Cells recorded near DBH-positive (DBH⁺) neurons had significantly longer action potentials and afterpotentials than those recorded at a distance from DBH⁺ cells.

<p>A: the scheme explaining how the half-widths of action potentials and afterpotentials were measured. Two spike waveforms are superimposed, one typical of a cell with a fast action potential and another for a cell with a slow action potential. The histograms in B and C show that both the action potentials and afterpotentials had longer half-widths for the cells recorded at sites containing DBH⁺ neurons than for the cells located at a distance from such sites. Since the majority of cells that were activated were found in the rostral part of the explored region of the VLM and adjacent to DBH⁺ neurons, the spike duration data support the conclusion that most of the cells activated during REMS-like episodes were the adrenergic cells of the C1 group.