ID 82 – Oscillatory activity in nonspecific nuclei of human thalamus during motor and cognitive tasks

Abstract

Objective The aim was to reveal the role of oscillatory unit activity in nonspecific nuclei of thalamus in the cognitive and movement human activity. Methods The extracellular activity of neurons in nonspecific human brain thalamic nuclei (Rt, CM-Pf, MD) obtained by means of microelectrode technique during stereotactic neurosurgical operations was analyzed. Oscillatory neuronal activity was investigated in awake patients with spasmodic torticollis at rest and in response to presentation of cognitive tasks and voluntary movement performance. Results Analysis of single unit activity at rest allowed to reveal several patterns of spontaneous neuronal activity with tendency to periodicity in low-frequency range: low-threshold Ca 2+ -dependent rhythmic bursts pattern (3–5 Hz) and grouping pattern (1–2 Hz). Stabilization of oscillatory neuronal activity (3–5 Hz) of bursting pattern accompanied by local synchronization was observed in neurons during both voluntary and involuntary pathological distonic movement realization. Appearance and/or stabilization of low-frequency rhythmicity also should be noted as an aftereffect of cognitive tasks on mathematic operations and during test on sensoroimotor tracking. Conclusions In general the data obtained shows involvement of rhythmic processes in nonspecific thalamic nuclei in the higher integrative functions of the brain. Key message microelectrode, single unit activity, thalamus, oscillations.