Publications by authors named "Theo Lambert"

The brain is composed of a dense and ramified vascular network of arteries, veins and capillaries of various sizes. One way to assess the risk of cerebrovascular pathologies is to use computational models to predict the physiological effects of reduced blood supply and correlate these responses with observations of brain damage. Therefore, it is crucial to establish a detailed 3D organization of the brain vasculature, which could be used to develop more accurate in silico models.

View Article and Find Full Text PDF

Over the last decade, functional ultrasound (fUS) has risen as a critical tool in functional neuroimaging, leveraging hemodynamic changes to infer neural activity indirectly. Recent studies have established a strong correlation between neural spike rates (SR) and functional ultrasound signals. However, understanding their spatial distribution and variability across different brain areas is required to thoroughly interpret fUS signals.

View Article and Find Full Text PDF

Positioning and navigation are essential components of neuroimaging as they improve the quality and reliability of data acquisition, leading to advances in diagnosis, treatment outcomes, and fundamental understanding of the brain. Functional ultrasound imaging is an emerging technology providing high-resolution images of the brain vasculature, allowing for the monitoring of brain activity. However, as the technology is relatively new, there is no standardized tool for inferring the position in the brain from the vascular images.

View Article and Find Full Text PDF
Article Synopsis
  • Neuronal cell types in the brain form circuits that influence behavior, specifically in the context of orienting and defensive actions in mice.
  • By using functional ultrasound imaging and optogenetics, researchers identified how stimulating different neuronal groups in the superior colliculus activates distinct brain regions and triggers various behaviors.
  • Interestingly, this study highlights the involvement of the posterior paralaminar nuclei of the thalamus in suppressing habituation and demonstrates that neurons in downstream areas respond more to threatening visual cues, providing new insights into the brain's organizational structure for controlling instinctive behaviors.
View Article and Find Full Text PDF

Imaging large-scale circuit dynamics is crucial to understanding brain function, but most techniques have a limited depth of field. Here, we describe volumetric functional ultrasound imaging (vfUSI), a platform for brain-wide vfUSI of hemodynamic activity in awake head-fixed mice. We combined a high-frequency 1,024-channel 2D-array transducer with advanced multiplexing and high-performance computing for real-time 3D power Doppler imaging at a high spatiotemporal resolution (220 × 280 × 175 μm, up to 6 Hz).

View Article and Find Full Text PDF