Fast-local and slow-global neural ensembles in the mouse brain

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Neuron ensembles are crucial for brain computations.
• Principles governing ensemble localization (single vs. multiple brain regions) remain unclear.

Purpose of the Study:

• Investigate the principles determining whether neural ensembles remain localized within a single brain region or span multiple regions.
• Analyze the relationship between timescale, firing rate, and neural ensemble organization.

Main Methods:

• Simultaneous electrophysiological recordings from hundreds of neurons across nine brain regions in awake mice.
• Analysis of spike count correlations at different timescales (subsecond vs. slower).
• Application of an ensemble detection algorithm to neural correlation data.

Main Results:

• At fast timescales, spike count correlations were stronger within brain regions than between them.
• At slower timescales, within- and between-region correlations were similar.
• Fast-timescale ensembles were primarily localized within single brain regions; slow-timescale ensembles spanned multiple regions.
• High-firing-rate neuron pairs showed a stronger timescale-dependent correlation than low-firing-rate pairs.

Conclusions:

• Neural ensembles exhibit distinct spatial organizations at different timescales.
• The mouse brain may perform fast, local computations and slow, global computations in parallel.