Biology subjects

Aroso, M.

Publications and source records attributed to Aroso, M..

2 recordsLinked to original sources

bioRxiv2021

A memristor-based neuromodulation device for real-time monitoring and adaptive control of in vitro neuronal populations

Neurons are specialized cells in information transmission and information processing. Following this, many neurologic disorders are directly linked not to cellular viability/homeostasis issues but rather to specific anomalies in electrical activity dynamics. Acknowledging this fact, therapeutic strategies based on direct modulation of neuronal electrical activity have been producing remarkable results, with successful examples ranging from cochlear implants to deep brain stimulation. Development on these implantable devices are hindered, however, by important challenges: power requirements, size factor, signal transduction, and adaptability/computational capabilities. Memristors, nanoscale electronic components able to emulate natural synapses, provide unique properties to address these constraints and their use in neuroprosthetic devices is being actively explored. Here we demonstrate for the first time the use of memristive devices in a clinically relevant setting where communication between two neuronal populations is conditioned to specific activity patterns in the source population. In our approach, the memristor device performs a simple pattern detection computation and acts as a synapstor capable of reversible short-term plasticity. Using in vitro hippocampal neuronal cultures, we show real-time adaptive control with a high degree of reproducibility using our monitor-compute-actuate paradigm. We envision very similar systems being used for automatic detection and suppression of seizures in epileptic patients.

neuroscience↗

bioRxiv2021

In vitro neuronal networks show bidirectional axonal conduction with antidromic action potentials effectively depolarizing the soma

Recent technological advances are revealing the complex physiology of the axon and challenging long-standing assumptions. Namely, while most action potential (AP) initiation occurs at the axon initial segment in central nervous system neurons, initiation in distal parts of the axon has been shown to occur in both physiological and pathological conditions. However, such ectopic action potential (EAP) activity has not been reported yet in studies using neuronal cultures and its functional role, if exists, is still not clear. Here, we show the spontaneous occurrence of EAPs and effective antidromic conduction in hippocampal neuronal cultures. We also observe a significant fraction of bidirectional axonal conduction in dorsal root ganglia neuronal cultures. We investigate and characterize this antidromic propagation via a combination of microfluidics, microelectrode arrays, advanced data analysis and in silico studies. We show that EAPs and antidromic conduction can occur spontaneously, and after distal axotomy or physiological changes in the axon biochemical environment. Conduction velocity is asymmetrical, with antidromic conduction being slower than orthodromic. Importantly, EAPs may carry information and can have a functional impact on the neuron, as they consistently depolarize the soma. Thus, plasticity or gene transduction mechanisms triggered by soma depolarization can also be affected by these antidromic APs. Altogether these findings have important implications for the study of neuronal function in vitro, reshaping our understanding on how information flows in neuronal cultures.

neuroscience↗