How do optogenetics and calcium imaging divide the work of writing to neurons and reading them? · Grey Matter

Both rely on genes delivered into chosen neurons and on light: calcium imaging makes active cells glow so a microscope can read which ones fired, and optogenetics makes cells fire or fall silent when light reaches them.

How do optogenetics and calcium imaging divide the work of writing to neurons and reading them?

Both rely on genes delivered into chosen neurons and on light: calcium imaging makes active cells glow so a microscope can read which ones fired, and optogenetics makes cells fire or fall silent when light reaches them. Combined in one experiment, with an indicator and an opsin excited by different colours, they close the loop, so a researcher can watch an ensemble form during a task and later switch the same cells on to test what they do. Both are limited to the depth that light can reach and to animals into which genes can be introduced.