The goal of this research is to establish new robust methods for manipulation of specific circuits and genetically defined neuron types in brains of model organisms with small molecules. While several chemical-genetic techniques are already available, these techniques have drawbacks that limit their utility. Our recent work demonstrates that these obstacles can be overcome by using a strategy for acute control of function of proteins of interest (POI) containing destabilizing domains (DD) with the inexpensive commercially available drug, TMP. This compound efficiently crosses the blood-brain barrier, stabilizes DD-POIs with a rapid time course, and does not produce undesired side effects by itself. Since DD tags can be attached to virtually any protein, TMP-inducible stabilization is applicable to a broad spectrum of experimental paradigms. We propose to generate mouse alleles and viral vectors encoding DD-POI fusions suitable for applications ranging from ultra-structural imaging to assessment of complex behaviors. We will develop tools for TMP-dependent recombination of DNA and genome editing (Aim1), acute labeling of behaviorally relevant neuron populations with a reporter compatible with optical imaging and electron microscopy (Aim2), and cell-type-specific control of neurotransmitter secretion (Aim3). Our collaborative team will demonstrate the advantages of these techniques by combining genomics, whole brain imaging, serial electron microscopy, electrophysiology, optogenetics and behavior. New tools will be compared side-by-side against existing technologies, and then distributed to the neuroscience community. We anticipate that these efforts will significantly benefit future studies of the normal brain and mechanisms underlying neurological diseases.

This proposal aims to develop new chemical-genetic techniques for targeting and manipulation of specific circuits and cell types in brains of model organisms with small molecules. We will generate tools useful for DNA recombination, genome editing, optical imaging, electron microscopy, and behavioral experiments. We will distribute the new toolbox to the research community to facilitate futures studies of normal brain function and mechanisms underlying neurological diseases.