Is a Divergent Central Serotonergic Activity Responsible for Either Despair or Learning Behavior in Intact Wistar or Sprague-Dawley CD Rats, Respectively? A Concomitant Behavioral and Electrochemical Analysis

Behavioral observations combined with electrochemical analysis have been performed in Wistar or Sprague-Dawley CD rats in the attempt to clarify earlier controversial behavioral reports. In particular, these rats were submitted to FST and to repeated Forced Swimming (rFS, during 4 days). In parallel, voltammetric in vivo analysis of serotonin (5-HT) levels in platelet-rich plasma (PRP) collected daily from these animals was also performed as it is known that peripheral 5-HT levels monitored in rat PRP mirror cerebral 5-HT contents. Thus, combined behavioral-voltammetric studies allow deducing changes of central 5-HT levels that could be correlated to FST or rFS, with the advantage of non invasive analysis of central neurotransmitter activities in intact behaving animals. In particular, combined behav-ioral-voltammetric results suggest that "behavioral despair" is the process interesting Wistar rats when submitted to FST or rFS while "learning to be immobile" is the process involving Sprague-Dawley CD rats.