Role of neuron‐target interactions in the development of a subpopulation of avian sensory neurons

Abstract

Subpopulations of sensory neurons appear in embryonic dorsal root ganglia during development. In this paper, we examine what role neuron-target interactions play in this process. Previous work has shown that alterations in the environment of developing sensory neurons regulate the proportion of neurons that express a cell surface antigen identified by the monoclonal antibody SN1 (Marusich et al.: Dev. Biol. 118: 505-510, 1986). We now report that neuron-target interactions may also act to stabilize the phenotype of sensory neurons. Thus, older SN1- neurons, which would normally remain SN1- if left undisturbed in vivo, can express SN1 immunoreactivity in vitro when they are deprived of contact with their normal peripheral targets. We also demonstrate that naive sensory neurons, i.e., those that have never made contact with peripheral targets, can be identified and maintained in culture. At least some of these naive neurons (all of which are initially SN1-) can express SN1 immunoreactivity in vitro, in the absence of contact with normal peripheral targets. We conclude that subpopulations of sensory neurons may arise from naive neurons in the absence of neuron-target interactions but that subsequent neuron-target interactions may act to stabilize or modulate subpopulation-specific phenotypes.

Developmental dynamics of functionally specific primary sensory afferent projections in the chicken embryo

“…), neurotransmitter profile (glutamate, substance P, CGRP), soma size and localization (Hamburger and Levi-Montalcini 1949;Hamburger et al 1981), cytoplasmic antigens (Omlin et al 1985;Philippe et al 1986), neurotrophin dependence (LoPresti and Scott 1994;Snider 1994;Bothwell 1995), and the composition of cell surface molecules (Tanaka and Obata 1984;Dodd et al 1984Dodd et al , 1988Jessell 1985, 1986;Jessell and Dodd 1985;Mori 1986;Nakagawa et al 1986;Scott et al 1990). A great deal of effort has been directed towards defining factors that determine sensory neuron phenotypes (Marusich et al 1986;New and Mudge 1986;Rohrer et al 1986;Rohrer and Thoenen 1987;Ernsberger and Rohrer 1988;Marusich and Weston 1988;Sieber-Blum 1991;Anderson 1993Anderson , 1994Vogel et al 1993;Davies 1994;Lewin and Barde 1996), elucidating the central connections specific to the different categories of sensory neurons (Brown et al 1977(Brown et al , 1978Brown and Fyffe 1978, 1981Burke et al 1979;Ishizuka et al 1979;Light and Perl 1979;Brown 1981;Jhaveri and Frank 1983;McMahon and Wall 1985;…”