Neuroscience MCAT Practice Question
A neuroscientist administers an antagonist of N-methyl-D-aspartate (NMDA) receptors to experimental animals and observes impaired performance on spatial memory tasks dependent on hippocampal function. NMDA receptors are voltage-gated, ligand-gated ion channels that require both glutamate and glycine binding plus membrane depolarization for activation. How does NMDA receptor antagonism specifically impair hippocampal-dependent learning?
Answer choices
- ABlockade prevents magnesium channel opening in the postsynaptic cell
- BAntagonism prevents calcium influx required for LTP inductionCorrect answer
- CInhibition increases GABAergic feedback inhibition in CA1
- DBlockade eliminates presynaptic action potentials in Schaffer collaterals
- EAntagonism enhances AMPA receptor desensitization kinetics
- FBlockade reduces glutamate binding affinity at non-NMDA ionotropic receptors
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