Repeated high-frequency stimulation of the perforant pathway produces a long-lasting increase in synaptic strength in the CA1 region of the hippocampus. Induction of this phenomenon requires postsynaptic calcium entry through which channel?

• A NMDA receptor channel ✓
• B AMPA receptor channel
• C Voltage-gated sodium channel
• D GABA-A chloride channel

Explanation

Long-term potentiation induction depends on glutamate depolarising the postsynaptic membrane enough to relieve the magnesium block of the NMDA receptor, allowing calcium influx into the dendritic spine. This calcium triggers kinase cascades and insertion of additional AMPA receptors, which sustains the potentiation. AMPA receptors mediate the initial depolarisation but do not conduct calcium under physiological conditions, so they cannot serve as the coincidence detector.

Reference: Principles of Neural Science, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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