Target-specific control of nicotinic receptor expression at developing interneuronal synapses in chick

Neuronal differentiation and development of synaptic specializations are st rongly influenced by cellular interactions. We compared the effects of inte raction with distinct autonomic targets on the molecular and biophysical di fferentiation of 'upstream' neuron-neuron synapses. Contact with cardiac ti ssue induced expression of nicotinic receptor channels (nAChRs) distinct fr om those induced by renal tissue in presynaptic autonomic neurons. The kine tics of cholinergic currents at interneuronal synapses are dictated by the peripheral target contacted. Analysis of the nAChR channel subtypes and sub units in individual neurons demonstrated that the profile of transmitter re ceptors expressed at mature neuron-neuron synapses develops from the conver gent influences of input-derived (anterograde) and target-specific (retrogr ade) signals.