Synthetic Neurons and Artificial Photoactivated Synapses

Projektbeschreibung

Künstliche Neuronen

Neuronen kommunizieren miteinander über als Synapsen bekannte Verknüpfungsstrukturen, in denen elektrische und chemische Signale auf modulierte Weise übertragen werden. Ein besseres Verständnis der beteiligten Kommunikationsprozesse könnte den Weg zu fortgeschrittenen chemischen Rechensystemen weisen. Das vom Europäischen Forschungsrat finanzierte Projekt SYNAPS zielt auf die Entwicklung künstlicher Synapsen ab, die natürliche Neuronen imitieren. Die Idee besteht darin, Liposomen als künstliche Zellen und Licht als äußeren Reiz einzusetzen, um Botenstoffe zu synthetisieren und zu übertragen. Die Forschenden werden Synapsen nachahmen, indem sie diese künstlichen Zellen in spezielle biomolekulare Strukturen einbauen, welche die Kommunikation erleichtern. Es wird erwartet, dass die SYNAPS-Struktur im Energiebereich sowie in der chemischen Sensorik und der intelligenten Arzneimittelverabreichung Anwendung finden wird.

Ziel

The brain is a complex network of inter-connected neurons that communicate through synapses. SYNAPS aims to for the first time mimic such synapses using liposomes as artificial cells, and visible light to trigger a signal from a ‘sender’- to a ‘receiver’-liposome. Mimicking such communication processes will help with understanding how complex natural emergent properties arise, and could ultimately allow for the construction of a chemical computer. SYNAPS will excel beyond the state-of-the-art by maintaining chemical isolation between liposome interiors, ensuring local, time-bound communication between connected liposomes, and using light as an external stimulus and fuel. These concepts are essential to construct artificial tissues that can communicate on an individual liposome-to-liposome basis, in contrast to the state-of-the-art where communication generally occurs with the bulk solution. To achieve this, a messenger compound will be locally photosynthesised through transmembrane electron transfer by porphyrin dimers that portray a charge-transfer excited state. The liposomes will be organised into a synaptic cleft through the use of synthetic complementary clustering compounds that provide stable adhesion between sender and receiver liposomes. The messenger compound will be recognised by reversible and selective membrane-spanning receptors in the receiver liposome, that will output the signal through fluorescence. In addition, a reaction cascade network will be constructed involving the messenger to produce an artificial action potential, that is, a transient peak in the concentration of the messenger, ensuring a time-bound dissipative signal. Altogether, SYNAPS will provide advances in systems chemistry by providing a nanoscale platform for communication between chemically isolated systems, but also results that are useful for applications such as light-to-chemical energy conversion, chemical sensing and smart drug-delivery.