Nocturnal sleep structure and temperature slope in MPTP treated monkeys

The nocturnal sleep of three 1-Methyl, 4-phenyl, 1,2,3,6-tetrahydropyridine (MPTP) treated monkeys (one non-motor disabled and two severely motor disa bled), while held in a primate chair was registered using a reversible syst em for head fixation and chronic recordings. Two electroencephalogram (EEG) channels, one electrooculogram (EOG) and one electromyogram (EMG) channel were monitored constantly and tape recorded during eight nights for posteri or analyses. Subcutaneous temperature was registered each minute using a ra dio telemetry system. An analysis of sleep patterns and temperature paramet ers revealed lighter sleep, decreased amounts of slow wave and rapid eye mo vement (REM) sleep and lower temperature values in the two motor disabled M PTP-treated monkeys than in the non-motor disabled monkey. The temperature linear slope was negative in the case of one disabled monkey for just one n ight. Although the motor disability of the two monkeys was similar, their s leep organization patterns and temperatures slopes differed. The present study confirmed the differential vulnerability of the nigrostri atal system of monkeys to MPTP, suggesting that if a high cumulative dose w as needed to reach stable motor alterations, the cumulative dose-effect of the toxin independent of the nigrostriatal system might be responsible for non-motor symptoms that also appear in Parkinson's disease besides the clas sic tetrad.