Abstract

Understanding how cortical circuits are wired is essential to decoding how the brain processes information. This webinar will introduce optomapping—a high-throughput, two-photon optogenetic method that accelerates microcircuit mapping nearly 100-fold compared to traditional patch-clamp techniques. This innovative approach has been used to map excitatory microcircuits in the visual cortex with single-cell spatial and millisecond temporal resolution. Using acute brain slices from mice, this work uncovered previously unknown patterns of excitatory inputs onto neocortical basket cells and Martinotti cells. The findings revealed that excitatory input strengths are log-normally distributed, not only onto excitatory neurons but also onto inhibitory ones, and that short-term synaptic dynamics depend on both the cell type and the presynaptic cortical layer, adding complexity to our understanding of circuit function.

This session will walk you through how optomapping works, what these findings tell us about the organizational principles of cortical microcircuits, and how this technique opens the door to exploring brain connectivity at unprecedented speed and resolution.

Highlights

- Introduction to optomapping. 

- Enhanced understanding of canonical circuits. 

- Revealing cell type–specific excitatory synaptic input patterns.

- Layer-specific synaptic dynamics.

- Overcoming limitations of traditional techniques with optomapping and its broader implications.