Fig. 1.

A and B: segments of original recordings and spike discriminator output demonstrating a single-unit discharge from rostral ventrolateral medulla (RVLM)-projecting PVN (PVN-RVLM) neuron. C: this neuron (a–c) was identified as a PVN-RVLM neuron with consistent onset latency using the collision test; a: neuronal activity with constant latency (31 ms) antidromic spikes evoked by stimulation of RVLM; b: RVLM stimulation evoked an antidromic spike that was cancelled when the interval between spontaneous action potentials and stimulation was reduced to <30 ms; and c: high-frequency (333 Hz, 3 ms) following test. All segments, a–c, represent 2 superimposed sweeps: ↓, electric stimulation; ●, spontaneous action potentials; #, stimulus artifacts; ○, antidromic spikes.