Rather, the growth hormone seems to be under the control of certain neurotransmitters - substances released by brain cells - that also affect behavior.

Amphetamines increase alertness by increasing the supply of certain neurotransmitters in the brain.

That is, the concentration levels of certain neurotransmitters are known to regulate the amount of oscillatory activity.

They appear to tone down the production of certain neurotransmitters, acting like the brakes of a car when the system is racing too fast.

Research into other mental impairments such as schizophrenia also found that too little activity of certain neurotransmitters were connected to these disorders.

Drugs that boost the brain's supply of certain neurotransmitters, for instance, might be able to keep their networks turned on longer.

They lack protein channels for sodium and are more sensitive to certain neurotransmitters.

It is possible that the parasite alters the production of certain neurotransmitters.

Ginkgo biloba helps the brain make certain neurotransmitters, which may alleviate depression.

There also seem to be problems with certain neurotransmitters (chemical signals in the brain), especially serotonin.