MTOR and Cognitive impairment: Recently, 5-HT6 receptor inverse agonists [53,54], including SB258585 (first described as a neutral antagonist [55], and also rapamycin (mTOR inhibitor), was shown to reverse mechanical hyperalgesia and reduce cognitive co-morbidities in STZ diabetic rats, demonstrating the role of the constitutive activity of 5-HT6 receptors in diabetic neuropathic pain and associated cognitive deficits and that of mTOR activation by constitutively active 5-HT6 receptors [56].