Projects per year
Abstract
The size principle underlies the orderly recruitment of motor units; however, motoneuron size is a poor predictor of recruitment amongst functionally defined motoneuron subtypes. Whilst intrinsic properties are key regulators of motoneuron recruitment, the underlying currents involved are not well defined. Whole-cell patch-clamp electrophysiology was deployed to study intrinsic properties, and the underlying currents, that contribute to the differential activation of delayed and immediate firing motoneuron subtypes. Motoneurons were studied during the first three postnatal weeks in mice to identify key properties that contribute to rheobase and may be important to establish orderly recruitment. We find that delayed and immediate firing motoneurons are functionally homogeneous during the first postnatal week and are activated based on size, irrespective of subtype. The rheobase of motoneuron subtypes become staggered during the second postnatal week, which coincides with the differential maturation of passive and active properties, particularly persistent inward currents. Rheobase of delayed firing motoneurons increases further in the third postnatal week due to the development of a prominent resting hyperpolarization-activated inward current. Our results suggest that motoneuron recruitment is multifactorial, with recruitment order established during postnatal development through the differential maturation of passive properties and sequential integration of persistent and hyperpolarization-activated inward currents.
Original language | English |
---|---|
Article number | e71385 |
Journal | eLife |
Volume | 10 |
Early online date | 16 Nov 2021 |
DOIs | |
Publication status | Published - 3 Dec 2021 |
Keywords
- Motoneuron
- Spinal cord
- Recruitment
- Size principle
- Intrinsic properties
- Postnatal development
- Electrophysiology
Fingerprint
Dive into the research topics of 'Maturation of persistent and hyperpolarization-activated inward currents shapes the differential activation of motoneuron subtypes during postnatal development'. Together they form a unique fingerprint.Projects
- 1 Finished
-
Mechanisms of spinal plasticity contribu: Mechanisms of spinal plasticity contributing to postnatal development of weight-bearing walking.
Sharples, S. A. (PI)
1/06/19 → 31/08/22
Project: Fellowship