Thoracic Interneurons, Motorneurons and Sensory Neurons of Locusta Migratoria (Insecta: Orthoptera) in Primary Cell Culture

The aim of this study was to establish a cell culture system with identified classes of locust neurons (interneurons, motorneurons and sensory neurons). The cells belonging to the different classes were distinguished in cell culture by vital dyes, which had been applied to the neurons in situ. From the various dyes tested fluorescent marked dextrans (10.000MW) gave the best results. The cells survived for up to 28 days in culture and approx. half of the cells grew processes, except of the sensory neurons, which never formed any processes. The different neurons were comparatively investigated, e.g. with immunhistochemistry: 86% of motorneuron were glutamate immunoreactive and 50% of the interneurons exhibited GABA-like immunoreactivity. The cells had resting potentials between -20 and -60mV and did not show spontanous action potentials. Action potentials could be elicited by current injection in 8% of interneurons and 26% of motorneurons, but not in sensory neurons. The vital marking of cells allowed to study distinct neurons in cell culture and to compare their morphology and physiology.