Behavioral effects and pattern of brain c-fos mRNA induced by 2,5-dihydro-2,4,5-trimethylthiazoline, a component of fox feces odor in GAD67-GFP knock-in C57BL/6 mice.
Behav Brain Res 2009;
202:218-24. [PMID:
19463704 DOI:
10.1016/j.bbr.2009.03.038]
[Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 03/23/2009] [Accepted: 03/27/2009] [Indexed: 11/28/2022]
Abstract
Predator odors, which are non-intrusive and naturalistic stressors of high ethological relevance, were used to study the neurobiology of innate fear in rodents. The present study investigates behavioral effects and the induction of c-fos mRNA in adult male predator naive mice caused by acute exposure to 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), a component of the fox feces odor. On the behavioral level, TMT potently increased unconditioned freezing and decreased non-defensive grooming behavior. With quantitative real time PCR we established a strong TMT-induced activation in the bed nucleus of the stria terminalis (BNST) (eight-fold increase, p<0.016) and in the ventral olfactory bulb (two-fold increase, p<0.036). In contrast, no significant TMT-induced c-fos induction could be observed in the dorsal olfactory bulb or in the amygdala. Our results display robust fear responses of GAD67-GFP knock-in mice exposed to TMT and suggest that the ventral olfactory bulb and the BNST are strongly activated during the elicitation of fear through predator odor in these transgenic mice.
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