Dialogue with the 'other brain' through astrocytes and graphene

Schematic image of an astrocyte embracing a graphene molecule

The paper was published in the journal Nature Nanotechnology under the title "Graphene oxide electrodes enable electrical stimulation of distinct calcium signalling in brain astrocytes". The research was co-ordinated by the Institute for Organic Synthesis and Photoreactivity of the National Research Council (CNR-Isof), in collaboration with the Institute for the Study of Nanostructured Materials (CNR-Ismn), the Departments of Pharmacy and Biotechnology (FaBiT) and Electrical and Information Engineering 'Guglielmo Marconi' (DEI) of the University of Bologna and the Institute of Experimental Medicine of the Czech Academy of Sciences in Prague (Czech Republic).

Research shows that by exploiting the different properties of graphene-based materials, it is possible to selectively control the signals of astrocytes, which in turn, when electrically stimulated, are able to alter the activity of neurons.

Astrocytes are star-shaped brain cells that, along with the neurons themselves, perform important functions in the brain, modulating synapses and participating in mechanisms involving memory, learning and behaviour. These stellate cells, also known as "the other brain", are present in large numbers in the human brain. They communicate with each other, with neurons and blood vessels, using a communication code based on calcium ions.

"By combining the different properties of graphene, we were able to create a new, simple and effective approach to selectively stimulate and interrogate astrocytes. The study confirmed that astrocytes can be excited by an electric field and that they provide a different response depending on the type of electrodes through which they are stimulated. This occurs through the activation of different calcium 'codes', thanks to the unique and controllable properties of graphene oxide", explains Vincenzo Palermo, researcher at CNR-Isof. Studies over the last forty years have completely revolutionised the neurocentric view of the brain, which attributed cognitive abilities to the activity of neurons alone. However, despite the importance of astrocytes, little is known about how they work and many technologies for studying the brain and treating diseases related to the nervous system, focus on the selective modulation of neurons.

"Our approach is to develop technologies that can communicate with astrocytes: a paradigm shift that we have pioneered and that more and more scientists are now adopting. By changing the way we communicate with brain cells, we may be able to address and understand what is still unclear about how the brain works. This will also make it possible to treat certain dysfunctions, such as those related to calcium signalling in astrocytes, which are implicated in pathologies such as stroke and epilepsy", concludes Valentina Benfenati, researcher at CNR-Isof and coordinator of the research with colleagues Vincenzo Palermo and Emanuele Treossi.

"Thanks to our ten-year collaboration with Dr. Benfenati in the field of astrocytes and their involvement in the pathophysiological processes of the nervous system," adds Prof. Marco Caprini from the University’s Department of Pharmacy and Biotechnology (FaBiT), "we are able to reconcile basic research with its application to complex systems, as in the case of this publication. I believe that it is crucial to continue to develop this type of collaboration between the University of Bologna and CNR".