Combining loose cell-attached stimulation and recording.

Many synaptic-physiology experiments require selective stimulation of presynaptic neurones. No single method for achieving this is entirely satisfactory. Presynaptic whole-cell or microelectrode recordings offer outstanding control, but establishing such recordings of synaptically-connected neurones can be very time consuming. Minimal stimulation provides too little information regarding the condition and excitation of the presynaptic neurone(s). In the loose cell-attached configuration, it is possible both to stimulate individual cells and to record their action potentials, but most commercially-available equipment will not enable combining stimulation and recording. We demonstrate simultaneous loose cell-attached stimulation and recording of action potentials using a specially-designed patch-clamp amplifier. Since no tight seal is required, the method permits electrode re-use, thus enabling rapid screening of presynaptic cells while stimulating them selectively.