Fig. 3.

Morphological and electrophysiological diversity within a neurochemically-defined population lamina II neurons. Targeted whole-cell patch-clamp recordings were carried out in spinal cord slices maintained in vitro from a transgenic mouse line where enhanced green fluorescent protein (eGFP) was expressed in calretinin (CR) interneurons. (a) The distribution of eGFP-labelled cells mirrors that of calretinin cells labelled using immunohistochemical approaches (CR-IR). (b) Five distinct action potential firing patterns were recorded in eGFP cells from lamina II. (c) The morphological features of recorded neurons were also determined, with five morphologically distinct groups being recorded, as well as a group of unclassified cells. The only correlation between morphology and firing pattern that could be established was that cells with tonic-firing discharge patterns were always islet cells (and all islet cells were tonic firing). Modified from reference 45