Figure 4.
Effects of pharmacological manipulation of VTAPBP on dural-evoked and spontaneous neuronal firing in the trigeminocervical complex (TCC).
(a) Time course changes in the average response of dural-evoked Aδ-fiber trigeminal neuronal firing following microinjection of glutamate (n = 8) and bicuculline (n = 11), which significantly decreased neuronal responses by a maximum of 38% and 23%, respectively. (b) Time course of ongoing spontaneous trigeminal neuronal firing in response to glutamate (n = 8), which significantly decreased neuronal responses by a maximum of 68% at 5 min and then recovered, and bicuculline (n = 11), which had no significant effect compared to pre-injection levels. (c) Time course of the average response of intracranial dural-evoked Aδ-fiber trigeminal neuronal firing following microinjection of naratriptan (n = 8), PACAP38 (n = 7) and quinpirole (n = 8), which significantly decreased neuronal responses by a maximum of 39%, 30% and 18%, respectively and (d) Time course of spontaneous trigeminal neuronal firing in response to naratriptan (n = 8), PACAP38 (n = 7) and quinpirole (n = 8), which significantly decreased neuronal responses by a maximum of 61%, 60% and 33%, respectively. In all panels vehicle control (n = 12) had no significant effects of neuronal responses. Data have been normalized to represent the percentage change from baseline, and are expressed as means ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.