Fig. 6.

Inhibition of neurons in the rRPa eliminates spontaneous tail CVC neuronal activity and prevents tail CVC neuron activation by PGE₂ in the POA. Spike frequency record of a tail CVC neuron illustrates elimination of spontaneous CVC neuronal activity following MUSC into rRPa (arrowhead). Left inset: average of 30 spontaneous CVC neuron action potentials prior to MUSC in rRPa (trace duration, 5.5 ms; peak amplitude, 30 μv). Subsequent PGE₂ into the POA (arrowhead) failed to evoke tail CVC neuronal activity. Single electrical stimuli (stim rRPa, between arrowheads) in the rRPa evoked CVC neuron action potentials (right inset: average of 30 stimulus-evoked CVC neuron action potentials, trace duration: 5.5 ms, peak amplitude, 23 μv), indicating that the CVC neuronal recording was maintained. Transections (TRANS X) at bregma −2 mm and −4 mm did not evoke tail CVC neuron activity after MUSC into the rRPa.