As a major hub of the central auditory system for hearing, the inferior colliculus (IC) receives both
bottom-up input from auditory brainstem nuclei, as well as feed-back input from the auditory cortex (AC).
IC contributes importantly to the processing of essential features of sounds for communication and
localization. Impaired IC processing has been associated with various hearing deficits. However,
despite extensive studies of central auditory processing in IC, our understanding of cell-type-specific
circuit mechanisms underlying the functional roles of the IC remains limited. In particular, how different
types of neurons in the three anatomical and functional subdivisions of IC, the central nucleus (ICc),
dorsal cortex (ICd), and external cortex (ICe), interact with each other and contribute differentially to the
auditory processing of IC remains largely unclear. Addressing this question requires identification of
molecular markers for cell types specifically located in each of the subdivisions. With 10X Genomics
single-nucleus RNA sequencing (snRNAseq), we made initial efforts in screening molecular markers
for different neuronal populations of IC. By identifying and verifying specific markers for IC subdivisions
and exploiting corresponding transgenic Cre mouse lines for the selected marker genes, we will then
characterize the anatomical connections and auditory response properties of the selected cell type and
its functional role in auditory processing functions. Our preliminary snRNAseq results suggest two
potential molecular markers specifically labeling subpopulations of excitatory neurons in the IC cortex.
Their verification will endow us with unique opportunities to investigate the specific and diverse
functional roles of ICd in auditory perception and behavior. Cutting-edge approaches in
electrophysiology, anatomy, and optogenetics coupled with intersectional or projection-based tagging
will be applied to address the differential functional contribution of diverse neuronal types in ICd as well
as the distinct underlying circuitry mechanisms.