A role for BDNF in the late-phase of hippocampal long-term potentiation

The neurotrophin family of growth factors has received enormous attention recently for its role in modulating synaptic strength in the developing and adult nervous system. Several recent studies have indicated a role for brain-derived neurotrophic factor (BDNF) in long-term potentiation (LTP), a form of long-lasting plasticity observed at synapses in the hippocampus and other brain areas. The late-phase (L-LTP; e.g. > 2 h) of LTP has been shown to require the synthesis of new proteins. We have examined whether BDNF or other TrkB ligands participate in L-LTP in two ways: by examining transgenic mice which lack BDNF or by acutely blocking TrkB function using function-blocking antibodies. Slices from BDNF knock-out animals or slices treated with TrkB antibodies failed to exhibit L-LTP, indicating that TrkB ligands participate in extending synaptic enhancement from a short-lasting to a long-lasting form.