Effects of clonidine, yohimbine and eserine on the quantified EEG of rats.
The effects of three different classes of drugs were analyzed on the EEG of rats on two cortical derivations (parieto-occipital and fronto-occipital) and one deep structure, the locus coeruleus. Clonidine, an alpha 2-agonist (0, 0.10, 0.30 and 0.50 mg/kg, i.p.), yohimbine, an alpha 2-antagonist (0, 2, 4 and 8 mg/kg, i.p.) and eserine, an anticholinesterase (0, 0.10, 0.30 and 0.50 mg/kg, i.p.), affected the EEG in different significant ways. Clonidine significantly decreased frequency in the theta-band (3.7-7.5 Hz) and increased it in the alpha-band (7.6-13.5 Hz). A general significant increase in power was also observed. For yohimbine, there was a significant dose-dependent increase of power, particularly in the theta-, alpha- and beta-bandwidth. Moreover, its effects on EEG varied in accordance to the derivations analyzed. Finally, eserine significantly decreased power in the high frequency bandwidths. A synchronization, as a function of dose, with a peak at 5-6 Hz was observed shortly after its administration. The results are discussed in terms of the potentiality of the technique of quantitative pharmaco-electro-encephalography and drug interaction studies in the analysis of psychoactive substances.
Emilien
G
G
University of Liège, Laboratory of Pharmacology, Sart Tilman, Belgium.
D000818:Animals; D003000:Clonidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004567:Electrodes, Implanted; D004569:Electroencephalography; D008297:Male; D010830:Physostigmine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D015016:Yohimbine / Q000494:pharmacology*
D015016:Yohimbine; D010830:Physostigmine; D003000:Clonidine