(A) The expression of β-1,4-GalT-I in cortex and hippocampus [E1, β-1,4-GalT-I; N, normal group (n=6); M, non-PQQ TBI group (n=6); 5, TBI+PQQ 5 mg/kg per day group (n=6); 7, TBI+PQQ 7 mg/kg per day group (n=6); 10, TBI+PQQ 10 mg/kg per day group (n=6)]. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was the internal reference. Results are shown as the mean±standard error of the mean (SEM) and represent three independent experiments [#p<0.05 versus normal (n=6)]. (B) The expression of β-1,4-GalT-V in cortex and hippocampus [E5, β-1,4-GalT-V; N, normal group (n=6); M, non-PQQ TBI group (n=6); 5, TBI+PQQ 5 mg/kg per day group (n=6); 7, TBI+PQQ 7 mg/kg per day group (n=6); 10, TBI+PQQ 10 mg/kg per day group (n=6)]. GAPDH was the internal reference. Results are shown as the mean±SEM and represent three independent experiments [#p<0.05 versus normal (n=6); PQQ, pyrroloquinoline quinine; TBI, traumatic brain injury; β-1,4-GalT-I, β-1,4-galactosyltransferase I; β-1,4-GalT-V, β-1,4-galactosyltransferase V].