Effect of chronic intra-accumbens administration of the TRH analogue CG3509 on histamine-induced behaviour in the rat.
1. The present study has investigated the effect of chronic intra-accumbens administration of the thyrotrophin-releasing hormone (TRH) analogue, CG3509, on CG3509- and histamine-induced spontaneous motor activity and brain TRH-like immunoreactive (TRH-LI) levels in the rat. 2. Chronic intra-accumbens administration of CG3509 (5 x 5 micrograms over 3 days) induced: (a) a significant (P less than 0.05) reduction in intra-accumbens CG3509 (0.5 micrograms)-induced hyperactivity, (b) reduced levels of TRH-LI in the nucleus accumbens but not other brain regions, (c) a marked increase (107%, P less than 0.01) in histamine-induced non-locomotor hyperactivity. 3. The present results demonstrate that alteration of central TRH function following treatment with a TRH analogue enhances the effect of intra-accumbens histamine on behavioural hyperactivity, possibly via changes in H1 receptors and suggest that the neuropeptide, TRH and histamine interact in behavioural arousal mechanisms in rat brain.
Bristow
L J
LJ
Department of Physiology & Pharmacology, Medical School, Queen's Medical Centre, Nottingham.
Bennett
G W
GW
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects; D006632:Histamine / Q000494:pharmacology*; D007267:Injections; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009714:Nucleus Accumbens; D051381:Rats; D011919:Rats, Inbred Strains; D013973:Thyrotropin-Releasing Hormone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
C036430:orotirelin; D013973:Thyrotropin-Releasing Hormone; D006632:Histamine