The Brazilian Neurobiodiversity Network - An Initiative for Collecting and Analyzing Cetacean Brains in Brazil
Presented by Kamilla Souza
Abstract:Cetacean brains have long intrigued scientists and the general public due to their large size and high gyrification, often associated with their complex social behavior and aquatic lifestyle. However, due to the rarity of well-preserved specimens and the challenges associated with their study, cetacean neuroanatomy remains largely underexplored. This is also the case in Brazil, which, despite its vast biodiversity, lacks comparative brain morphology studies, hindering a more systematic understanding of the brain anatomy and evolution of its endemic species. To address this, we have established a network to collect and analyze the brains of stranded Brazilian cetaceans. Through this initiative, we currently have 60 specimens representing 16 species sourced from 17 collaborating research institutes. Using ultra-high-field magnetic resonance imaging and advanced methodologies, we aim to examine diverse aspects of brain morphology at both intra and inter-species levels. This initiative has provided an unprecedented opportunity to describe the brains of species such as the Guiana dolphin (Sotalia guianensis) for the first time and to update data on well-known species such as the Bottlenose dolphin (Tursiops truncatus). Additionally, it has enabled novel neuroimaging of endangered river dolphin species, including the Tucuxi (Sotalia fluviatilis) and the Amazon River dolphin (Inia geoffrensis), supporting comparative analyses between riverine and marine dolphins while also serving as an additional resource for their conservation. The structural and volumetric data from a diverse range of cetacean brains, both collected and planned for acquisition, as well as from other aquatic mammals recently collected to expand our dataset, will fill significant gaps in scientific literature, offering a more comprehensive understanding of brain diversity in cetaceans and mammals as a whole.
In-vivo submillimeter diffusion MRI for high-resolution, SNR-efficient brain imaging
Presented by Ziyu Li
Abstract: Diffusion MRI (dMRI) is a powerful tool for mapping brain connectivity, but resolution limitations hinder the study of fine-scale structures. In this talk, I will present a novel acquisition and reconstruction framework that enables ultrahigh-resolution in-vivo dMRI (0.53–0.65 mm isotropic). By combining 3D multi-slab imaging with in-plane segmentation, we improve SNR efficiency while reducing distortions and blurring. A denoiser-regularized reconstruction further enhances SNR without introducing biases. At 3T, our method achieves 0.53–0.65 mm resolution, improving U-fiber mapping and reducing gyral bias. At 7T, we robustly acquire 0.61 mm data that closely align with post-mortem data, demonstrating its potential for ultra-high-field applications. By implementing this method using open-source and scanner-agnostic framework “Pulseq”, we aim to facilitate adoption across different research and clinical settings. We are particularly interested in collaborations to explore applications in gray matter, including studies of cortical connectivity, laminar structure, and neurodegenerative diseases.
The Brazilian Neurobiodiversity Network - An Initiative for Collecting and Analyzing Cetacean Brains in Brazil
In-vivo submillimeter diffusion MRI for high-resolution, SNR-efficient brain imaging