Making in situ whole-cell patch-clamp recordings from Xenopus laevis tadpole neurons

Xenopus laevis tadpoles have been an excellent, simple vertebrate model for studying the basic organization and physiology of the spinal cord and motor centers in the brainstem. In the past, intracellular recordings from the spinal and brainstem neurons were primarily made using sharp electrodes, although whole-cell patch-clamp technology has been around since the early 1980s. In this protocol, I describe the dissections and procedures needed for in situ whole-cell patch-clamp recording, which has become routine in tadpole neurophysiology since the early 2000s. The critical step in the dissections is to delicately remove some ependymal cells lining the tadpole neurocoele in order to expose clean neuronal somata without severing axon tracts. Whole-cell recordings can then be made from the somata in either current- or voltage-clamp mode.