An in vivo mouse spinal cord preparation for patch-clamp analysis of nociceptive processing

The laboratory mouse is now considered the preferred mammalian species for molecular and genetic analysis in neurobiology. In part, this is due to the existence, in the mouse, of several well characterised naturally occurring mutations in ligand gated ion channels and recent knockout, knockin, and transgenic techniques, which facilitate the manipulation of key molecules. These techniques have recently been applied to pain research with in vitro electrophysiological and behavioural techniques traditionally developed for the rat, now being adapted for the mouse particularly at the level of the spinal cord. Here, we describe an in vivo preparation of the mouse spinal cord for patch-clamp recording of nociceptive processing in the superficial dorsal horn (SDH) that permits analysis in the intact nervous system. We have recorded from SDH neurons and characterised their background synaptic activity, discharge properties, and evoked synaptic responses following controlled application of innocuous and noxious stimuli to the hind paw. Application of these techniques along with genetic, biomolecular, in vitro and behavioural approaches will allow future studies to comprehensively analyse the contributions of specific molecules involved in nociceptive processing in the spinal cord of a single species.