by ELISA (MMP-9 and BDNF – R&D Systems Inc., Minneapolis, USA; pro-BDNF –
Aviscera Bioscience, Santa Clara, CA, USA) according to the manufacturer’s
protocol. A total of 30 μg/μl of protein from each plasma sample
was diluted 70-fold (MMP-9) or 20-fold (BDNF and pro-BDNF) with calibration
diluent from the assays and analyzed in duplicate. The optical density of wells
was measured at 450 nm using an automated microplate reader (Sunrise Microplate
Absorbance Reader).