Understanding Brain Biochemistry Through Chemical Messengers
- Reviewed9 Mar 2023
- Author Susan Rojahn
- Source BrainFacts/SfN
Although we typically talk a lot about the electrical signals transmitted along neurons, the brain also communicates with molecular and chemical signals.
Neurotransmitters are chemical messengers that travel across a synapse, carrying signals from one neuron to the next. Using a method called microdialysis, researchers can monitor neurotransmitters in action. With thin tubes inserted into the brain, scientists can collect tiny volumes of liquid from just outside neurons and then analyze the compounds in that liquid. For example, a researcher could analyze liquid captured during learning to identify molecules that are important for that process.
Microdialysis can also be used to deliver compounds to the brain. Many drugs have powerful effects on the brain, so scientists can use these substances to tweak brain function in order to understand it better. Pharmacology, the study of the effects of drugs, is also dedicated to identifying new drugs to treat conditions like pain or psychiatric illness, as well as understanding addiction and other negative consequences of drug use.
Another important method employed to study the molecules and chemicals at work in the brain is mass spectrometry. Once a sample has been collected — perhaps by using microdialysis — the compounds it contains are ionized (given an electric charge) and then sent through an electric or magnetic field. The behavior of each molecule in that field indicates its mass. That information alone provides valuable clues for identifying a molecule. Mass spectrometry has also been very useful in exploring neurodegenerative disorders. For example, one treatment for Parkinson’s disease causes severe side effects, including involuntary movements. With mass spectrometry, researchers have identified the location within the brain where this side effect is caused; that information could point the way to interventions that can reduce or prevent those side effects.
Adapted from the 8th edition of Brain Facts by Susan Rojahn.
About the Author
Susan Rojahn is a science writer in Galveston, Texas. After earning her PhD in molecular and cellular biology from UC Berkeley, she studied science journalism at UC Santa Cruz. She has a passion for writing about brain science, and has contributed news stories, press releases, and a book chapter to the Society for Neuroscience.
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BrainFacts/SfN
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