Control and role of plateau potential properties in the spinal cord

TY - JOUR

T1 - Control and role of plateau potential properties in the spinal cord

AU - Hultborn, Hans

AU - Zhang, Mengliang

AU - Meehan, Claire F

PY - 2013

Y1 - 2013

N2 - In this review we will first give a historical account of how the discovery of persistent inward currents (PICs) and plateau potentials changed the understanding of the operation and function of the "final common path", i.e. the motoneurons themselves. A major function of voltage-dependent PICs is to serve as an adjustable amplifier of classical synaptic inputs. The complex control of this, and other intrinsic properties, certainly adjusts the performance of the motoneurons to the needs of the behavioral settings. It has emerged that supraspinal facilitation, mainly by monoaminergic projections, is a prerequisite for the normal function of the PIC channels. When these pathways are interrupted following a spinal lesion the "gain" of the transmission across the motoneurons is reduced and this is likely to be an important explanation for the spinal shock. However, after a few weeks the "plateau properties" of the motoneurons return - now without descending monoaminergic control. This plasticity after spinal lesion is likely to contribute to the hyperreflexia (spasticity) seen after spinal lesions. We then review the current knowledge on PICs in other spinal (inter-)neurons. The monoaminergic systems seem to play a pivotal role in activating the spinal network generating the rhythm and basic motor pattern of locomotion and scratch - the spinal "central pattern generators" (CPGs). We give a short historical background of this research with a special emphasis on the importance of the descending monoaminergic systems.

AB - In this review we will first give a historical account of how the discovery of persistent inward currents (PICs) and plateau potentials changed the understanding of the operation and function of the "final common path", i.e. the motoneurons themselves. A major function of voltage-dependent PICs is to serve as an adjustable amplifier of classical synaptic inputs. The complex control of this, and other intrinsic properties, certainly adjusts the performance of the motoneurons to the needs of the behavioral settings. It has emerged that supraspinal facilitation, mainly by monoaminergic projections, is a prerequisite for the normal function of the PIC channels. When these pathways are interrupted following a spinal lesion the "gain" of the transmission across the motoneurons is reduced and this is likely to be an important explanation for the spinal shock. However, after a few weeks the "plateau properties" of the motoneurons return - now without descending monoaminergic control. This plasticity after spinal lesion is likely to contribute to the hyperreflexia (spasticity) seen after spinal lesions. We then review the current knowledge on PICs in other spinal (inter-)neurons. The monoaminergic systems seem to play a pivotal role in activating the spinal network generating the rhythm and basic motor pattern of locomotion and scratch - the spinal "central pattern generators" (CPGs). We give a short historical background of this research with a special emphasis on the importance of the descending monoaminergic systems.

KW - Action Potentials

KW - Animals

KW - Biogenic Monoamines

KW - Calcium Channels, L-Type

KW - Humans

KW - Locomotion

KW - Motor Neurons

KW - Neurotransmitter Agents

KW - Patch-Clamp Techniques

KW - Spinal Cord

KW - Spinal Cord Injuries

KW - Synaptic Transmission

KW - Journal Article

U2 - 10.2174/1381612811319240004

DO - 10.2174/1381612811319240004

M3 - Journal article

C2 - 23360269

SN - 1381-6128

VL - 19

SP - 4357

EP - 4370

JO - Current Pharmaceutical Design

JF - Current Pharmaceutical Design

IS - 24

ER -