Abstract
We have monitored the incorporation of tritiated uridine into RNA by the giant neuron of the Aplysia abdominal ganglion. Synaptic stimulation evoking a mean of 3,000 impulses in the neuron increased incorporation by about 67%. Incorporation was proportional to the number of stimuli given and to the number of synaptically evoked action potentials produced in the stimulated neuron. Stimulation did not alter uridine uptake or the percentage of intracellular label appearing in UTP. The effect of stimulation cannot be accounted for by glial incorporation.