing stress ulcer formation. Furthermore, it suggests an involvement of the endogenous SLI in its anti-ulcer function.
Journal of Human Psychology
Cholecystokinin (CCK) is found in high concentrations in cortical and limbic structures including... more Cholecystokinin (CCK) is found in high concentrations in cortical and limbic structures including the amygdala of rodents, and evidence has been gathered supporting a role for CCK in the neurobiology of anxiety. A variety of animal models have been used to study a central state of fear or anxiety, state that appears to produce a complex pattern of behaviors highly correlated with each other. It is now well established that the amygdala in particular is a critical link in the pathway through which sensory stimuli come to acquire fear evoking properties. The purpose of the proposed experiments is to study the role of the putative neurotransmitter CCK in fear and anxiety in vivo by means of a methodology coupling electrochemical and electrophysiological measurements in various brain areas. Indeed, the association of in vivo differential pulse voltammetry (DPV) with in vivo extracellular single unit recording could be able to provide concomitant physiological and neurochemical indicatio...
Biomedical Journal of Scientific and Technical Research, May 10, 2022
Nicotine induces neurochemical and behavioral changes similar to those induced by the commonly ab... more Nicotine induces neurochemical and behavioral changes similar to those induced by the commonly abused drugs and the mesolimbic dopamine pathway, specifically originating from the Ventral Tegmental Area (VTA) and projecting to the Nucleus Accumbens may be an important component in the neural circuitry of reward. Various classes of amine carrier blockers have been studied for potential therapeutic application in drug addiction. One of these compounds, i.e. bupropion, has been shown to be effective for smoking cessation via its effect upon dopaminergic activities. Such effects are mediated via its metabolites and in particular (+)hydroxybupropion. In rat, bupropion has a different metabolism with no formation of (+)OH-bupropion metabolite making it a good species for comparing the effect of exogenous (+)OHbupropion versus exogenous bupropion itself. Therefore, we have examined the acute effect of these two compounds upon the DA system via concomitant Differential Pulse Voltammetric measurements of DA levels and electrophysiological recordings of the firing rates within the VTA.
Journal of analytical & bioanalytical techniques, Sep 8, 2014
Neuroscience and Neurological Surgery, 2021
Sigma receptors are widespread in the central nervous system and are differentiated in two subtyp... more Sigma receptors are widespread in the central nervous system and are differentiated in two subtypes, sigma1 and sigma2. In particular, the sigma1 receptor subtype appears to be able to influence biological mechanisms connected with neuro-degeneration. Furthermore, several studies are implicating sigma1 receptor agonists within antidepressant activity. Evidence of prefrontal cortex abnormalities in clinically depressed subjects have been reported by several works and that monoamines such as serotonin and cathecolamines can be involved in such malfunctions. Up to now the most of the preclinical work performed to analyze the influence of sigma1 receptor agonists upon catecholaminergic and serotoninergic activities in brain areas has been done by means of in vitro as well as ex vivo methodologies. Here, SA-4503, a selective sigma1 receptor agonist with potential antidepressant activity has been tested in vivo upon dopamine (DA), noradrenaline (NA) and serotonin (5-HT) levels detected by...
Biology, Engineering and Medicine, 2018
Biomedical Journal of Scientific & Technical Research, 2020
Nitric Oxide (NO) is a free radicalinvolved in diverse cellular functions, it also mediates cellu... more Nitric Oxide (NO) is a free radicalinvolved in diverse cellular functions, it also mediates cellular damage through direct reaction with cell proteins or through generation of a number of chemical products such as peroxynitrite ONOO-A number of works suggest a role of NO in psychiatric illness such as schizophrenia and anxiety disorders and that SSRI such as paroxetine act as NOS inhibitor. Our hypothesis is that the increase in nNOS observed after stressful conditions may be followed by intracellular NO increase. This increase could lead to a major production of ONOO-and then to the α-tubulin nitrotyrosination which is irreversible and result in the block of the tyrosination/ detyrosination cycle and to the microtubular dysfunction that may be responsible for the observed neuronal plasticity failure (atrophy, cell death and neurogenesis decrease) in response to stress and depression.The present Research Proposal aims to verify such hypothesis that could lead to potential new therapeutic indication for SSRI i.e. the modulation of NOS activities and therefore modulation of NO levels within abnormal conditions in which the increase of NO activity would influence negatively cell functions in particular at the level of cytoskeleton.
A titrimetric technique has been successfully employed to measure esterase activities in differen... more A titrimetric technique has been successfully employed to measure esterase activities in different tissues. We have applied this tech nique to investigate the distribution of the esterase enzymes in spinal cord and five different brain areas of the rat (telencephalon, mesencephalon, diencephalon, cerebellum and medulla oblongata). The presence of non-specific esterase activity has been determined using alpha-napthyl acetate, a widely employed substrate for these en zymes, whereby the possible existence of “heroin-esterases” has been tested. Our results suggest that the activity of cerebral esterase’s on heroin can be studied selectively at pH 8.5, showing quantitative differences in the distribution of these so-called “ heroin-es terases” in spinal cord and in the five brain areas studied. In parallel, the efficacy of such “heroin-esterases” has been verified using voltammetric analysis of the influence of the brain enzymes upon the substrate heroin resulting in the evidence of an o...
