RAPID DEVELOPMENT OF SYNAPTIC CONNECTIONS AND PLASTICITY BETWEEN SENSORY NEURONS AND MOTOR NEURONS OF APLYSIA IN CELL CULTURE: IMPLICATIONS FOR LEARNING AND REGULATION OF SYNAPTIC STRENGTH. Rosalind L. Coulson and Marc Klein. Clinical Research Institute of Montreal and University of Montreal, Centre de recherche en sciences neurologiques, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada.
APStracts 4:0045N, 1997.
We describe here the time course of functional synapse formation and of the development of short-term synaptic plasticity at Aplysia sensorimotor synapses in cell culture, as well as the effects of blocking protein synthesis or postsynaptic receptors on the development of synaptic transmission and plasticity. We find that synaptic responses can be elicited in 50% of sensory neuron-motor neuron pairs by one hour after cell contact and that short-term homosynaptic depression and synaptic augmentation and restoration by the endogenous facilitatory transmitter serotonin are present at the earliest stages of synapse formation. Neither block of protein synthesis with anisomycin nor block of two types of postsynaptic glutamate receptor has any effect on the development of synaptic transmission or synaptic plasticity. The rapidity of synapse formation and maturation and their independence of protein synthesis suggest that changes in the number of functional synapses could contribute to short- and intermediate-term forms of synaptic plasticity and learning.

Received 8 November 1996; accepted in final form 13 January 1997.
APS Manuscript Number J888-6.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 5 February 1997