Abstract
Naloxone, morphine, and morphine plus naloxone were injected IP into rats immediately after training in several different behavioral tasks, and their effect on retention was evaluated in test sessions carried out 1 or 7 days later. Naloxone (0.4 mg/kg) enhanced and morphine (1.0 mg/kg) depressed retention for a standard shuttle avoidance task acquired with contiguous tone-footshock presentations. Retention of this behavior is known to result from the independent operation of four memory channels (Izquierdo and Elisabetsky, 1978). In consequence, the effect of naloxone on each of those channels was investigated. The channel which stores responses acquired through an avoidance mode and makes them available for retrieval in the same mode, was facilitate by as little as 0.2 mg/kg of the drug. The other channels were sensitive only to 0.4 or 0.8 mg/kg naloxone. Retention of the habituation of a rearing response to a tone from one day to the next was also enhanced by naloxone (0.8 mg/kg) and depressed by morphine (1.0 mg/kg), and, again, there was an antagonistic interaction between the two drugs. The results suggest a role for endogenous opiate substances as general inhibitory modulators of memory consolidation, point to a differential sensitivity of the various memory channels to naloxone (therefore, presumably to endogenous opiate modulation), and demonstrate that the post-training effect of naloxone and morphine on memory (or the role of endogenous opiates thus suggested) does not depend on the presence of foot shocks in the training session to become manifest.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bliss, C. I.: Statistics in biology, vol. I. New York: McGraw-Hill 1967
DeWied, D., Bohus, B., van Ree, J. M., Urban, I.: Behavioral and electrophysiological effects of peptides related to lipotropin(β-LPH). J. Pharmacol. Exp. Ther. 204, 570–580 (1978)
Elisabetsky, E., Vendite, D. A., Izquierdo, I.: Memory channels in the rat: Effect of post-training application of potassium chloride on the hippocampus. Behav. Neural Biol. 26, (in press 1979)
Gallagher, M., Kapp, B. S.: Opiate administration into the amygdala: Effects on memory processes. Abstracts Eighth Annual Meeting of the Society for Neuroscience, p. 258 (1978)
Gold, P. E., McGaugh, J. L.: Hormones and memory. In: Neuropeptide influences on the brain and behavior, L. H. Miller, C. A. Sandman, A. J. Kastin, eds., pp. 127–143. New York: Raven 1977
Gold, P. E., van Buskirk, R.: Effects of α- and β-adrenergic receptor antagonists on post-trial epinephrine modulation of memory: Relationship to post-training brain norepinephrine concentrations. Behav. Biol. 24, 168–184 (1978)
Goldstein, A., Pryor, G. T., Otis, L. S., Larsen, F.: On the role of endogenous opioid peptides: Failure of naloxone to influence shock escape threshold in the rat. Life Sci. 18, 599–604 (1976)
Izquierdo, I.: Relations between orienting, pseudoconditioned and conditioned responses in the shuttle-box: A pharmacological analysis by means of LSD and dibenamine. Behav. Biol. 15, 193–205 (1975)
Izquierdo, I., Beamish, D. G., Anisman, H.: Effect of an inhibitor of dopamine-beta-hydroxylase on the acquisition and retention of four different avoidance tasks in mice. Psychopharmacology, 63, 173–178 (1979)
Izquierdo, I., Cavalheiro, E. A.: Three main factors in rat shuttle behavior: Their pharmacology and sequential entry in operation during a two-way avoidance session. Psychopharmacology 49, 145–157 (1976)
Izquierdo, I., Elisabetsky, E.: Four memory channels in the rat brain. Psychopharmacology 57, 215–222 (1978)
Izquierdo, I., Elisabetsky, E.: Physiological and pharmacological dissection of the main factors in the acquisition and retention of rat shuttle behavior. In: Brain mechanisms in memory and learning, M. A. B. Brazier, ed., pp. 227–248. New York: Raven 1979
Jacob, J. J., Tremblay E. C., Colombel, M.-C.: Facilitation de réactions nociceptives par la naloxone chez la souris et chez le rat. Psychopharmacologia 37, 217–223 (1974)
Jensen, R. A., Martinez, J. L. Jr., Messing, R. B., Spiehler, V., Vásquez, B. J., Soumireu-Mourat, B., Liang, K. C., McGaugh, J. L.: Morphine and naloxone alter memory in the rat. Abstracts Eighth Annual Meeting of the Society for Neuroscience, p. 260 (1978)
Katz, R. J., Gelbart, J.: Endogenous opiates and behavioral responses to experimental novelty. Behav. Biol. 24, 338–348 (1978)
Lauzi Gozzani, J., Izquierdo, I.: Possible peripheral adrenergic and central dopaminergic influences in memory consolidation. Psychopharmacology 49, 109–111 (1976)
McGaugh, J. L., Herz, M. J.: Memory consolidation. San Francisco: Albion 1972
Martin, W. R.: Opioid antagonists. Pharmacol. Rev. 19, 463–521 (1967)
Mullis, K. B., Perry, D. C., Finn, A. M., Stafford, B., Sadée, W.: Morphine persistence in rat brain and serum after single doses. J. Pharmacol. Exp. Ther. 208, 228–231 (1979)
Pace, V. L., Parrish, R. G., Lieberman, M. M., Wong, K. C., Blatnick, R. A.: Pharmacokinetics of naloxone and naltrexone in the dog. J. Pharmacol. Exp. Ther. 208, 254–256 (1979)
Rachid, C., de Souza, A. S., Izquierdo, I.: Effect of pre-and post-trial tyramine and guanethidine injections on an appetitive task in rats. Behav. Biol. 21, 294–299 (1977)
Schütz, R. A., Izquierdo, I.: Effect of brain lesions on rat shuttle behavior in four different tests. Physiol. Behav., (in press 1979)
Terenius, L.: Endogenous peptides and analgesia. Ann. Rev. Pharmacol. Toxicol. 18, 189–204 (1978)
Thompson, R. W., Spencer, W. A.: Habituation: A model phenomenon for the study of neural substrates of behavior. Psychol. Rev. 173, 16–43 (1966)
Zornetzer, S. F.: Neurotransmitter modulation and memory: A new neuropharmacological phrenology? In: Psychopharmacology: A generation of progress, M. A. Lipton, A. DiMascio, K. F. Killam, eds., pp. 637–649 New York: Raven 1978
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Izquierdo, I. Effect of naloxone and morphine on various forms of memory in the rat: Possible role of endogenous opiate mechanisms in memory consolidation. Psychopharmacology 66, 199–203 (1979). https://doi.org/10.1007/BF00427631
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00427631