Throughout a person’s life, their brains adapt to what they learn and memorise. The brain is indeed made up of complex networks of neurons and synapses that are constantly re-configured. However, in order for learning to leave a trace, connections must be stabilized. A team at the University of Geneva (UNIGE) discovered a new cellular mechanism involved in the long-term stabilization of neuron connections, in which non-neuronal cells, called astrocytes, play a role unidentified until now. These results, published in Current Biology, will lead to a better understanding of neurodegenerative and neurodevelopmental diseases.
The central nervous system excitatory synapses, points of contact between neurons that allow them to transmit signals, are highly dynamic structures, which are continuously forming and dissolving. They are surrounded by non-neuronal cells, or glial cells, which include the distinctively star-shaped astrocytes. These cells form complex structures around synapses, and play a role in the transmission of cerebral information which was widely unknown before.
By increasing neuronal activity through whiskers stimulation of adult mice, the scientists were able to observe, in both the somatosensory cortex and the hippocampus, that this increased neuronal activity provokes an increase in astrocytes movements around synapses. The synapses, surrounded by astrocytes, re-organise their architecture, which protects them and increases their longevity.
The team developed new techniques that allowed them to specifically control the different synaptic structures, and to show that the phenomenon took place exclusively in the connections between neurons involved in learning. In summary, the more the astrocytes surround the synapses, the longer the synapses last, thus allowing learning to leave a mark on memory.
This study identifies a new, two-way interaction between neurons and astrocytes, in which the learning process regulates the structural plasticity of astrocytes, who in turn determine the fate of the synapses. This mechanism indicates that astrocytes apparently play an important role in the processes of learning and memory, which present abnormally in various neurodegenerative and neurodevelopmental diseases, among which Alzheimer’s, autism, or Fragile X syndrome.
This discovery highlights the until now underestimated importance of cells which, despite being non-neuronal, participate in a crucial way in the cerebral mechanisms that allow humans to learn and retain memories of what they have learned.
Source: The University of Geneva (UNIGE)
Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.
Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.
Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio, BioPortfolio.com, the life science, pharmaceutical and healthcare portal.
Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.
Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.
An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.