Molecular control of the development and function of primary and secondary sensory neurons

Project Leader: Carmen Birchmeier e-mail

 

Primary and secondary sensory neurons detect and process somatosensory stimuli. Primary sensory neurons are located in dorsal root and cranial ganglia and mediate the sensation of touch, itch, temperature or pain. The primary sensory neurons transmit the information to secondary sensory neurons in the dorsal spinal cord and hindbrain that relay the information. Primary and secondary sensory neurons are stunningly heterogeneous, and the scarcity of molecular data has made it difficult to analyze their development and to define the basis of their diversity and function. We identified a number of key transcription factors, c-Maf, Lbx1 and Olig3, which control development and function of primary and secondary sensory neurons.

Itch is a little understood sensory modality, and our ongoing work defines a new and distinct population of secondary sensory neurons that modulates the sensation of itch. We tentatively assign this to a neuron class in lamina III of the spinal cord defined by expression of c-Maf and Lbx1. Thus, c-Maf is expressed and functional not only in primary, but also in a subpopulation of secondary sensory neurons. In the next funding period, we aim to define the basis of the dysfunction of such neurons in c-Maf mutant mice. In addition, we are using Olig3 and Lbx1 mutant mice as models to understand better the role of breathing centers in the hindbrain.