[Effects of psychotropic drugs and the roles of the noradrenergic and dopaminergic systems in the lateral hypothalamic self-stimulation behavior].
A bipolar electrode was stereotaxically implanted in or near the medial forebrain bundle at the level of the posterior lateral hypothalamus of male albino Wistar-Imamichi rats. 1) Two electrode sites implanted in a rat both in the lateral hypothalamus and in the dorsal noradrenaline bundle supported self-stimulation (SS) behavior. 2) Methamphetamine facilitated the SS dose-dependently in the "threshold"-intensity reinforcement. The pretreatment of imipramine enhanced the effects of methamphetamine, but that of chlorpromazine inhibited those effects. Methamphetamine facilitated the SS also in the moderate-intensity reinforcement. Imipramine had no significant effects. On the other hand, chlorpromazine inhibited markedly the SS behavior. 3) FLA63 and U-14,624, dopamine beta-hydroxylase inhibitors, suppressed the SS behavior. Both drugs significantly reduced brain norepinephrine levels. FLA63 significantly increased the levels of dopamine, but the increase with U-14,624 was not significant. 4) Apomorphine, stimulant of dopamine receptor, did not facilitate, but rather suppressed the SS in the "threshold"-intensity reinforcement. 5) l-Norepinephrine injected into the lateral ventricle facilitated the rate of SS, dose-dependently. On the other hand, dopamine had no detectable effects. 7) These results suggest that the noradrenergic system in the brain plays a more important role in the positive reinforcement of the lateral hypothalamic SS behavior than does the dopaminergic system.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D005406:Bis(4-Methyl-1-Homopiperazinylthiocarbonyl)disulfide / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D002746:Chlorpromazine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D004299:Dopamine beta-Hydroxylase / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation; D007031:Hypothalamus / Q000502:physiology*; D007034:Hypothalamus, Posterior / Q000502:physiology*; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D009638:Norepinephrine / Q000502:physiology*; D010668:Phenylthiazolylthiourea / Q000494:pharmacology; D011619:Psychotropic Drugs / Q000494:pharmacology*; D051381:Rats; D012653:Self Stimulation / Q000187:drug effects*
D002395:Catecholamines; D011619:Psychotropic Drugs; D010668:Phenylthiazolylthiourea; D005406:Bis(4-Methyl-1-Homopiperazinylthiocarbonyl)disulfide; D008694:Methamphetamine; D004299:Dopamine beta-Hydroxylase; D001058:Apomorphine; D007099:Imipramine; D002746:Chlorpromazine; D004298:Dopamine; D009638:Norepinephrine