Search results for " DOP"
showing 10 items of 770 documents
Modulation of high impulsivity and attentional performance in rats by selective direct and indirect dopaminergic and noradrenergic receptor agonists
2011
Rationale Impulsivity is associated with a number of psychiatric disorders, most notably attention deficit/hyperactivity disorder (ADHD). Drugs that augment catecholamine function (e.g. methylphenidate and the selective noradrenaline reuptake inhibitor atomoxetine) have clinical efficacy in ADHD, but their precise mechanism of action is unclear. Objective The objective of this study is to investigate the relative contribution of dopamine (DA) and noradrenaline (NA) to the therapeutic effects of clinically effective drugs in ADHD using rats selected for high impulsivity on the five-choice serial reaction time task (5CSRTT). Methods We examined the effects of direct and indirect DA and NA rec…
Involvement of Dopamine D2 Receptors in Addictive-Like Behaviour for Acetaldehyde
2014
Acetaldehyde, the first metabolite of ethanol, is active in the central nervous system, where it exerts motivational properties. Acetaldehyde is able to induce drinking behaviour in operant-conflict paradigms that resemble the core features of the addictive phenotype: drug-intake acquisition and maintenance, drug-seeking, relapse and drug use despite negative consequences. Since acetaldehyde directly stimulates dopamine neuronal firing in the mesolimbic system, the aim of this study was the investigation of dopamine D2-receptors' role in the onset of the operant drinking behaviour for acetaldehyde in different functional stages, by the administration of two different D2-receptor agonists, q…
Intraoperative monitoring of cerebral blood flow during ventricular shunting in hydrocephalic pediatric patients.
1995
Several studies have demonstrated lowered cerebral blood flow (CBF) in patients with hydrocephalus and symptoms of raised intracranial pressure. Ventricular shunting in such cases permits a sudden increase in CBF. The pathophysiology of functional brain deficit secondary to hydrocephalus is little understood. Improvement of the patient's clinical status after drainage of CSF suggests that cerebral dysfunction is not necessarily due to permanent brain damage. In fact, it improves rapidly after ventricular taps. In view of this it would be helpful to monitor cerebral perfusion. The transcranial Doppler (TCD) ultrasonography technique allows real-time monitoring of the intracranial circulation…
Partial replication of a DRD4 association in ADHD individuals using a statistically derived quantitative trait for ADHD in a family-based association…
2007
Contains fulltext : 52515.pdf (Publisher’s version ) (Closed access) BACKGROUND: Previous research found an association between single nucleotide polymorphisms (SNPs) in the promoter region of DRD4 and statistically derived phenotypes generated from attention-deficit/hyperactivity disorder (ADHD) symptoms. We sought to replicate this finding by using the same methodology in an independent sample of ADHD individuals. METHODS: Four SNPs were genotyped in and around DRD4 in 2631 individuals in 642 families. We developed a quantitative phenotype at each SNP by weighting nine inattentive and nine hyperactive-impulsive symptoms. The weights were selected to maximize the heritability at each SNP. …
Effects of risperidone and SCH 23390 on isolation-induced aggression in male mice.
1998
In this study, the antiaggressive effects of risperidone and SCH 23390 have been explored. Using the paradigm of isolation-induced aggression, 150 albino male mice of the OF1 strain were allocated to control and experimental groups which received three doses of risperidone (0.01, 0.05 and 0.1 mg/kg) or two doses of SCH 23390 (0.05 and 0.1 mg/kg). Only the highest doses of risperidone decreased threat and attack behaviours but all doses significantly impaired motor behaviour. SCH 23390 decreased attack with the two doses used and also produced significant increases in immobility. Although both antipsychotics are antiaggressive, this action seems to be more specific in the case of risperidone…
Investigating the mechanisms of cardiovascular and cerebrovascular regulation in orthostatic syncope through an information decomposition strategy
2012
Some previous evidence suggests that postural related syncope is associated with defective mechanisms of cerebrovascular (CB) and cardiovascular (CV) control. We characterized the information processing in short-term CB regulation, from the variability of mean cerebral blood flow velocity (CBFV) and mean arterial pressure (AP), and in CV regulation, from the variability of heart period (HP) and systolic AP (SAP), in ten young subjects developing orthostatic syncope in response to prolonged head-up tilt testing. We exploited a novel information-theoretic approach that decomposes the information associated with a variability series into three amounts: the information stored in the series, the…
Time course of cerebrovascular autoregulation during extreme Trendelenburg position for robotic-assisted prostatic surgery
2013
Trendelenburg positioning in combination with pneumoperitoneum during robotic-assisted prostatic surgery possibly impairs cerebrovascular autoregulation. If cerebrovascular autoregulation is disturbed, arterial hypertension might induce cerebral hyperaemia and brain oedema, while low arterial blood pressure can induce cerebral ischaemia. The time course of cerebrovascular autoregulation was investigated during use of the Trendelenburg position and a pneumoperitoneum for robotic-assisted prostatic surgery using transcranial Doppler ultrasound. Cerebral blood flow velocity was correlated with arterial blood pressure and the autoregulation index (Mx) was calculated. In 23 male patients, Mx was…
Tetrahydroisoquinolines as dopaminergic ligands: 1-Butyl-7-chloro-6-hydroxy-tetrahydroisoquinoline, a new compound with antidepressant-like activity …
2009
International audience; Three series of 1-substituted-7-chloro-6-hydroxy-tetrahydroisoquinolines (1-butyl-, 1-phenyl- and 1-benzyl derivatives) were prepared to explore the influence of each of these groups at the 1-position on the affinity for dopamine receptors. All the compounds displayed affinity for D(1)-like and/or D(2)-like dopamine receptors in striatal membranes, and were unable to inhibit [(3)H]-dopamine uptake in striatal synaptosomes. Different structure requirements have been observed for adequate D(1) or D(2) affinities. This paper details the synthesis, structural elucidation, dopaminergic binding assays, structure-activity relationships (SAR) of these three series of isoquin…
Extended Granger causality: a new tool to identify the structure of physiological networks.
2015
Granger causality (GC) is a very popular tool for assessing the presence of directional interactions between two time series of a multivariate data set. In its original formulation, GC does not account for zero-lag correlations possibly existing between the observed time series. In the present study we compare the GC with a novel measure, termed extended GC (eGC), able to capture instantaneous causal relationships. We present a two-step procedure for the practical estimation of eGC based on first detecting the existence of zero-lag correlations, and then assigning them to one of the two possible causal directions using pairwise measures of non-Gaussianity. The proposed method was validated …
Effects of DA D1 and D2 antagonists on the sensitisation to the motor effects of morphine in mice
2002
Abstract Acute morphine administration produces hyperactivity in mice and repeated treatment induces an enhancement of this effect. In this experiment, we study the sensitisation to the hyperactivity induced by intermittent morphine administration (40 mg/kg) and the effects of dopamine (DA) antagonists on this phenomenon. Animals received three injections, separated by 48 h, and after each injection, their activity was registered between 30 and 60 min. In Experiment 1, animals were divided into two groups, which received saline and morphine (S–S–M) or only morphine (M–M–M). In Experiment 2, animals were divided into 12 groups. Half, which was designed to study the effects of DA antagonists …