When an Axon Is Severed, What Likely Causes the Presynaptic

question 52

Multiple Choice

When an axon is severed, what likely causes the presynaptic cell to withdraw axons?

• A) The postsynaptic neuron dying, initiating apoptotic cascades
• B) The postsynaptic neuron condensing, and widening the synapse to pull axons away
• C) Invading macrophages crowding into the synapse, effectively pushing the presynaptic neuron away
• D) The de-differentiation of Schwann cells pulling the postsynaptic neuron away
• E) Both the pre- and postsynaptic neurons expressing repulsive cues, such as Slit and its Robo receptor