What is the perisomatic region of a neuron? In the scholarpedia page on interneurons I encountered the following passage: > The **perisomatic domain** is responsible for the summation of postsynaptic potentials arriving from all dendritic branches [...]. Thus, **the perisomatic region** \- and particularly the axon initial segment [...] plays a crucial role in the generation of output. The page, however, does not define what the perisomatic region really is. **What comprises the perisomatic region of an interneuron?**

In cortical GABAergic cells with local axonal projections, the perisomatic region is defined as that part of the plasma membrane including the proximal dendrites, the cell body and the axon initial segment (Zabó _et al_., 2010).

**Reference**
**-** Zabó _et al_., _Eur J Neurosci_ (2010); **31** (12): 2234–46