A Drosophila mutant with a temperature-sensitive block in nerve conduction.

A mutant, napts (no action potential, temperature-sensitive), is described in which axonal conduction fails at high temperature. Synaptic transmission at the larval neuromuscular junction is unimpaired. Larvae and adults are rapidly paralyzed at restrictive temperatures; they recover rapidly when the temperature is decreased. The mutant gene is recessive and is located on the second chromosome at map position 56.