An emerging challenge in understanding neuron communication is the realization that many neurons release more than one type of chemical signal or neurotransmitter. In collaboration with Steve Stowers at MSU, we are asking how does the release of more than one neurotransmitter from a single neuron impact circuits that control behavior. The neurons we are examining co-express the monaomine octopamine and the classical transmitter glutamate. Our readout of dual neurotransmission function is aggression. Aggression is a behavior that is highly conserved between organisms and present in many human disease states, including depression and Alzheimer’s disease. Our ongoing studies show that aggressive behavior requires the release of both neurotransmitters in dual-transmitting neurons and suggests within this set of neurons, glutamate may provide a new therapeutic target to modulate aggression in pathological conditions.
The focus of this project is to examine how proteins within the extracellular matrix impact monoamine signaling and regulate cell-microenvironment interactions. Many extracellular matrix components are expressed in the brain and many have been implicated in the pathogenesis of major neurological conditions including depression, autism spectrum disorder, and bipolar disorder. We are studying the Drosophila member of the CCN (CYR61/CTGF/NOV) family of matricellular proteins and determining the role of dCCN during the development of monoamine neurons as well as how it is required for monoamine communication in the mature nervous system. This project is an ongoing collaboration with Evelyne Ruchti and Brian McCabe at EPFL Lausanne Switzerland.
In recent years, two new areas of study have transformed the way neuroscientists consider how the central nervous system functions. These two areas are the impact of the gut microbiome and the impact of sex differences, i.e. whether each cell in an organism is male or female. We are examining how bacteria, the sex of the gut, and the expression of monoamine receptors influence aggressive behavior.