From NeuroScienceNews:
How a Gene Mutation Causes Higher Intelligence
May 10, 2022
Summary: A rare genetic mutation that causes blindness also appears to be associated with above-average intelligence, a new study reports.Source: University of Leipzig press release
Synapses are the contact points in the brain via which nerve cells ‘talk’ to each other. Disturbances in this communication lead to diseases of the nervous system, since altered synaptic proteins, for example, can impair this complex molecular mechanism. This can result in mild symptoms, but also very severe disabilities in those affected.
The interest of the two neurobiologists Professor Tobias Langenhan and Professor Manfred Heckmann, from Leipzig and Würzburg respectively, was aroused when they read in a scientific publication about a mutation that damages a synaptic protein.
At first, the affected patients attracted scientists’ attention because the mutation caused them to go blind. However, doctors then noticed that the patients were also of above-average intelligence.
I’m told the eight family members average 27 points higher IQ than their unaffected relatives.
“It’s very rare for a mutation to lead to improvement rather than loss of function,” says Langenhan, professor and holder of a chair at the Rudolf Schönheimer Institute of Biochemistry at the Faculty of Medicine.
The two neurobiologists from Leipzig and Würzburg have been using fruit flies to analyze synaptic functions for many years.
“Our research project was designed to insert the patients’ mutation into the corresponding gene in the fly and use techniques such as electrophysiology to test what then happens to the synapses. It was our assumption that the mutation makes patients so clever because it improves communication between the neurons which involve the injured protein,” explains Langenhan. …
First, the scientists, together with researchers from Oxford, showed that the fly protein called RIM looks molecularly identical to that of humans. This was essential in order to be able to study the changes in the human brain in the fly. In the next step, the neurobiologists inserted mutations into the fly genome that looked exactly as they did in the diseased people. They then took electrophysiological measurements of synaptic activity.
“We actually observed that the animals with the mutation showed a much increased transmission of information at the synapses. This amazing effect on the fly synapses is probably found in the same or a similar way in human patients, and could explain their increased cognitive performance, but also their blindness,” concludes Professor Langenhan.
