Luteinizing hormone releasing hormone (LHRH) in the periaqueductal gray substance increases some subcategories of grooming behavior in male rats.
Locomotion, holeboard exploration and grooming behavior were measured in male rats after injection of LHRH or cerebrospinal fluid (CSF) into the mesencephalic periaqueductal gray substance (PGS). LHRH injection at doses of 75 ng did not alter locomotion and rearing but decreased significantly the scores of head dipping and defecation. Several subcategories of grooming responses were evaluated in a home cage-like environment. Head, body and genital grooming increased significantly after injection of 75 ng LHRH. The frequency of gnawing and head shakes increased as well. Lower doses (50 ng) also raised the scores of head and body grooming and produced a tendency for genital grooming increase. Higher doses (100 ng) did not affect genital grooming responses and produced drowsiness in most of animals. These results demonstrate that some motor activities are selectively modified by the localized administration of LHRH in the PGS.
Gargiulo
P A
PA
Laboratorio de Investigaciones Cerebrales, Facultad de Ciencias Medicas Universidad N. de Cuyo, Mendoza, Argentina.
Donoso
A O
AO
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects*; D007987:Gonadotropin-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006120:Grooming / Q000187:drug effects*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010487:Periaqueductal Gray / Q000187:drug effects*; D051381:Rats
D007987:Gonadotropin-Releasing Hormone