NEUROPHYSIOLOGICAL STUDIES ON THE OLFACTORY RECEPTIVE MECHANISM.
Rept. no. 2 (Final), Jan 67-Jan 68,
GUNMA UNIV MAEBASHI (JAPAN) DEPT OF PHYSIOLOGY
Pagination or Media Count:
The olfactory nerve twig preparations of 20 microns thick were made and spike discharges were recorded therefrom by applying odours of eight groups classified by Amoore 1962. Differential sensitivity was found in different areas of the olfactory epithelium. By means of a microelectrode, differential sensitivity to various odours of single olfactory cells were shown. Thus, it was assumed that the spatial difference of the sensitivity of the olfactory receptor cells plays an important role for olfactory discrimination. The mechanism of olfactory fatigue was studied by recording the response of the olfactory nerve twigs. It was found that about half of the olfactory adaptation occurs in the receptor cells. The result indicates that the olfactory adaptation essentially occurs in the higher olfactory centers. The importance in olfaction of the trigeminal nerve was shown by recording the responses to many kinds of odours. This nerve is more sensitive to camphoraceous, pepperminty and pungent odours than the olfactory nerve. In order to clarify the mechanism of odour discrimination in the olfactory bulb, four camphoraceous and four pepperminty odours Amoore, 1962 were applied and the members of the spike discharges of single cells to these odours were counted. Correlations were examined between the spike numbers for pairs of the odours and then they were compared with the similarity or dissimilarity of the shapes of the odorous molecules calculated by shadow matching method Amoore, 1962. Good correlations were generally found between the numbers of spike discharges and the profiles of the odorous molecules, although there were some exceptions. Author
- Anatomy and Physiology