(A, B) No significant alterations in either isoform of BDNF are observed in HP, CTX, and STR when animals are 2 months old. (C, D) Decrease of mBDNF without upregulation of proBDNF in the striatum of zQ175 heterozygous and homozygous mice compared with wild type (WT) mice at 6 months of age. proBDNF level decreases while no change of mBDNF level is detected in both HP and CTX. (E, F) Total BDNF levels of both CTX and STR reduce significantly in zQ175 heterozygous and homozygous mice when animals are 12 months old. proBDNF is not induced in either CTX or STR, and there is a decrease of proBDNF level in HP lysates of zQ175 mice compared to WT.