Accession Number : ADA299872

Title :   Rhythmically Firing (20 - 50 Hz) Neurons in Monkey Primary Somatosensory Cortex: Activity Patterns during Initiation of Vibratory-Cued Hand Movements. Enclosure Number 1.

Descriptive Note : Final technical rept.,

Corporate Author : TENNESSEE UNIV MEMPHIS DEPT OF ANATOMY AND NEUROBIOLOGY

Personal Author(s) : Lebedev, Michael A. ; Nelson, Randall J.

PDF Url : ADA299872

Report Date : 26 JUN 1995

Pagination or Media Count : 29

Abstract : The activity patterns of rhythmically firing neurons in monkey primary somatosensory cortex (SI) were studied during trained wrist movements that were performed in response to palmar vibration. Of 1,222 neurons extracellularly recorded in SI, 129 cells (11%) discharged rhythmically (at 30 Hz) during maintained wrist position. During the initiation of vibratory-cued movements, neuronal activity usually decreased at 25 ms after vibration onset followed by an additional decrease in activity at 60 ms prior to movement onset. Rhythmically firing neurons are not likely to be integrate-and-fire neurons because, during activity changes, their rhythmic firing pattern was disrupted rather than modulated. The activity pattern of rhythmically firing neurons was complimentary to that of quickly adapting SI neurons recorded during the performance of this task (Nelson et al., 1991). Moreover, disruptions of rhythmic activity of individual SI neurons were similar to those reported previously for local field potential (LFP) oscillations in sensorimotor cortex during trained movements (Sanes and Donoghue, 1993). However, rhythmic activity of SI neurons did not wax and wane like LFP oscillations (Murphy and Fetz, 1992; Sanes and Donoghue, 1993). It has been suggested that fast (20 - 50 Hz) cortical oscillations may be initiated by inhibitory interneurons (Cowan and Wilson, 1994; Llinas et al., 1991; Stern and Wilson,

Descriptors :   *BEHAVIOR, *RESPONSE(BIOLOGY), *NERVE TRANSMISSION, POSITION(LOCATION), VIBRATION, CIRCADIAN RHYTHMS, PATTERNS, NERVE CELLS, OSCILLATION, WAXES, HANDS, MOTOR NEURONS, WRIST, FIRING RATE.

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE