Memory facilitation by naloxone is due to release of dopaminergic and beta-adrenergic systems from tonic inhibition
✍ Scribed by Ivan Izquierdo; Marcia Graudenz
- Book ID
- 104771208
- Publisher
- Springer
- Year
- 1980
- Tongue
- English
- Weight
- 369 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0033-3158
No coin nor oath required. For personal study only.
✦ Synopsis
The post-training IP administration of naloxone (0.8 mg/kg) facilitates memory consolidation of the habituation of a rearing response to a tone in rats. Amphetamine (1.0 - 2.5 mg/kg or nicotine (0.2 - 0.5 mg/kg), and amphetamine (2.5 mg/kg) plus nicotine (0.5 mg/kg) have no effect. The higher doses of amphetamine or nicotine, however, when given together with a dose of naloxone which is ineffective alone (0.2 mg/kg), markedly enhance consolidation. Haloperidol (0.5 mg/kg), propranolol (0.5 mg/kg), and phenoxybenzamine (2.0 mg/kg) have no effect on their own; whereas tolazoline (2.0 mg/kg) impairs consolidation. The effect of naloxone (0.8 mg/kg) is antagonized by haloperidol and by propranolol, but not by phenoxybenzamine or tolazoline. The results suggest that naloxone causes memory facilitation through the release of central dopaminergic and beta-adrenergic mechanisms from a tonic inhibitory influence of endogenous opiate peptide systems.