Kappa opioid receptor activity modulates memory for peck-avoidance training in the 2-day-old chick.
To examine the role of kappa opioid receptors in memory formation, 2-day-old chicks were injected intracerebrally with either the endogenous opioid peptide dynorphin(1-13), the highly kappa selective agonist U-50,488 or the kappa selective antagonist nor-binaltorphimine (nor-BNI), given one-trial peck-avoidance training, and tested 24 h later. Dynorphin(1-13) impaired memory in a dose dependent manner at 24 h test. Injection of U-50,488 caused a biphasic dose-dependent effect on memory; low doses caused a trend toward enhanced memory and high doses caused significant impairment. Conversely, injection of low doses of nor-BNI caused a trend toward memory impairment, and higher doses caused significant memory enhancement. The results indicate that memory formation for one-trial peck-avoidance training may be modulated by kappa opioid receptor activity.
Department of Psychology, University of California, Berkeley 94720.
P J
PJ
Colombo
J L
JL
Martinez
E L
EL
Bennett
M R
MR
Rosenzweig
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D004399:Dynorphins / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D017473:Receptors, Opioid, kappa / Q000502:physiology*
D000700:Analgesics; D010446:Peptide Fragments; D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; C051844:norbinaltorphimine; D009271:Naltrexone; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; C026843:dynorphin (1-13); D004399:Dynorphins