[The effect of cholino- and adrenoblockers on limbic-sympathetic evoked potentials]. / Issledovanie vliianiia kholino- i adrenoblokatorov na limbiko-simpaticheskie vyzvannye potentsialy.

Effects of i.v. administration of cholino- and adrenergic blocking agents on limbic-sympathetic discharges of L2-L3 white rami, evoked by stimulation of the anterior, visceral area of the limbic cortex and on arterial blood pressure were studied in anesthetized cats. M- and N-cholinoreceptor blocking agents atropine and ganglerone do not induce any apparent changes in limbic-sympathetic discharge and the blood pressure level. Beta-adrenoreceptor blocking agent propranolol evoked a small fall of the blood pressure with no apparent changes of limbic-sympathetic discharges. Alpha-adrenoreceptor blocking agent phenotolamine evoked obvious drop of the blood pressure and, in two out of eight experiments, a marked increase of the amplitude of limbic-sympathetic evoked discharges. Neurochemical regulatory mechanism of limbic-spinal sympathetic activity are discussed.

[Comparative study of the discharges of sympathetic and parasympathetic nerves during stimulation of the visceral field of the limbic cortex]. / Sravnitel'noe issledovanie razriadov simpaticheskikh i parasimpaticheskikh nervov pri razdrazhenii vistseral'nogo polia limbicheskoi kory.

Comparative characteristics of parasympathetic responses in pelvic nerve and sympathetic responses in lumbar white communicating rami to stimulation of dorsal and ventral parts of anterior, visceral area of limbic cortex were studied in anesthetized and immobilized cats. Single shocks or short trains of stimuli of the area 25 in limbic cortex evoked a complex response in pelvic nerve, consisting mostly of three waves: the late waves II and III of the parasympathetic discharge with a mean latency of 63.3 and 180.4 msec, and a mean magnitude of 11.0 and 16.7 microV, resp. A short latency component was rarely observed and its latency was about 15.9 msec. The EPs in pelvic nerve and white rami had the lowest threshold in stimulation of the ventral part of area 25. Comparative study of the excitability-recovery properties of cingulo-parasympathetic and cingulo-sympathetic responses revealed a long-lasting inhibition of the test responses for 2000 and 900 msec, resp.

[Comparative study of mechanisms of change in vasomotor sympathetic activity upon stimulation of different structures of the limbic cortex and hypothalamus]. / Sravnitel'noe issledovanie mekhanizmov izmeneniia vazomotornoi simpaticheskoi aktivnosti pri razdrazhenii razlichnykh struktur limbicheskoi kory i gipotalamusa.

Responses of arterial blood pressure to low- and high-frequency stimulation of different structures of the limbic cortex and hypothalamus were studied in anesthetized and immobilized cats. The low-frequency (5 Hz) stimulation induced depressor reactions, the high-frequency (100 Hz) one-pressor responses. Both kinds of stimulation in the dorsal level of area 25 and of area 23 of the limbic cortex and of the anterior hypothalamus induced similar depressor responses, whereas the hypothalamic structures in the posterolateral region induced only pressor responses. The role of poly-effectory, sympatho-inhibitory and sympatho-activating neurons responsible for the observed three patterns of the blood pressure changes in low- and high-frequency stimulation of limbic cortex and hypothalamus, is discussed.

[Discharges in the white rami communicantes evoked by stimulation of different fields of the limbic system]. / Razriady v belykh soedinitel'nykh vetochkakh, vyzvannye razdrazheniem razlichnykh polei limbicheskoi kori.

Electrical responses to stimulation of different areas of the cingulate gyrus were studied in L2-L3 white rami in anesthetized and immobilized cats. The stimulation evoked a sympathetic discharge mostly consisting of a wave with a mean latency of 71.2 +/- 2.3 ms. In a few cases, the main wave was preceded by a short-latency component. Thresholds for eliciting sympathetic discharges were lower in case of stimulation of the ventral region of area 25 in comparison to those of the dorsal region of the same area. A comparative study showed that the lowest were the thresholds of hypothalamic evoked discharges, somewhat higher were the thresholds of amygdala stimulation and the highest were those of the cingulate cortex evoked discharges. In experiments with simultaneous recording of arterial pressure and cingulo-sympathetic discharges, after 10-sec period of tetanic (100/sec) stimulation of the limbic cortex, the early components were facilitated while the late component of the cingulo-sympathetic discharges was depressed. The duration of this inhibition corresponded to the period of pressure reaction and, therefore, was of a baroreceptor origin. Possible mechanisms of cingulate cortex regulation of the activity of sympathetic preganglionic neurons, are discussed.

[Effect of stimulation of the hypothalamus on the rhythmogenic activity of the smooth musculature of the ureters and systemic arterial pressure]. / Vliianie razdrazheniia gipotalamusa na ritmogennuiu deiatel'nost' gladkoi muskulatury mochetochnikov i sistemnoe arterial'noe davlenie.

The influence of low- and high-frequency stimulation of anterior, tuberal and posterior hypothalamic areas on the spontaneous rhythmogenesis in the ureter smooth muscles and on arterial blood pressure, was studied in anesthetized cats. High-frequency stimulation of all hypothalamic areas induced pressor responses with activating effects on motor activity of the ureter. The changes in the ureter rhythmic activity were synchronous with those of systemic arterial blood pressure. The low-frequency stimulation induced both pressor and depressor responses in different proportion. The depressor responses were not accompanied by any changes of the ureter rhythmic activity. Possible mechanisms of reversal of vasomotor responses in stimulation of hypothalamus, organization of sympathico-activating and sympathoinhibitory mechanisms and hypothalamic regulation of rhythmogenic function of the ureter, are discussed.