Biology subjects

Petik, A.

Publications and source records attributed to Petik, A..

3 recordsLinked to original sources

bioRxiv2026

Modular chronic cranial platform for longitudinal functional ultrasound, optical, and ECoG recording in a gyrencephalic model species

Understanding cortical function in large, gyrencephalic brains requires following the same tissue over time and interrogating it through complementary methods - yet in practice each recording modality is run on its own preparation, across separate animals and sessions that cannot be quantitatively related, while the recorded cortex can rarely be revisited. Functional ultrasound (fUS), widefield optical imaging, and electrocorticography (ECoG) are individually mature and strongly complementary, but no single preparation has combined all three within the same chronically accessible tissue in a gyrencephalic brain. Here we present a modular chronic cranial platform, validated in three cats with implants remaining functional for up to 3.3 years that unites these modalities in one customized chamber built around fUS as an anchor modality. The platform also supports fUS imaging in awake, head-unrestrained animals, with activation maps remaining spatially consistent across imaging days. By providing stable, quantitatively reproducible access to the same cortical region over time, this platform enables longitudinal, multimodal characterization of cortical function within individual subjects.

neuroscience↗

bioRxiv2026

Pharmacokinetically optimized anesthesia enables long-term functional ultrasound imaging in the cat visual cortex

Functional ultrasound imaging (fUSI) measures cerebral blood-volume responses, so anesthesia protocols developed for BOLD fMRI may not preserve its signal. We screened three fMRI-derived anesthesia regimens for visually evoked fUSI in the cat visual cortex. Isoflurane-ketamine-medetomidine produced the strongest and most consistent responses, but the standard intramuscular medetomidine bolus suppressed the signal in one sensitive cat. Pharmacokinetic modeling guided replacement of this bolus with controlled intravenous dosing, restoring the visual response while maintaining physiological stability. The same weight-based regimen produced robust responses in the other animals. In a direct within-session test, response strength was equivalent in recordings separated by more than three hours. Across 464 recordings from 51 sessions in three cats, it showed no temporal drift during follow-up extending to 23 months. Visually evoked activation also remained clear relative to a small awake dataset, although equivalence was not established. PK-guided control of medetomidine exposure therefore enables stable, repeated fUSI of the cat visual cortex over hours to years.

neuroscience↗

bioRxiv2026

Preserved functions with profound morphological reorganization in human organotypic cultures

Human organotypic slice cultures provide experimental access to adult human neuronal circuits ex vivo, yet it remains unclear whether these networks preserve function or undergo fundamental reorganization following the profound perturbation of slice preparation. Here, we combined extracellular population and single-unit electrophysiology, longitudinal calcium imaging, and quantitative histology to track the changes of human cortical slice cultures over several weeks in vitro. Early phases were marked by pronounced variability and instability, with reduced firing rates, increased burst propensity in principal cells, elevated discharge irregularity, and heterogeneous recruitment during population activity. These functional changes coincided with substantial structural remodeling, including considerable neuronal loss, disruption of laminar architecture, reactive gliosis, and selective vulnerability of inhibitory interneurons. Strikingly, despite this progressive structural degradation, neuronal activity did not diverge but instead converged. By the fourth week in culture, electrophysiological properties, cell-type-specific firing patterns, and population-event recruitment became stable and highly consistent across patients. Calcium imaging revealed persistent, spatially confined regions of synchronous activity, indicating the preservation of structured network dynamics. These events remained within physiological regimes and lacked features of epileptiform discharges. Thus, human neuronal circuits exhibit a robust capacity for self-organization, transitioning from heterogeneous, injury-driven dynamics to stable and homogeneous functional states. This dissociation between structural deterioration and functional convergence establishes human organotypic slice cultures as a reproducible and translationally relevant platform for studying human brain network dynamics ex vivo.

neuroscience↗