The importance of touch is undeniable: it is an essential sense for our survival that allows us to navigate the physical world. It is vital not onl for simple daily activities such as feeding and dressing, but also for appropriate cognitive development. The long-term goal of this research is to analyze the basic developmental mechanisms mechanisms that mediate proper somatosensory innervation of target skin structures. The objective of this application is to identify the role of peripheral target cell populations in the recruitment of Merkel-cell afferents to specialized sensory domains. Merkel cells together with cutaneous sensory afferents form gentle-touch receptors that are important for encoding shapes, edges, and curvature. These touch receptors are enriched in skin areas that mediate discriminative touch sensation, including fingertips and whisker follicles. Though Merkel cells are innervated by A afferents, these cells are not required for directing A afferents to Merkel-cell-enriched skin areas during development. This application's central hypothesis is that specialized cell types that are juxtaposed to Merkel cells during development are responsible for the recruitment of Merkel-cell afferents.
Aim 1 will analyze the spatiotemporal dynamics of the appearance of these cells relative to the innervation of Merkel-cell afferents in high-acuity skin areas. I will use transgenic fluorescent reporter mice and antibodies against cell-type specific markers to label these components.
Aim 2 will test whether these cell types are sufficient to recruit Merkel-cell afferents both in vivo and in vitro. These studies will define the mechanisms that drive guidance of afferents to their targets and will enhance our understanding of how body sites are specialized for distinct somatosensory functions.

Public Health Relevance

Touch is an essential sense for navigating our physical world, yet, after years of research, little is known about how touch-sensitive neurons find their peripheral targets. Merkel cell-neurite complexes are gentle-touch receptors that convey tactile information regarding an object's shape and curvature, and these studies will analyze the underlying developmental mechanisms that enable them to target precise receptive fields. This project will contribute to our basic knowledge of how axons are guided to their specific targets during development, which will help us understand the fundamental mechanisms of peripheral neuron development.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS094023-02
Application #
9101819
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Gnadt, James W
Project Start
2015-07-01
Project End
2019-06-30
Budget Start
2016-07-01
Budget End
2017-06-30
Support Year
2
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Dermatology
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Jenkins, Blair A; Lumpkin, Ellen A (2017) Developing a sense of touch. Development 144:4078-4090