The adamantane derivatives adapromine, midantane, and bromantane modify bioelectrical activity of brain cortex and subcortical structures. Neurophysiological effects of these preparations indicate that they possess psychostimulating activity. The effect of bromantane on electrical potentials from left and right sensorimotor cortex, dorsal hippocampus, and lateral hypothalamus was stronger than that of adapromine and midantane. This effect was observed as greater quantitative changes in the characteristics of electroencephalogram and changes practically in all characteristics of the power spectrum of electroencephalogram.
Key Words: bioelectrical activity; EEG Fourier spectra; psychostimulating drugs; adamantane derivativesAdamantane derivatives have a broad spectrum of pharmacological activities, including psychostimulating, antidepressant, and nootropic [1,2,4,7,9,10,13,14]. Some of them produce pronounced effects on the central nervous system and brain biopotentials in intact animals [3]. However, their effects have not been studied in detail and compared.In the present study we compared the effects of three adamantane derivatives (adapromine, midantane, and bromantane) on bioelectrical activity and Fourier power spectra of electroencephalograms (EEG) recorded from different brain structures in intact nonrestrained rats.
MATERIALS AND METHODSExperiments were carried out on outbred male albino rats weighting 200-250 g. Adapromine, midantane, and bromantane (20 mg/kg) were administered through a gastral tube. Since bromantane is water-insoluble, itInstitute of Pharmacology, Russian Academy of Medical Sciences, Moscow was administered as a 5% solution in polyethylene glycol-400 (PEG-400).Effects of the preparations on biopotentials from different brain structures were examined in unrestrained rats using Fourier quantitative spectral analysis. Detailed technique of electrode insertion into the sensorimotor cortex, dorsal hippocampus, and lateral hypothalamus, recording and processing of bioelectrical activity, and quantitative spectral analysis were described elsewhere [6]. Electroencephalograms of the studied brain structures were recorded with an MF-Alpha apparatus (W.A.B. Technology or O.T.E. Biomedica) before (background) and 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, and 8 after administration of the preparations. The data were analyzed by paired nonparametrical sign test.
RESULTSA significant 20-30% decrease in the total power (TP) of left and right cortex EEG predominantly due to a decrease in the absolute power (AP) in the 0 and 13t ranges was observed after administration of adapromine (Table 1). This effect reached the maxi-
