GlyT2-Positive Interneurons Regulate Timing and Variability of Information Transfer in a Cerebellar-Behavioral Loop.

Area of Science:

• Neuroscience
• Cerebellar Physiology

Background:

• Glycine transporter 2 (GlyT2)-positive interneurons, including Golgi and Lugaro cells, are strategically located in the cerebellar cortex's input layer.
• These interneurons play a critical role in modulating information processing within the cerebellum.

Purpose of the Study:

• To investigate the contribution of GlyT2-positive interneurons to cerebellar network dynamics during free whisking in mice.
• To understand how altering the activity of these interneurons impacts sensorimotor representations and behavior.

Main Methods:

• Neuronal population activity was recorded using Neuropixels probes in Crus 1 of the mouse lateral cerebellar cortex.
• Chemogenetic downregulation of GlyT2-positive interneurons was performed in male and female mice.
• Analysis focused on network activity before and after the manipulation.

Main Results:

• Cerebellar population activity encoded whisker movements under resting conditions.
• Reduced GlyT2-positive cell activity caused minor increases in neural activity without significantly impairing sensorimotor representations.
• Decreased inhibition from Golgi and Lugaro cells enhanced the temporal alignment of local network activity at movement initiation.
• Behavioral impacts were variable, with both increases and decreases in whisking velocity observed.

Conclusions:

• GlyT2-positive interneuron inhibition is a key regulator of the temporal patterning of cerebellar population activity.
• This temporal control is essential for supporting downstream cerebellar dynamics and coordinated motor behavior.
• The findings highlight the specific role of these interneurons in refining motor output through precise timing mechanisms.