Spatiotemporal memory is an intrinsic property of networks of dissociated cortical neurons.
The ability to process complex spatiotemporal information is a fundamental process underlying the behavior of all higher organisms. However, how the brain processes information in the temporal domain remains incompletely understood. We have explored the spatiotemporal information-processing capability of networks formed from dissociated rat E18 cortical neurons growing in culture. By combining optogenetics with microelectrode array recording, we show that these randomly organized cortical microcircuits are able to process complex spatiotemporal information, allowing the identification of a large number of temporal sequences and classification of musical styles. These experiments uncovered spatiotemporal memory processes lasting several seconds. Neural network simulations indicated that both short-term synaptic plasticity and recurrent connections are required for the emergence of this capability. Interestingly, NMDA receptor function is not a requisite for these short-term spatiotemporal memory processes. Indeed, blocking the NMDA receptor with the antagonist APV significantly improved the temporal processing ability of the networks, by reducing spontaneously occurring network bursts. These highly synchronized events have disastrous effects on spatiotemporal information processing, by transiently erasing short-term memory. These results show that the ability to process and integrate complex spatiotemporal information is an intrinsic property of generic cortical networks that does not require specifically designed circuits.
Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
Han
http://orcid.org/0000-0003-1604-3227
H
Ju
Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
Mark R
http://orcid.org/0000-0003-4615-1069
MR
Dranias
Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
Gokulakrishna
http://orcid.org/0000-0002-9141-7295
G
Banumurthy
Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, Singapore 169857, Singapore antonius.vandongen@duke-nus.edu.sg.
Antonius M J
http://orcid.org/0000-0002-9923-3407
AM
VanDongen
D000161:Acoustic Stimulation; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D008839:Microelectrodes; D009146:Music / Q000523:psychology; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D062308:Optogenetics; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*
D016194:Receptors, N-Methyl-D-Aspartate
classification; multielectrode array; neuronal networks; optogenetics