summary: Astrocytes, star-shaped glial cells in the brain, play a key role in learning and memory by regulating synaptic plasticity. Researchers have developed a biophysical model that shows how astrocytes interact with neurons to promote rapid adaptation to new information.
This study revealed that astrocyte dysfunction can severely impair cognitive processes. This study bridges the gap between theoretical models of plasticity and experimental findings, and points to the possibility of new therapeutic approaches that target astrocytes to enhance cognitive function.
Key Facts:
- Astrocytes regulate synaptic plasticity, which is essential for learning and memory.
- Biophysical models highlight the role of astrocytes in regulating the neurotransmitter D-serine.
- Dysfunction of astrocytes can lead to significant cognitive impairment.
sauce: University of Bonn
Star-shaped glial cells, the so-called astrocytes, are more than just brain support cells. They are actively involved in the learning process and interact with neurons. So what exactly do astrocytes do?
Researchers from the University Hospital Bonn (UKB) and the University of Bonn are using biophysical models to reveal how astrocytes interact with neurons to control rapid adaptation to new information.
The results of this study are currently Communication Biology.
In the brain, synaptic plasticity – the ability to change neuronal connections over time – is fundamental to learning and memory. Traditionally, science has focused on neurons and their synapses. Intracellular CaAges 2+ Studies of signaling in astrocytes have led to the idea that astrocytes are more than just the glue that holds the brain together; they play a key role in this process.
“Dysfunction of astrocytes can severely impair learning abilities, highlighting their importance in cognitive processes. However, the exact function of astrocytes has remained a mystery for a long time,” says corresponding and co-first author Prof. Tatyana Chumachenko, Research Group Leader at the UKB Institute of Experimental Epileptology and Cognitive Research and member of the Transdisciplinary Research Area (TRA) “Modelling” at the University of Bonn.
Unravelling the complex dance of cellular interactions during learning
“As computational neuroscientists, our job is to use the language of mathematics to interpret experimental observations and build coherent models of the brain,” says Dr Pietro Verzelli, a postdoctoral researcher in Chumachenco’s group and co-senior author on the study.
In this case, the researchers developed a biophysical model of learning based on a biochemical feedback loop between astrocytes and neurons recently discovered by Dr. Kirsten Baumbach, Prof. Christian Henneberger and other researchers from DZNE and UKB.
This biophysical model explains the learning deficits seen in mice with impaired astrocytic regulation and highlights the critical role that astrocytes play in rapid adaptation to new information. By regulating levels of the neurotransmitter D-serine, astrocytes can promote the brain’s ability to efficiently adapt and rewire synaptic connections.
“Our mathematical framework not only explains experimental observations, but also provides new testable predictions about learning processes,” says first author Lorenzo Squadrani, a doctoral student in Chumachenco’s group.
This study bridges the gap between theoretical models of plasticity and experimental findings on neuronal-glial interactions and highlights astrocytic regulation as the physiological basis of dynamic synaptic adaptation, a central concept in synaptic plasticity.
“Our findings contribute to a better understanding of the molecular and cellular mechanisms underlying learning and memory and provide new opportunities for therapeutic interventions targeting astrocytes to improve cognitive function,” says Professor Chumachenco.
About this Learning and Memory Research News
author: Lorenzo Squadrani
sauce: University of Bonn
contact: Lorenzo Squadrani – University of Bonn
image: Image courtesy of Neuroscience News
Original Research: Open access.
“Astrocytes enhance plastic responses during reversal learningLorenzo Squadrani et al. Communication Biology
Abstract
Astrocytes enhance plastic responses during reversal learning
Astrocytes play a key role in regulating synaptic strength and are thought to orchestrate synaptic plasticity and memory, but how specifically astrocytes and their neuroactive transmitters control learning and memory is currently an open question.
Recent experiments have revealed an astrocyte-mediated feedback loop in CA1 pyramidal neurons that is initiated by endocannabinoid release by active neurons and closed by astrocytic modulation of D-serine levels in dendrites. D-serine is a co-agonist of NMDA receptors that regulates the strength and direction of synaptic plasticity.
Thus, activity-dependent D-serine release mediated by astrocytes is a candidate for mediating long-term synaptic depression (LTD) and potentiation (LTP) during learning.
Here we show that a mathematical description of this mechanism leads to a biophysical model of synaptic plasticity that is consistent with a phenomenological model known as the BCM model.
The resulting mathematical framework is able to explain the learning impairment observed in mice upon disruption of the D-serine regulatory mechanism, indicating that D-serine enhances plasticity during reversal learning and ensures rapid responses to changes in the external environment.
This model provides new testable predictions about the learning process and improves our understanding of the functional role of neuronal-glial interactions in learning.
