Figure 6
A CRF1 receptor antagonist reverses CRF-induced increases of audible vocalizations and spinal reflexes. Administration of CRF (1 μM, concentration in microdialysis fiber) into the CeLC increased the duration of audible (A) and ultrasonic (B) vocalizations (voc.) evoked by innocuous (500 g/30 mm2) and noxious (2000 g/30 mm2) stimulation of the knee (n = 6 rats). (C) CRF decreased reflex thresholds for mechanical stimulation of the knee (n = 5 rats). Behaviors were measured at 15 and 30 min of CRF administration. The effects of CRF persisted during continued administration. (D,E) Coapplication of a CRF1 receptor antagonist (NBI27914, 100 μM, concentration in microdialysis probe, 15 min) with CRF decreased CRF-enhanced audible and ultrasonic vocalizations significantly (n = 6 rats). (F) NBI27914 also inhibited the CRF effect on spinal reflex thresholds (n = 5 rats). Bar histograms show means ± SEM. *,**,*** P < 0.05-0.001, compared to predrug (ACSF) before CRF; #,##,### P < 0.05-0.001, compared to CRF (15 min time point); Bonferroni posttests.