Search results for "void"
showing 10 items of 435 documents
Modification of depressant and disinhibitory action of flurazepam during short term treatment in the rat
1972
Employing a fixed-interval schedule of reinforcement (temporal discrimination), alternated punished (fixed-ratio) and unpunished (variable-ratio) schedules of reinforcement, a Conditioned Avoidance Response, and studying its interaction with Pentobarbital on general anaesthesia, it has been shown that flurazepam hydrochloride after a single treatment induces very intense depressant effects and slight disinhibitory effects. Short term treatment at longer than daily intervals reduces the depressant effect and unmasks the disinhibitory effect. The phenomenon is probably caused by selective tolerance concerning the depressant action. The results are discussed from the point of view of the signi…
Hypericum Extract and Hyperforin: Memory-Enhancing Properties in Rodents
2001
Effects of a Hypericum extract in therapeutic use and hyperforin sodium salt were evaluated in rat and mouse avoidance tests. In a conditioned avoidance response (CAR) test on the rat, oral daily administration of hyperforin (1.25 mg/kg/day) or of the extract (50 mg/kg/day) before the training sessions considerably improved learning ability from the second day onwards until the day 7. In addition, the memory of the learned responses acquired during 7 consecutive days of administration and training was largely retained even after 9 days without further treatment or training. The observations made using different doses indicate that these learning-facilitating and/or memory-consolidating effe…
Chronic Moderate Hyperammonemia Impairs Active and Passive Avoidance Behavior and Conditional Discrimination Learning in Rats
2000
Abstract The cerebral dysfunction associated with hepatic encephalopathy is generally considered to have hyperammonemia as one of its main causes. Hyperammonemia impairs the neuronal glutamate–nitric oxide–cyclic GMP pathway and the induction of NMDA receptor-dependent long-term potentiation in the hippocampus. We studied the performance of pre/neonatally and postnatally exposed rats to hyperammonemia on active avoidance, passive avoidance, and conditional discrimination tasks. Pre/neonatal hyperammonemia slowed learning of active avoidance behaviors and impaired memory for the passive avoidance task while postnatal hyperammonemia impaired learning on the conditional discrimination task. Hy…
Mother knows best: dominant females determine offspring dispersal in red foxes (Vulpes vulpes).
2011
Background: Relatedness between group members is central to understanding the causes of animal dispersal. In many group-living mammals this can be complicated as extra-pair copulations result in offspring having varying levels of relatedness to the dominant animals, leading to a potential conflict between male and female dominants over offspring dispersal strategies. To avoid resource competition and inbreeding, dominant males might be expected to evict unrelated males and related females, whereas the reverse strategy would be expected for dominant females. Methodology/Principal Findings: We used microsatellites and long-term data from an urban fox (Vulpes vulpes) population to compare disp…
Students' academic and emotional adjustment during the transition from primary to secondary school
2019
The current study examined several indicators of students' academic and emotional adjustment during the transition from primary (i.e., grade 6) to secondary school (i.e., grades 7 and 9). Specifically, the study investigated how students' engagement, achievement, and burnout, as well as student-teacher conflict, evolve together over time. A total of 356 adolescents (57.3% boys) filled out questionnaires about their burnout and their behavioral and cognitive engagement. Students' achievement was measured using standardized test scores. Conflict in the teacher-student relationship was assessed using teacher ratings. Cross-lagged models revealed bi-directional associations between behavioral a…
Stable same-sex friendships with higher achieving partners promote mathematical reasoning in lower achieving primary school children
2015
This study is designed to investigate friend influence over mathematical reasoning in a sample of 374 children in 187 same-sex friend dyads (184 girls in 92 friendships; 190 boys in 95 friendships). Participants completed surveys that measured mathematical reasoning in the 3rd grade (approximately 9 years old) and one year later in the 4th grade (approximately 10 years old). Analyses designed for dyadic data (i.e., longitudinal Actor-Partner Interdependence Models) indicated that higher achieving friends influenced the mathematical reasoning of lower achieving friends, but not the reverse. Specifically, greater initial levels of mathematical reasoning among higher achieving partners in the …
Voluntary wheel running protects against the increase in ethanol consumption induced by social stress in mice
2020
Abstract Previous studies have shown that exposure to social defeat (SD), a model of social stress, produces a long-term increase in the consumption of ethanol, most likely through an increase in the neuroinflammation response. The aim of the present study was to evaluate whether exposure to physical activity in the form of voluntary wheel running (VWR) could block the increase in ethanol consumption and the neuroinflammatory response induced by social stress. Mice were exposed to either 4 sessions of repeated social defeat (RSD) or a non-stressful experience. During the whole procedure, half of the mice were exposed to controlled physical activity, being allowed 1 h access to a low-profile…
Are the effects of the antidepressants amitriptyline, maprotiline, and fluoxetine on inhibitory avoidance state-dependent?
2005
Abstract State-dependent learning (SDL) is a phenomenon in which the retrieval of newly acquired information is possible if the subject is in the same physiological state as during the encoding phase. SDL makes it possible to separate the effects of drugs per se on learning from the effects due to changes in drug state during the task. The present work was designed to investigate whether the antidepressants amitriptyline (30 mg/kg), maprotiline (25 mg/kg), and fluoxetine (15 mg/kg) produce SDL of the inhibitory avoidance conditioning in male and female CD1 mice. In three separate experiments, independent groups were used for each pharmacological treatment and for each sex using a 2 × 2 expe…
The role of temperament and character in the outcome of depressive mood in eating disorders.
2014
Abstract Objectives The aims were to see which temperament and character dimensions were associated with depression, mainly with its outcome at two-year follow up in eating disorders (EDs). Methods Participants (N = 151) were 44 Anorexia nervosa (AN), 55 Bulimia nervosa (BN) and 52 Eating disorders not otherwise specified (EDNOS) patients. The Beck Depression Inventory (BDI), State and Trait Anxiety Inventory (STAI), Rosenberg Self Esteem Questionnaire (RSE), Eating Disorder Inventory (EDI-2) and Temperament and Character Inventory (TCI) were administered. Results Depression at the beginning (t0) was severe in 22% of the cases. Harm Avoidance and Novelty Seeking had an effect on depressed m…
Sex differences in escape-avoidance response in mice after acute administration of raclopride, clozapine, and SCH 23390.
1998
Sex differences in the effects of haloperidol in the escape-avoidance response in mice have previously been found in various studies carried out in our laboratory. Males were more affected than females by the disruptive effects of this neuroleptic. The work described herein extended the study of these sex differences to raclopride, clozapine, and SCH 23390, using several doses of each drug in acute administration. The results showed dose-dependent sex differences in the deteriorating effects of these dopamine antagonists in the escape-avoidance response. Male mice were more affected by the inhibitory effects of these drugs, showing fewer escape responses and more nonresponses than females. …