ABSTRACT
The use of event-related fMRI makes it possible to investigate spatio-temporal dynamics of cortical and subcortical human brain structures activity during voluntary movement performance in response to presentation of relevant verbal stimuli. The results of the study showed that voluntary movement was associated with higher contralateral brain activation in a number of areas: primary motor and somatosensory cortex, premotor cortex, supplementary motor area and insula with adjacent regions. Ipsilateral activation of the cerebellum also was observed. It should be emphasized that contralateral strio-pallidal complex and ventral thalamus showed significant response to motor tasks. Similarly, the dynamics of cortex and deep brain structures activation involving in the phasic and tonic components of voluntary movement was uncovered. We showed, in particular, the noticeable difference in brain activation between the right and left hand movement performance. The obtained results enable to enhance understanding of the role of deep brain structures in voluntary movement organization in human and motor control system as a whole.
Subject(s)
Cerebellum/physiology , Cerebral Cortex/physiology , Nervous System Physiological Phenomena , Somatosensory Cortex/physiology , Adult , Cerebellum/diagnostic imaging , Cerebral Cortex/diagnostic imaging , Female , Hand , Humans , Magnetic Resonance Imaging , Male , Motor Cortex/diagnostic imaging , Motor Cortex/physiology , Movement/physiology , Radiography , Somatosensory Cortex/diagnostic imagingABSTRACT
The time-frequency characteristics and interneuron interaction in the cell ensembles of non-specific (CM-Pf) and motor (Voi) thalamus were analyzed. Neuronal activity was registered by microelectrode technique during 18 stereotactic neurosurgery operations in spasmodic torticollis patients. The presentation of functionally significant verbal stimuli was accompanied by the emergence of short-term (0.5-1.5 s) local synchronization and stabilization of the oscillatory (3-6 Hz) activity in nearby neurons of nonspecific (CM-Pf) thalamus. These focuses of synchronized oscillatory neuronal activity were correlated with the moment of the greatest concentration of selective attention. Similar phenomenon of short-term synchronization was observed in the motor (Voi) and nonspecific (CM-Pf) thalamus of the human brain during the voluntary movements. Synchronization of neuronal activity occurred at the height of the motor act implementation, correlating with the maximum muscle tension, as well as in aftereffect of the voluntary movement. Overall, the findings suggest an important role of the local oscillations (3-6 Hz) and synchronization ofthalamic neurons in the mechanisms of relevant information transmission during goal-directed human behavior.
Subject(s)
Behavior/physiology , Neurons/physiology , Thalamus/physiology , Torticollis/physiopathology , Attention/physiology , Female , Goals , Humans , Male , Movement/physiology , Neurosurgery , Stereotaxic Techniques , Thalamus/surgery , Torticollis/surgeryABSTRACT
Activity of 144 parafascicular CM-Pf thalamic neurons was studied and recorded by means of microelectrodes during 18 stereotactical neurosurgical operations in spasmodic torticollis patients. High reactivity of two previously classified neurons with single sporadic activity (A-type) and bursts of Ca2(+)-dependent activity (B-type) were found during verbally ordered voluntary movements. There are coordinated reciprocal activation-inhibition A-type and B-type neuronal responses at the stage of verbal command presentation and synergic activation responses on the high of movement and in the aftereffect. Voluntary movement realization was accompanied by short-term local synchronization and stabilization of oscillatory (3-5 Hz) neuronal activity. The neuronal response differences between voluntary movements with and without neck muscle exertion and involuntary pathological movements prove the CM-Pf involvement in the pathology of spasmodic torticollis desease.
Subject(s)
Dyskinesias/physiopathology , Neurons , Thalamus/physiopathology , Torticollis/physiopathology , Female , Humans , MaleABSTRACT
It has been shown that prophylactic administration of ubiquinone protects rats liver from the toxic damage by D-galactosamine both on ultrastructural and on cell levels. Ubiquinone administration prevents necrosis in hepatocytes and preserves their ability for compensatory reactions expressed in activation of protein-synthesis regulating structures in the cell. Ubiquinone decreases hyperfermentemia and hyperbilirubinemia as well as prevents the decrease in liver protein content caused by galactosamine. Ubiquinone exerts an antioxidant effect, blocking the induction of lipid peroxidation both in intact and hepatic rats.
