Discovery of the Neurotransmitter Octopamine and its Function in Preventing Brain Cell Death

The function of octopamine, a neurotransmitter present in trace amounts in mammals, has been revealed. A research team at Northwestern University Medical School found that in the human brain, octopamine interacts with brain cells to prevent cell death. It is pointed out that it is similar to the brain’s SOS signal to urge astrocytes to make energy to prevent cell death due to lack of energy ATP for life activities. The research could help find treatments for Alzheimer’s disease, Parkinson’s disease and bipolar disorder, which are related to dysregulated octopamine levels in the brain.

The research team has uncovered how octopamine communicates with other cells in the mammalian brain to prevent cell death. The discovery that introducing octopamine into the culture of astrocytes that help neurons in the brain induces the production of lactic acid that promotes cell survival.

Octopamine is found in trace amounts in the mammalian brain, but its function has been replaced by epinephrine. For a long time, octopamine was considered a remnant of evolution, and its role in the human brain was unknown.

This study first sought to know how astrocytes, which constitute the majority of cells in the human central nervous system, are involved in brain dysfunction in neurodegenerative diseases. The research team found that introducing octopamine at a specific stage through the culture of astrocytes from the cerebral cortex of mice promoted lactic acid production in astrocytes while promoting cell survival.

“Our study is significant because we discovered how octopamine works in the mammalian brain,” said Gabriela Carabo Piso, Ph.D. “Think of it as an SOS signal.” The stressed neurons send these signals to the astrocytes, causing them to send energy. Adequate levels of octopamine cause astrocytes to read this distress signal and produce energy to protect cells from death due to lack of ATP. However, if there is too much octopamine, the astrocytes cannot read the distress signal, just as the SOS signal is shrouded in smoke.

“Lactic acid has long been considered a waste product, but it turns out that it is not,” said Dr. Piso. “It is a very important fuel that neurons need to convert to higher forms of energy.” “This is important because it may have implications for diseases in which octopamine levels are altered, such as Alzheimer’s disease and other psychiatric disorders,” he added.

The study was published in the Proceedings of the National Academy of Sciences of the United States. The original title is ‘Octopamine metabolically reprograms astrocytes to confer neuroprotection against α-synuclein’.