Functional Neurovascular Mapping Team will develop high-resolution MRI and optical imaging approaches for detecting neural or hemodynamic responses to external (including optogenetic and electric) stimuli, and map functional activities in animals and humans. Two major approaches are used; macro- and meso-scale functional imaging with ultrahigh field MRI and wide-field optics, and microscale mapping with multi-photon microscopy in health and disease. With combined recording tools with neural modulation, functional circuits and neurovascular coupling will be investigated in health and disease. This Team consists of “Advanced MR Neuroimaging” and “Neurovascular Coupling” Unit.

(1) Advanced MR Neuroimaging (PIs: Seong-Gi Kim and Kamil Uludag)

MRI is the most powerful and versatile neuroimaging tool for non-invasively measuring brain structure, physiology, and function with high spatial and temporal resolution. The Advanced MR Neuroimaging Unit aims to develop novel neuroimaging techniques, to investigate underlying biophysics, physiology, and biology, and to utilize new tools for animal and human brain research. With availability of ultrahigh magnetic fields (7T for humans and 15.2T for mice), this team focuses on developments of ultrahigh resolution fMRI, layer-specific fMRI, and dynamic BOLD MRI with hypoxic/hypercapnia challenge in animals and humans. These fMRI techniques are combined with cell-type-specific optogenetic, chemogenetic, or electric modulations for determining neural circuits in healthy and diseased animals.

(2) Neurovascular Coupling (PIs: Minah Suh and Yong Ho Kim)

We utilize cellular-resolution optical imaging techniques to investigate the relationship among neurons, glial cells, and the vascular system for developing novel treatments of brain disorders, including Alzheimer's disease, epilepsy, and brain cancer. In such brain disease conditions, the interaction between immune cells introduced from the periphery and innate glial cells present in the brain can play a critical role in the pathological development process. We employ in vivo real-time two-photon imaging combined with a chronic cranial window system to measure the dynamics of microglial cells and the calcium signals of astrocytes in both healthy and diseased conditions. Through these studies, we conduct basic mechanistic studies to determine the role of glial cells in neurological disease situations. Through the collaborative studies with Animal MR Team and Neural Interface Team, the findings will serve as the foundation for developing new therapeutic approaches for intractable brain diseases.

SELECTED PUBLICATIONS

1. Whole-brain mapping of effective connectivity by fMRI with cortex-wide patterned optogenetics, Kim S. et al. (2023), Neuron, 111, 1-16

2. Dissection of brain-wide resting-state and functional somatosensory circuits by fMRI with optogenetic silencing, Jung W.B. et al. (2022), Proc Natl Acad Sci USA, 119, e2113313119

3. Improved laminar specificity and sensitivity by combining SE and GE BOLD signals, Han S.H. et al. (2022), Neuroimage, 264, 119675

4. Whole-brain perfusion mapping in mice by dynamic BOLD MRI with transient hypoxia, Lee D.K. et al. (2022), J Cereb Blood Flow Metab, 42, 2270- 2286

5. Deep brain stimulation of the anterior nuclei of the thalamus can alleviate seizure severity and induce hippocampal GABAergic neuronal changes in a pilocarpine-induced epileptic mouse brain, Bae S. et al. (2022), Cereb Cortex, 32, 5530-5543