ATXN2 and autosomal dominant cerebellar ataxia: We reasoned that if calcium levels were responsible for enhancing mGluR responses in SCA PNs, then buffering basal calcium concentration at a physiological level (~140 nM) might prevent the increase in mGluR function observed in SCA2 PNs and conversely that buffering calcium at elevated levels (~450 nM) in WT PNs might mimic the enhancement observed in SCA2 PNs.