POSTER PRESENTATION Open Access Functional requirements for homeostatic inhibitory plasticity in recurrent networks

Homeostatic regulation of neuronal firing rates has been reliably observed in response to chronic manipulation of neural activity. From such experiments a variety of puta-tive homeostatic mechanisms have been reported, includ-ing compensatory changes for several synapse types [1]. Unfortunately, it is sometimes unclear whether these synaptic changes occur in response to persistent rate deviations in individual neurons (local control) or in larger populations (global control). One variant of the former type is the recently proposed Hebbian learning rule of Vogels et al., which modifies inhibitory-to-excitatory synapses to maintain a target rate in each postsynaptic cell [2]. Since this rule asserts its control by changing inhibi-tion, one might expect that in recurrent networks, similar synaptic plasticity rules elsewhere within the inhibitor