Interaction of beta-endorphin and GABAergic drugs in the regulation of memory storage.
These experiments examined the interaction of beta-endorphin and GABAergic drugs, administered post-training, in influencing retention of an inhibitory avoidance response. Male CD1 mice were trained in an inhibitory avoidance task, given immediate post-training ip injections and tested 24 h later for retention. beta-Endorphin (0.5, 1.0, or 2.0 micrograms/kg) and muscimol (0.5, 1.0, or 2.0 mg/kg) produced dose-dependent impairment of retention; picrotoxin (0.25, 0.5, or 1.0 mg/kg) and bicuculline (0.1, 0.25, or 0.5 mg/kg) produced dose-dependent enhancement of retention. A low subeffective dose of muscimol (0.5 mg/kg) potentiated the retention-impairing effect of beta-endorphin (1.0 microgram/kg). In addition, concurrent administration of low, subeffective doses of bicuculline (0.1 mg/kg) or picrotoxin (0.25 mg/kg) attenuated the retention-impairing effects of beta-endorphin (1.0 microgram/kg). The findings are consistent with previous evidence indicating that beta-endorphin influences memory through an interaction with GABAergic mechanisms.
Castellano
C
C
Istituto de Psicobiologia e Psicofarmacologia del CNR, Rome, Italy.
Introini-Collison
I B
IB
McGaugh
J L
JL
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects* / Q000502:physiology; D001640:Bicuculline / Q000494:pharmacology; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D005239:Fear / Q000187:drug effects / Q000502:physiology; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D009118:Muscimol / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D009271:Naltrexone / Q000494:pharmacology; D010852:Picrotoxin / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018079:Receptors, GABA / Q000187:drug effects* / Q000502:physiology; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D012153:Retention, Psychology / Q000187:drug effects* / Q000502:physiology; D001615:beta-Endorphin / Q000494:pharmacology* / Q000502:physiology
D001640:Bicuculline; D009118:Muscimol; D009270:Naloxone; D009271:Naltrexone; D010852:Picrotoxin; D018079:Receptors, GABA; D011957:Receptors, Opioid; D001615:beta-Endorphin