Scientists discover learning and memory formation in model membranes

A groundbreaking discovery by scientists at the Department of Energy's Oak Ridge National Laboratory (ORNL) has revealed that cellular membranes play a crucial role in the formation of learning and memory in the brain. The research, a result of a decades-long collaboration between two ORNL scientists, John Katsaras and Pat Collier, could pave the way for the development of advanced materials for neuromorphic computing and deeper understanding of neurological disorders.

Neurons, the building blocks of the brain, communicate through electrical signals, with ion activity being a key driver. Katsaras and Collier's work has demonstrated that lipid bilayers, the foundational structure of cellular membranes, actively regulate ion flow through membrane proteins. By incorporating electrical properties known as memristance and memcapacitance into these bilayers, the researchers have shown how biological memory and learning processes can occur within them.

Lipid bilayers are composed of a double layer of lipid molecules, each containing a hydrophilic head and a hydrophobic tail, that can readily change shape. This soft matter property allows researchers to study membrane behavior under electrical stimulation using water droplets suspended in oil, known as a droplet interface bilayer. In earlier experiments, the scientists observed unexpected electrical data, which led them to focus on neuronal membranes.

Their latest findings indicate that lipid bilayers can exhibit memristance and memcapacitance, properties that could enable the creation of new types of soft materials with enhanced neural sensing and computing capabilities. By manipulating the structure of these bilayers, the researchers hope to develop artificial synapses, electronic components that mimic the connections between brain cells, and other neuromorphic computing technologies.

To further investigate the mechanisms behind these phenomena, researchers plan to use neutron scattering and lithium, a compound known for its potential neuroprotective effects in neurodegenerative diseases such as Alzheimer's. By capturing atomic-scale measurements of membrane alterations and lithium interactions, the team aims to shed new light on the use of lithium in artificial synapses and the development of new therapeutic strategies.

This research, made possible by ORNL's unique combination of expertise in soft matter science, neutron capabilities, and co-located user facilities, highlights the potential of multidisciplinary science in driving discoveries and innovation at the intersection of biology, materials science, and computing.