Plasticity and stability of hippocampal circuits: From basic principles to malfunctions

Maintaining average activity level within a set-point range constitutes a fundamental property of central neural circuits. Accumulated evidence suggests that mean firing rate (MFR), reflecting an average level of spontaneous spiking activity over extended timescales, represents a physiological variable regulated by homeostatic systems in central neural circuits. However, some central questions have remained open. What are the mechanisms that establish the specific values of MFR set-points? Are MFR set-points dysregulated in brain disorders? And finally, whether re-adjustment of dysregulated firing set-points may provide a new conceptual way to treat brain disorders associated with aberrant network activity? I will show our new results on regulation of MFR set-points in hippocampal circuits ex vivo and in vivo in physiological and pathological conditions.