Figure 6. Depression of expiratory neuronal discharges during activation of 5-HT-1A receptors.

Results shown in A and B were obtained from two different animals. Recordings illustrate membrane potential (V_m) of expiratory neurones in the caudal ventral respiratory group and phrenic nerve activity (PN). A, apnoea was produced by i.v. injection of 8-OH-DPAT (20 μg kg⁻¹). B, a similar apnoeic response was produced by injecting 8-OH-DPAT (0.23 nmol; 50 μm solution) into the ipsilateral pre-Bötzinger complex (PBC). Recovery was complete after 20 min in each test.