Inna Slutsky, Tel Aviv University

Maintaining the balance between stability and plasticity in hippocampal networks

How neuronal circuits maintain the balance between stability and plasticity in a constantly changing environment remains a fundamental question in neuroscience. Empirical and theoretical studies suggest that homeostatic negative feedback mechanisms operate to stabilize the function of a system at a set point level of activity. While extensive research uncovered diverse homeostatic mechanisms that maintain activity of neural circuits at extended timescales, several key questions remain open. First, what are the basic principles and the molecular machinery underlying invariant population dynamics of neural circuits, composed from intrinsically unstable activity patterns of individual neurons? Second, does aberrant brain activity, associated with distinct types of neurodegenerative disorders, result from failures of homeostatic control system? To target these questions, we have developed an integrative approach to study the relationships between ongoing spiking activity of individual neurons and neuronal populations, inhibition-excitation balance, intrinsic excitability of neurons and signaling processes at the level of individual hippocampal synapses ex vivo. I will describe the basic relationships between ongoing spiking properties of individual neurons, population dynamics and neuronal adaptive mechanisms.