[Role of the reticular formation in regulating movement. Several intrareticular mechanisms and functional properties of the reticulospinal system]. / Rol' retikuliarnoi formatsii v reguliatsii motoriki. Issledovanie nekotorykh vnutriretikliarnykh mekhanizmov i funktsional'nykh svoistv retikulo-spinal'noi sistemy.

The aim of this work was to obtain further information about some mechanisms of participation of the reticular formation and its descending reticulo-spinal systems in the regulation of the motor functions of the spinal cord. Following questions were studied: membrane characteristics of the reticulospinal neurons with slow and rapid axonal conduction and peculiarities of monosynaptic control influences on these groups of reticulospinal neurons from the motor cortex; characteristics of population responses of the reticular formation with respect to its ability to discriminative sensory and motor functions; reactions of the reticular formation neurons correlated with learned movements. Data obtained evidence that the reticular formation can be involved in control of specialized motor actions. Functional significance of the specific properties of the reticular formation as well as further prospects of exploration of its functional organization are discussed.

[Synaptic activation of the interneurons of the thoracic portion of the spinal cord by reticulospinal fibers of the lateral funiculus]. / Sinapticheskaia aktivatsiia promezhutochnykh neironov grudnogo otdela spinnogo mozga retikulo-spinal'nymi voloknami lateral'nogo kanatika.

Synaptic processes evoked in various functional groups of thoracic interneurons (Th10,11) by stimulation of ipsi- and contralateral bulbar reticular formation were studied in anesthetized cats with lesions of the spinal cord that remained intact only the ipsilateral funiculus. Activation of reticulospinal fibres of the lateral funiculus with conduction velocities of 30-100 m/s evoked monosynaptic EPSPs in the following types of cells tested: monosynaptically excited by group la muscle afferents; excited by flexor reflex afferents; excited mainly by descending systems; excited by low-threshold cutaneous afferents to a less extent. All these neurons with responses to reticular stimulation were located predominantly in the central and lateral regions of Rexed's lamina VII. Most of the cells in the dorsal horn were not affected by short-latency reticulofugal influences. The only exception were 6 neurons located in the horn most dorsal laminae. Functional organization of connections between the lateral reticulospinal pathways and spinal neurons is discussed as compared to that of medial reticulo-spinal pathways as well as to the organization of "lateral" descending systems: cortico- and rubro-spinal.

[Effect of bulbar microinjections of noradrenaline, isoproterenol and phentolamine on the spino-bulbo-spinal reflex in the cat]. / Vliianie bul'barnykh mikroin"ektsii noradrenalina, izoproterenola i fentolamina na spino-bul'bo-spinal'nyi refleks u koshki.

In chloralose-anesthetized cats a long lasting depression of spino-bulbo-spinal (SBS) reflex discharges following microinjections of noradrenaline and its agonist (isoproterenol) in the medial bulbar reticular formation was revealed. Microinjections of phentolamine (alpha-adrenoceptor antagonist) were followed by prominent enhancement of SBS-reflexes. Depressive action of the locus coeruleus stimulation on SBS-responses essentially decreased after these microinjections. The data evidence for a specific noradrenergic nature of inhibitory locus coeruleus influences on reticular centre of SBS-reflexes.

[Changes in the postsynaptic responses of spinal cord motor neurons against a background of rhythmic stimulation of the locus coeruleus]. / Issledovanie izmenenii postsinapticheskikh reaktsii v motoneironakh spinnogo mozga na fone ritmicheskoi stimuliatsii golubogo piatna.

Influences of locus coeruleus rhythmical stimulation on the postsynaptic reactions of spinal motoneurons were studied in chloralose anesthetized cats. IPSPs evoked by flexor reflex afferent (FRA) stimulation were inhibited, but EPSPs evoked by FRA and PSPs evoked by low-threshold muscle afferents stimulation were unchanged under these conditions. The inhibition of IPSPs disappeared in reserpine-pretreated animals. Both IPSPs and EPSPs evoked by FRA stimulation were diminished also during rhythmical stimulation of nucleus reticularis pontis oralis. However this effect was not of monoaminergic nature because it was present in reserpine-pretreated animals.