Circadian modulation of fos responses to odor of the red fox, a rodent predator, in the rat olfactory system.
We have previously shown that neuronal responses to a biologically neutral odor, cedar wood oil, in the olfactory system are greater in the subjective night compared to subjective day. In the present study, we confirm these results and extend them to a biologically relevant odor, the urine of the red fox, a rodent predator. Fos induced by exposure of rats to fox urine or a neutral odor, mineral oil, was markedly enhanced during the subjective night compared to subjective day in the main olfactory bulb, primary olfactory cortex, and other structures related to olfaction. These results show that neuronal responses to an ethologically relevant odor follow a circadian rhythm similar to biologically neutral odors. Fos responses induced by fox urine were observed to be of greater magnitude than a neutral odor in brain areas involved in fear responses, suggesting that fox urine activates fear circuitry.
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Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, 1455 De Maisonneuve Blvd. West, Quebec, H3G 1M8, Montreal, Canada.
Amir
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D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects* / Q000502:physiology; D005239:Fear / Q000187:drug effects / Q000502:physiology; D005589:Foxes; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009812:Odorants; D009830:Olfactory Bulb / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009833:Olfactory Pathways / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D016760:Proto-Oncogene Proteins c-fos