PMID- 31031606 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20201001 IS - 1662-5153 (Print) IS - 1662-5153 (Electronic) IS - 1662-5153 (Linking) VI - 13 DP - 2019 TI - Low Daytime Light Intensity Disrupts Male Copulatory Behavior, and Upregulates Medial Preoptic Area Steroid Hormone and Dopamine Receptor Expression, in a Diurnal Rodent Model of Seasonal Affective Disorder. PG - 72 LID - 10.3389/fnbeh.2019.00072 [doi] LID - 72 AB - Seasonal affective disorder (SAD) involves a number of psychological and behavioral impairments that emerge during the low daytime light intensity associated with winter, but which remit during the high daytime light intensity associated with summer. One symptom frequently reported by SAD patients is reduced sexual interest and activity, but the endocrine and neural bases of this particular impairment during low daylight intensity is unknown. Using a diurnal laboratory rodent, the Nile grass rat (Arvicanthis niloticus), we determined how chronic housing under a 12:12 h day/night cycle involving dim low-intensity daylight (50 lux) or bright high-intensity daylight (1,000 lux) affects males' copulatory behavior, reproductive organ weight, and circulating testosterone. We also examined the expression of mRNAs for the aromatase enzyme, estrogen receptor 1 (ESR1), and androgen receptor (AR) in the medial preoptic area (mPOA; brain site involved in the sensory and hormonal control of copulation), and mRNAs for the dopamine (DA) D1 and D2 receptors in both the mPOA and nucleus accumbens (NAC; brain site involved in stimulus salience and motivation to respond to reward). Compared to male grass rats housed in high-intensity daylight, males in low-intensity daylight displayed fewer mounts and intromissions when interacting with females, but the groups did not differ in their testes or seminal vesicle weights, or in their circulating levels of testosterone. Males in low-intensity daylight unexpectedly had higher ESR1, AR and D1 receptor mRNA in the mPOA, but did not differ from high-intensity daylight males in D1 or D2 mRNA expression in the NAC. Reminiscent of humans with SAD, dim winter-like daylight intensity impairs aspects of sexual behavior in a male diurnal rodent. This effect is not due to reduced circulating testosterone and is associated with upregulation of mPOA steroid and DA receptors that may help maintain some sexual motivation and behavior under winter-like lighting conditions. FAU - Lonstein, Joseph S AU - Lonstein JS AD - Neuroscience Program & Department of Psychology, Michigan State University, East Lansing, MI, United States. FAU - Linning-Duffy, Katrina AU - Linning-Duffy K AD - Neuroscience Program & Department of Psychology, Michigan State University, East Lansing, MI, United States. FAU - Yan, Lily AU - Yan L AD - Neuroscience Program & Department of Psychology, Michigan State University, East Lansing, MI, United States. LA - eng GR - R01 MH111276/MH/NIMH NIH HHS/United States PT - Journal Article DEP - 20190412 PL - Switzerland TA - Front Behav Neurosci JT - Frontiers in behavioral neuroscience JID - 101477952 PMC - PMC6473160 OTO - NOTNLM OT - hormones OT - light OT - medial preoptic area OT - nucleus accumbens OT - seasonal affective disorder OT - sexual behavior EDAT- 2019/04/30 06:00 MHDA- 2019/04/30 06:01 PMCR- 2019/01/01 CRDT- 2019/04/30 06:00 PHST- 2019/02/04 00:00 [received] PHST- 2019/03/25 00:00 [accepted] PHST- 2019/04/30 06:00 [entrez] PHST- 2019/04/30 06:00 [pubmed] PHST- 2019/04/30 06:01 [medline] PHST- 2019/01/01 00:00 [pmc-release] AID - 10.3389/fnbeh.2019.00072 [doi] PST - epublish SO - Front Behav Neurosci. 2019 Apr 12;13:72. doi: 10.3389/fnbeh.2019.00072. eCollection 2019.