Activity of phasic motor neurons partially transforms the neuronal and muscle phenotype to a tonic-like state
✍ Scribed by Robin L. Cooper; Wendy M. Warren; Harty E. Ashby
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 736 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0148-639X
No coin nor oath required. For personal study only.
✦ Synopsis
We present a model preparation, the crayfish, to investigate chronic stimulation effects in muscle fiber type and neuronal conversion from fast to slow. The results show a presynaptic alteration in transmitter release after 1 week of stimulation at 5 Hz for a 2-h daily regime. With the same stimulation paradigm, the muscle proteins displayed on a polyacrylamide gel only start to show changes after 3 weeks. The original phasic motoneurons within 1 week display an enhanced ability to resist synaptic depression, as do tonic motoneurons. The results show that identified phasic motoneurons and muscle fibers in the crayfish can be transformed to a toniclike state, and that the nerve terminals convert prior to the muscle fibers. Electrophysiological clinical measures indicating a change in transmitter release properties may not necessarily mean that the muscle fibers have fully adapted for long-lasting effects. This preparation allows stimulation conditions to be examined with ease.