Correlation of effects of general anesthetics on somatosensory neurons in the primate thalamus and cortical EEG power

Dougherty, P. M., Y. J. Li, F. A. Lenz, L. Rowland, and S. Mittman. Correlation of effects of general anesthetics on somatosensory neurons in the primate thalamus and cortical EEG power. J. Neurophysiol. 77: 1375–1392, 1997. The effects of two types of general anesthetic on the neurophysiological properties of the primate somatosensory thalamus were correlated with effects on frontal cortex electroencephalographic (EEG) power and spectral properties. Graded doses of the intravenous agent methohexital sodium (METH) were studied in 12 cells in three monkeys on a halothane baseline anesthetic. Low doses of METH (0.2–1.0 mg/kg) produced a reduction of EEG power but had no effects on spontaneous or evoked thalamic activity. EEG power showed maximal attenuation after 2.0 mg/kg METH, whereas decreases in thalamic activity were first noted over a similar moderate dose range (2.0–5.0 mg/kg). The physiological parameter most sensitive to METH was the spontaneous activity, which showed initial changes in rate and pa...