Whole cell recordings from respiratory neurones in an arterially perfused in situ neonatal rat preparation.

For synaptic and cellular analyses of the mammalian respiratory network, intracellular recording and good pharmacological access to respiratory neurones is required. Using an existing arterially perfused in situ preparation of neonatal rat, we report on a method allowing stable intracellular recordings of ventrolateral medullary respiratory neurones. The in situ preparation generates a recognizable eupnoeic respiratory motor pattern similar to that reported in vivo. Using this preparation, we have developed a methodology for the use of patch pipettes to record from neurones within the ventral respiratory group. This technique in the arterially perfused neonatal rat is novel and has the advantage that neurones can be recorded from an intact and well-oxygenated brainstem in which the pontine regions are known to be viable. We describe the methods, present the first whole cell recordings of numerous types of respiratory neurones from neonatal rats in such a preparation, and demonstrate the applicability of the model for neuropharmacological experiments.