研究会のご案内
リエゾンラボ研究会
発表内容

Title:
Neuronal mechanisms to control odor evoked emotions and behaviors

Ko Kobayakawa Ph.D. Research Associate
Department of Functional neuroscience, Osaka Bioscience Institute

Abstract:
The mammalian olfactory system mediates various responses, including aversive behaviours to spoiled foods and fear responses to predator odors. In the olfactory bulb, each glomerulus represents a single species of odorant receptor. Because a single odorant can interact with several different receptor species, the odor information received in the olfactory epithelium is converted to a topographical map of multiple glomeruli activated in distinct areas in the olfactory bulb. To study how the odor map is interpreted in the brain, we generated mutant mice in which olfactory sensory neurons in a specific area of the olfactory epithelium are ablated by targeted expression of the diphtheria toxin gene. Here we show that, in dorsal-zone-depleted mice, the dorsal domain of the olfactory bulb was devoid of glomerular structures, although second-order neurons were present in the vacant areas. The mutant mice lacked innate responses to aversive odorants, even though they were capable of detecting them and could be conditioned for aversion with the remaining glomeruli. The mutant mice also showed abnormal innate behaviors toward attractive odorants. These results indicate that, in mice, odor information is received in the olfactory bulb by separate sets of glomeruli, those dedicated for innate and those for learned responses.


References:
The dorsal-zone-depleted mouse pictured can detect odorants of a cat however it does not recognize them as dangerous signals and approaches to the cat (well-fed) without any sign of fear.

Kobayakawa et al., Nature . 2007 Nov 22;450(7169):503-8.
Imai et al., Science. 2009 Jul 31;325(5940):585-90