Crustacean peptidergic neurons in culture show immediate outgrowth in simple medium

The survival and outgrowth of neurons in culture has usually required conditioning factors. We now report that crustacean neurons, taken from the peptidergic neurosecretory system of the eyestalk of crabs (Cardisoma carnifex) and lobsters (Panulirus marginatus), show immediate outgrowth, sustained for a week or more, in defined medium as simple as physiological saline with glucose and glutamine. The neurons show peptide hormone immunoreactivity that is prominent at growth cones, exhibit differences in form correlated with their immunoreactivity, release peptides to the medium, and have voltage-dependent currents, including a well-sustained Ca current. Cd blocks secretion, growth, and the Ca current. Peptidergic secretory neurons may be able to utilize existing membrane from their store of granules and already active synthetic, transport, and secretory mechanisms for immediate outgrowth.