RESUMEN
Effects of high frequency stimulation of the amygdala central nucleus involved a selective decrease in the activity: an increase in the activity of the inferior cardiac nerve and a simultaneous decrease in the activity of the vertebral nerve, as well as an obvious BP increase. Bilateral electrolytic lesions of the same amygdala structure accompanied with an overload of the higher nervous activity induced no hypertensions. The role of the amygdala central nucleus in control of cardiovascular functions is discussed.
Asunto(s)
Amígdala del Cerebelo/fisiología , Fenómenos Fisiológicos Cardiovasculares , Animales , Presión Sanguínea , Gatos , Condicionamiento Operante/fisiología , Vasos Coronarios/inervación , Estimulación Eléctrica , Electroencefalografía , Electrofisiología , Hipertensión/etiología , Hipertensión/fisiopatología , Médula Espinal/fisiología , Estrés Fisiológico/complicacionesRESUMEN
Effects of bilateral electric lesion of the hypothalamic paraventricular nuclei on cardiovascular components of the defense response and on the self-stimulation operant behaviour, were studied in rats. Overloading of the highest nervous activity induced no hypertension in these animals, though the self-stimulation frequency increased.
Asunto(s)
Hipertensión/etiología , Núcleo Hipotalámico Paraventricular/fisiología , Autoestimulación/fisiología , Animales , Reacción de Prevención/fisiología , Enfermedad Crónica , Condicionamiento Clásico/fisiología , Estimulación Eléctrica , Electrodos Implantados , Hipertensión/fisiopatología , Hipotálamo Posterior/fisiología , Masculino , Ratas , Estrés Psicológico/complicaciones , Estrés Psicológico/fisiopatologíaRESUMEN
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.
Asunto(s)
Sistema Límbico/fisiología , Sistema Nervioso Parasimpático/fisiología , Sistema Nervioso Simpático/fisiología , Potenciales de Acción , Animales , Gatos , Estimulación Eléctrica/métodos , Electrodos Implantados , Tiempo de Reacción/fisiología , Nervios Esplácnicos/fisiologíaRESUMEN
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.
Asunto(s)
Hipotálamo/fisiología , Sistema Límbico/fisiología , Sistema Vasomotor/fisiología , Animales , Presión Sanguínea , Mapeo Encefálico , Gatos , Estimulación Eléctrica , Hipotálamo Anterior/fisiología , Hipotálamo Posterior/fisiología , Tuber Cinereum/fisiologíaRESUMEN
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.
Asunto(s)
Presión Sanguínea , Músculo Liso/fisiología , Uréter/fisiología , Animales , Mapeo Encefálico , Gatos , Estimulación Eléctrica , Hipotálamo Anterior/fisiología , Hipotálamo Posterior/fisiología , Tuber Cinereum/fisiología , Sistema Vasomotor/fisiologíaRESUMEN
Effect of stimulation of some medulla oblongata's areas on the spontaneous rhythmogenesis in smooth muscles of the ureter as well as on heart activity and systemic arterial blood pressure revealed certain structures in medulla oblongata with activating and inhibiting influences on motor activity of the ureter in cats. In most cases the changes in the ureter rhythmic activity were synchronous with those of systemic arterial blood pressure as well as heart activity rhythm (heart pulse). Complete cutting of the spinal cord at C1-C2 level eliminated the above changes.
Asunto(s)
Bulbo Raquídeo/fisiología , Músculo Liso Vascular/fisiología , Músculo Liso/fisiología , Potenciales de Acción , Animales , Presión Sanguínea , Gatos , Estimulación Eléctrica , Electrocardiografía , Corazón/fisiología , Periodicidad , Uréter/fisiología , VagotomíaRESUMEN
Electric stimulation of the colliculus superior evokes potentials (EP) in the visual cortex of the ipsilateral hemisphere of the rat brain, their localization coinciding with the zone of flash-evoked potentials. EPs of maximal amplitude were observed during stimulation of the central layers of the colliculus superior. Short latency of the EPs (3.2 +/- 1.1 msec; p less than 0.05) and the relevant morphological data suggest a single relay in rat's tecto-cortical visual system. The data are discussed in regard to the comparative telecephalisation of the retino-tectal system in submammalian vertebrates and in mammals.