The brain functions thanks to neurons and their ability to process and transmit information. To support them in this task, glial cells perform a number of structural, energetic and immune functions. Some of these, known as astrocytes, surround synapses, the contact points where neurotransmitters are released to spread information between neurons.

For this reason, neuroscientists have long suggested that astrocytes might play an active role in synaptic transmission and participate in information processing.

International research, coordinated by Andrea Volterra of the University of Lausanne in collaboration with a group of neuroscientists from Sapienza University and the Wyss Centre in Geneva, has led to the discovery of a new sub-population of astrocytes, a hybrid in composition and function between the two types of brain cells known so far, neurons and glial cells, which can control the level of communication and excitation of neurons.

"The study", says Maria Amalia Di Castro of Sapienza's Department of Physiology and Pharmacology, "shows that the subgroup responds to selective stimulation with rapid release of glutamate in spatially delimited areas that resemble synapses. The release of glutamate by these specialised cells exerts an influence on synaptic transmission and regulates neuronal circuits".

Researchers have observed experimentally that without this functional mechanism, the neural process involved in long-term memorisation is impaired.

The implications of this discovery also extend to brain disorders such as epilepsy or Parkinson's disease. By specifically disrupting glutamatergic astrocytes, the research team has shown that both memory consolidation and the negative effects of certain diseases such as epilepsy are impaired, with patients experiencing an increase in seizures.

The study therefore shows that glutamatergic astrocytes also play a role in the regulation of brain circuits involved in movement control and could offer therapeutic targets for Parkinson's disease.

References:

Specialized astrocytes mediate glutamatergic gliotransmission in the CNS - Roberta de Ceglia, Ada Ledonne, David Gregory Litvin, Barbara Lykke Lind, Giovanni Carriero, Emanuele Claudio Latagliata, Erika Bindocci, Maria Amalia Di Castro, Iaroslav Savtchouk, Ilaria Vitali, Anurag Ranjak, Mauro Congiu, Tara Canonica, William Wisden, Kenneth Harris, Manuel Mameli, Nicola Mercuri, Ludovic Telley & Andrea Volterra – Nature 2023. https://www.nature.com/articles/s41586-023-06502-w

Further Infomation

Maria Amalia Di Castro
Department of Physiology and Pharmacology "Vittorio Erspamer"
mariaamalia.dicastro@uniroma1.it