Medical and Clinical Archives, 2018
Biology, Engineering and Medicine, 2019
Brain and Nerves
The present work proposes an original approach to study the effectiveness of antisense interventi... more The present work proposes an original approach to study the effectiveness of antisense intervention in the brain via the association of molecular biological applications and In vivo neuro-pharmacological analysis. In particular, direct influence of specific antisense oligonucleotide of GABAA receptors upon physiological parameters such as sleep duration as well as presynaptic and post synaptic activities via In vivo and in real time electrochemical analysis of neurotransmitters and cell firing in discrete rat brain areas have been monitored.
Serotonin or 5-hydroxytryptamine (5HT) is a monoamine neurotransmitter. Biochemically derived fro... more Serotonin or 5-hydroxytryptamine (5HT) is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system (CNS) of animals, including humans. Discovered and crystallized over sixty years ago, serotonin operates as a short-range neurotransmitter as well as a long-range signalling modulator, with multiple effects on whole organism functions via plasma, platelet and neuroendocrine, gut, adrenal and other peripheral systems across many species. All of the important functions of serotonin in the brain and body were identified over the ensuing years by neurochemical, physiological and pharmacological investigations. Mainly, all these investigations have been performed via invasive methodologies, particularly in the CNS studies. Here we present a rapid overview of such methodological approaches focussing on voltammetry, one of the most recent technical approaches for serotonin anal...
Psychology, 2010
Behavioral observations combined with electrochemical analysis have been performed in Wistar or S... more Behavioral observations combined with electrochemical analysis have been performed in Wistar or Sprague-Dawley CD rats in the attempt to clarify earlier controversial behavioral reports. In particular, these rats were submitted to FST and to repeated Forced Swimming (rFS, during 4 days). In parallel, voltammetric in vivo analysis of serotonin (5-HT) levels in platelet-rich plasma (PRP) collected daily from these animals was also performed as it is known that peripheral 5-HT levels monitored in rat PRP mirror cerebral 5-HT contents. Thus, combined behavioral-voltammetric studies allow deducing changes of central 5-HT levels that could be correlated to FST or rFS, with the advantage of non invasive analysis of central neurotransmitter activities in intact behaving animals. In particular, combined behavioral-voltammetric results suggest that "behavioral despair" is the process interesting Wistar rats when submitted to FST or rFS while "learning to be immobile" is the process involving Sprague-Dawley CD rats.
In order to support the effectiveness of Near Infrared Spectroscopy (NIRS) to enhance the WELFARE... more In order to support the effectiveness of Near Infrared Spectroscopy (NIRS) to enhance the WELFARE of laboratory animals comparative studies have been performed. In particular NIRS has been coupled with MRI as these are two major in vivo non invasive methodologies more and more applied in research. Furthermore NIRS has been coupled with Standard Liquid chromatography-mass spectrometry (LCMSMS) analysis that allow determination of pharmacokinetic-pharmacodinamic (PK-PD) values of chemicals i.e. in brain. This in order to verify the possibility that changes of hemoglobin oxygenation in rat brain as measured by NIRS might be a useful index of brain penetration of chemical entities.
Current opinion in investigational drugs (London, England : 2000), 2002
Nefiracetam (DM-9384) is a cerebral metabolic product under development by Daiichi for the potent... more Nefiracetam (DM-9384) is a cerebral metabolic product under development by Daiichi for the potential treatment of the after-effects of cerebrovascular disorders. By September 1999, nefiracetam was In phase II trials in the US for the treatment of mental symptoms associated with sequelae of stroke and Alzheimer's type dementia. By August 2000, clinical trials in China had been completed in preparation for an NDA filing In November 2000, the companypredicted a launch in 2002. Modified phase III trials of the compound were being repeated in Japan in preparation for re-filing of an NDA. The protocol for the initial Japanese phase III retrial in patients with sequelae of cerebral infarction was approved at the end of July 1999, with completion of the trial expected by the end of 2000. However, in February 2002 Daiichi withdrew its Japanese NDA due to insufficient efficacy in the revised trial. In December 2001, analysts at Morgan Stanley predicted that nefiracetam would be submitted ...
