Neuromuscular transmission
| Type of Neurotransmitter |
Neurotransmitters |
Function |
| Class I |
Acetylcholine |
Mostly excitatory |
| Class II: Bioactive amines |
Dopamine |
Excitatory and inhibitory |
| Epinephrine |
Excitatory |
| Norepinephrine |
Excitatory |
| Serotonin |
Excitatory |
| Class III: Amino acids |
Glutamate |
Excitatory |
| Glycine |
Mostly inhibitory |
| g-Aminobutiricacid (GABA) |
Inhibitor |
| Aspartate |
Excitatory |
| Table 3.a: Neurotransmitters |
Transmission at neuromuscular junction
Neurohumoral transmitters (acetylcholine) are key players at the neuromuscular junctions. As the action potential reaches terminal arborization of the axon it stimulates release of acetylcholine which diffuses across the small gap between the neuron and the end plate of the muscle. Acetylcholine interacts with specific receptor complex thus increasing permeability of the endplate membrane to all ions. If this change is sufficient to produce a suprathreshold depolarization at the endplate, an impulse gets generated. Acetylcholine gets destroyed by acetylcholinesterase, an enzyme, which are stored in the endplates of the muscles in high concentration.
|
