A new study reveals how octopamine, the "fight or flight" neurotransmitter, gets in touch with other cells in the brains of mammals in order to stop cells from dying.
Octopamine: Minimally Understood 'Fight-or-Flight' Neurotransmitter
According to Neuroscience News, octopamine is a neurotransmitter in invertebrates that is involved in responses pertaining to fight-or-flight.
It has also been thought to be a mammalian "evolutionary leftover." While the neurotransmitter can still be found in minimal amounts in mammalian brains, epinephrine has replaced its function. With this, octopamine's role in the human brain has remained minimally understood.
Researchers from Northwestern University's Feinberg School of Medicine set out to study the contribution of astrocytes, which account for the majority of cells in the central nervous system of humans, to brain dysfunction in neurodegenerative conditions.
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Octopamine Promotes Cell Survival
In the cerebral cortex of mice, scientists observed in astrocyte cultures that introducing certain levels of octopamine prompted and promoted astrocyte lactate production. This, in turn, promotes the survival of cells. This was detailed further in the PNAS journal.
Assistant professor Gabriela Caraveo Piso, Ph.D., from the Ken and Ruth Davee Department of Neurology Division of Movement Disorders, notes that the findings are crucial. This is because the researchers were able to discover a way in which the neurotransmitter works in the brains of mammals.
It can be thought of as an SOS signal of some sort, wherein neurons deliver signals to astrocytes in order to extend energy for lactate sending. At certain levels, the neurotransmitter may enable the astrocytes to decipher the signals and start the energy production that may protect cells from dying due to ATP shortage.
However, with high levels of octopamine, the astrocytes may find it hard to read the signals.
Caraveo Piso notes that these findings could help in the development of treatments for Parkinson's, Alzheimer's, and Bipolar disorder. All of these have been linked to octopamine dysregulation in the brain.
For a long time, lactate was thought to be a waste. However, this study shows that it actually plays a valuable role in fueling neurons that need to convert energy. Caraveo Piso notes that they adhere to its importance because of how it may affect conditions where levels of octopamine are altered.
Now, researchers are curious if such a phenomenon only occurs under conditions where diseases or illnesses are present. They also wonder if octopamine has a role in certain physiological aspects, such as memory and learning.
Moreover, considering optopamine's capacity to harness lactate for astrocytes, the researchers are also interested in knowing more about how lactate metabolism plays a role in the brain when it comes to aging, learning, and memory.
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