Repeated treatment with a low dose of reserpine as a progressive model of Parkinson's disease.

Animal models are widely used to study alterations caused by Parkinson's disease (PD). However, in general, pharmacological models do not express the progressive nature of the disease, being characterized by immediate severe motor impairment after a single dose of the drug. Reserpine administration in rodents has been suggested as a pharmacological model of PD based on the effects of this monoamine-depleting agent on motor activity.

Sex differences in aversive memory in rats: possible role of extinction and reactive emotional factors.

Studies usually show better spatial learning in males and stronger emotional memory in females. Spatial memory differences could relate to diverse strategies, while dissimilar stress reactions could cause emotional memory differences. We compared male and female rats in two emotional (classical emotional conditioning and aversive discrimination memory) and two emotionally "neutral" tasks: (1) plus-maze discriminative avoidance, containing two open and two enclosed arms, one of which presenting aversive stimuli (light/noise).

A rodent model of appetitive discrimination with concomitant evaluation of anxiety-like behavior.

The plus-maze discriminative avoidance paradigm has been used to study the relationship between aversive memory and anxiety. The present study aims to verify if the elevated plus-maze can provide information about appetitive memory and anxiety-like behavior, through a task motivated by food reward. Animals were allowed to explore an elevated plus-maze and received reinforcement in one of the enclosed arms.

Memory impairment induced by low doses of reserpine in rats: possible relationship with emotional processing deficits in Parkinson disease.

We have recently verified that the monoamine-depleting drug reserpine--at doses that do not modify motor function--impairs memory in a rodent model of aversive discrimination. In this study, the effects of reserpine (0.1-0.