In HF-LTPi the high-frequency stimulation may promote a BDNF-dependent increase in inhibitory synaptic conductance through modulation of presynaptic release probability (Figure 1(b), left panel) [14], while the lower frequency of stimulation required by STD-LTDi induction may favor BNDF-dependent downregulation of the KCC2 transporter [42]. Here, BDNF is linked to hydrops fetalis.