FIGURE 1.

Optical and mechanical signals recorded independently from the neurosecretory terminals of three mouse neurohypophyses in response to trains of stimuli delivered at 15 Hz. (A) Action potentials recorded optically (−ΔF) using the fluorescent potentiometric dye di-4-ANEPPDHQ. (B) Light-scattering changes recorded as changes in transmission (−ΔI) in response to an identical stimulus in an unstained preparation. (Increase in transmitted light intensity is plotted downward.) (C) Mechanical events triggered by action potentials, monitored with a modified HBAFM. The inset shows the first mechanical spike and dip from this train on an expanded time base. All traces were low-pass filtered at 1 kHz.