This molecular system would control electrical signals in the brain and thus promote learning and memory. A valuable discovery, which could help better manage neurodegenerative diseases such as Alzheimer’s and Parkinson’s.
- Researchers have identified the molecular process responsible for forming our learning and memories.
- This dimmer makes it possible to modulate the power of the cerebral circuits and explains, for example, how our brain is capable of generating memory and learning, even when it only emits low-intensity electrical impulse rates.
- Contrary to what we thought until now, our brain is not equipped with an “on/off” button in the transmission of electrical messages, but with a “molecular volume button” which is used to modulate the electrical signals that cross synapses and neurons.
It is a discovery that revolutionizes the way we think about memory and learning. A new study from Dartmouth College (USA), published in the Proceedings of the National Academy of Sciences, reveals that our brains have a “molecular volume knob” that is used to control the electrical signals that pass through synapses and neurons. It would therefore have a determining role to play in the quantity of neurotransmitters released, which modifies the number and characteristics of neurons activated in the circuits of the brain. This remodeling of the strength of synaptic connections is at the origin of learning and the formation of memories.
The discovery of this control mechanism and the identification of the molecule that regulates it could help researchers in their search for ways to manage neurological disorders, in particular Alzheimer’s disease, Parkinson’s disease or epilepsy. “The synapses in our brain are very dynamic and speak in a range of whispers and cries, schematizes Michael Hoppa, assistant professor of biological sciences at Dartmouth and responsible for the study. This discovery puts us on a straighter path to being able to cure stubborn neurological disorders.”
A modulation of our cerebral messages
How does this “molecular button” work? Thanks to synapses, tiny contact points that allow neurons in the brain to communicate at different frequencies. The brain converts electrical inputs from neurons into chemical neurotransmitters that travel through these synaptic spaces and are responsible for our learning and memory.
Two functions support these memory and learning processes. The first, called facilitation, is a series of faster and faster spikes that amplify signals and change the shape of a synapse. The other, depression, reduces signals. Together, these two forms of plasticity keep the brain in balance and prevent neurological disorders such as epileptic seizures. “As we age, being able to maintain these synapses is essential. We need a good balance of plasticity in our brain, but also stabilization of synaptic connections”explains Michael Hoppa.
By focusing on the hippocampus, the area of the brain where our learning and memories are formed, the researchers discovered that the electrical spikes are delivered as analog signals whose shape impacts the magnitude of the neurotransmitter chemical released. across synapses.
Basically, it works like a dimmer with variable settings, not like a switch with “on” and “off” buttons. According to the scientists, this dimmer makes it possible to modulate the power of the cerebral circuits.
The brain, “supercomputer” at low frequency
In addition to discovering that the electrical signals that cross synapses in the brain’s hippocampus are analogous, the researchers also identified the molecule that regulates the electrical signals. Called Kvβ1, it influences our learning, memory and sleep.
They also discovered the processes that allow the brain to have such high computing power at such low energy. A single analog electrical pulse can carry multiple information, allowing better control with low frequency signals. “It helps us understand how our brain is able to work at supercomputer levels with much lower electrical impulse rates and the energy equivalent of a refrigerator light bulb. The more we learn about these levels of control , the more it helps us understand how our brain is so efficient”says Professor Hoppa.
The research team now wishes to focus on the influence of this molecular system on the changes in cerebral metabolism that occur during aging and which are at the root of common neurological disorders.
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