1.   But the new results go one step further, revealing when in life and where in the brain the link between serotonin receptors and anxiety behavior is forged.

2.   Having the ability to make both normal-strength serotonin receptors and weaker ones enables the brain to modulate, or fine-tune, serotonin effects as it needs to.

3.   He believes anorexics are caught in a vicious cycle, starving themselves to reduce brain levels of serotonin, which causes the brain to add more serotonin receptors.

4.   Zyban, a prescription drug, works on the serotonin receptors in the brain that affect nicotine addiction.

5.   In the experiments, Hen and colleagues effectively blocked serotonin receptors in different locations of the brains of bioengineered mice by a variety of methods.

6.   Later, they repeated many of the experiments with mice that were bioengineered so the serotonin receptors were only active in their forebrains, which control complex behaviors.