0000000000758981
AUTHOR
G. Di Giovanni
Role of serotonin in central dopamine dysfunction
The interaction between serotonin (5-HT) and dopamine (DA)-containing neurons in the brain is a research topic that has raised the interest of many scientists working in the field of neuroscience since the first demonstration of the presence of monoamine-containing neurons in the mid 1960. The bulk of neuroanatomical data available clearly indicate that DA-containing neurons in the brain receive a prominent innervation from serotonin (5-hydroxytryptamine, 5-HT) originating in the raphe nuclei of the brainstem. Compelling electrophysiological and neurochemical data show that 5-HT can exert complex effects on the activity of midbrain DA neurons mediated by its various receptor subtypes. The m…
Previous observations have suggested a role for nitric oxide in the activity of the globus pallidus, but this functional involvement has not yet been tested in vivo. The extracellular activity of single units of the globus pallidus was recorded, and neuronal nitric oxide synthase was inhibited by systemically administering 7-nitro-indazole to a group of anaesthetised rats. Forty-five per cent of cells responded with a decrease in the firing rate. In another group of rats, the microiontophoretic administration of 3-morpholino-sydnonimin-hydrocloride (a nitric oxide donor) induced an increase in neuronal firing rate (24/28 cells), whereas the administration of Nω-nitro-L-arginine methyl ester…
Involvement of nitric oxide in maximal dentate activation, in the rat
Temporal patterns of rat behaviour in the central platform of the elevated plus maze. Comparative analysis between male subjects of strains with different basal levels of emotionality
We have analyzed the temporal patterns of behaviour of male rats of the Wistar and DA/Han strains on the central platform of the elevated plus maze. The ethogram encompassed 10 behavioural elements. Durations, frequencies and latencies showed quantitative differences as to walking and sniffing activities. Wistar rats displayed significantly lower latency and significantly higher durations and frequencies of walking activities. DA/Han rats showed a significant increase of sniffing duration. In addition, DA/Han rats showed a significantly higher amount of time spent in the central platform. Multivariate T-pattern analysis revealed differences in the temporal organization of behaviour of the t…
T-pattern analysis for the study of temporal structure of animal and human behavior : a comprehensive review
A basic tenet in the realm of modern behavioral sciences is that behavior consists of patterns in time. For this reason, investigations of behavior deal with sequences that are not easily perceivable by the unaided observer. This problem calls for improved means of detection, data handling and analysis. This review focuses on the analysis of the temporal structure of behavior carried out by means of a multivariate approach known as T-pattern analysis. Using this technique, recurring sequences of behavioral events, usually hard to detect, can be unveiled and carefully described. T-pattern analysis has been successfully applied in the study of various aspects of human or animal behavior such …
Microiontophoretic Evidence that Nitric Oxide Alters Spontaneous Activity of the Substantia Nigra Pars Reticulata Neurons in the Rat
T-pattern detection and analysis for the discovery of hidden features of behaviour
Abstract Background The behaviour of all living beings consists of hidden patterns in time; consequently, its nature and its underlying dynamics are intrinsically difficult to be perceived and detected by the unaided observer. Method Such a scientific challenge calls for improved means of detection, data handling and analysis. By using a powerful and versatile technique known as T-pattern detection and analysis (TPA) it is possible to unveil hidden relationships among the behavioural events in time. Results TPA is demonstrated to be a solid and versatile tool to study the deep structure of behaviour in different experimental contexts, both in human and non human subjects. Conclusion This re…
Ultrasound detection of abdominal lymph nodes in chronic liver diseases. A retrospective analysis
Aim: To retrospectively evaluate the prevalence of lymph nodes of the hepato-duodenal ligament in a group of patients with chronic liver disease of various aetiologies and to investigate what clinical, aetiological and laboratory data may lead to their appearance. Materials and methods: One thousand and three patients (554 men, 449 women) were studied, including 557 with chronic hepatitis and 446 with liver cirrhosis. The presence of lymph nodes near the trunk of the portal vein, hepatic artery, celiac axis, superior mesenteric vein and pancreas head was investigated using ultrasound. Results: Lymph nodes were detected in 394 out of the 1003 study patients (39.3%); their number ranged from …
Hemodynamic changes in splanchnic circulation after orthotopic liver transplantation in patients with liver cirrhosis
Background: Liver cirrhosis increases portal vein pressure and alters the splanchnic circulation. With Doppler sonography, we investigated the hemodynamic changes in the portal vein, superior mesenteric artery, hepatic and splenic arteries and spleen size in a group of patients with end-stage liver disease before and after orthotopic liver transplantation (OLT). Methods: Ten patients (seven male, three female; mean age = 48.8 ± 7.6 years) who underwent OLT for liver cirrhosis mainly associated with hepatitis C virus infection completed the study. The control group consisted of 10 patients matched by sex and age who had no gastroenterologic or vascular diseases. All patients underwent duplex…
Serotonin-Dopamine interaction in Nicotine Addiction: Focus on 5-HT2C Receptors
Central dopaminergic systems play a critical role in the regulation of normal and abnormal behaviors. Recent evidence suggests that a dysfunction of dopamine (DA) and serotonin (5-HT) neurotransmitter systems contribute to various pathological conditions. Substantial evidence indicates that the mesolimbic pathway, particularly the DA cells innervating accumbal areas, is implicated in the reward value of both natural and drug reinforcers, such as sexual behavior or psychostimulants, respectively. Nicotine, the major psychoactive agent present in tobacco, acts as a potent addictive drug both in humans and laboratory animals. The locomotor activation and the reinforcing effects of nicotine may…
Selective activation of 5-HT(2C) receptors stimulates GABA-ergic function in the rat substantia nigra pars reticulata: a combined in vivo electrophysiological and neurochemical study.
