Barcelona University scientists identify specific neurons that cause the sensation of dizziness

SCIENTISTS from the Institut de Neurociències of the UAB (INc-UAB) have identified the specific neurons that transmit the signals that cause the sensation of dizziness.

In collaboration with researchers the University of Washington, the Barcelona University researchers conducted tests on mice that could eventually help in the development of anti-sickness drugs that do not cause drowsiness in humans.

Their joint study was published in the journal ‘Proceedings of the National Academy of Sciences (PNAS)’. They analysed the cells of the vestibular nuclei of mice subjected to short and repeated turns, demonstrating the importance of neurons that release the VGLUT2 protein in dizziness.

According to the authors, these neurons produce the effects of rotation-induced motion sickness. These include decreased appetite, a lowering of body temperature, reduced mobility, and conditioned taste avoidance.

By blocking these neurons by chemogenetics (molecules specially designed to interact with these cells), the scientists confirmed that it helped to prevent dizziness in mice subjected to rotating conditions.

On the other hand, its activation by means of a beam of light (optogenetics) reproduced the same symptoms of dizziness in mice as when they were subjected to being spun around.

What did their study identify?

Specifically, a subgroup of VGLUT2 neurons that release the cholecystokinin gene (CCK-neurons) responsible for the effects of dizziness were identified.

It was discovered that they sent signals to an area of ​​the brain called the parabrachial nucleus, which is responsible for generating unpleasant sensations in the human body.

‘The mice to which we administered a drug that blocks the CCK-A receptor showed less activation of the parabrachial nucleus and had fewer symptoms of dizziness,’, explained Elisenda Sanz, an INc-UAB researcher and one of the authors of the study.

‘Common anti-sickness drugs target the histaminergic system, causing drowsiness’, explained Albert Quintana, a researcher at INc-UAB and coordinator of the study.

‘CCK-A receptor blocking drugs, which are already approved by the North American and European Medicines Associations (FDA and EMA) as a treatment for gastric motion sickness, are safe, and do not have that unwanted effect, so they would be an excellent option to treat dizziness’, he continued.

Quintana concluded: ‘In future studies, researchers want to define the contribution of these neurons to other situations that can cause dizziness to advance the approval of drugs that block the CCK-A receptor as a new therapy against this discomfort’.