“…Initial physiological studies of these neurons had indicated that they were glutamatergic and excitatory (Aungst et al, 2003); however, subsequent studies demonstrated that they are GABAergic and dopaminergic (Liu et al, 2013), and indeed probably constitute one extreme of a single morphologically heterogeneous class of interneurons that includes periglomerular cells (Kiyokage et al, 2010;McGann, 2013;Sethupathy et al, 2013). This is interesting because recent work has shown that, despite their GABAergic phenotype, sSA cells are clearly the effectors of a functionally excitatory lateral network that results in the broad and graded inhibition of mitral cells (Marbach and Albeanu, 2011). This lateral excitatory effect across the sSA network potentially could arise via gap-junction coupling among sSA and periglomerular cells, or by rendering GABAergic synapses onto periglomerular and sSA cells excitatory owing to a reversed chloride gradient in these neurons.…”