Dr. Krimm examines the mechanisms underlying developmental interactions between sensory fibers and peripheral organs. During development, growth factors called neurotrophins are released by peripheral tissue. These factors direct neural innervation, resulting in precise connections between peripheral neurons and target organs. The taste system is a perfect model for studying these neural-target interactions during development. Taste buds arise in discrete, predictable, locations and both taste bud and the neurons innervating them can be quantified. Neurotrophins are easily examined in transgenic overexpressing, knockout, or conditional/inducible knockout mice for one or more neurotrophins and/or their receptors. Dr. Krimm's laboratory has two long terms goals: 1) to determine the cellular and molecular mechanisms that allow gustatory neurons to innervate the correct target (taste buds) with a specific amount of innervation, and 2) to determine if and/or how these connections are important for central gustatory development or taste function. Currently, the laboratory is focused on the role of neurotrophins in regulating gustatory neuron number and peripheral and central targeting during development. Elucidating these basic developmental mechanisms has important implications for use of these growth factors as therapeutic agents to enhance sensory regeneration following nerve injury, with aging, and in disease states. Techniques used in Dr. Krimm's laboratory include use of transgenic mice, anatomical tract tracing, immunohistochemistry,
in situ hybridization, confocal microscopy, basic histology and quantitative anatomy.
Huang T and Krimm RF (2011) Developmental expression of bdnf, nt4 and trkB, in the mouse peripheral taste system. Dev. Dynamics, in press.
Patel A.V., Huang T., Krimm R.F. (2010) Lingual and palatal gustatory afferents each depend on both BDNF and NT-4, but dependence is greater for lingual than palatal afferents. J. Comp Neurol., 518(16):3290-301.
Patel A.V., and Krimm R.F. (2010) BDNF is required the survival of differentiated geniculate ganglion neurons. Dev. Biology 340(2):419-29.
Thirumangalathu S., Harlow D.E., Driskell A.L., Krimm R.F., Barlow L.A. (2009) Fate mapping of mammalian embryonic taste bud progenitors. Development 136(9):1519-28.
Ma L., Lopez G.F., Krimm R.F. (2009) Epithelial-derived brain-derived neurotrophic factor is required for gustatory neuron targeting during a critical developmental period. J Neurosci.
Krimm RF (2007) Factors that regulate embryonic gustatory development. BMC Neurosci., 27:13875-81.
Lopez G.F. and R.F. Krimm. (2006) Epithelial overexpression of BDNF and NT4 each produce distinct spatial patterns of altered chorda tympani innervation. Devel. Biology. 292(2):457-68.
Lopez G.F. and R.F. Krimm. (2006) Refinement of Innervation Accuracy Following Initial Targeting of Peripheral Gustatory Fibers. 2006 J. Neurobiol., 66(10):1033-1043.
Krimm, R.F., Davis, B.M., Noel, T and K.M. Albers. (2006) Overexpression of Neurotrophin 4 in Skin Enhances Myelinated Endings but does not Influence Sensory Neuron Number. J. Comp. Neurol., 498:455-465.
Krimm R.F. The p75 receptor is required for the normal development, but not the adult maintenance, of taste buds. (2006) Anat Rec A Discov Mol Cell Evol Biol., 288(12):1294-302.
Krimm, R.F., Davis B. M. Woodbury J.C., and K. M. Albers. 2004. Skin-expressed NT3 causes prenatal enhancement of SA1 sensory neurons and initially delays postnatal enhancement of Merkel cells. J. Comp. Neurol 471: 352-360.
Shuler, M.G., Krimm, R. F., and D.L. Hill. 2004. Neuron/target plasticity in the peripheral gustatory system. J. Comp. Neurol. 472:183-192.
Krimm, R.F., Miller, K.K., Kitzman, P.H., and K.M. Albers. 2001 Epithelial overexpression of BDNF or NT-4 disrupts targeting of taste neurons innervating the anterior tongue. Devel. Biology. 232, 508-521.