Correlation transfer by layer 5 cortical neurons under recreated synaptic inputs in vitro

TL;DR

This study investigates how different layer 5 cortical neurons convert correlated synaptic inputs into correlated outputs, revealing cell-type specific mechanisms and their implications for cortical microcircuit function.

Contribution

It provides the first detailed comparison of correlation transfer properties among pyramidal neurons and interneurons in layer 5 using realistic input simulations.

Findings

Distinct cell types show unique correlation transfer features.

Cellular properties influence gain and timescale of correlation transfer.

Results link single-cell features to network-level interactions.

Abstract

Correlated electrical activity in neurons is a prominent characteristic of cortical microcircuits. Despite a growing amount of evidence concerning both spike-count and subthreshold membrane potential pairwise correlations, little is known about how different types of cortical neurons convert correlated inputs into correlated outputs. We studied pyramidal neurons and two classes of GABAergic interneurons of layer 5 in neocortical brain slices obtained from rats of both sexes, and we stimulated them with biophysically realistic correlated inputs, generated using dynamic clamp. We found that the physiological differences between cell types manifested unique features in their capacity to transfer correlated inputs. We used linear response theory and computational modeling to gain clear insights into how cellular properties determine both the gain and timescale of correlation transfer, thus tying single-cell features with network interactions. Our results provide further ground for the functionally distinct roles played by various types of neuronal cells in the cortical microcircuit.