Biology subjects

Royo, J.

Publications and source records attributed to Royo, J..

3 recordsLinked to original sources

bioRxiv2025

Transcranial in-depth ultrafast ultrasound brain imaging in non-human primates

Ultrasound Localization Microscopy (ULM) offers sub-diffraction resolution vascular imaging by tracking individual contrast microbubbles. However, transcranial implementation in non-human primates remains challenging due to the skulls acoustic attenuation and distortion. This study presents a method for non-invasive transcranial ULM imaging of the anesthetized squirrel monkey through intact skull and skin. We systematically evaluated key ultrasound acquisition parameters and identified an optimal configuration balancing resolution, depth, and vascular representation. Using these refined parameters, we achieved a system resolution of 9.5 {micro}m, measured by Fourier Ring Correlation (FRC), and consistently visualized vessels as small as 23 {micro}m. Full-brain coronal and sagittal acquisitions revealed major vascular landmarks that were reproducible across animals and slices. Importantly, this resolution enables reliable detection of penetrating arterioles and venules, key elements in neurovascular coupling and implicated in various cerebrovascular pathologies. Finally, by tracking microbubbles, we quantified flow velocities from 8.8 to 55 mm/s, corresponding to flow rates ranging from 0.1 to 279 {micro}L/min, demonstrating the techniques ability to access micro- and macrovascular dynamics. This work establishes a framework for high-resolution, non-invasive brain imaging in non-human primates, and opens promising perspectives for studying cerebral structure, function, and dysfunction in translational neuroscience.

neuroscience↗

bioRxiv2021

The Supplementary Eye Field Tracks Cognitive Efforts

Pupil dilation is known to be an index of cognitive effort. Nevertheless, our lack of knowledge of the precise dynamics through which pupil size and activity of the medial prefrontal cortex are conjugated during cognitive tasks highlights the need for its further investigation before, during, and after changes in pupil size. Here, we tested whether pupil dynamics are related to the activity of the supplementary eye field (SEF) during a mixed pro/anti-saccade oculomotor task in two macaque monkeys. We used functional ultrasound imaging (fUS) to examine temporal changes in brain activity at the 0.1-s time scale and 0.1-mm spatial resolution in relation to behavioral performance and pupil dynamics. By combining the pupil signals and real-time imaging of NHP during cognitive tasks, we were able to infer localized CBV responses within a restricted part of the dorsomedial prefrontal cortex, referred to as the SEF, an area in which anti-saccade preparation activity is also recorded. Inversely, SEF neurovascular activity measured by fUS imaging was found to be a robust predictor of specific variations in pupil diameter over short and long time scales. Furthermore, we directly manipulated pupil diameter and CBV in the SEF using reward and cognitive effort. These results demonstrate that the SEF is an underestimated but pivotal cortical area for the monitoring and implementation of cognitive effort signals.

neuroscience↗

bioRxiv2018

Genomic from Plasmodium falciparum field isolates from Benin allows the identification of PfEMP1 variants by LC-MS/MS at the patient’s level

PfEMP1 are the major protein family from parasitic origin involves in the pathophysiology of severe malaria, and PfEMP1 domain subtypes are associated with the infection outcome. In addition, PfEMP1 variability in endless and current protein repository do not reflect the immense diversity of the sequences of PfEMP1 proteins. The aim of our study was to identify the different PfEMP1 variants expressed within a patient sample by mass spectrometry. We performed a proteogenomic approach to decipher at the patients level PfEMP1 expression in different clinical settings: cerebral malaria, severe anemia and uncomplicated malaria. The combination of whole genome sequencing approach, RNAsequencing, and mass spectrometry proteomic analysis allowed to attribute PfEMP1 sequences to each sample and classify the relative expression level of PfEMP1 proteins within each sample. We predicted PfEMP1 structures using the newly identified protein sequences. We confirmed the involvement of DBL{beta} in malaria pathogenesis and observed that CIDR domains linked to ICAM-1 binding DBL{beta} domains displayed EPCR binding structure.

microbiology↗