Plasticity of the Axon Initial Segment: Fast and Slow Processes with Multiple Functional Roles

TY - JOUR

T1 - Plasticity of the Axon Initial Segment

T2 - Fast and Slow Processes with Multiple Functional Roles

AU - Petersen, Anders Victor

AU - Cotel, Florence

AU - Perrier, Jean François

PY - 2017

Y1 - 2017

N2 - The axon initial segment (AIS) is a key neuronal compartment because it is responsible for action potential initiation. The local density of Na+ channels, the biophysical properties of K+ channels, as well as the length and diameter of the AIS determine the spiking of neurons. These parameters undergo important modifications during development. The development of the AIS is governed by intrinsic mechanisms. In addition, surrounding neuronal networks modify its maturation. As a result, neurons get tuned to particular physiological functions. Neuronal activity also influences the morphology of the mature AIS. When excitatory neurons are hyperactive, their AIS undergo structural changes that decrease their excitability and thereby maintain the activity within a given range. These slow homeostatic regulatory mechanisms occur on a time scale of hours or days. In contrast, the activation of metabotropic receptors modulates the properties of ion channels expressed at the AIS within seconds and consequently produces fast adjustments of neuronal excitability. Recent results suggest that this plasticity plays important roles in physiological functions as diverse as memory formation, hearing, and motor control.

AB - The axon initial segment (AIS) is a key neuronal compartment because it is responsible for action potential initiation. The local density of Na+ channels, the biophysical properties of K+ channels, as well as the length and diameter of the AIS determine the spiking of neurons. These parameters undergo important modifications during development. The development of the AIS is governed by intrinsic mechanisms. In addition, surrounding neuronal networks modify its maturation. As a result, neurons get tuned to particular physiological functions. Neuronal activity also influences the morphology of the mature AIS. When excitatory neurons are hyperactive, their AIS undergo structural changes that decrease their excitability and thereby maintain the activity within a given range. These slow homeostatic regulatory mechanisms occur on a time scale of hours or days. In contrast, the activation of metabotropic receptors modulates the properties of ion channels expressed at the AIS within seconds and consequently produces fast adjustments of neuronal excitability. Recent results suggest that this plasticity plays important roles in physiological functions as diverse as memory formation, hearing, and motor control.

KW - action potential

KW - axon initial segment

KW - neuromodulation

KW - physiology

KW - plasticity

U2 - 10.1177/1073858416648311

DO - 10.1177/1073858416648311

M3 - Review

C2 - 27143656

AN - SCOPUS:85024479559

SN - 1073-8584

VL - 23

SP - 364

EP - 373

JO - Neuroscientist

JF - Neuroscientist

IS - 4

ER -