Robin Krimm, Ph.D.
Research Focus
Taste bud cells detect chemical information (e.g. sweet or salty) in the food we eat; taste bud cells connect to peripheral sensory neurons which carry taste information to the brain. Taste bud cells exist as different types, each transducing one or several chemicals, but peripheral sensory neuron types remain poorly defined. We are interested in defining the relationships between genetic expression, morphology, and function of peripheral gustatory neurons types. One of the unique features of the adult taste system is that taste receptors die and are continuously replaced. We are interested in understanding how taste neurons connect to taste bud cells during development, during taste bud cell turnover, and following disrupted taste cell turnover caused by chemotherapies. In addition to taste, we perceive the location and texture of food in our mouth. We are interested in what type of neuron detects this information and if this input modulates taste centrally. We are using a combination of sparse cell genetic labeling and fiber tracing, whole mount imaging, intra vital imaging, and calcium imaging to tackle these problems. These studies will inform fundamental questions in the field of taste such as: How is the peripheral taste system organized? How is this organization maintained when the receptor cells are continuously renewed? How are tastes localized on the tongue? Understanding these basic issues is a prerequisite to trying to repair damage to this system.
Current Projects:
1) We have defined neuron morphologies using using sparse cell genetic labeling and determined that some are sparsely branched, and some are heavily branched. We are now trying to determine how these methodologies are regulated. Specifically, we are asking if neurons of different types have divergent morphologies and if that influences neuron function.
2) Because taste receptor cells connect with new neurons over time, we are interested in the specific movements (or plasticity) that influence neuron morphology and are required for a neuron to form a new connection. We are also interested in how taste bud damage and/or signaling pathways which influence the taste receptor cell cycle alter peripheral neuron morphologies.
3) The sense of taste is localized by touch. We are interested in identifying the non-taste light touch mechanoreceptor that mediates taste localization in the tongue.
Key Publications
Huang T., Ohman L.C., Whiddon, Z.D. and R.F Krimm. (2021) Variable branching characteristics of periperal taste neurons indicates differential convergence. J Neurosci., 41(22):4850-4866.
Ohman L.C. and R.F. Krimm. (2021) Whole-mount staining, visualization, and analysis of fungiform, circumvallate and palate taste buds. JoVE 14(1) 3.
Rios-Pilier J. and R.F. Krimm. (2019) TrkB expression and dependence divides gustatory neurons into three subpopulations . Neural Dev. 14(1):3.
Sun C., Krimm, R. and D.L. Hill (2018) Maintenance of mouse gustatory terminal field organization is dependent on BDNF at adulthood. J. Neurosci., 38(31):6873-6887.
Ohman-Gault, L. Huang, T. and Krimm R.F. 2017. The transcription factor Phox2b distinguishes between oral and non-oral sensory neurons in the geniculate ganglion. J Comp. Neurol. 525(18):3935-3950.
Tang, T., Rios-Pilier, J. and Krimm, R. F. 2017. Taste bud derived BDNF maintains innervation of a subset of TrkB-expressing gustatory nerve fibers. Mol Cell Neurosci. 82:195-203.
Meng, L., Huang, T., Sun C., Hill, D.L. and Krimm, R. F. 2017. BDNF is required for taste axon regeneration and contralateral plasticity following unilateral chorda tympani nerve section. Exp. Neurol. 293:27-42.
Huang, T. Ma, L, and R.F. Krimm, 2015. Postnatal reduction of BDNF regulates the developmental remodeling of taste bud innervation. Developmental Biology, 405(2)225-36.
Fei, D, Huang, T and R. F. Krimm. 2014. The neurotrophin receptor p75 regulates gustatory axon branching and promotes innervation of the tongue during development. Neural Dev. 9:15
Huang, T and RF. Krimm.2014. BDNF and NT4 play interchangeable roles in gustatory development.Dev. Biology. 386(2):308-20.
Fei, D and R. F. Krimm. 2013. Taste neurons consist of both a large TrkB-receptor-dependent and a small TrkB-receptor-independent subpopulation. Plos One. 8(12): e83460.
Patel, A.V. and R. F. Krimm. 2012. Neurotrophin-4 regulates the survival of gustatory neurons earlier in development using a different mechanism than brain-derived neurotrophic factor. Dev. Biology 365(1):50-60.