The Expression of Cholinergic and Adrenergic Properties by Autonomic Neurons in Tissue Culture

Abstract

Both circumstance and paradox dictate that this chapter should center primarily on the autonomic adrenergic (sympathetic) neuron in tissue culture. The particular circumstance is the availability of a well-defined trophic factor, nerve growth factor (NGF), for this neuron, allowing its long-term culture isolated from all other tissues; no comparable factor has been characterized for neurons from other portions of the autonomic nervous system. The paradox is that adrenergic neurons in tissue culture have provided much new information on the development of cholinergic mechanisms: when taken for culture from the perinatal animal, the adrenergic neuron has the unexpected property of developing the ability to synthesize and release acetylcholine and to establish cholinergic interactions with adjacent neurons of its own type. Because of the intense interest in exploring the nature and mechanism of this transmitter shift, a substantial portion of recent work on the adrenergic neuron in culture is centered on these problems. The sympathetic neuron may also provide adrenergic Innervation to a variety of target tissues in culture and thus has been useful for the study of both adrenergic and cholinergic mechanisms.