CENTRAL NERVOUS-SYSTEM RESPONSES TO CIGARETTE-SMOKE INHALATION IN THE CAT

  • 1 January 1979
    • journal article
    • research article
    • Vol. 237  (2) , 191-212
Abstract
Intact, pentobarbital anesthetized cats (with and without brainstem stimulating electrode implants) and unanesthetized Sherrington (.gamma.-driven) decerebrate cats smoked cigarettes of varying nicotine content (0.2-2.5 mg). Nicotine free lettus leaf cigarettes were used as controls. Smoking doses of nicotine base (10-25 .mu.g/kg) were administered i.v. for comparison. Smoke inhalation produced motor reflex depression which paralleled the nicotine content of the cigarettes smoked. Patellar reflex facilitation due to mesencephalic reticular stimulation was reduced by doses of nicotine and cigarette smoke. Cigarettes (2.5 mg nicotine) and doses of nicotine (25-50.mu.g/kg, i.v.) significantly reduced rigidity and patellar reflex amplitude .gamma.-decerebrate cat. Dihydro-.beta.-erythroidine reduced the nicotine and cigarette smoke induced patellar reflex depression but not the diminution in the rigidity. Smoking doses of nicotine suppressed pentobarbital-induced EEG spindles in acutely prepared cats. Nicotine (10-25 .mu.g/kg) produced EEG and behavioral arousal in cats with chronic deep electrodes. Cigarette smoke may produce its pharmacological effects via its nicotine content.