How brain forms 'Mexican waves'

Scientists have revealed the mechanism that enables certain brain cells to persuade others to create "Mexican waves" linked with cognitive function.

The work may help researchers understand more about normal brain function and about neurocognitive disorders such as dementia.

Neurons belong to one of two groups - inhibitory or excitatory.

While much is known about excitatory neurons, the role of inhibitory neurons is still being debated.

Inhibitory neurons can vibrate and they are equipped with mechanisms that enable them to persuade networks of other neurons into imitating their vibrations - setting off 'Mexican waves' in the brain.

The scientists believe these collective, oscillating vibrations play a key role in cognitive function.

"These brain cells are similar to spectators in a football stadium, encouraging others into imitating them in a 'Mexican wave'. We suspect that there is a very close relationship between the collective vibrations that they set off and many important cognitive functions," explained co-author Claudia Clopath from department of bioengineering at Imperial College London.

"When the vibrations are degraded so that the wave is disrupted, we think it may contribute to neurocognitive disorders such as dementia. Our hope is that ultimately our research will lead to new insights into these disorders and how they can be treated," Clopath maintained.

The researchers have developed a mathematical model showing the two mechanisms that inhibitory neurons need in order to convince others to join them in their rhythmical vibrations.

Their research sheds light on how inhibitory neurons use different communication processes to excitatory neurons which share information via an internal pulsing mechanism.

This study, carried out by Imperial College London and the Max Planck Institute for Brain Research, was published in the journal Nature Communications.