A novel memory control mechanism is revealed

To fix a memory, neurones add neurotransmitter receptors to their synapses. This form of regulation is notably involved in the learning process.

Neurotransmitter receptors located at the level of synapses ensure the diffusion of neural messages in the human brain. Yet it has been known for several years that these small proteinaceous structures are in constant movement, thus modulating the efficiency of the nervous signal. With the help of molecular tools that are capable of controlling the motion of these receptors, researchers1Interdisciplinary Institute for Neuroscience (IINS—CNRS/Université de Bordeaux), Bordeaux Imaging Center (BIC—CNRS/Université de Bordeaux/INSERM), Institute of Neurodegenerative Diseases (IMN—CNRS/Université de Bordeaux) have been able to study the influence of their immobilization on cultured sections of the hippocampus. By combining chemistry, electrophysiology and high-resolution imaging techniques, they demonstrated that the absence of movement of the receptors in this region of the brain plays a central role in memory, preventing regulation of neuronal activity.

The scientists then studied the impact of the blockage of these same receptors in mice conditioned to become stationary when they are in an environment that they associate with fear. However, when placed in such conditions, the rodents did not show any abnormal behaviour, as the blockage of their synaptic receptors had had the effect of short-circuiting their learning memory. This research opens the way to understanding other learning mechanisms in the brain. Additionally, it could inspire new therapeutic strategies aimed at blocking traumatic memories in victims of assaults by controlling the movement of receptors and neurotransmitters.

Nature, September 2017