title: [Avoidance conditioned-reflex behavior in rats chronically administered leucine enkephalin and its synthetic tetrapeptide analog into the neostriatum].
abstract: The three-week daily administration of 5 and 15 micrograms leu-enkephalin and its synthetic tetrapeptide analogue into the rat neostriatum led to an inhibition of avoidance conditioning in shuttlebox. Starting on the 10th day of the synthetic analogue injections, a motor excitation and a stereotyped behaviour were observed. No withdrawal effects were found. The tetrapeptide analogue was more effective than the natural leu-enkephalin in the same dose. A possible dopaminergic mechanism involved in the enkephalin long-term treatment, is discussed.
authors: N F
authors: NF
authors: Suvorov
authors: A F
authors: AF
authors: Iakimovskiĭ
authors: A V
authors: AV
authors: Eremeev
authors: I V
authors: IV
authors: Bobrova
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D003214:Conditioning, Classical / Q000187:drug effects*; D003342:Corpus Striatum; D008297:Male; D008845:Microinjections / Q000379:methods; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors
chemical_list: D009842:Oligopeptides; C061530:tyrosyl-arginyl-glycyl-phenylalanine ethyl ester
vernacular_title: Izbegatel'noe uslovnoreflektornoe povedenie u krys pri khronicheskom vvedenii v neostriatum leĭtsin-énkefalina i ego sinteticheskogo analoga-tetrapeptida.