Thyrotrophin releasing hormone--5-hydroxytryptamine interactions in the brain studied using chronic immunization and chemical lesioning techniques.
This study investigates the effects of chemically lesioning 5-hydroxytryptamine (5HT) neurones and chronic passive immunization of central thyrotrophin releasing hormone (TRH) on 5HT and TRH mediated behavioural responses. 5HT lesions produced by 5,7-dihydroxytryptamine (5,7-DHT) enhanced the behavioural response produced by the 5HT receptor agonist 5-methoxy-N,N-dimethyltryptamine (5-MEODMT) while decreasing the locomotor hyperactivity observed following administration of the TRH analogue CG 3509 but having no effect on the reversal of pentobarbitone sleep-time produced by CG 3509. Chronic intracerebroventricular infusion of the purified TRH antibody markedly increased the length of pentobarbitone-induced sleep-time while enhancing the effects of CG 3509 both on locomotor activity and pentobarbitone-induced sleep. TRH antibody infusion also increased the response produced by 5-MEODMT. The results indicate that chronic passive immunization of central TRH induces changes in TRH receptor responsiveness and that there is a functional interaction between TRH and 5HT neuronal systems.
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage; D007116:Immunization, Passive; D007074:Immunoglobulin G / Q000008:administration & dosage; D008297:Male; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects*; D010424:Pentobarbital / Q000037:antagonists & inhibitors; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D018025:Receptors, Thyrotropin-Releasing Hormone; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*; D012890:Sleep / Q000187:drug effects*; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000276:immunology / Q000494:pharmacology / Q000502:physiology*
D000906:Antibodies; D007074:Immunoglobulin G; D008732:Methoxydimethyltryptamines; D017981:Receptors, Neurotransmitter; D018025:Receptors, Thyrotropin-Releasing Hormone; C036430:orotirelin; D012701:Serotonin; D013973:Thyrotropin-Releasing Hormone; D010424:Pentobarbital