| Popis: |
The mechanism by which a motor nerve axon “nourishes” or maintains a “trophic influence” on the muscle fiber it reaches remains unknown, despite much investigation and interest. A large body of literature, including several excellent reviews [12, 13, 15, 16] suggests that the presynaptic element exerts its control in one of three ways: (a) by release of the normal transmitter, acetylcholine (ACh), (b) by some aspect of the stimulus-evoked postsynaptic response itself, i.e., in muscle, the contraction, and (c) by the release of other substances delivered to the presynaptic axon terminals by centrifugal axoplasmic flow from the motor neuron soma. |
