[The neurophysiological and biochemical mechanisms of the dose-dependent amphetamine modulation of the sensorimotor...

The resulting data give evidences, that after injection of the low doses of amphetamine the decrease of amplitudes both negative (NC-3), and positive components (PC-3) of the thalamo-cortical responses (TCR) of the sensorimotor cortex (SMC) takes place in 2nd-3d-weeks-old rabbits of their postnatal life. At the same time the amplitudes of these phases in 45-50-days-old animals change to greatly less extent, without any system, with low level of statistical significance. After injection of medium doses of amphetamine in 2nd-3d-weeks-old rabbits, the increase in amplitudes of both components of TCR SMC in observed, at the same time in definitive animals the amplitudes of these responses decrease greatly. After injection of the high doses of amphetamine in 2nd-3d-weeks-old rabbits the further increase in amplitude PC-3 and NC-3 is displayed, at the same time the growth of amplitude parameters of TCR SMC appears for elder animals under this concentration of amphetamine only. Neurophysiological and neurochemical analyses of these phenomena are developed. Neuro-ontogenesis hypothesis of causes of high vulnerability of the nervous system in young animals and children during critical period of increased risk under the exposure to both psychotropic drugs and endogenous psychopathogenic factors being proposed, that can simplify search for adequate psychopharmacology protector, etc.