Abstract
Pretraining administration of the opiate antagonist naloxone on the first 4 of 5 days of training enhanced the acquisition of spatial information in the Morris water maze. Naloxone-treated rats learned to find an invisible escape platform located in a fixed position relative to environmental cues more rapidly than did control rats. Naloxone-treated rats also displayed better knowledge of the platform location during a probe trial conducted in the absence of the escape platform on Day 5. In contrast, posttraining administration of naloxone did not significantly affect performance, even when a higher dose was used or when the training protocol was altered. These results suggest a role for endogenous opioid-peptidergic systems in the acquisition of spatial information.
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This work was supported by USPHS Postdoctoral Fellowship AG05446 (M.W.D.) and USPHS Grant MH12526 and Office of Naval Research Contract N00014-87-K-0518 (J.L.M.).
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Decker, M.W., Introini-Collison, I.B. & Mcgaugh, J.L. Effects of naloxone on Morris water maze learning in the rat: Enhanced acquisition with pretraining but not posttraining administration. Psychobiology 17, 270–275 (1989). https://doi.org/10.1007/BF03337778
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DOI: https://doi.org/10.1007/BF03337778