Information processing in the primate basal ganglia during sensory-guided and internally driven rhythmic tapping

Area of Science:

• Neuroscience
• Motor Control
• Computational Neuroscience

Background:

• Cortico-basal ganglia-thalamo-cortical (CBGT) circuits are crucial for motor behavior.
• Gamma (γ) and beta (β) oscillations are implicated in distinct neural functions within these circuits.

Purpose of the Study:

• To investigate the differential roles of γ and β oscillations in the putamen during rhythmic motor tasks.
• To analyze time-varying changes in neuronal firing and local field potential (LFP) spectral power.
• To differentiate the functions of γ and β bands in stimulus-driven versus internally-generated movements.

Main Methods:

• Recorded putaminal spiking activity and LFP spectral power in monkeys performing rhythmic tapping tasks.
• Analyzed neural activity during synchronization (stimulus-guided) and continuation (internally-timed) phases.
• Quantified changes in oscillation power and cell discharge rates relative to interval duration and serial order.

Main Results:

• Both γ and β band power, along with cell discharge rates, changed systematically with interval duration and serial order.
• More LFPs were tuned to duration/serial order in the β-band compared to the γ-band.
• Serial order-tuned β-band LFPs showed a bias towards the continuation phase (movement-aligned), while γ-band LFPs biased towards the synchronization phase (stimulus-aligned).

Conclusions:

• γ-oscillations likely support local computations related to stimulus processing.
• β-activity appears to involve larger putaminal circuit entrainment for internally driven rhythmic tapping.
• These findings highlight complementary roles for γ and β oscillations in motor control within the CBGT circuit.