1.   And when the monkey expected to get juice but got none, the dopamine neurons decreased their firing rate, as if to signal a lack of reward.

2.   As in monkeys, human dopamine neurons project to areas that plan and control movements, he said.

3.   As in most animals, the dopamine neuron at rest fires signals at a steady, base-line rate.

4.   Each time a virtual bee landed on a flower, its dopamine neuron was alerted.

5.   In another experiment, dopamine neurons were severed in mice.

6.   Schultz found that when the monkey got more juice than it expected, dopamine neurons fired vigorously.

7.   The bee brain has only one dopamine neuron.

8.   When the dopamine neuron encounters an empty flower, it throws the bee brain into an unhappy state.

9.   When the monkey got an amount of juice that it expected, based on previous squirts, dopamine neurons did nothing.