Space matters:: local and global dendritic Ca2+ compartmentalization in cortical interneurons

Dendrites of pyramidal neurons are complex, electrically active structures that can produce local and global Ca2+ compartments. Recent studies indicate that dendrites of cortical GABAergic interneurons are also highly specialized, and that different subtypes vary in their morphology, in their intrinsic and synaptic conductances and in the Ca2+ signals they generate. Because interneurons play a major role in oscillations, understanding their dendrites could offer key insights into rhythmogenesis. Different interneuron subtypes have different synaptic integration properties and generate differentially timed inhibition at distinct sites of the pyramidal neuraxis. In addition, interneuron dendrites generate diverse Ca2+ signals that reflect this circuit function and probably also implement subclass-specific plasticity and homeostasis.