Toxicologic Pathology, 2004
The present study investigated the anti-atherosclerotic activity of lacidipine, a calcium antagon... more The present study investigated the anti-atherosclerotic activity of lacidipine, a calcium antagonist with antioxidant properties in apoE-deficient mice. These mice show widespread vascular lesions which closely resemble the inflammatory-fibrous plaques seen in humans in atherosclerosis. Mice were fed a Western-type diet (WTD), and treated for 8 weeks with either vehicle or lacidipine at 3 or 10 mg/kg/day. In parallel with histological studies of atherosclerotic lesions in the aorta, functional studies on vascular acetylcholine (ACh) reactivity and analysis of voltammetric levels of nitric oxide (NO) were performed. Recent work has suggested that dihydropyridines (DHPs) modulate vascular relaxation via an increase in the release of NO. Lacidipine treatment had no effect on the plasma lipid profile. However, a significant (p < 0.01) dose-related reduction of 36.4% and 43.3% of the aortic lesion area in respect to methocel-treated mice was observed. Moreover, the aortic ring from control apoE-deficient mice fed a WTD for 8 weeks showed a lower relaxation in response to ACh in comparison to wild-type C57BL/6J mice; on the contrary, lacidipine-treated apoE-deficient mice lacidipine-treated displayed a response similar to that of wildtype C57BL/6J mice. Voltammetric analyses demonstrated a significant decrease of NO release in apoE-deficient mice, while lacidipine-treated mice showed enhanced activity of the NO system. We conclude that lacidipine reduced the extent of atherosclerotic area in hypercholesterolemic apoE-deficient mice, and this reduction may be associated with the capacity of the drug to maintain endothelial NO levels at concentrations useful to protect against vascular damage.
Brain Research, 2012
Melatonin, an indoleamine hormone synthesized in the pinealocytes, has been implicated as influen... more Melatonin, an indoleamine hormone synthesized in the pinealocytes, has been implicated as influencing the intake of alcohol in rats. It has been shown that this hormone is voltammetrically electroactive at the surface of pretreated carbon fiber microelectrodes in vitro and in vivo, in rat cerebral melatonergic regions such the pineal gland. The aim of this work consisted in the study of the influence of melatonin on spontaneously ethanol drinking or ethanol avoiding rats selected throughout a free choice two bottle test. It appeared that only the water preferring rats were affected by treatment with the hormone and that in vivo voltammetric related levels of melatonin were higher in the pineal gland of ethanol drinking rats versus water preferring rats. In addition, when treated with the melatonin antagonist GR128107 ethanol drinking rats significantly reduced the spontaneous consumption of alcohol.
Journal of New Developments in Chemistry
International Physiology Journal
The pineal gland constitutes a major neuroendocrine organ in the brain. By mean of its neurohormo... more The pineal gland constitutes a major neuroendocrine organ in the brain. By mean of its neurohormone melatonin it transduces exogenous signals such as circadian and seasonal variations of light and temperature into proper hormonal changes which adjust and adapt internal endocrine functions. Alteration of circadian rhythms has been associated with affective disorders, psychosomatic diseases and cancer. It has been observed that light deprivation, which stimulates (the enzymes responsible for) melatonin production in the pineal, enhances the animal's ethanol preference. Similarly, administration of the pineal hormone to rats maintained under normal conditions of constant photoperiod also induced ethanol drinking. Our hypothesis is that in normal conditions melatonin might be acting as a cerebral "pacemaker", sensitive to endogenous as well as exogenous stimuli in the attempt to maintain an equilibrate circadian interaction between the cerebral activities of endogenous ami...
Biosensors
Somatostatin (SRIF) is widely distributed throughout the body, and regulates the endocrine system... more Somatostatin (SRIF) is widely distributed throughout the body, and regulates the endocrine system via interactions with various hormones, including the pituitary growth hormone, the thyroid stimulating hormone and the majority of the hormones of the gastrointestinal tract. SRIF is present in the central nervous system (CNS), where it affects rates of neurotransmission, and is also reported to be active in the intestinal tract, with evidence that stressed rats present a significant decrease in antral somatostatin-like immunoreactivity (SLI). Analysis of SRIF has mainly been carried out by means of radioimmunoassay methods. Here, we propose the use of an electrochemical method, such as voltammetry, applied with carbon-based sensors and, in particular, the combination of differential pulse voltammetry with treated carbon fiber micro electrodes (DPV-µCFE) to facilitate the analysis of such peptidergic electro active hormones in the rat striatum and gastric tissue; the effect of growth hormone (GH) and epidermal growth factor (EGF), in particular, upon the SRIF signal has been studied in such tissues. a cyto-protective activity on gastric mucosa and, taken together with the evidence that EGF treatment determines levels of antral SLI significantly higher than that in control rats, proposes a role for EGF in preventing stress ulcer formation. Furthermore, it suggests an involvement of the endogenous SLI in its anti-ulcer function.
Journal of Human Psychology
Cholecystokinin (CCK) is found in high concentrations in cortical and limbic structures including... more Cholecystokinin (CCK) is found in high concentrations in cortical and limbic structures including the amygdala of rodents, and evidence has been gathered supporting a role for CCK in the neurobiology of anxiety. A variety of animal models have been used to study a central state of fear or anxiety, state that appears to produce a complex pattern of behaviors highly correlated with each other. It is now well established that the amygdala in particular is a critical link in the pathway through which sensory stimuli come to acquire fear evoking properties. The purpose of the proposed experiments is to study the role of the putative neurotransmitter CCK in fear and anxiety in vivo by means of a methodology coupling electrochemical and electrophysiological measurements in various brain areas. Indeed, the association of in vivo differential pulse voltammetry (DPV) with in vivo extracellular single unit recording could be able to provide concomitant physiological and neurochemical indicatio...