In vivo electrophysiology and microdialysis were used to investigate the physiological role of 5-HT(2C) receptors in the control of substantia nigra pars reticulata (SNr) function. Extracellular single-unit recordings were performed from putative GABA-containing neurons in the SNr of anesthetized rats, and local GABA release was studied by in vivo microdialysis in the SNr of awake freely-moving rats. Systemic administration of the selective 5-HT(2C) receptor agonist (S)-2-(chloro-5-fluoro-indol-1-yl)-1-methylethylamine 1:1 C(4)H(4)O(4) (RO 60-0175) caused a dose-dependent excitation of about 30% of the SNr neurons recorded. However, the remaining neurons were either inhibited or unaffected …
ROLE OF NITRIC OXIDE IN THE CONTROL OF MAXIMAL DENTATE GYRUS ACTIVATION BY LAMOTRIGINE IN THE RAT.
Alcohol, Cannabinoids and Nicotine in liver pathophysiology
The liver can be affected by a wide range of therapeutic and environmental chemicals and here we want to provide a summary of the complex effects of alcohol, cannabinoids and nicotine on liver function. Alcohol is the most important agent that produces liver injury, manifesting as alcoholic fatty liver disease. In addition, it is one of the main etiologic agents for hepatocellular carcinoma development. Studies reviewed in this article regarding cannabinoids, show that Δ9-THC does not produce any harmful effects on the liver, while cannabidiol has hepatoprotective effects in ischemia/reperfusion and alcohol-induced liver injuries. The liver is negatively affected by nicotine exposure, but s…
Molecular and functional interactions between tumor necrosis factor-alpha receptors and the glutamatergic system in the mouse hippocampus: Implications for seizure susceptibility.
Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine acting on two distinct receptor subtypes, namely p55 and p75 receptors. TNF-alpha p55 and p75 receptor knockout mice were previously shown to display a decreased or enhanced susceptibility to seizures, respectively, suggesting intrinsic modifications in neuronal excitability. We investigated whether alterations in glutamate system function occur in these naive knockout mice with perturbed cytokine signaling that could explain their different propensity to develop seizures. Using Western blot analysis of hippocampal homogenates, we found that p55(-/-) mice have decreased levels of membrane GluR3 and NR1 glutamate receptor subuni…
Screening for Autoantibodies to Tissue Transglutaminase Reveals a Low Prevalence of Celiac Disease in Blood Donors with Cryptogenic Hypertransaminasemia
Patients with chronic cryptogenic hypertransaminasemia are at high risk of developing celiac disease (CD). In fact, among the various serological disorders, CD patients at onset frequently present hypertransaminasemia. In this study, we evaluated usefulness and reliability of the new test for antitissue transglutaminase (tTG) in screening for CD as well as in estimating the prevalence of CD in a population of blood donors presenting unexplained hypertransaminasemia at donation. Controls were 180 consecutive healthy donors without hypertransaminasemia and 20 CD patients with known antiendomysial antibody (EmA) positivity. Out of 22,204 blood donors over a period of 2 years, we found 258 subj…
Lateral Habenula contribution in nicotine addiction: Focus on dopamine, GABA and serotonin interactions
Compelling evidence has shown a pivotal role of dopaminergic function in drug addiction. Recently, the Habenula (Hb) has attracted a great deal of attention as another target for nicotine in the brain because of its role in regulating dopamine (DA), gamma-aminobutyric acid (GABA) and serotonin (5-HT) systems. Nicotine acts binding to acetylcholine receptors that are widely distributed in the brain. Interestingly, the receptor subtypes that mediate nicotine withdrawal responses are highly expressed in the Hb. Moreover, the block of habenular nicotinic receptors in animals chronically treated with nicotine enhances withdrawal responses once nicotine is discontinued. Furthermore, it has been s…
m-Chlorophenylpiperazine excites non-dopaminergic neurons in the rat Substantia Nigra and Ventral Tegmental Area by activating serotonin-2c receptors
In vivo electrophysiological techniques were used to study the effect of m-chlorophenylpiperazine, a non-selective serotonin-2C receptor agonist, on the activity of non-dopaminergic neurons in the substantia nigra pars reticulata and the ventral tegmental area of anesthetized rats. Intravenous administration of m-chlorophenylpiperazine (5–320 μg/kg) caused a dose-dependent increase in the basal firing rate of a subpopulation of nigral neurons which do not respond to a footpinch stimulus [P(0) neurons], whereas it did not affect the activity of neurons which are responsive to the footpinch [P(+) neurons]. However, m-chlorophenylpiperazine (5–320 μg/kg) excited all non-dopaminergic neurons sa…