Figure 2.

BDNF secretion depends on the neuronal output rather than synaptic inputs. Supra-threshold excitatory postsynaptic potentials (EPSPs) trigger action potentials that back-propagate (b-APs) from the soma to the dendrites. Center: the b-APs induced BDNF secretion and synaptic strengthening. Left: this process can be reinforced by conditions that facilitate the back propagation of APs such as the neuromodulatory action of ACh. Right: when the same supra-threshold glutamatergic activity is generated in a context that prevents APs backpropagation, such as a concomitant activation of dendritic inhibition (GABA), BDNF secretion and synaptic strengthening will not occur.