Bar-pressing for water reward: effects of nootropic drugs and peptides on discrimination learning in rats.
Rats maintained on 23-hr water deprivation were first trained to bar-press for continuous water reinforcement and then to discriminate between regularly alternating periods (24 sec) during which time a light signal was either on and each response was reinforced or the light was off and bar-presses were not rewarded. The following drugs were injected s. c. prior to the sessions of discriminative learning: piracetam, 1-(4-Methyl-piperazinocarbonylmethyl)-2-pyrrolidone/hydrogen maleate (VUFB 13763), N alpha-glycyl-glycyl[8-lysine]des-9-glycinamide-vasopressin (DG-Trigly-LVP) and an analog of MIF, EUC-Leu-beta-Ala-NH2 (EUC, 2-oxoimidazolidine-1-carboxylic acid). None of the drugs influenced the total number of bar-pressing (sum of reinforced and non reinforced responses). Piracetam (100 mg.kg-1), VUFB 13763 (40 mg.kg-1) and EUC-Leu-beta-Ala-NH2 (1 mg.kg-1) improved the performance of rats on the discrimination learning task, DG-Trigly-LVP slowed the rate of acquisition.
D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology; D048289:Imidazolidines; D008236:Lypressin / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D010455:Peptides / Q000494:pharmacology*; D010889:Piracetam / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012201:Reward; D014867:Water
D007093:Imidazoles; D048289:Imidazolidines; D010455:Peptides; D011760:Pyrrolidinones; D014867:Water; D008236:Lypressin; C042486:vasopressin, N-alpha-Gly-Gly-Gly-8-Lys-9-des-GlyNH2-; C042488:2-oxoimidazolidine-1-carboxylic acid-leucyl-beta-alaninamide; C042485:VUFB 13763; D010889:Piracetam