TY - JOUR
T1 - It is darkness and not light
T2 - Depression-like behaviors of diurnal unstriped Nile grass rats maintained under a short photoperiod schedule
AU - Ashkenazy-Frolinger, Tal
AU - Kronfeld-Schor, Noga
AU - Juetten, Jesse
AU - Einat, Haim
N1 - Funding Information:
Study was supported by a University of Minnesota graduate School Grant in Aid of Science to HE and a UROP award to JJ. The Nile rats breeding colony at Michigan State University is supported by a National Institute of Mental Health grant ( MH53433 ) to L. Smale.
PY - 2010/2/15
Y1 - 2010/2/15
N2 - Circadian rhythms are strongly implicated in affective disorders and some recent studies suggested that diurnal rodents might be advantageous model animals for them. In line with this possibility, previous work demonstrated that in the diurnal fat sand rat, short photoperiod conditions result in depression- and anxiety-like behavioral phenotype that is relieved with bright light treatment. To further explore the possibility of using diurnal species as model animals for affective disorders, the present study examined the effects of short photoperiod schedule in an additional diurnal rodent, the unstriped Nile grass rat. Results indicate that 6 weeks short photoperiod (5 h light/19 h dark) regimen induced depression-like behavior in the forced swim test and the saccharin preference test compared with animals maintained in a neutral photoperiod regimen (12 h light/12 h dark). No effects were shown in the light/dark box model of anxiety or in a test for spontaneous activity. These results demonstrate that photoperiod manipulations in diurnal rodents induce affective-like behavioral change and support the possibility that diurnal rodents might provide a good potential as model animals for depression spectrum disorders.
AB - Circadian rhythms are strongly implicated in affective disorders and some recent studies suggested that diurnal rodents might be advantageous model animals for them. In line with this possibility, previous work demonstrated that in the diurnal fat sand rat, short photoperiod conditions result in depression- and anxiety-like behavioral phenotype that is relieved with bright light treatment. To further explore the possibility of using diurnal species as model animals for affective disorders, the present study examined the effects of short photoperiod schedule in an additional diurnal rodent, the unstriped Nile grass rat. Results indicate that 6 weeks short photoperiod (5 h light/19 h dark) regimen induced depression-like behavior in the forced swim test and the saccharin preference test compared with animals maintained in a neutral photoperiod regimen (12 h light/12 h dark). No effects were shown in the light/dark box model of anxiety or in a test for spontaneous activity. These results demonstrate that photoperiod manipulations in diurnal rodents induce affective-like behavioral change and support the possibility that diurnal rodents might provide a good potential as model animals for depression spectrum disorders.
KW - Animal model
KW - Arvicanthis niloticus
KW - Behavior
KW - Depression
KW - Diurnal
KW - Nocturnal
UR - http://www.scopus.com/inward/record.url?scp=74149085505&partnerID=8YFLogxK
U2 - 10.1016/j.jneumeth.2009.11.013
DO - 10.1016/j.jneumeth.2009.11.013
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C2 - 19932714
AN - SCOPUS:74149085505
SN - 0165-0270
VL - 186
SP - 165
EP - 170
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
IS - 2
ER -