Friday, Jun 27: 11:30 AM - 12:45 PM
Oral Sessions
Brisbane Convention & Exhibition Centre
Room: M2 (Mezzanine Level)
Presentations
Muscle sympathetic nerve activity (MSNA) is composed of bursts of action potentials generated by muscle vasoconstrictor neurones that supply arterioles in skeletal muscles. MSNA is tightly coupled to the cardiac cycle via the arterial baroreflex, and by controlling blood flow to muscle, contributes importantly to the beat-to-beat regulation of blood pressure through variations in arteriolar diameter. MSNA originates within a nucleus of the brainstem - the rostral ventrolateral medulla (RVLM). Using MSNA-coupled functional MRI (fMRI) (Macefield, 2010) - in which we record MSNA and perform fMRI simultaneously, we can exploit the higher spatial resolution and signal-to-noise found at ultra-high field 7 Tesla. We aim to functionally identify the brainstem nuclei responsible for generating sympathetic drive using high-resolution 7T fMRI coupled with direct recordings of MSNA
Presenter
Rebecca Glarin, The University of Melbourne Melbourne, VIC
Australia
Glucose is the primary fuel of the human brain, and its metabolism is tightly regulated on a cellular level. Neurons and glial cells, including astrocytes (Ast), microglia (Mic), and oligodendrocytes (Oli), distribute heterogeneously across the brain and possess divergent metabolic profiles [1]. These metabolic profiles have not been studied in the human brain. Metabolic differences within the cell types emerge from differential gene expressions. We leveraged transcriptomic data of post-mortem brains from the Allen Human Brain Atlas (AHBA) to characterize the metabolic profiles of brain cells and investigate their expression patterns across the human cortex and subcortex [2].
Epilepsy is one of the most common neurological conditions worldwide. Although many epileptic patients improve with anti-seizure medication, up to 40% of them are drug-resistant (Engel, 2016). For these patients, the most successful treatment is epilepsy surgery, whereby the region giving rise to seizures is removed. Non-invasive techniques such as magnetic resonance imaging (MRI) are key to identifying the surgical target and ensuring a seizure-free future in drug-resistant patients. Where conventional MRI is inconclusive, patients need to undergo intracranial electroencephalography (iEEG), an invasive procedure not without risk of complication, that offers restricted spatial sampling. While whole-brain structural and functional alterations have been widely studied in the epileptic brain using a tandem iEEG-MRI approach, finer-scale local alterations have yet to be assessed.
Presenter
Yigu Zhou, Montréal Neurological Institute Montréal, Québec
Canada
White matter connections coordinate functional brain activity by interconnecting various brain regions, weaving together a complex pattern with functional specializations refined throughout ontogeny and phylogeny (Thiebaut de Schotten & Forkel, 2022). Comparative analysis of white matter connections including a broader range of species could provide valuable insights into the mechanisms involved in human-specific cognitive functions. As a highly vocal Platyrrhine monkey that shares key anatomical and functional features with humans, marmosets provide a unique opportunity to chart white matter tracts for investigating brain evolution in the primate lineage.
Presenter
Yufan Wang, Institute of Automation, Chinese Academy of Science Beijing, China
China
The cortical and laminar distribution of neurotransmitter receptors is vital for brain function, yet the mechanisms for this remain poorly understood. High-resolution imaging of receptors is feasible only through ex vivo techniques like 2D autoradiography. We developed a 3D reconstruction algorithm, BrainBuilder[1], and used it to create 12 neurotransmitter receptor atlases for the macaque brain at 0.25mm³ resolution. Laminar receptor distributions from these atlases were compared with fMRI activation maps[2] and functional networks[3] to elucidate the role of neurotransmitters in brain function.
Presenter
Thomas Funck, Child Mind Institute Montréal, QC
Canada
Understanding developmental changes in brain structure is a key goal of psychiatry as the peak incidence of many mental disorders falls in adolescence. MRI enables non-invasive imaging of brain structural networks, where regions are modelled as nodes and connections as edges [1]. Structural similarity networks, based on statistical relationships between regional morphological features [2], have revealed distinct developmental processes within paralimbic and isocortical regions [3]. Perturbation to these processes may underlie globally reduced structural similarity seen in psychosis [4].
Morphometric Inverse Divergence (MIND), a novel method for estimating structural similarity from MRI, captures known aspects of biology and outperforms DTI in age prediction tasks [5]. However, similarity networks generated from multiple features can be hard to interpret. Here, we generate MIND similarity networks using T1/2w ratio, interpretable as a measure of myelin [6], and assess 1) whether networks are biologically valid and 2) what age-related changes are present in these networks. We use the common marmoset as an animal model due to an abundance of openly accessible biological data against which to validate T1/2w networks.
Presenter
Ed Hutchings, University of Cambridge Cambridge, Cambridge
United Kingdom