BACKGROUND AND PURPOSE The caudate circuit takes part in cognitive control of motor activity. The purpose of the present work was registration and analysis of basic bioelectrical activity of ventral and dorsal sensory-motor cortex and nucleus caudate, study of the changes in EEG after nucleus caudate electrical stimulation and to identify of threshold level of electrical stimuli responsible for changes of electrical activity in registered brain area. MATERIALS AND METHODS We used 28 albino Wistar rat of both genders. After the animal fixation on stereotaxic apparatus to dry bone, the places for electrode fixation were marked. Two days after the electrodes had been implanted an EEG was registered so that the animals would adjust to the conditions and so they would repair the tissue reactions. EEG was registered with bipolar electrodes with ten-channeled apparatus. For first half an hour spontaneous activity of the brain was registered, and after that the head of nucleus caudate was stimulated with altered impulses of various voltages, frequency and duration. RESULTS AND CONCLUSIONS Threshold values of electric stimulus intensity from 3 to 5 V, frequency from 3 to 5 Hz, duration from 3 to 5 ms, by stimulation the head of nucleus caudate of rat, lead to the change of basal bioelectric activity of cerebrum. The change of bioelectric activity is firstly recorded in equilateral cortex, and with the higher intensity of the stimulus the changes overtake the contra lateral cortex.

An experiment was performed under in vivo conditions on bone marrow cells of Wistar rats. The following doses of levamisole hydrochloride were tested: a therapeutic dose of 2.2 mg/kg bm, a dose of 4.4 mg/kg bm, LD50 -25% mg/kg bm, and LD50 -75% mg/kg bm. We followed the effect of levamisole hydrochloride on kinetics of the cell cycle and the appearance of structural and numeric changes in chromosomes in bone marrow cells. The therapeutic dose of levamisole of 2.2 mg/kg bm exhibited a capability to increase mitotic activity in the observed cells, thus confirming knowledge of the immunostimulative effect of this dose of the medicine under in vivo conditions. The other tested doses of levamisole in this experiment, observed in comparison with the control group, had an opposite effect, namely, they caused a reduction in the mitotic activity of bone marrow cells. All the examined doses in vivo exhibited the ability to induce numeric (aneuploid and polyploid) and structural (lesions, breaks and insertions) chromosomal aberrations. It can be concluded on the grounds of these findings that the examined doses have a genotoxic effect.

Cytotoxic and genotoxic examinations were performed of the effect of levamisole hydrochloride (2.2 mg/kg bm, 4.4 mg/kg bm, LD50-25% mg/kg bm and LD50-75% mg/kg bm) on bone marrow cells of mice of the BALB/c strain. The effect of levamisole hydrochloride on kinetics of the cellular cycle and the appearance of structural and numerical changes in chromosomes of bone marrow cells were followed. The therapeutic dose of levamisole of 2.2 mg/kg bm showed the ability to increase the mitotic activity of the observed cells, thus confirming knowledge of the immunostimulative effect of this dose of the medicine under in vivo conditions. The other tested doses of levamisole in this experiment, observed in comparison with the control group, had an opposite effect, i.e. they caused a reduction in the mitotic activity of bone marrow cells. All the examined doses in vivo showed the ability of inducing numeric (aneuloid and polyploid) and structural (lesions, breaks and insertions) chromosomal aberrations. On this basis, it can be concluded that the examined doses have a genotoxic effect.