Proneurotrophin Binding to P75 Neurotrophin Receptor (P75ntr) Is Essential for Brain Lesion Formation and Functional Impairment after Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) initiates an excessive mediator release of e.g. neurotrophins, which promote neuronal survival, differentiation, and modulate synaptic plasticity. Paradoxically, mature forms of neurotrophins promote neuronal survival, whereas unprocessed forms of neurotrophins induce cell death through p75 neurotrophin receptor (p75NTR) signaling. p75NTR is widely expressed during synaptogenesis and is subsequently downregulated in adulthood. Repair mechanisms after acute cerebral insults can reactivate its expression. Therefore, the influence of p75NTR on secondary brain damage was addressed. mRNA levels of p75NTR and its ligands were quantified in brain tissue up to 7 days af…