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. Author manuscript; available in PMC: 2010 May 1.
Published in final edited form as: Neuropharmacology. 2009 Mar 3;56(6-7):1017–1026. doi: 10.1016/j.neuropharm.2009.02.005

Fig. 5.

Fig. 5

Effects of CTAP on paw withdrawal latency (PWL) in saline- and CFA-treated rats. Top panels: Coadministration of 33 ng CTAP antagonizes the antinociception produced by microinjection of 1 ng DAMGO in the locus coeruleus (LC) in saline-treated rats. Microinjection of this dose of CTAP alone in the LC does not alter PWL compared to the effects of saline alone. Bottom panels: In CFA-treated rats, microinjection of 33 ng CTAP alone into the LC does not exacerbate thermal hyperalgesia in the ipsilateral hindpaw, nor does it produce hyperalgesia in the contralateral hindpaw of CFA-treated rats compared to the effects of saline. The antagonism of the anti-hyperalgesic effect of 1 ng DAMGO in the ipsilateral hindpaw of CFA-treated rats by CTAP did not achieve statistical significance (p = 0.06; two-tailed t-test). Each bar is the mean ± S.E.M. of determinations in 4–7 rats. * p < 0.05, ** p < 0.01 compared to 1 ng DAMGO at the corresponding time point. Horizontal dashed lines delineate the upper and lower 1 SD from the mean baseline PWL determined for all rats immediately before microinjection of drug in the LC. Data are values determined 15 min after microinjection, the time of peak effect for all agents.