Cell-type specificity of neuronal excitability and morphology in the central amygdala

ABSTRACT Central amygdala (CeA) neurons expressing protein kinase C delta (PKCδ + ) or Somatostatin (Som + ) differentially modulate diverse behaviors. The underlying features supporting cell-type-specific function in the CeA, however, remain unknown. Using whole-cell patch-clamp electrophysiology in acute mouse brain slices and biocytin-based neuronal reconstructions, we demonstrate that neuronal morphology and relative excitability are two distinguishing features between Som + and PKCδ + CeLC neurons. Som + neurons, for example, are more excitable, compact and with more complex dendritic arborizations than PKCδ + neurons. Cell size, intrinsic membrane properties, and anatomical localization were further shown to correlate with cell-type-specific differences in excitability. Lastly, in the context of neuropathic pain, we show a shift in the excitability equilibrium between PKCδ + and Som + neurons, suggesting that imbalances in the relative output of these cells underlie maladaptive changes in behaviors. Together, our results identify fundamentally important distinguishing features of PKCδ + and Som + cells that support cell-type-specific function in the CeA.