SHANK1 and post-traumatic stress disorder: An additional layer of confirmation is provided by a PET study showing significantly higher availability of metabotropic glutamate receptor 5 (mGluR5) in the PFC and ventral striatum of PTSD patients, a finding that was corroborated by upregulation of the expression of SH3 And Multiple Ankyrin Repeat Domains 1 (SHANK1), which anchors mGluR5 to the cell surface [192].