Abstract
Morphine (5, 10, and 20 mg/kg, subcutaneously) both suppressed and elevated lateral hypothalamic self-stimulation response output. The duration of the depressant effect and the temporal appearance of the excitatory influence were dose dependent. With repeated daily injection tolerance developed to the suppressive effect while the facilitatory effect appeared ealier and tended to be enhanced. Thus the facilitatory action is not due simply to a rebound phenomenon. Finally, no correlation between the effects of morphine on self-stimulation behavior and on wheel-running activity was observed.
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This research was suppored in part by USPHS Grant No. MH-06564. The authors wish to acknowledge the able assistance of Mr. W. J. Adams and Mrs. Janice Schaefer during the course of this investigation. A report of this work was presented to the Society of Neurosciences, 1972.
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Lorens, S.A., Mitchell, C.L. Influence of morphine on lateral hypothalamic self-stimulation in the rat. Psychopharmacologia 32, 271–277 (1973). https://doi.org/10.1007/BF00422149
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DOI: https://doi.org/10.1007/BF00422149