Effect of bradykinin and morphine on sensomotor cortical neurons in rats

Acute experiments on rats showed that bradykinin, injected by microiontophoresis, activates sensomotor cortical neurons in rats. Morphine, administered in the same way, prevents the development of the bradykinin effect. Bradykinin, it is suggested, acts on opiate receptors in cerebral cortical neurons.Laboratory of Pharmacology of the Nervous System, Institute of Pharmacology, Academy of Medical Sciences of the USSR. Laboratory of Emotions and Emotional Stresses, P. K. Anokhin Institute of Normal Physiology, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 10, pp. 450–452, October, 1978.     

Effect of morphine and naloxone on acupuncture analgesia in unrestrained rats

Experiments on unrestrained rats showed that electroacupuncture of an acupuncture point distinctly reduces the nociceptive response to electrical stimulation of the base of the tail. Morphine, in a subanalgesic dose (5 mg/kg), potentiated the analgesic effect of acupuncture. Naloxone, in a dose of 5 mg/kg, completely abolished acupuncture analgesia. The possible mechanisms of analgesia production by electroacupuncture are discussed.Department of Pharmacology, I. P. Pavlov First Leningrad Medical Institute. Course of Reflex Therapy, S. M. Kirov Leningrad Postgraduate Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 11, pp. 566–569, November, 1979.     

Effect of colchicine on analgesic effects of morphine and DADL in rats

P. K. Anokhin Research Institute of Normal Physiology, Academy of Medical Sciences of the USSR, Moscow (Presented by Academician of the Academy of Medical Sciences of the USSR K. V. Sudakov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 8, pp. 168–170, August, 1990.     

Effect of 5,7-dihydroxytryptamine on nociceptive sensitivity and on the analgesic effect of morphine

Department of Pharmacology, Academician I. P. Pavlov First Leningrad Medical Institute. Department of Morphology, Research Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman). Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 9, pp. 311–314, September, 1988.     

Action of naloxone on emotionally positive and antinociceptive effects of hypothalamic stimulation in rats

Naloxone (5 mg/kg, subcutaneously) had no significant effect on the electrical self-stimulation response in rats with electrodes in the lateral hypothalamus. An analgesic effect of stimulation of the reward zones was found in three animals, in the form of raising of the threshold of pain vocalization during electrical stimulation of the tail. The antinociceptive action was abolished by naloxone. Morphine (3 mg/kg) activated the self-stimulation response, whereas naloxone antagonized this action. The role of opiate receptors in self-stimulation effects and in central analgesia is discussed.Department of Pharmacology, I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 11, pp. 569–572, November, 1979.     

Interaction between bradykinin,morphine, and naloxone at the sensomotor cortical unit level

The effects of bradykinin, morphine, and naloxone applied by microiontophoresis on sensomotor cortical neurons were studied in waking rabbits. Bradykinin increased the discharge frequency of most neurons. Morphine inhibited unit activity. Against the background of morphine, bradykinin had no activating action. Naloxone abolished the depriming effect of morphine and restored the response of the neurons to bradykinin. It is concluded that bradykinin interacts with opiate receptors in the brain.Laboratory of Molecular Neurophysiology and Biochemistry, P. K. Anokhin Institute of Normal Physiology, Academy of Medical Sciences of the USSR, Moscow. Laboratory of Pharmacology of the Nervous System, Institute of Pharmacology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 12, pp. 683–685, December, 1979.     

Effect of destruction of gyrus cinguli in rat brain on the development of tolerance to the analgesic effect of morphine and physical dependence on morphine

We studied the effect of bilateral laser destruction of rat anterior cingulate gyrus on the analgesic effect of morphine and development of tolerance and physical dependence on morphine. Bilateral laser destruction of the anterior cingulate gyrus did not modulate pain sensitivity, analgesic effect of morphine, and development of morphine tolerance. Destruction of the cingulate gyrus alleviated symptoms of the abstinence syndrome in morphine-dependent animals. We showed that morphine-induced analgesia and morphine tolerance are not associated with activity of the anterior cingulate gyrus. However, this structure plays a key role in the development of physical dependence on morphine and abstinence syndrome.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 540–543, November, 2004     

Neuroanatomical dissociation between reinforcing and analgesic effects of morphine

Department of Pharmacology and Section of Pharmacology, Central Research Laboratory, I. P. Pavlov First Leningrad Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Val'dman.) Translated from Byulleten' Éksperimental'noi Biologii i Metitsiny, Vol. 107, No. 1, pp. 45–47, January, 1989.