Spinocerebellar ataxia type 1 (SCA1) is a fatal neurodegenerative disease caused by expansion of a translated CAG repeat in Ataxin-1 (ATXN1). To determine the long-term effects of exercise, we implemented a mild exercise regimen in a mouse model of SCA1 and found a considerable improvement in survival accompanied by upregulation of epidermal growth factor and consequential downregulation of Capicua, an ATXN1 interactor. Offspring of Capicua mutant mice bred to SCA1 mice showed significant improvement of all disease phenotypes. Although polyglutamine-expanded Atxn1 caused some loss of Capicua function, further reducing Capicua levels, either genetically or by exercise, mitigated the disease phenotypes. Thus, exercise might have long-term beneficial effects in other ataxias and neurodegenerative diseases.

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Neuropathology of resected brain tissue has revealed an association of focal cortical dysplasia (FCD) with drug resistant epilepsy (DRE). Recent studies have shown that the mechanistic target of rapamycin (mTOR) pathway is hyperactivated in FCD as evidenced by increased phosphorylation of the ribosomal protein S6 (S6) at serine 240/244 (S240/244), a downstream target of mTOR. Moreover, extracellular regulated kinase (ERK) has been shown to phosphorylate S6 at serine 235/236 (S235/236) and tuberous sclerosis complex 2 (TSC2) at serine 664 (S664) leading to hyperactive mTOR signaling. We evaluated ERK phosphorylation of S6 and TSC2 in two types of FCD (FCD I and FCDII) as a candidate mechanism contributing to mTOR pathway dysregulation in this disorder. Tissue samples from patients with tuberous sclerosis (TS) served as a positive control. Immunostaining for phospho-S6 (pS6240/244 and pS6235/236), phospho-ERK (pERK), and phospho-TSC2 (pTSC2) was performed on resected brain tissue with FCD and TS. We found increased pS6240/244 and pS6235/236 staining in FCD I, FCD II, and TS compared to normal appearing tissue, while pERK and pTSC2 staining was increased only in FCD IIb and TS tissue. Our results suggest that both the ERK and mTOR pathways are dysregulated in FCD and TS; however, the signaling alterations are different for FCD I as compared to FCD II and TS.