Improvement of shuttle-box avoidance following post-training treatment in paradoxical sleep deprivation platforms in rats

Abstract

The effects of post-training paradoxical sleep deprivation (PSD), via the platform method, on acquisition and long-term retention (LTR) of shuttle-box avoidance were studied in Wistar rats. Animals had a daily training session for 5 days (acquisition), following which each rat was placed for 5 hr either on a small platform (7 cm) surrounded by water (PSD group) or on a large platform (16 cm) surrounded by water (Yoked control group), or was given no treatment (Dry control group). Another identical training session (LTR test) was also given to every subject 14 days after the last acquisition session. The treatment on the large platform (Yoked animals) improved learning in successive training sessions. A similar but not statistically significant improvement was also observed in the PSD group. In the LTR test, the PSD animals tended to decrease performance as compared with the conditioning level achieved in the previous acquisition session. Locomotor and emotional changes produced by PSD and PSD procedures are ruled out as the cause for these findings. We suggest that arousal produced by both PSD and PSD procedures could have improved the acquisition of the conditioning, whereas PSD per se could have been detrimental for LTR of the learned response.