caa a22 4500 477118038 CHVBK 20180405111628.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF02691453 doi (NATIONALLICENCE)springer-10.1007/BF02691453 Dextrorphan effects on cocaine and brainstem perturbation [Elektronische Daten] [M. Lundien, O. Andy, R. Rockhold, M. Andrews, C. Dearman] Dextrorphan is a noncompetitive blocker of N-methyl-D-aspartate (NMDA) receptors. Since NMDA blockers are known to reduce the locomotor stimulatory and toxic effects of cocaine, it was speculated that dextrorphan would attenuate cocaine-induced behavioral excitatory motor activity associated with and without mechanical perturbation of the brainstem. Technique: Motor activity was recorded following dextrorphan and/or cocaine challenge in 25 SHR rats. Ten were naive subjects. Mini-osmotic pumps delivering cocaine (2.5 mg/0.49 ul/hr) were placed in 15 subjects, and infusion was halted after the third infusion day. On the fifth day either a dextrorphan (25 mg/kg, subcutaneous) or a dextrorphan and cocaine (40 mg/kg, intraperitoneal) challenge was done. Ten rats had bipolar electrode implants in the bilateral brainstem. Five were treated with DC current lesions in each of 12 days over a 3-week period. The effects of brainstem lesions on escape behavior were also evaluated in those five subjects. Results: In the naive subjects, dextrorphan reduced motor activity (P=.0001), whereas combined cocaine and dextrorphan increased motor activity (P=0.04). In lesioned subjects, dextrorphan decreased motor activity (P=0.0001). In electrode implant subjects, combined dextrorphan and cocaine challenge decreased the motor activity (P=0.04). Hyperactivity in the electrode implant group was greater than in the lesioned subjects. Midbrain electrolytic lesions attenuated escape behavior. A variety of behaviors were produced by brainstem lesions. Conclusions: Dextrorphan and brainstem lesions reduced motor hyperactivity and escape behavior. In electrode implant subjects dextrorphan counteracted the expected cocaine excitatory motor effects. Dextrorphan did not activate nor facilitate seizures. Transaction Publishers, 1996 dextrorphan nationallicence cocaine nationallicence seizures nationallicence motor activity nationallicence brainstem nationallicence electrolytic stimulation nationallicence behavior nationallicence Lundien M. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut Andy O. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut Rockhold R. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut Andrews M. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut Dearman C. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut Integrative Physiological and Behavioral Science Springer-Verlag 31/3(1996-07-01), 224-230 1053-881X 31:3<224 1996 31 12124 https://doi.org/10.1007/BF02691453 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02691453 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lundien M. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut NATIONALLICENCE 700 1- Andy O. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut NATIONALLICENCE 700 1- Rockhold R. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut NATIONALLICENCE 700 1- Andrews M. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut NATIONALLICENCE 700 1- Dearman C. Depts. of Neurosurgery, Pharmacology and Toxicology and Preventive Med., U. of Mississippi Med. Center, Jackson, MS aut NATIONALLICENCE 773 0- Integrative Physiological and Behavioral Science Springer-Verlag 31/3(1996-07-01), 224-230 1053-881X 31:3<224 1996 31 12124 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer