Global and local synaptic regulation determine the stability of homeostatic plasticity

TL;DR

This paper investigates how neurons use local and global feedback mechanisms to regulate synaptic components, ensuring stable electrical activity and input normalization, with analysis showing their coexistence and complex interactions.

Contribution

It provides a formal proof of the coexistence of local and global homeostatic mechanisms under certain conditions and analyzes their interplay through simulations.

Findings

Global and local homeostasis can coexist with sufficient timescale separation.

Activity-dependent degradation can both stabilize and destabilize neuron performance.

Simulations reveal bidirectional effects of feedback mechanisms on stability.

Abstract

Neurons regulate the distribution of signaling components across an extended tree-like cellular structure using both local and global feedback control. This is hypothesized to allow homeostatic control of the electrical activity of a neuron and at the same time enable normalization of distribution of inputs received from other cells. The performance and robustness of these mechanisms are poorly understood, and are subject to nonlinearities, making their analysis difficult. Firstly, we formally show that global homeostasis of electrical activity and local activity-dependent degradation can coexist under sufficient timescale separation. The interplay of the two feedback mechanisms is also analyzed through simulations, which reveal a bidirectional effect (stabilizing and destabilizing) of activity-dependent degradation on the overall neuron performance.