IA. Neurons - Structure/Function
A. Characteristics of normal neurons (review) (cont)
2. Synaptic transmission
Calcium influx at voltage-gated ion channels is an important mechanism triggering release of neurotransmitter from synaptic vesicles in the pre-synaptic terminal. The main excitatory transmitter in the CNS is glutamate and the main inhibitory transmitter is GABA. Many other transmitters, including peptides, catecholamines (e.g. dopamine, norepinephrine), serotonin, and acetylcholine, modulate the strength of transmission at excitatory and inhibitory synapses.Postsynaptic receptors may be either ligand-gated ion channels or G-protein linked receptors. Summation of postsynaptic EPSPs and IPSPs at the axon hillock determines if an action potential will be generated.