Inhibition of medullary reticulospinal neurons by excitation of the dorsolateral parts of the pons which block movement and muscle tone in rats.

Analysis of the response of 128 reticulospinal neurons in the magnocellular and ventral reticular nuclei showed that 36.7% of these cells responded with short-latency (2-4 msec) action potentials and increased their tonic activity in response to electrical stimulation of the central parts of the hypothalamus, which evoked increases in hindlimb muscle tone in rats. These cells completely stopped producing action potentials during electrical stimulation and during chemical stimulation of the dorsolateral parts of the pons, which inhibited movement and muscle tone.

[Changes in the neuronal activity in the dorsolateral pontine region caused by electrical stimulation of the brainstem regions inhibiting movement and the muscle tone].

Activity of 44 mesencephalic locomotor area's (MLR) units and 38 pontine inhibitory area's (PIA) units was recorded during stimulation of the giganto-cellular reticular nucleus and oral pontine reticular nucleus inducing the hindlimb muscle tone inhibition in decerebrated rats. The muscle tone suppression was always accompanied by a decrease in the MLR and an increase in the PIA unit discharges. Stimulation of the brainstem inhibitory area seems to activate reticulospinal inhibitory system and suppress some MLR units relating to locomotion and muscle tone.

[The inhibition of medullary reticulospinal neurons during the excitation of the dorsolateral portions of the pons blocking movement and muscle tonus in rats].

Hypothalamic stimulation increasing the muscle tone in hindlimbs, and excitation of the pontine dorsolateral areas inhibiting movements and the muscle tone in rats, were studied. Hypothalamic stimulation made 36.7% of the reticulospinal neurones to discharge in the form of short-latency spikes and to increase the muscle tone.

[Neuron reactions of brain structures suppressing motion during development of animal hypnosis in guinea pigs].

Multisensory and motor units are suppressed in hypnosis in the guinea pig giganto-cellular reticular nucleus and in the dorsolateral. pons. In contrast, inhibitory intexneuvons neurons and the ponto-medulla neurons are activated in hypnosis.

[Electrophysiological analysis of interaction between the neuron populations of pons and medulla participating in inhibition of the motor activity].

Neurons of cuneiform, subcuneiform, medial parabrachial, median raphe nuclei were studied. 26-47% units were found to send monosynaptic inputs to the raphe magnus nucleus, gigantocellular reticular and ventral reticular nuclei. 17-43% responded to stimulation of the inhibitory brain stem areas with excitatory-inhibitory reactions.