TITLE:
Differential Effect of Acute Stress on Visuospatial Working Memory and Sexual Motivation in Male Rats
AUTHORS:
Marisela Hernández-González, Enrique Hernández-Arteaga, Mayra Linné Almanza-Sepúlveda, Miguel Ángel Guevara
KEYWORDS:
Stress, Working Memory, Sexual Behavior
JOURNAL NAME:
Journal of Behavioral and Brain Science,
Vol.5 No.7,
July
7,
2015
ABSTRACT: Working memory is an executive function that is highly
dependent on the functioning of the prefrontal cortex. Several studies using food or drink as rewards have
demonstrated that rats are capable of performing tasks that involve
working memory. Sexual behavior is another highly-rewarding, motivated
behavior that has proven to be an efficient incentive in classical operant
tasks. Considering that both sexual behavior and working memory are sensitive
to the effects of stress, the aim of this study was to determine the effect of
acute stress on visuospatial working memory during a sexually-motivated task (a
nonmatching-to-sample task in a T-maze) in male rats. Thirty-two male Wistar
rats were trained in the T-maze using sexual interaction (intromission and
ejaculation) as a reinforcer during a 4-day training period (training sessions
held every 4th day). On the basis of their performance, the rats were
classified as good-learners (n = 12) and bad-learners (n = 20), and on the
fifth day, 6 good-learners and 10 bad-learners were subjected to stress using
the cold water immersion model (CWI, 15°C) for 15 minutes before they were evaluated
in the T-maze. The remaining rats made up the control group (i.e., they performed the task without
previous stress). Results showed that acute stress by CWI improved working
memory in the bad-learners but did not affect the performance of the
good-learners, although in both groups (good- and bad-learners) stress
decreased the sexual motivation to perform the task. It is probable that the increased
levels of corticosterone in the stress situation could activate glutamatergic
transmission in the prefrontal cortex, thus facilitating working memory and,
simultaneously, decreasing testosterone levels, which exerts a negative effect
on sexual motivation in these male rats.