Combined organizational and activational effects of short and long photoperiods on spatial and temporal memory in rats.
The present study examined the effects of photoperiod on spatial and temporal memory in adult Sprague-Dawley rats that were conceived and reared in different day lengths, i.e., short day (SD-8:16 light/dark) and long day (LD-16:8 light/dark). Both male and female LD rats demonstrated increased spatial memory capacity as evidenced by a lower number of choices to criterion in a 12-arm radial maze task relative to the performance of SD rats. SD rats also demonstrated a distortion in the content of temporal memory as evidenced by a proportional rightward shift in the 20 and 60 s temporal criteria trained using the peak-interval procedure that is consistent with reduced cholinergic function. The conclusion is that both spatial and temporal memory are sensitive to photoperiod variation in laboratory rats in a manner similar to that previously observed for reproductive behaviour.
MacDonald
Christopher J
CJ
Department of Psychology and Neuroscience, Genome Sciences Research Building II, 3rd Floor, 572 Research Drive, Box 91050, Duke University, Durham, NC 27708, USA.
Cheng
Ruey-Kuang
RK
Williams
Christina L
CL
Meck
Warren H
WH
D000704:Analysis of Variance; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology*; D005260:Female; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D016011:Normal Distribution; D017440:Photoperiod; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013028:Space Perception / Q000502:physiology; D013998:Time Perception / Q000502:physiology*