Section 8.4 Neurophysiology and Cognitive Neuroscience: Adaptive modulation of excitability in motor neurons
Technical Report,30 Aug 2015,29 May 2016
Delaware State University Dover United States
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The long-term objective of this exploratory research project was to uncover cellular mechanisms involved in adaptation in the excitability of spinal motoneurons, in response to changes in overall motor activity. The central hypothesis of the work was that alteration of the function of KCNQKv7.2 potassium channels and changes in the properties of the axonal initial segment AIS are the primary mechanisms by which motoneurons adapt to prolonged network activation the cellular equivalent of physical fatigue. Work to achieve the goals of this proposal included a combination of immunohistochemistry and electrophysiological techniques to investigate the extent that changes in the somatodendritic and AIS responsiveness of motoneurons and the shape of the AIS can explain the complex effects of prolonged spinal network activation on motoneuron excitability. Specific KC QKv7 potassium channel modulating drugs will be used to dissect the contribution of the channels to the excitability of spinal motoneurons in both baseline and adapted states, differentiating their somatodendritic and axonal contributions. Immunohistochemical labeling of the AIS in baseline and adapted neurons can identify activity-dependent changes in AlS geometry and distance from the soma. We also developed detailed computational models of spinal motoneuron activity before and after persistent network activation.
- Medicine and Medical Research
- Anatomy and Physiology