Afferent projections of the infralimbic region of the medial prefrontal cortex of the rat

S271

19-01

CORTEX OF Department 260 JAPAN

AFFERENT PROJECTIONS OF THE INFRALIMBIC REGION OF THE MEDIAL PREFRONTAL AND TANEMICHI CHIBA, THE RAT. MICHIO AZUMA. MASAMITSU TAKAGISHI of Anatomy, Chiba University, School of Medicine, 1-8-1 Inohana, Chiba --

In a previous study, we have demonstrated the efferent projections of the infralimbic region (IL) of the medial prefrontal cortex of the rat. In this study, we examined the afferent and efferent projections of IL of the rat by using the wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP) retr-ograde and anterograde tracing technique. Resiprocal connections were revealed with the agranular insular cortex, dorsal endopiriform nucleus, piriform cortex, midline thalamic area, paraventricular nucleus, dorsal and posterior areas of the hypothalamus, ventral tegmental area, central gray, dorsal raphe and lateral parabrachial nucleus. In amygdaloid body, lateral and basolateral nucleus showed resiprocal connections, but central and medial nucleus showed afferent projections alone. Topographic relationships were seen, that is, caudal and rostra1 part of IL connected with the anterior insular cortex, piriform cortex,

dorsal endopiriform cortex and reticular thalamic nucleus, ventrolateral thalamic nucleus, respeLtiveIy. Only affer-entconnections were found from CA1 and amygdaloidpiriform transition, while only efferent

projections

to olfactory

tubercule,

caudate

putamen

and accumbens

nucleus.

19-02 INCREASE IN TURNOVER RATE OF BRAIN HISTAMINE DUE TO ACTIVATION OF OROPHARINGEAL SENSATION. TAKAKO FUJISE, HIRONOBU YOSHIMATSU*, AKIHIKO OOHARA*, MASAHIRO KANG* AND TOSHIIE SAKATA*. Department of Pediatric Dentistry. Faculty of University, 3-l-l Maidashi. Hiuashi-ku. Fukuoka 810. and Dentistry, Kyushu *Faculty of Internalmedicine I, Oita Medical University, Hasama, Oita 879-55, Japan in histamine turnover rate of the hypothalamus and the mesencephalic Changes trigeminal nucleus (Me5) were measured during and after feeding in rats. Turnover rate of neuronal histamine (HA) during feeding calculated from pargyline-induced in the Me5 (~(0.05). accumulation of the tele-methylhistamine (t-MH), increased rate 60 min after initiation of feeding increased both in the Me5 Turnover (p
19-03

AMINOGLUCOSE-INDUCED FEEDING SUPPRESION DUE TO HISTAMINE. HR HIR N B Y 3 D epartment KR U OKA W A AND TOSHIIE SAKA T A, of Internal Universitv

HYPOTHALAMIC Medicine

NEURONAL MAMORI, Oita Medical

To clarify the mechanism of feeding suppression induced by l-deoxy-Dglucosamine (l-DGLN) and 1-deoxy-N-acetylglucosamine (l-DGLNAc), we investigated involvement of hypothalamic neuronal histamine (HA) in their suppressive effects. Depletion of neuronal HA due to intraperitoneal injection (ip) of cc-fluoromethdecarboxylase, ylhistidine (FMH), an inhibitor of a HA synthesizing attenuated the l-DGLN-induced feeding suppression (pcO.01). Blockade of postsynaptic H.receptor by 26 pmol chlorpheniramine also attenuated the suppressive effecit of hypothalamic HA and tele-methylhistamine (t-MH), a mojor (p
suppresses

food

intake

through

activation

of

the

hypothalamic

HA

system.