‘Spontaneous brain activity in babies prepares their brains for the rest of their lives’

Interview with Christian Lohmann

Biologist Christian Lohmann is interested in the spontaneous activity in the brain. ‘It is important for brain development. If it falters, then things will go wrong.’

Spontaneous brain activity was not discovered until the late 1980s. It falls somewhere in between nature and nurture: it is not genetically determined and already occurs before experience or learning come into the picture. ‘Consider, for instance, the fascinating fact that babies can see immediately after they are born,’ says Lohmann. ‘It takes them only very little time to begin to recognize faces, without the involvement of any learning processes. The brain must have been prepared for it.’

It is a known fact that spontaneous activity is important for the organization of the connections between neurons. But how? To discover that, researchers from Lohmann’s group looked at the activity pattern of individual synapses. ‘We discovered that a synapse works best when it is active at the same time that its neighboring synapses are active too. But if a synapse is not active at the same moment as its neighbors, it is in trouble: its activity wanes progressively. Even when we stimulate a synapse at the same time as synapses that are further away, it becomes less and less active. A synapse thus only works well when it is active synchronously with its immediate neighbors.’ Conclusion: Even in spontaneous brain activity the right connections are made according to a plan – even though the word ‘spontaneous’ suggests a certain randomness.

‘Even in spontaneous brain activity the right connections are made according to a plan’

When spontaneous activity is blocked by pharmaceuticals, then this ‘neighborly behavior’ goes out the window and the activity just flies off in all directions. ‘If this happens, then a great deal of information is lost, because it does not reach its destination.’ This effect might be playing a role in neurological developmental disorders,’ he says. ‘But we do not know this yet; first we need to find out what information is dispersed in clusters by neighboring synapses, and how this is done.’ Also if it concerns insufficient spontaneous activity or if the activity has the wrong pattern, mistakes will arise in the developing brain.

Lohmann’s next objective is to investigate this mechanism, which he has been looking at in slices of brain tissue, in newborn mice. Mice babies do not open their eyes until two weeks after they have been born. Until then they are blind. ‘This gives us the opportunity to examine spontaneous activity in these mice.’ It is a complicated puzzle, he says. ‘This will keep us busy for at least five more years.’