Question

Sort the following events in a sequence that would lead to long-term potentiation (LTP). Your answer would be a five-digit number composed of numbers 1 to 5 only, e.g. 13245

(A) Activation of AMPA receptors
(B) Glutamate release into the synaptic clefts
(C) Activation of calcium-dependent protein kinases in the postsynaptic cell
(D) Postsynaptic membrane depolarization
(E) Activation of NMDA receptors

Answer 1

To induce long-term potentiation (LTP), the correct sequence of events is glutamate release (B), followed by postsynaptic membrane depolarization (D), then activation of NMDA receptors (E), activation of calcium-dependent protein kinases (C), and finally the activation of AMPA receptors (A). This process strengthens synaptic connections and plays a key role in memory and learning.

Step-by-step explanation:

The sequence of events leading to long-term potentiation (LTP) can be understood as a complex process involving multiple steps that strengthen synaptic connections. This process is essential for memory formation and learning in the nervous system. To sort the given events into a sequence that leads to LTP, one must understand the roles of glutamate, NMDA and AMPA receptors, and the changes in the postsynaptic neuron.

1. Glutamate release into the synaptic cleft (B)
2. Postsynaptic membrane depolarization (D)
3. Activation of NMDA receptors (E)
4. Activation of calcium-dependent protein kinases in the postsynaptic cell (C)
5. Activation of AMPA receptors (A)

The correct sequence of events for LTP is: Glutamate is first released from the presynaptic neuron (B). This release leads to the depolarization of the postsynaptic membrane (D), which is necessary to remove the magnesium block from the NMDA receptors (E). Once activated, NMDA receptors allow calcium ions to enter the postsynaptic neuron, triggering the activation of calcium-dependent protein kinases (C). These kinases then lead to the activation and insertion of more AMPA receptors into the postsynaptic membrane (A), thereby strengthening the synaptic response to future glutamate release.