title: Combined organizational and activational effects of short and long photoperiods on spatial and temporal memory in rats.
abstract: 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.
authors.affiliation: Department of Psychology and Neuroscience, Genome Sciences Research Building II, 3rd Floor, 572 Research Drive, Box 91050, Duke University, Durham, NC 27708, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: MacDonald
authors.forename: Ruey-Kuang
authors.initials: RK
authors.lastname: Cheng
authors.forename: Christina L
authors.initials: CL
authors.lastname: Williams
authors.forename: Warren H
authors.initials: WH
authors.lastname: Meck
mesh_terms: 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*