title: Naloxone modulates the behavioral effects of cholinergic agonists and antagonists.
abstract: Peripheral glucose administration enhances memory in rodents and humans. Recent findings suggest that glucose may affect behavior, in part, by augmenting central cholinergic functions and by attenuating central opiate functions. The present experiments examined interactions between an opiate antagonist, naloxone, and cholinergic agents to determine whether the effects would parallel those found with glucose. Three behavioral measures were assessed: tremors, hyperactivity, and spontaneous alternation. Naloxone (1 mg/kg) significantly augmented tremors elicited by physostigmine (0.3 mg/kg). Naloxone (1 mg/kg) also attenuated increases in locomotor activity and impairments in spontaneous alternation performance elicited by scopolamine (1 and 3 mg/kg for activity and alternation measures, respectively). Thus, across three diverse measures, naloxone produced effects similar to those previously reported for glucose. These findings are consistent with the hypothesis that release of cholinergic activity from opiate inhibition may contribute to glucose effects on behavior.
authors.affiliation: Department of Psychology and Neuroscience Graduate Program, University of Virginia, Charlottesville 22903.
authors.forename: D L
authors.initials: DL
authors.lastname: Walker
authors.forename: T
authors.initials: T
authors.lastname: McGlynn
authors.forename: C
authors.initials: C
authors.lastname: Grey
authors.forename: M
authors.initials: M
authors.lastname: Ragozzino
authors.forename: P E
authors.initials: PE
authors.lastname: Gold
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D005260:Female; D005947:Glucose / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000037:antagonists & inhibitors; D009043:Motor Activity / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology*; D010277:Parasympathomimetics / Q000494:pharmacology*; D010830:Physostigmine / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects; D012601:Scopolamine / Q000037:antagonists & inhibitors; D014202:Tremor / Q000139:chemically induced
chemical_list: D010276:Parasympatholytics; D010277:Parasympathomimetics; D009270:Naloxone; D009020:Morphine; D010830:Physostigmine; D012601:Scopolamine; D005947:Glucose