“…Therefore, endogenous GH/IGF-I axis or exogenously administered GH or IGF-I act in neuroprotection, neurogenesis, angiogenesis, and synaptogenesis [ 22 , 34 , 35 , 36 , 37 , 38 , 39 ], as well as modulate neurotransmission through the synuclein (SYN) signal [ 36 ] and increases key mechanisms for a series of brain functions [ 28 , 37 , 38 , 39 ] and brain repair after an injury [ 34 , 36 , 37 ]. These reasons led to the use of GH or IGF-I in different models of brain injuries [ 34 , 35 , 36 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 ]. Regardless of the fact that TBI can produce GH-deficiency (GHD) [ 42 ], which contributes to the cognitive sequelae associated with TBI [ 43 ], and GH treatment in rats after TBI improves their cognitive, motor and behavioral activities [ 45 , 46 , 47 ].…”