Morphological and biochemical differences expressed in separate dissociated cell cultures of dorsal and ventral halves of the mouse spinal cord.

The neuronal properties of separate dissociated cell cultures of dorsal and ventral halves of the embryonic mouse spinal cord (E 13.5) were investigated. Ventral-half cultures grew on a variety of substrates and in a variety of media; dorsal-half cultures required a non-neuronal feeder layer and supplemented medium for survival. The two types of cultures differed in their morphological and biochemical properties. Ventral-half neurons remained well separated on the culture plate, whereas dorsal-half neurons tended to aggregate. Lucifer yellow fills showed that ventral-half neurons were substantially larger and had more processes than dorsal-half neurons. Because of the large size and good separation of the neurons, ventral-half cultures provide an especially attractive system for electrophysiologic and morphologic studies. Ventral-half cultures were highly enriched for choline acetyltransferase (ChAT) activity and had more neurons that stained for intracellular acetylcholinesterase (AChE); dorsal-half cultures were enriched for glutamic acid decarboxylase (GAD) activity, and high-affinity gamma-aminobutyric acid (GABA) uptake. The clear differences between the two cultures indicate that many morphological and biochemical properties are already specified on embryonic day 13.5.