GIRK1-LI in L4-5 segments of control spinal cord. A GIRK1-LI in the L4-5 spinal cord at low magnification. B GIRK1-LI in the dorsal horn (DH). GIRK1-IR processes are mainly present in superficial layers. NeuN-LI (here and below) is used to identify neurons. B1–B2 Double-staining shows the distribution of GIRK1-IR cell bodies in different DH laminae, from the superficial to deep layers. C GIRK1-IR multipolar neurons are seen both in white matter and deep DH layers at the white matter border. D GIRK1 is extensively expressed in ventral horn (VH) neurons, in lamina VI to IX, and around the central canal (lamina X). D1 High magnification image shows the typical expression pattern of GIRK1-LI in a VH neuron. E, F A few GIRK1+ neurons in DH show dot-like immunoreactivity in soma (solid arrowheads) and processes (open arrowheads). (G–G2) CGRP+ motor neurons (G1) express GIRK1 (G). (H–H2) GIRK1-LI (H, H2) and CGRP-LI (H1, H2) show only limited overlap. (I–I2) GIRK1-LI (I) overlaps with PV-LI (I1) in inner lamina II (I2). Scale bars indicate 500 μm (A), 200 μm (D, G–G2), 100 μm (B, H–I2), 20 μm (B1, B2, C, D1, E), 10 μm (F).