Brain Stim Lab

A special day for our lab! Marta Estévez Rodríguez successfully defended her PhD thesis on March 12, receiving the highest possible distinction: sobresaliente cum laude.

Her doctoral work, “Exploring the effects of transcranial Direct Current Stimulation on the cortical excitation/inhibition balance: an optogenetic approach” , was carried out under the supervision of Prof. Javier Márquez Ruiz at the Translational Brain Stimulation Lab.

🧠 From circuits to mechanisms

Rather than focusing solely on global effects of stimulation, Marta’s thesis dives into the circuit-level mechanisms underlying tDCS. By combining optogenetic strategies with in vivo electrophysiology, her work disentangles how specific neuronal populations respond to externally applied electric fields.

A central contribution of the thesis is showing that the impact of tDCS cannot be fully understood without considering the balance between excitation and inhibition at the microcircuit level. Her findings provide:

• A refined view of how excitatory and inhibitory neurons differentially contribute to stimulation outcomes
• Experimental evidence supporting a cell-type-dependent interpretation of tDCS effects
• A framework to better connect stimulation protocols with physiological responses in cortical networks

Altogether, this work pushes the field toward a more mechanistically grounded and precision-oriented approach to non-invasive brain stimulation.

👩‍⚖️ Evaluation committee

The thesis was evaluated by an international panel of experts:

• Dr. Raudel Sánchez Campusano (Universidad Pablo de Olavide, Spain) – President
• Dr. Desire Humanes Valera (HM CINAC / HM Hospitales, Spain) – Secretary
• Dr. Marco Cambiaghi (Università di Verona, Italy) – Member

Their discussion highlighted both the technical strength and the conceptual clarity of the work.

🌟 Looking ahead

Marta’s PhD represents a significant contribution to ongoing efforts to understand how brain stimulation interacts with neural circuits. It also reinforces one of the key directions of our lab: bridging cellular-level mechanisms and translational applications.

Congratulations, Marta! This is just the beginning—we’re excited to see where your research goes next 🚀