In the cerebral cortex the constant computation of incoming sensory information is dynamically integrated to provide a coherent representation of the world and generate highly sophisticated cognitive functions. Cortical circuits are made of different neuron types connecting one another through a staggering number of synaptic connections that are responsible for the propagation of information between neurons. The result is the generation of complex functional networks, whose specific activities often produce a wide range of synchronous rhythms, believed to provide the computational substrate for different aspects of cognition. In this context, a tight balance between excitation and inhibition is fundamental for correct brain functioning, as serious neurological and psychiatric diseases can develop when this equilibrium is altered.
Among all cell types, inhibitory cortical neurons (also known as interneurons, which use GABA as neurotransmitter) are highly heterogeneous. In particular, we are focused on (i) how different types of neurons of the cerebral cortex connect one another; (ii) how specific cell types produce different forms of synaptic transmission and plasticity; and (iii) how specific synaptic properties contribute generating various forms of network oscillations. Indeed, GABAergic neurotransmission is fundamental for integrating and filtering incoming information as well as for dictating postsynaptic neuronal spike timing, therefore providing a tight temporal code used by each neuron, or ensemble of neurons, to perform sophisticated computational operations. Altogether, results of these experiments will lead to a better understanding of GABAergic interneuron regulation of neocortical excitability, relevant to both normal and pathological cortical function.