text: <unk> s are a family of tyrosine kinases that regulates synaptic strength and plasticity in the mammalian nervous system.<unk> s affect neuronal survival and differentiation through several signal cascades. However, the activation of these<unk> s also has significant effects on functional properties of neurons.
  The common ligands of<unk> s are neurotrophins, a family of growth factors critical to the functioning of the nervous system. The binding of these molecules is highly specific. Each type of neurotrophin has different binding affinity toward its corresponding<unk> . The activation of<unk> s by neurotrophin binding may lead to activation of signal cascades resulting in promoting survival and other functional regulation of cells.
option_0: Trk receptor
option_1: AMPA receptor
option_2: P2X receptor
option_3: 5-HT receptor
option_4: NMDA receptor
option_5: Eph receptor
option_6: Baroreceptor
option_7: Opioid receptor