Molecule may help maintain brain's synaptic balance

June 13, 2017
Fruit fly brain labeled in different colors using the Brainbow method that allows researchers to distinguish one neuron from another. Credit: Timothy Mosca

Many neurological diseases are malfunctions of synapses, or the points of contact between neurons that allow senses and other information to pass from finger to brain. In the brain, there is a careful balance between the excitatory synapses that allow messages to pass, and the inhibitory synapses that dampen the signal. When that balance is off, the brain becomes unable to process information normally, leading to conditions like epilepsy.

Now researchers at Jefferson have discovered a molecule that may play a role in helping maintain the balance of excitatory and . The results were published in the journal eLife, a project of the Howard Hughes Medical Institute, the Wellcome Trust and the Max Planck Institute.

Timothy Mosca, Ph.D., Assistant Professor in the Department of Neuroscience at the Vickie and Jack Farber Institute for Neuroscience of Thomas Jefferson University, discovered that a molecule called LRP4, was important in creating excitatory synapses—the ones that keep a message passing from one neuron to the next. When the researchers knocked out the LRP4 gene in fruit flies, they saw a 40 percent loss of excitatory synaptic connections in the brain, but no such loss of , suggesting that the molecule was specific to one kind of synapse.

The researchers used a new technology called expansion microscopy to get a better view of the fruit fly . "In most cases, if you want to see very small things with better resolution, you get a better microscope," says Mosca. "The other option is to make the small things bigger." By infusing the neurons they were studying with the chemical in diapers that swells as it absorbs water, they were able to make the neurons and their synapses enlarged enough to see them more clearly.

"Most involved in synapse biology are vital to both excitatory and inhibitory neurons," says Mosca. "The idea that we now have a molecule that appears to be specific to suggests there is probably a parallel molecule that exists that helps form inhibitory ones, that we just haven't found yet."

A better understanding of the unique biology of excitatory and inhibitory may go a long way in helping researchers untangle the many diseases that are thought to be related to synapse dysfunction such as epilepsy, but also autism and schizophrenia.

Explore further: Visualization of newly formed synapses with unprecedented resolution

More information: Timothy J Mosca et al, Presynaptic LRP4 promotes synapse number and function of excitatory CNS neurons, eLife (2017). DOI: 10.7554/eLife.27347

Related Stories

Visualization of newly formed synapses with unprecedented resolution

August 11, 2016
The formation of excitatory and inhibitory synapses between neurons during early development gives rise to the neuronal networks that enable sensory and cognitive functions in humans. Inhibitory synapses decrease the likelihood ...

Brain connections are more sophisticated than thought

September 8, 2016
In 1959, a scientist named Edward Gray showed that the miniscule gaps between neurons where chemical messages are sent, called synapses, come in two main varieties, which researchers later dubbed "excitatory" and "inhibitory."

Bipolar disorder candidate gene, validated in mouse experiment

February 15, 2017
A team of researchers, affiliated with UNIST has made a significant breakthrough in the search for the potential root causes of bipolar disorder.

Blame it on the astrocytes

July 11, 2014
In the brains of all vertebrates, information is transmitted through synapses, a mechanism that allows an electric or chemical signal to be passed from one brain cell to another. Chemical synapses, which are the most abundant ...

Protein family linked to autism suppresses the development of inhibitory synapses

January 28, 2013
Synapse development is promoted by a variety of cell adhesion molecules that connect neurons and organize synaptic proteins. Many of these adhesion molecules are linked to neurodevelopmental disorders; mutations in neuroligin ...

Scientists find sensor that makes synapses fast

January 17, 2017
Synapses, the connections between neurons, come in different flavors, depending on the chemical they use as transmitter. Signal transmitters, or neurotransmitters, are released at the synapse after calcium ions flow into ...

Recommended for you

Researchers create tool to measure, control protein aggregation

October 22, 2017
A common thread ties seemingly unlinked disorders like Alzheimer's disease and type II diabetes together. This thread is known as protein aggregation and happens when proteins clump together. These complexes are a hallmark ...

'Selfish brain' wins out when competing with muscle power, study finds

October 20, 2017
Human brains are expensive - metabolically speaking. It takes lot of energy to run our sophisticated grey matter, and that comes at an evolutionary cost.

Want to control your dreams? Here's how

October 19, 2017
New research at the University of Adelaide has found that a specific combination of techniques will increase people's chances of having lucid dreams, in which the dreamer is aware they're dreaming while it's still happening ...

Researchers find shifting relationship between flexibility, modularity in the brain

October 19, 2017
A new study by Rice University researchers takes a step toward what they see as key to the advance of neuroscience: a better understanding of the relationship between the brain's flexibility and its modularity.

Brain training can improve our understanding of speech in noisy places

October 19, 2017
For many people with hearing challenges, trying to follow a conversation in a crowded restaurant or other noisy venue is a major struggle, even with hearing aids. Now researchers reporting in Current Biology on October 19th ...

Investigating the most common genetic contributor to Parkinson's disease

October 19, 2017
LRRK2 gene mutations are the most common genetic cause of Parkinson's disease (PD), but the normal physiological role of this gene in the brain remains unclear. In a paper published in Neuron, Brigham and Women's Hospital ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.