It is very important to be able to inhibit a neuronal population in order to understand its function. However, I have found it more difficult to achieve than activating neurones. Inhibitory DREADDs (hM4Di) are notoriously poor; knocking out a gene of interest can often be negated by compensation from other genes during development. The best method I’ve found is to use cre-dependent caspase to ablate the population, but this is not ideal as it literally kills off the cells. TetTox is similar, in that it stops the neurones from functioning, without actually killing them off.
So my question is, what method to people use for switching off a population of neurones? Something I’m interested in trying is using the new long-term inhibitory opsin from Rodger et al. (“Lamplight”), as this ought to function similarly to an inhibitory DREADD.