✍️ Marta Estévez-Rodríguez, Guillermo Sánchez-Garrido Campos, Ángela M. Zafra, Isabel Cordones & Javier Márquez-Ruiz @pablodeolavide.upo.es

📘 Full article:
👉 doi.org/10.3389/fnin...

#tES #neuroscience #animalmodels #tDCS #tACS #tRNS #neuromodulation #EIbalance #Neurotwin #E-Brain

4/ We also discuss translational challenges, such as anatomical differences and current density scaling, and highlight how computational modeling and biomarker-based strategies can help bridge animal and human research.

3/ Each tES modality operates through distinct mechanisms:
✔️ tDCS: polarity-dependent plasticity
✔️ tACS: frequency-specific entrainment
✔️ tRNS: stochastic resonance & GABAergic modulation

2/ E/I balance is essential for healthy brain function, and its disruption is linked to disorders like epilepsy, autism, and Alzheimer’s. tES offers a way to shift this balance by modulating synaptic plasticity, glial activity, and neural dynamics.

🧵1/ In this mini-review, we explore how transcranial electrical stimulation (tES)—including tDCS, tACS, and tRNS—modulates the brain’s excitation/inhibition (E/I) balance through cellular, synaptic, and network-level mechanisms.
📄 doi.org/10.3389/fnin...

7/
📬 Feedback and discussion welcome!
🧵End of thread

6/
👨‍🔬 Authors: @carlosasleon.bsky.social‬, Isabel Cordones, Alba Jiménez-Díaz, Guy Cheron, Javier F. Medina & Javier Márquez-Ruiz
📍 Brain Stimulation Translational Lab, ‪@pablodeolavide.upo.es‬ + international collaborators

5/
In brief:
⚡️ Cb-tDCS differentially modulates cerebellar and cortical circuits
🌐 Effects extend beyond the stimulated area, highlighting remote network modulation — key for clinical applications

4/
📊 We also analyzed oscillatory dynamics:
Cathodal Cb-tDCS increased low gamma (30–45 Hz) and decreased high-frequency oscillations (255–300 Hz) in S1
No spectral changes in Crus I/II

3/
What about long-term effects?
🔹 Crus I/II: modulation limited to the stimulation period
🔹 S1: anodal Cb-tDCS induced a sustained increase in excitability and reduced GAD 65–67 immunoreactivity → suggesting decreased inhibition

2/
Using sensory-evoked potentials (SEPs), we show polarity-specific modulation:
➕ Anodal Cb-tDCS increases SEP amplitude in Crus I/II but decreases it in S1
➖ Cathodal Cb-tDCS decreases SEP amplitude in Crus I/II but increases it in S1

🔗 Full paper here: doi.org/10.7554/eLif...
🙏 Thanks to our great team at @pablodeolavide.upo.es, UCLA, UPV/EHU, and Baylor
🧠 #Neuroscience #tDCS #Cerebellum #Neuromodulation #eLife #OpenScience

🛠️ So what now?
Let’s bring in high-definition tDCS with field direction control.
Designing protocols that consider neuron alignment could boost reliability and open the door to personalized neuromodulation 🧑‍⚕️⚡

Not just PCs! Other cerebellar neurons also showed heterogeneous responses. But orientation explains much of the puzzle 🧩

By labeling and reconstructing PCs, we showed that if their dendrites point toward the electrode, anodal tDCS ⬆️ excites them. If they point away, it ⬇️ inhibits them.

🔍 Using single-cell recordings, morphological reconstructions, and Neuropixels probes, we found that PCs respond very differently to the same tDCS depending on how their dendrites align with the electric field. Some increase their firing, others decrease it—same current, opposite effects! 🤯

We show that this variability has an anatomical explanation: the orientation of Purkinje cells (PCs)—the sole output of the cerebellar cortex—relative to the electric field determines how they respond to stimulation. 🧠⚡.

🔬 From animal models to early clinical trials, we highlight the mechanistic and translational aspects of this cutting-edge technique — with a focus on its therapeutic application in Alzheimer’s and Parkinson’s disease.

#Neurostimulation #Neuroscience #Neurodegeneration #BrainOscillations #tACS