Figure 1.

Schematic illustration of pro-BDNF/mBDNF ratio in normal brain and in Alzheimer’s disease (AD). (A) In a physiological condition, BDNF-TrkB signalling exerts protective effects, improving hippocampal long-term potentiation (LTP) and synaptic plasticity and promoting neuronal survival. (B) In AD, the alteration of pro-BDNF/mBDNF ratio and the accumulation of pro-BDNF leads to the activation of p75^NTR signalling pathway involved in programmed cell death, activation of long-term depression (LTD), and the biogenesis of Ab amyloid protein (amyloidogenesis), promoting neuronal damage.