Post-fasting anorexia in rats is governed by enhanced activity of hypothalamic histamine

Post-fasting anorexia in rats is governed by enhanced activity of hypothalamic histamine

s147 SELF-MUTILATION BEHAVIOR AND BRAIN DOPAMINE IN NEONATAL 6-HYDROXYDOPAMINE TREATED RATS. 1 TOPOGRAPHIC SYSTEMSOF THE RAT BYIN. IMMUNOCYTOCHEMICA~...

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SELF-MUTILATION BEHAVIOR AND BRAIN DOPAMINE IN NEONATAL 6-HYDROXYDOPAMINE TREATED RATS. 1 TOPOGRAPHIC SYSTEMSOF THE RAT BYIN. IMMUNOCYTOCHEMICA~ ANALYSISOF INJU3EDDOPAMINERGIC CHIHIRO YOKOYAMA , HITOSHI OKAMURA AND YASUHIKO IBATA . DeDartments of Psychiatry and 'Anatomy, Kyoto -~ Prefectural University of Medicine, KaHaramachi_Hirokoi Kamikyo-ku, Kyoto 602. Japan. Neonatal intracisternal treatment of 6-hydroxydopamine (6-OHDA) causes the destruction of the dopaminergic neurons and induces selfmutilation behavior at adult age after loading of dopamine agonists. Previous biochemical studies by other investigations have revealed the severe depletion of dopamine and its metabolites in the basal ganglia, but the affected region has not been fully investigated. In the present study, we investigated the damaged area of dopaminergic neurons by ABC-immunocytochemistry using anti-tyrosine hydroxylase serum and anti-dopasine serum. Desipramine pretreated (20 ?g/kg) ? neonatal Wistar rats were injected with 6-OHDA (100 ug/5 ul with 0.1% ascorbic acid in saline, 2 times) intracisternally, and for control, the same solution without GOHDA was injected. Their behavior after Ro-4-4602 (50 mg/kg) and L-DOPA loading (100 mg/kg, i.p.) was evaluated at 6 weeks of age, and the rats In SMB(t), were divided into two groups with or without selfmultilation behavior (SMB(+) and SMB(-)). dopaminergic neurons and terminals were severely depleted in the caudate-putamen (CP), the suhstantia nigra (SN), the nucleus accumbens (Acb), the ventral tegmental area (VTA) and the tuberculum olfactorium (TuO), but almost unaffected in the insula of Calleja, medial prefrontal cortex, piriform cortex, entorhinal cortex, hypothalamus, interfascicular nucleus, rostra1 and caudal linear raphe nuclei and dorsal raphe nucleus. In SMB(-), CP and SN were severely depleted, but Acb, TuO and VTA were only moderately damaged. In SMB(+) rats, both nigrostriatal and VTA-ventral striatal dopaminergic systems were destructed, and the resulted altered dopaminergic neurotransmission may be a cause of SMB after loading of L-DOPA.

THE ROLE OF BRAXN HISTAMINE IN MASTICqTORY TAKAKO FUJISE, HIRONOBU TAMARI, * MASAHIRO KANG.

YOSHIMATSU, AND *TOSHIIE

FUNCTION IN R$TS. MAMORU KUROKAWA, AKIHIKO SAKATA.

OOHARA.

*YUICHI

Department of Pediatric Dentistry. Facultv of Dentistry, and *Department of Internal Medicine I, Faculty of Medicine, Kyushu Universitv 71, Fukuoka. 812 Japan. The mesencephalic trigeminal nucleus (Me5) has been shown to receive rich innervation from hypothalamic histaminergic neuron. To clarify the involvement of histamine in masticatory function, we investigated effects of histamine depletion from the nucleus on rat feeding behavior after treatment of a-fluoromethylhistidine (FMH). Food intake, meal duration and eating speed of the first meal were evaluated during 5 hr after the treatment. Intraperitoneal (ip) injection of lOOmg/kg FMH decreased eating speed (p
POST-FASTING ANOREXIA IN RATS IS GOVERNED BY HISTAMINE AKIHIKO OOHARA. HIRONOBU YOSHIMATSU, MAMORU TAMARI. AND TOSHIIE SAKATA, Department of

Medicine. Kvushu University

ENHANCED KUROKAWA.

Internal 71, Fukuoka. 812 Japan.

ACTIVITY TAKAKO

Medicine

OF

HYPOTHALAMIC

FUJISE,

I,

YUICHI

Faculty

of

Long-term fasting is known to induce anorexia. To clarify the mechanism, we investigate involvement of hypothalamic histamine (HA) in this phenomenon. Contents of HA and tele-methylhistamine (t-MH), a major metabolite of HA, were simultaneously evaluated in rats by the method using high performance liquid chromatography. After B-days fasting, food intake decreased on the first day after refeeding, compared to that at the pre-deprivation period (~(0.05). Levels (~(0.05 for each). of both HA and t-MH increased after B-days fasting Intraperitoneal (ip) pretreatment with 0.2Qsnol chlorphenylamine, antagonist, attenuated this decrease of food intake (P