The mice that had been kept busy also showed changes in the striatum region of the brain, which helps to co-ordinate movement.

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The team suggests lead is having this effect because it attaches itself selectively to sites in the brain's frontal cortex and striatum.

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For instance, one brain region called the striatum, which is involved in motivation, reward, and cognitive control, was also reduced in females with CD.

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This work shows that sleep trains the brain and promotes memory reorganisation from the hippocampus to the striatum, meaning that navigation becomes more automatic.

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The researchers had previously discovered that the same area of the brain affected in this study, the striatum, is activated when a person is rewarded a compliment or cash.

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The hypothalamus also has connections to the cortex via the striatum and the nucleus accumbens, a structure that secretes its own dopamine and opioids in response to food (see graphic).

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Dr. James Stone, who authored the research, says that the signaling between these two types of neurotransmitter is happening between a part of the brain called the hippocampus and another called the striatum.

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If Dr. Wang's previous studies are any indication, he will see that a test subject's striatum, a sort of communications hub inside the brain, has fewer dopamine receptors than the striatum of someone with normal eating habits.

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