Question

The induction of long-term potentiation occurs in?

1) the presynaptic neuron.
2) the synapse.
3) the postsynaptic neuron.
4) the motor neuron.
5) both the pre- and postsynaptic neurons.

Answer 1

Long-term potentiation (LTP) primarily takes place in the postsynaptic neuron, where calcium entry following postsynaptic depolarization leads to the insertion of more AMPA receptors, enhancing synaptic strength.

Step-by-step explanation:

Induction of Long-term Potentiation (LTP)

Long-term potentiation (LTP) is a form of synaptic plasticity and involves the persistent strengthening of synapses. The process primarily occurs in the postsynaptic neuron. When the postsynaptic neuron is sufficiently depolarized, it allows for the removal of magnesium ions (Mg2+) that normally block the NMDA receptors. Once displaced, calcium ions (Ca2+) can flow into the postsynaptic cell initiating a cascade of events.

This cascade leads to the insertion of AMPA receptors into the postsynaptic membrane, ultimately enhancing the response to subsequent releases of glutamate from the presynaptic neuron. While LTP involves presynaptic changes as well, the major changes known to occur and be required for LTP induction are indeed post-synaptic changes, including the activation and increase in number of AMPA receptors.