Hippocampal basket cells target somata and proximal dendrites of pyramidal neurons. Like their counterparts in the cortex,hippocampal basket cells are also parvalbumin-expressing and fast-spiking. In the CA3 region of the hippocampus, basket cells can often form recurrent inhibition loops with pyramidal cells.  Projections from a pyramidal cell will innervate the basket cell, which in turn has a projection back onto the original pyramidal cells. Since basket cells are inhibitory, this generates a closed loop that can help dampen excitatory responses.
In the cortex, basket cells have sparsely branched axons giving off small pericellular, basket-shaped elaborations at several intervals along their length. There are three types of basket cells in the cortex, the small, large and nest type: The axon of a small basket cell arborizes in the vicinity of that same cell's dendritic range. In contrast, large basket cells innervate somata in different cortical columns. The nest basket cells are an intermediate form of the small and large cells, their axons are confined mainly to the same cortical layer as their somata.