[Functional characteristics of the input-output correlation in the frog vestibular nuclei]. / Funktsional'nye osobennosti korreliatsii vkhoda-vykhoda v vestibuliarnom iadernom komplekse liagushki.

Field and intracellular potentials were recorded in the vestibular nuclear complex of the frog perfused brain following stimulation of the anterior branch of the ipsilateral vestibular nerve and spinal cord. Mono- and polysynaptic EPSPs with orthodromic APs were recorded from vestibular neurones following vestibular nerve stimulation. Antidromic activation of neurones sending their axons to the labyrinth was also recorded. Antidromic APs of vestibulo-spinal neurones evoked with mean latency of 1.43 and 2.19 ms to stimulation of cervical and lumbar cords, respectively, were revealed.

[Monosynaptic activation of motor neurons of the nucleus of the facial nerve evoked by stimulation of midbrain structures]. / Monosinapticheskaia aktivatsiia motoneironov iadra litsevogo nerva, vyzvannaia stimuliatsiei struktur srednego mozga.

Synaptic inputs of the midbrain structures to the facial nucleus motoneurons were studied in acute experiments in cats by means of intracellular recording. Stimulation of periaqueductal gray and pretectal area was found to evoke mono- and polysynaptic activation of facial motoneurons. Functional significance of the midbrain structures as an intermediate link transmitting descending signals to the facial nucleus, is discussed.

[Synaptic mechanisms of the effect of subcortical structures on motor neurons of the facial nerve in the cat]. / Sinapticheskie mekhanizmy vliianii podkorkovykh obrazovanii na motoneirony iadra litsevogo nerva koshki.

Peculiarities of synaptic processes in motoneurons of the facial nucleus evoked by stimulation of the head of caudate nucleus, globus pallidus and nucleus amygdalae centralis were studied in acute experiments on cats by means of intracellular recording technique. It is found that stimulation of the first two structures causes only polysynaptic excitation, while stimulation of the nucleus amygdalae centralis--mono- and polysynaptic excitation of motoneurons of the facial nucleus. Convergence of influences from above mentioned structures on the same motoneurons is shown. Possible ways and mechanisms of subcortical regulation of the activity of facial nucleus motoneurons are discussed.

[Postsynaptic potentials of the motor neuron of the facial nerve nucleus evoked by stimulation of the cerebellar nuclei]. / Postsinapticheskie potentsialy motoneironov iadra litsevogo nerva, vyzvannye stimuliatsiei iader mozzhechka.

Synaptic processes induced in the facial motoneurons by stimulation of the red nucleus and the cerebellar interpositus and dentate nuclei were studied in anesthetized and immobilized cats. The stimulation of the red nucleus evoked monosynaptic EPSPs in the motoneurons whereas oligo--and polysynaptic EPSPs were recorded in response to the stimulation of the interpositus and dentate nuclei. Based on the experiments with the lesion of the red nucleus, a conclusion was drawn about its participation in the mechanisms and pathways of the cerebellar influence on the facial motoneurons.

[Monosynaptic excitation of the motor neurons of the nucleus of the facial nerve induced by stimulation of brainstem structures]. / Monosinapticheskoe vozbuzhdenie motoneironov iadra litsevogo nerva, vyzvannoe stimuliatsiei struktur stvola mozga.

Synaptic inputs from the midbrain and medulla oblongata to the facial motoneurones were studied in anesthetized cats in acute experiments: the effects of stimulation of the n. reticularis parvocellularis, the interstitial nucleus of Cajal and the nucleus of Darkschewitsch. Stimulation of these nuclei evoked monosynaptic excitatory postsynaptic potentials in facial motoneurones which in turn generated single APs. The somatic localization of these synapses is suggested. Convergence of the inputs has been revealed.

[Synaptic mechanisms of descending influences on the facial nucleus motor neurons in the cat]. / Sinapticheskie mekhanizmy niskhodiashchikh vliianii na motoneirony iadra litsevogo nerva koshki.

Intracellular recording of potentials revealed that stimulation of cerebral cortex, gyrus proreus and pyramidal tact evoked polysynaptic excitatory and postsynaptic potentials in the cat's facial motoneurons. Stimulation of lateral hypothalamus was characterized by exclusively excitatory polysynaptic effects. High degree of convergence of the above influences onto the facial motoneurons and possible mechanisms and pathways of cortical and hypothalamic control of facial motoneurons activity are discussed.

[Factors responsible for generation of multiple discharges in motor neurons of the nucleus of the facial nerve in cats]. / Faktory, otvetstvennye za generatsiiu gruppovogo razriada v motoneironakh iadra litsevog nerva koshki.

Peculiarities of multiple discharges of facial nucleus motoneurons evoked to stimulation of caudal trigeminal nucleus were studied in acute experiments on cats by intracellular recording technique. The multiple discharge is shown to appear on the basis of gradual depolarization of the motoneuron membrane resulted from effective summation of high-frequency excitatory synaptic influences from the caudal trigeminal nucleus. Factors supporting the development of the gradual depolarization are dendritic location of synaptic terminals of trigeminal projecting neurons, dendritic origin of depolarizing after-potentials and high input resistance of the facial motoneuron membrane.

[Synaptic processes in motor neurons of the nucleus of the facial nerve upon stimulation of the caudal trigeminal nucleus]. / Sinapticheskie protsessy v motoneironakh iadra litsevogo nerva pri razdrazhenii kaudal 'nogo troinichnogo nerva.

Focal and postsynaptic potentials of facial motoneurons evoked by stimulation of the caudal trigeminal nucleus were studied in cats using extra- and intracellular recording technique. Pre- and post-synaptic components of focal potentials are shown. Four types of motoneuron responses are distinguished: EPSP generating single action potentials; gradual shift of depolarization evoking multiple discharges; rhythmical discharge of action potentials appearing at a low level of depolarization; EPSP and a sequence of EPSP-IPSP. Mono- and predominantly polysynaptic origin of these responses is shown. Possible mechanisms of afferent control of facial motoneuron activity are discussed.

[Electrophysiologic characteristics of motor neurons of the cat facial nerve nucleus]. / Elektrofiziologicheskie osobennosti motoneironov iadra litsevogo nerva koshki.

The antidromic activation of facial nucleus motoneurons to the stimulation of various branches of the facial nerve was studied by means of intracellular recording in cats. The time and amplitude characteristics of separate components of the antidromic spike were analyzed and fast and slow after-potentials were distinguished. A correlation was shown between the duration of the falling phase of the SD spike, the duration of its after-hyperpolarization and the impulse conductance time in the axon. Data indicating the absence of the recurrent collateral pathway in the facial nucleus motoneurons were obtained. The possible functional significance of the after-potentials is discussed.

[Classification of the vestibulospinal neurons of the cat Deiter's nucleus]. / Klassifikatsiia vestibulo-spinal'nykh neironov iadra Deitersa koshki

The antidromic activation of neurons in the cat Deiters nucleus to stimulation of spinal cerevical segments was studied using the intracellular microelectrode recording technique. Separate components of the antidromic action potential and its after-deflections were analyzed in fast- and slow-conducting neurons. A direct dependence between the parameters of the after-deflections and duration of the refractory period was revealed for these neurons. Variable responsivity of neurons with the same axonal conductance velocity is shown to be dependent on the after-depolarizing potential.