A study at Brandeis University in the US may have discovered an in-built ‘neural thermostat’ that might be regulating brain activity. This may help scientists better understand epilepsy – and treat it
Scientists noticed this ‘thermostat’ effect in the brains of laboratory animals. These animals’ brains appeared able to regulate the rate of firing in neurons. Even after periods of overexcitement or understimulation, their brains returned to a static base rate of activity.
Neurons signal rapidly when they receive information from our senses. (This is very like what happens during a seizure in someone with epilepsy.) In the same way, neural firing slows right down when there is no sensory information. (This is much more like what happens in someone with an autistic spectrum disorder.)
Scientists tested this by temporarily depriving laboratory animals of their sight in one eye. Over the next 48 hours, they recorded a sharp reduction in neuronal firing in the brain hemisphere linked to the blinded eye – just as they expected. However, during the following 48 hours, the rate of neuronal firing in that hemisphere gradually returned to normal levels. Rates of firing matched those in the unaffected hemisphere, despite the lack of sensory information.
The scientists at Brandeis University now want to develop their research to figure out how these base rates of activity are set. If they can figure that out, it may be possible to re-set them in the brain of a person with epilepsy – preventing seizures altogether. The full research findings were published in an online edition of the medical journal Neuron on 16 October.