Updated project metadata. Two mouse models were developed that expressed mutated human alpha synuclein under the control of endogenous murine αSyn (mαSyn) regulatory regions. The expression of the mαSyn was thereby abolished. The genetically ingeneered mice expressed either human αSyn (hαSyn) with a C-terminal deletion ending hαSyn at amino acid 119 or hαSyn with 3 alanine to proline substitutions at residues 30, 56, and 76. Here we tested the expression of different αSyn variants in the hippocampus of respective mouse models and their parental lines.