Guidepost cells

One possibility is that axons navigate along a discontinuous path of guidepost cells. A variety of different cell types has been suggested to serve this function. 

Whitington, 1989). Neuronal somata may also function as guidepost cells for efferent axons in the leech. Braun and Stent (1989a) have shown that motor axons contact peripheral neuron somata during outgrowth and that the rate of growth of the motor axons transiently decreases when they contact these somata. 

Non-neuronal guidepost cells primitive glial cells... 

Schubiger, M. and Palka, J. (1985) Genetic suppression of putative guidepost cells effect on establishment of nerve pathways in Drosophila wings. Dev. Biol. 108 399-410. 

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