Neuronal class-specific patterns of calcium activity and target dependence of neurotransmitter expression in the developing spinal cord

摘要: The proper functioning of all nervous systems requires efficient communication among neurons. Neurotransmitters provide the fundamental basis for neural communication. Establishing expression appropriate neurotransmitters in different populations neurons is a critical challenge development. This complicated process that involves multiple mechanisms, including intrinsic genetic coding, early neuronal activity and signal transduction cascades driven by targets. Embryonic Xenopus spinal generate spontaneous transient elevations intracellular calcium. Different classes exhibit this calcium spike distinct patterns, altering modulates transmitter expression. However neurotransmitter sensitive to only during an period Both spiking sensitivity activity-dependent specification decrease disappear as embryos mature. I showed transection causes resume activity, enhancing leads increased inhibitory GABA. These results indicate potential reopening exists earlier Using neuron-muscle co-culture system, muscle, target, plays important role regulating Muscle contact refines cultured reducing non-cholinergic transmitters, GABA, glycine glutamate, while leaving choline acetyltransferase (ChAT) unaltered. Trophic factors are normally released at synapses delivered retrogradely along axons appear be sufficient induce such changes. Further investigation revealed muscle electrical required muscle-dependent suppression In addition, also suppresses abolishes embryonic stages