Dissociation of the effects of ethanol on memory, anxiety, and motor behavior in mice tested in the plus-maze discriminative avoidance task.

RATIONALE: Several studies have shown the amnestic effects of ethanol (ETOH). However, while memory tasks in rodents can be markedly influenced by anxiety-like behavior and motor function, ETOH induces anxiolysis and different effects on locomotion, depending on the dose. OBJECTIVE: Verify the effects of ETOH in mice tested in the plus-maze discriminative avoidance task (PMDAT) concomitantly evaluating memory, anxiety-like behavior, and motor behavior. METHODS: ETOH acutely or repeatedly treated mice were submitted to the training session in a modified elevated plus-maze with two open and two enclosed arms, aversive stimuli in one of the enclosed arms, and tested 24 h later without aversive stimuli. Learning/memory, locomotion, and anxiety-related behavior were evaluated by aversive arm exploration, number of entries in all the arms and open arms exploration, respectively. RESULTS: Acute ETOH: (1) either increased (1.2-1.8 g/kg) or decreased (3.0 g/kg) locomotion; (2) decreased anxiety levels (1.2-3.0 g/kg); and (3) induced learning deficits (1.2-3.0 g/kg) and memory deficits (0.3-3.0 g/kg). After repeated treatment, sensitization and tolerance to hyperlocomotion and anxiolysis induced by 1.8 g/kg ETOH were observed, respectively, and tolerance to the amnestic effect of 0.6 (but not 1.8) g/kg ETOH occurred. CONCLUSION: Neither the anxiolytic nor the locomotor effects of ETOH seem to be related to its amnestic effect in the PMDAT. Additionally, data give support to the effectiveness of the PMDAT in simultaneously evaluating learning, memory, anxiety-like behavior, and motor activity by different parameters. Possible relationships between the behavioral alterations found are discussed.

Drug-induced home cage conspecifics' behavior can potentiate behavioral sensitization in mice.

The effect of home cage conspecifics' behavior on locomotor sensitization to amphetamine (AMP) or ethanol (ETOH) were investigated. Female mice were repeatedly treated with saline or AMP (2.0 mg/kg for 13 days--Experiment 1) or saline or ETOH (1.8 g/kg for 21 days--Experiment 2) in home cages where all the animals had the same treatment (homogeneous home cages--HOM-HC) or in home cages where half of the animals were drug-treated and half of them were saline-treated (heterogeneous home cages--HET-HC). Behavioral sensitization was evaluated by the quantification of open-field locomotor activity after AMP or ETOH challenge injection, respectively. In both experiments, behavioral sensitization was potentiated in HOM-HC maintained animals. These results suggest that the behavioral sensitization phenomenon can be modified by home cage conspecifics' behavior.

Effects of social isolation on aging-induced orofacial movements in rats.

World population is becoming older, and aging is a common risk factor for a number of pathologies. In this respect, it is important to study possible factors that could modify alterations implicated in the process of aging. The aim of the present study is to verify the effects of social isolation on the expression of orofacial movements in adult and old rats. Adult and old rats were housed isolated for 5 days or kept in their home cages in groups of six. Before and after this period, orofacial movements and open-field general activity were evaluated. Aging-induced orofacial movements were abolished by isolation. On the other hand, isolated adult rats presented an increase in orofacial movements. General activity was decreased by aging but was not modified by isolation. Our results indicate that social isolation produces different effects in adult and old rats, and these effects are specific for orofacial movements and not related to a decrease in general motor activity.

Family history of alcoholism and psychiatric co-morbidity in Brazilian male alcoholics and controls.

The present study was aimed at replicating, in a sample of Brazilian subjects, findings generated mostly in developed countries on the relative prevalence of alcohol problems, associated psychiatric disorders, family history of alcoholism and other familial psychiatric disorders in alcoholics and controls. A group of Brazilian male alcoholics (n = 103) and controls (n = 63) at first admission to ambulatory or inpatient treatment were interviewed individually using sections of the Structured Clinical Interview for DSM-III-R. Information on demographic characteristics, alcohol-related problems, psychiatric problems and family history of alcoholism and depression were collected from all subjects. Alcoholics had a higher prevalence of a family history of alcoholism, a family history of depression and of a personal history of other psychiatric disorders when compared to controls. Comparisons between FHP and FHN alcoholics, although preliminary, showed few significant differences between these subgroups. Comparisons between FHP and FHN control showed a non-significant trend towards a higher prevalence of psychiatric problems and towards antisocial behaviours among those with a positive family history of alcoholism. The findings point to the importance of cross-cultural studies on genetic and environmental factors related to alcohol dependence.