Restraint-induced hypoactivity in an elevated plus-maze

AUTOR(ES)

Padovan, C.M., Guimarães, F.S.

FONTE

Brazilian Journal of Medical and Biological Research

DATA DE PUBLICAÇÃO

2000-01

RESUMO

Rodents submitted to restraint stress show decreased activity in an elevated plus-maze (EPM) 24 h later. The objective of the present study was to determine if a certain amount of time is needed after stress for the development of these changes. We also wanted to verify if behavioral tolerance of repeated daily restraint would be detectable in this model. Male Wistar rats were restrained for 2 h and tested in the EPM 1, 2, 24 or 48 h later. Another group of animals was immobilized daily for 2 h for 7 days, being tested in the EPM 24 h after the last restraint period. Restraint induced a significant decrease in the percent of entries and time spent in the open arms, as well as a decrease in the number of enclosed arm entries. The significant effect in the number of entries and the percentage of time spent in the open arms disappeared when the data were submitted to analysis of covariance using the number of enclosed arm entries as a covariate. This suggests that the restraint-induced hypoactivity influences the measures of open arm exploration. The modifications of restraint-induced hypoactivity are evident 24 or 48 h, but not 1 or 2 h, after stress. In addition, rats stressed daily for seven days became tolerant to this effect.

Documentos Relacionados

• Cues to the usefulness of grooming behavior in the evaluation of anxiety in the elevated plus-maze
• L-histidine provokes a state-dependent memory retrieval deficit in mice re-exposed to the elevated plus-maze
• Dose-response effects of systemic anandamide administration in mice sequentially submitted to the open field and elevated plus-maze tests
• Effects of tactile stimulation and underwater trauma on the behavior of protein-malnourished rats in the elevated plus-maze test
• The interaction of housing condition and acute immobilization stress on the elevated plus-maze behaviors of protein-malnourished rats