Activation of the Mammalian Target of Rapamycin in the Rostral Ventromedial Medulla Contributes to the Maintenance of Nerve Injury-Induced Neuropathic Pain in Rat

Figure 4

p-mTOR was mainly colocalized with 5-HTergic neurons in the RVM, and the number of 5-HT-positive p-mTOR neurons was significantly increased 7 days after SNI. (a)–(f) Representative fluorescence photomicrographs showing the expression of 5-HT (green) and p-mTOR (red) double-labeled neurons in the RVM in the sham control (a–c) versus the SNI 7-day group (d–f). Single arrows indicate p-mTOR/5-HT double-labeled (yellow) neurons. Scale bars = 100 μm. (g) The average number of 5-HT-positive p-mTOR neurons per section increased significantly in the SNI rats 7 days after surgery compared to the sham (). (h) In contrast, the average number of 5-HT-negative p-mTOR neurons did not change after SNI ( rats/group).

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