Figure 6.

Transfection of ventrolateral brainstem neurons following intracellular penetration in vivo. Once membrane potential had stabilized plasmid DNA encoding fluorescent protein was electrophoretically injected by −10 V pulses (50 × 1 ms pulses, 1 s). Membrane potential was retained after electrophoresis until withdrawal of the pipette (indicated by dashed lines). (A) Electrophysiological recording from a silent neuron that started firing after penetration. A’ shows EGFP‐labeled neuron recovered at the corresponding stereotaxic coordinates. (B) Slowly firing spontaneously active neuron: extracellular spikes (blue data, detailed in Bi.) were resolved prior to cell penetration (*). (B’) Colocalization of EGFP with ChAT immunoreactivity indicates that this example is a cholinergic motor neuron in nucleus ambiguus. (C + D) show examples of other neurons transfected using the same approach.