Everything we do all of our movements, thoughts and feelings are the result of neurons talking with one another, and recent studies have suggested that some of the conversations might not be all that private. Brain cells known as astrocytes may be listening in on, or even participating in, some of those discussions. But a new mouse study suggests that astrocytes might only be tuning in part of the time specifically, when the neurons get really excited about something. This research, published in Neuron, was supported by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health.
For a long time, researchers thought that the star-shaped astrocytes (the name comes from the Greek word for star) were simply support cells for the neurons.
It turns out that these cells have a number of important jobs, including providing nutrients and signaling molecules to neurons, regulating blood flow, and removing brain chemicals called neurotransmitters from the synapse. The synapse is the point of information transfer between two neurons. At this connection point, neurotransmitters are released from one neuron to affect the electrical properties of the other. Long arms of astrocytes are located next to synapses, where they can keep tabs on the conversations going on between neurons.
In recent years, it has been shown that astrocytes may also play a role in neuronal communication. When neurons release neurotransmitters, levels of calcium change within astrocytes. Calcium is critical for many processes, including release of molecules from the cell, and activation of a host of proteins within the cell. The role of this astrocytic calcium signaling for brain function remains a mystery.
In this study, Baljit S. Khakh, Ph.D., of the University of California, Los Angeles and his colleagues wanted to know when astrocytes responded to neuron activity with changes in their internal c
|Contact: Barbara McMakin|
NIH/National Institute of Neurological Disorders and Stroke