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. Author manuscript; available in PMC: 2013 Dec 13.
Published in final edited form as: Neuroscience. 2012 Sep 19;226:165–177. doi: 10.1016/j.neuroscience.2012.09.028

Figure 6. Density of Neuronal Nitric Oxide Synthase (nNOS) Neurons in Ventral Periaqueductal Gray with Pharmacological Treatment.

Figure 6

Graphs in Panels A and A’ show average density (#profiles/section/brain ± SD) of nNOS immunoreactive neurons, while Panels B and B’ show average density of nNOS neurons double-labeled (DL) with Fos following different pharmacological treatment: control, acute morphine, and chronic morphine both in the PD7 (A and B) and the adult rat (A’ and B’). There was no statistically significant difference in density of nNOS neurons in different anatomical regions following different pharmacological treatment for either PD7 or adult rat. Very few double-labeled neurons (nNOS neurons with Fos nuclei) were identified in the adult rat that did not change among the different treatment groups. Double-labeling in the PD7 rat was negligible. (C and C’) Average intensity of nNOS immunolabeling per individual neuron in the cluster of nNOS immunoreactive neurons with treatment. Region of analysis included nNOS neurons at inferior colliculus (shown in Fig. 1B) of PD7 and the adult rat. No changes were found in PD7 rats among different treatment (F(2, 12)=0.59, p=0.57; C). In the adult rat, percent (%) increase from control of average intensity of nNOS immunoreactive labeling per neuron in chronic morphine group was significantly increased (26%; F(2,15)=10.4; p=0.001; C’) when compared to control (p=0.02) and acute morphine groups (p=0.02). Asterisk (*) indicates p<0.05, significant difference.