Biology subjects

Musienko, P.

Publications and source records attributed to Musienko, P..

4 recordsLinked to original sources

bioRxiv2026

Cross-excitation in dorsal root ganglia redistributes coding capacity from stimulus intensity to stimulus location

The phenomenon of cross-excitation between neurons of dorsal root ganglia (DRGs) of mammals is widely known, yet its exact mechanism remains underexplored. In this work, we analyze the phenomenon as part of the signal processing performed by the body's somatosensory system. We argue that, if the mechanism is indeed as prevalent as it is reported in experimental works, it should provide a significant computational advantage. Here, we created a model network in which sensory A-type neurons are interconnected only via a chemical agent and showed that such a connection, when fitted with parameters similar to those observed in experiments, improves the stimulus-localization properties of the ganglia at the expense of intensity-encoding accuracy. Although this exchange is near-neutral in raw bits, it becomes favorable once the logarithmic compression of intensity perception - the Weber--Fechner law - is taken into account, since the sacrificed intensity capacity is largely perceptually redundant. We therefore propose that cross-excitation is not an imperfection of somatic isolation but an effective, chemically mediated pre-processing stage that sharpens spatial localization.

neuroscience↗

bioRxiv2025

What is happening in Dorsal Root Ganglia? A computational analysis of cross-excitation phenomenon

The phenomenon of cross-excitation - interaction between neurons of a dorsal root ganglion (DRG) in intact organism, presents a great challenge since its discovery. It can not be addressed to classical neuron-neuron interactions, as the mentioned neurons are believed to be physiologically isolated by glial sheaths from one another. In this work we test existing hypotheses which explain the phenomenon from both biophysical and statistical perspectives. Our conclusion is that neither each proposed mechanism alone, nor interactions of them can adequately describe cross-excitation in normal conditions. We wish to draw greater attention towards the phenomenon, as it seems to be an important part of normal sensory information processing. Author summaryCross-excitation is a phenomenon discovered in Dorsal Root Ganglia (DRG), whereby activation of one neuron leads to increased excitability of its neighbors. As the mechanism is still poorly understood, we present a computational modelling study, in which we tested primary hypotheses which were proposed to the phenomenon. The objectives were to test two main ideas - diffusion-mediated and gap-junction mediated cross-excitation in biologically plausible setups. Firstly, we evaluated a diffusion-based hypothesis, which states that diffusion of K+ ions is the main mechanism by which cross-excitation is mediated. Our results suggest miniscule effect of ion diffusion, even if tightly-packed space of DRG is considered. Secondly, we analyzed the gap-junction hypothesis, which relates the phenomenon to physical connection between neurons glial envelopes. According to the results, this solution would require for each neuron to have an enormous amount of immediate neighbors, in order to sustain high-enough prevalence of connection. Geometrical conclusion is that, no matter how tightly packed the DRG, it is impossible to create enough contacts. As a result, our findings suggest that none of the leading hypotheses explain the phenomenon.

neuroscience↗

bioRxiv2023

Biomimetic computer-to-brain communication restoring naturalistic touch sensations via peripheral nerve stimulation

Artificial communication with the brain through peripheral nerve stimulation recently showed promising results in people with sensorimotor deficits. However, these efforts fall short in delivering close-to-natural rich sensory experience, resulting in the necessity to propose novel venues for converting sensory information into neural stimulation patterns, which would possibly enable intuitive and natural sensations. To this aim, we designed and tested a biomimetic neurostimulation framework inspired by nature, able "to write" physiologically plausible information back into the residual healthy nervous system. Starting from the in-silico model of mechanoreceptors, we designed biomimetic policies of stimulation, emulating the activity of different afferent units. Then, we experimentally assessed these novel paradigms, alongside mechanical touch and commonly used, linear neuromodulations. We explored the somatosensory neuroaxis by stimulating the nerve while recording the neural responses at the dorsal root ganglion and spinal cord of decerebrated cats. Biomimetic stimulation resulted in a neural activity that travels consistently along the neuroaxis, producing the spatio-temporal neural dynamic more like the naturally evoked one. Finally, we then implemented these paradigms within the bionic device and tested it with patients. Biomimetic neurostimulations resulted in higher mobility and decreased mental effort compared to traditional approaches. The results of this neuroscience-driven technology inspired by the human body could be a model for the development of novel assistive neurotechnologies.

neuroscience↗

bioRxiv2021

Disruption Of Proprioceptive Information During Electrical Stimulation Of The Cutaneous Afferents

While neurostimulation technologies are rapidly approaching clinical applications for sensorimotor disorders, the impact of electrical stimulation on network dynamics is still unknown. Given the high degree of shared processing in neural structures, it is critical to understand if neurostimulation affects functions that are related to, but not targeted by the intervention. Here we approached this question by studying the effects of electrical stimulation of cutaneous afferents on unrelated processing of proprioceptive inputs. We recorded intra-spinal neural activity in four monkeys while generating proprioceptive inputs from the radial nerve. We then applied continuous stimulation to the radial nerve cutaneous branch and quantified the impact of the stimulation on spinal processing of proprioceptive inputs via neural population dynamics. Proprioceptive pulses consistently produced neural trajectories that were disrupted by concurrent cutaneous stimulation. This disruption propagated to the somatosensory cortex, suggesting that electrical stimulation can perturb natural information processing across the neural axis.

neuroscience↗