In this study, authors claimed that 5-HT6 receptor inverse agonists (SB258585, PZ-1386, PZ-1388, and PZ-1179) effectively alleviate pain in female rats with STZ-induce T1D for at least 60–90 minutes. As 5-HT6 receptors are associated with the mTOR pathway to mediate mechanical hypersensitivity, the authors intrathecally administered the mTOR pathway inhibitor Rapamycin and found it exerted analgesic effect in STZ-T1D female rats for at least 120 minutes. Blocking 5-HT6 receptor-mTOR pathway interaction with Tat-VEPE peptide similarly alleviated pain in STZ-T1D female rats. Further, authors showed that PZ-1386, SB258585, Rapamycin, and Tat-VEPE improved episodic memory in STZ-T1D female rats. In a ketamine-induced cognitive impairment model, PZ-1386 appeared to mitigate diabetes-associated cognitive decline by directly alleviating pain. Finally, authors utilized 5-HT6-GFP kI mice to examine potential sex-based differences in 5-HT6 receptor expression in the spinal cord, revealing no significant differences in 5-HT6 receptor expression in primary cilia of the spinal dorsal horn between sexes.

Advice：
In the supplementary materials, it would be beneficial to include tables presenting the Area under the Curve (A.U.C.) of vocalization threshold variations for both male (Mokhtar et al. 2023a) and female rats with STZ-T1D under the same drug dosages. This addition would allow readers to easily compare the efficacy of different drugs in alleviating pain across sexes.

Additional experiments required:
1. Western blot analysis to assess mTOR pathway activation in the spinal cord of STZ-T1D female rats before and after treatment with 5-HT6 receptor inverse agonists.

Using a streptozotocin (STZ)-induced diabetic rat model in female subjects, this study comprehensively evaluated the therapeutic effects of a 5-HT6 receptor inverse agonist on neuropathic pain and associated cognitive dysfunction. Mechanistic investigations revealed mTOR pathway modulation as the underlying therapeutic mechanism. The rigorous experimental design and robust data address a critical knowledge gap in sex-specific neuropathic pain mechanisms, offering valuable implications for precision medicine approaches.