Cover legend: A transverse section of a rat lumbar dorsal root ganglion stained with fluorescent markers to distinguish sensory neuron subpopulations involved in the pain pathway. Large myelinated mechanoreceptive neurons are positive for neurofilament-200 (green), while small neurons are divided into peptidergic (red) and non-peptidergic (blue) nociceptors expressing calcitonin gene-related peptide or isolectin B4, respectively. The image is overlaid with radioactive in situ hybridization for Kv9.1 mRNA (silver grains over cells), illustrating selective expression of this potassium channel subunit in large neurons, where it exerts a critical role in myelinated fiber hyperexcitability and chronic pain. For more information, see the article by Tsantoulas et al. (pages 17502–17513).