J. Physiol. Soc. Japan, 50: 418.
GUSTATORY RESPONSES OF LATERAL HYPOTHALAMIC GLUCOSENSITTVE (GS) AND GLUCOSE-INSENSITIVE (GIS) NEURONS IN THE MONKEY.
KARADI,Z., OOMURA, Y., NISHINO, H., JIANG, L., ITO, C., MING, B. AND FUJITA, I.
Natl. Inst. for Physiol. Sci., Okazaki 444 and Dept. of Physiol., Kyushu Univ., Fukuoka 812.
Single unit recordings from the monkey lateral hypothalamic area (LHA) during operant bar press feeding tasks as well as electric brain stimulatians revealed details of the functional organization of the LHA GS- and GIS-neurons. To elucidate these neurons' specific function in the taste and odor information processing their activity changes for gustatory and olfactory stimulatians were studied. For repeated applications of different taste-solutions the most GS-neurons (95% of neurons tested) responded, predominantly to two or more taste qualities, while fewer responses (59%)- ususally far one taste quality - of the GIS-neurons were seen. Since gestation and olfaction guide food searching and selecting behaviors together, odor stimulations were also performed. Correspondingly to the functional relationship between these two senses, similar activity changes were found to those seen after taste stimulations. Furthermore, overwhelming majority of the GS-neurons showed "bimodal" taste and odor responsiveness (96%), in contxast eaith the GIS-neurons, responding prevailingly to either taste or odor. The GS-neurons of the LHA seem to integrate multimodal sensory informations in regulating feeding behavior, while the GIS-neurons distinguish specific sensory cues to control selection and acquisition of foods.