Head of Laboratory – Full member of the Russian Academy of Sciences,

Dr.Sc. (Medicine), Prof. Victor Gurfinkel

Tel.: (095) 209-28-95, (095) 951-09-60; E-mail: lab9@iitp.ru

The leading researchers of the laboratory include:

Laboratory of neurobiology of motor control investigates the mechanisms of control of posture and movements for more then 25 years. At present time the efforts are focused at study of system of internal representation and its role in motor control and at the investigations of reference systems used by brain for organization of motor behavior. During last years it was shown that in situations with discrepancy between real and perceived position of body segments many motor reactions such as vestibulo-motor and neck influences on leg muscles or oculomotor reactions are determined not by real body configuration but by its description in the system of the internal representation.

In the activity of laboratory the studies of neural mechanisms of locomotion in cat traditionally took an important place. Now we begin to study stepping automatisms in humans. These studies successfully advance.

Manned spacefights open a possibility for studying how the human central nervous system adapts to the microgravity, to what extent the gravitation is essential for processing of proprioceptive information and for motor control. A series of joint research projects with France was accomplished in this direction during 1982-1999 under conditions of real spaceflights.

The data received in researches of the influence of vibratory stimulation of muscle receptors on a body position during standing, have allowed to concretise the concepts about participation of proprioception in the construction of the generalised description of a body used by the central nervous system for maintenance of a vertical posture. This description using afferentation from the set of receptive fields of skeletal-muscular system, is organised on the basis of the body scheme and gives the information about body deviation in a forward-back and lateral direction from a reference vertical and about the degree of its torsion, i.e. deviation from a symmetric position. Such description is quite natural from the point of view of the mechanics. Interestingly, the "natural" system of reference for a vertical posture used by CNS, is based on the same three basic components.

In studies on the healthy people and patients with deficiency of vestibular function the new data on interaction of proprioception and vestibular apparatus were received. In particular, is was shown, that the vibration of neck muscles causes the local segmental responses in the patients with spastic torsicolis, but does not cause a general forward inclination of a body, characteristic for the healthy people. It demonstrates, that in this disease the neck proprioceptive inputs conserves the efficiency at a local level, but cease to be used in system of spatial orientation and in regulation of a whole body position.

We investigated the effect of influences raising a level of activity central tonogenic structures (Jendrassik manoeuvre, Kohnstamm phenomenon), on the generation of locomotor rhythmic in human under the conditions of leg suspension in a horizontal plane. On a background of Jendrassik manoeuvre single passive movements of one leg initiated involuntary stepping movements, in which both legs were involved. This effect, and also initiation of stepping movements on a background of a combination of subthreshold muscular vibration and Jendrassik manoeuvre allow to assume, that a necessary condition for activation of spinal mechanisms of stepping generation is not limited to amplified afferent inflow, but also includes the increase of a level of tonic readiness of tonogenic CNS structures, participating in realisation of the locomotor program. Thus, the locomotor drive in human must be as a minimum two-component.

The technique was developed and the experiments concerning various aspects of a role of gravitation in elaboration of internal representation of the own body and external space in a human brain were carried out. The hypothesis was checked that the information on a gravitational vertical is used for interface of sensory and motor systems; the role of gravitation in construction of reference systems for coding visual, proprioceptive and haptic of the information was investigated; the characteristics of visual, proprioceptive and haptic perception under the conditions of weightlessness were studied. The preparation of astronauts and background pre-flight trials were carried out. The experiment onboard the orbital station "MIR" was carried out in the period from February 20 till August 28, 1999 during joint Russian-French space flight (expedition EO-27). After the flight post-flight studies were carried out. The registrations of high quality were received, and now these data are processed and analysed.

Under the conditions of turns of a support platform relative to the space-fixed head, or shoulder girdle the torque of resistance of different segments of a spine were measured at different angular speeds. The preliminary data about distinct neck influences on distribution of tonic muscular activity of a trunk and legs were received. Is was shown, that the torques of resistance to torsion of a spine, were due, basically, by mechanical properties of tonicaly activated muscles of a neck and trunk, including their active reactions to the changes of length. It was shown that oculomotor reactions can be evoked not only from the neck segment of a spine, but also from upper torso; they could be evoked also in vestibulodeficient patients. The hypothesis that anti-compensatory eye of movement an eye during spine torsion were determined by changes of internal representation of a configuration of a body, instead of direct proprioceptive inputs was confirmed.

• Russian Basic Research Foundation (No. 97-04-48775): “The investigation of mechanisms of equilibrium maintenance on unstable support” (head Yu. Ivanen-ko).
• “Universities of Russia – Basic Research” (No. 2605): “Brain, movement and reference systems” (head V. Gurfinkel).
• Russian Academy of Sciences (Grant for young scientists): “The relative role of different sources of somato-sensory information in the regulation of human vertical posture” (head V. Talis).
• Russian Basic Research Foundation (No. 99-04-48015): “Experimental study of locomotor automatisms in human” (head Yu. Levik).
• Russian Basic Research Foundation (No. 99-04-48450): “Internal reference system for sensory-motor interactions” (head M. Lipshits).
• Russian Basic Research Foundation (No. 99-04-48758): “Axial muscles: motor and perceptive effect of proprioceptive stimulation and postiral tone” (head V. Gurfinkel).
• Russian Basic Research Foundation (No. 99-04-48305): “The influence of visual destabilisation on vestibular postural reactions in humans” (head K. Popov).
• Russian Basic Research Foundation (No. 98-04-48935): “Investigation of a role of additional support for stance control in human” (head V. Shlykov).