N-acetyl cysteine ameliorates depression-induced cognitive deficits by restoring the volumes of hippocampal subfields and associated neurochemical changes.
Neurochem Int. 2020 Jan ;132:104605. Epub 2019 Nov 18. PMID: 31751620
Depression is highly comorbid with anxiety disorders and associated with profound cognitive impairment. Moreover, cognitive deficits associated with hippocampal dysfunction are central in depression and anxiety disorders. Furthermore, depression is accompanied by glutamatergic dysfunction which can further impair the functioning of the hippocampus. Recent studies have shown that N-acetyl cysteine (NAC), a glutamate modulator produces an antidepressant-like effect by normalization of the periterminal release of glutamate and/or antioxidant effects. However, the effects of repeated NAC treatment on depression-induced anxiety, cognitive deficits, and associated neurochemical and structural alterations are relatively unknown. Accordingly, we investigated whether chronic NAC treatment could reverse cognitive deficits, and associated hippocampal volume loss and monoaminergic alterations in the neonatal clomipramine (CLI) model of depression. We found that chronic NAC treatment produces antidepressive and antianhedonic-like effects. NAC treatment also reversed CLI-induced anxiety. Interestingly, repeated NAC treatment improved the performance of CLI rats in rewarded alternation task in T-maze. The antidepressive-like and procognitive effects of NAC was associated with normalization of volume loss in CA1, dentate gyrus (DG) and hilar subfields of the hippocampus. Furthermore, NAC restored CLI-induced decrease in levels of monoamines and normalized enhanced metabolism in the hippocampus. Taken together, chronic NAC treatment ameliorates depressive and anxiety-like behavior, spatial learning deficits, and reverses CLI-induced pathological alterations at structural and neurochemical levels in the hippocampus. Our findings might help in evolving NAC as a viable pharmacotherapy for reversal of cognitive deficits in depression and associated disorders.