In a study, researchers administered a drug to mice that blocked the reuptake of serotonin at the synaptic cleft. They then compared the mice with a control group that received saline. Behavioral observations indicated that the drug-treated mice showed reduced anxiety-related behaviors in an open-field test, while the saline group showed typical anxiety responses. Synaptic recordings confirmed elevated serotonin levels in the cleft for the experimental group.
If researchers added a second drug that blocked postsynaptic serotonin receptors, what would most likely happen to the experimental group's behavior?
- A
Anxiety reduction would intensify due to compounded effects
- Bcheck_circle
Anxiety reduction would be eliminated despite high serotonin levels
- C
Reuptake would resume normally and serotonin levels would drop
- D
Serotonin would no longer be released from the presynaptic neuron
Explanation
Even with elevated serotonin in the cleft, blocked postsynaptic receptors prevent the neurotransmitter from binding and influencing the next neuron, so the behavioral effect would disappear.