Abstract: Brain functions are accomplished by circuits formed by selective wiring of specific neurons. However, the inability to define neuronal types has been a major bottleneck in the analysis of neuronal circuits and brain disorders. Fortunately, the emergence of intersectional genetics has opened up new avenues to address this challenge. The multi-component intersectional genetic strategies have advanced beyond the earlier single-component system to provide more precise and more versatile targeting of cell types. In this talk, I will discuss a recent project in my lab using Cre/Flp intersectional genetics to identify glutamate/GABA co-transmission neurons in the brain and then mapped their projections. Glutamate/GABA co-transmission neurons are special players in neuronal circuits and often provide diverse and flexible means to regulate synaptic transmission between individual synaptic partners. By creating intersections between vesicular glutamate transporters (VGLUT) and vesicular GABA transporters (VGAT), we mapped 30 brain regions containing neurons that co-express VGLUT and VGAT, and we further identified the lateral habenula (LHb) as the primarily targeted brain region for glutamate/GABA co-transmission. Focusing on the LHb as a target, we identified glutamatergic, GABAergic, or co-glutamatergic/GABAergic innervations from ~40 brain regions. Collectively, our results highlight the power of intersectional genetics in anatomical and functional dissections of neuronal circuitry.

Biography: Yongling Zhu obtained her Ph.D. in Physiology & Biophysics from the State University of New York at Buffalo in the laboratory of Professor Anthony Auerbach, where she studied ion permeation in NMDA receptors. She received postdoctoral training at the Salk Institute for Biological Studies with Professor Charles Stevens and Professor Stephen Heinemann, where she studied synaptic transmission and plasticity. Zhu is currently an Assistant Professor in the Department of Ophthalmology at Northwestern University Feinberg School of Medicine, with a secondary appointment in the Department of Neuroscience. Her research focuses on identifying the various cell types and functional circuitry involved in visual processing in the retina and the brain.