TY - JOUR
T1 - Sand rats see the light
T2 - Short photoperiod induces a depression-like response in a diurnal rodent
AU - Einat, Haim
AU - Kronfeld-Schor, Noga
AU - Eilam, David
N1 - Funding Information:
We are grateful to Chen Shemesh and Pazit Zadicario for their help in testing and behavioral analysis, to Barak Levy and the zookeepers of the I. Meier Segals Gardens for Zoological Research in Tel-Aviv University for providing us with the sand rats, and to Naomi Paz for editing this manuscript. The study was carried out under the regulations and approval of TAU institutional committee for animal experimentation (permit # L-05-056). The study was supported by The Charles E. Smith National Institute for Psychobiology in Israel award to NKS.
PY - 2006/10/2
Y1 - 2006/10/2
N2 - The present study examined the effect of simulated change in day length on the behavior of a diurnal rodent, the fat sand rat (a species of gerbil). Animals were housed under a short photoperiod (5/19 light/dark cycle) for 3 weeks and compared with controls living under a 12/12 light/dark cycle. All sand rats then underwent the forced swim test for depression-like behavior, and the open-field test for overall activity. Sand rats exposed to the short photoperiod displayed a significantly earlier sinking in the swim test, but there was no difference between their open-field activity compared with controls. Taking these responses as indicative of depression-like behavior, we suggest that a short photoperiod may induce affective-like changes, and that the sand rat may thus offer an appropriate animal model to explore the effect of photoperiod on normal, and perhaps also abnormal, seasonal mood changes (e.g., SAD), which in humans is a prevalent disorder, with winter depression episodes and spring/summer remissions.
AB - The present study examined the effect of simulated change in day length on the behavior of a diurnal rodent, the fat sand rat (a species of gerbil). Animals were housed under a short photoperiod (5/19 light/dark cycle) for 3 weeks and compared with controls living under a 12/12 light/dark cycle. All sand rats then underwent the forced swim test for depression-like behavior, and the open-field test for overall activity. Sand rats exposed to the short photoperiod displayed a significantly earlier sinking in the swim test, but there was no difference between their open-field activity compared with controls. Taking these responses as indicative of depression-like behavior, we suggest that a short photoperiod may induce affective-like changes, and that the sand rat may thus offer an appropriate animal model to explore the effect of photoperiod on normal, and perhaps also abnormal, seasonal mood changes (e.g., SAD), which in humans is a prevalent disorder, with winter depression episodes and spring/summer remissions.
KW - Animal model
KW - Circadian rhythms
KW - Forced swim test
KW - Photoperiod
KW - Psammomys obesus
KW - Seasonal affective disorder (SAD)
UR - http://www.scopus.com/inward/record.url?scp=33750018292&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2006.06.006
DO - 10.1016/j.bbr.2006.06.006
M3 - Article
C2 - 16831474
AN - SCOPUS:33750018292
SN - 0166-4328
VL - 173
SP - 153
EP - 157
JO - Behavioural Brain Research
JF - Behavioural Brain Research
IS - 1
ER -