BioMedicine 2024

Seminar: Impact of microglia-astrocyte communication on neuronal function and survival (July 5)

Synopsis: Dr. MacVicar will describe how communication between the brain’s glial cells (microglia and astrocytes) is important in supporting many important brain functions including the maintenance of neuronal activity and even neuronal repair. In this talk Dr. MacVicar will describe how brain function is supported by metabolic reprogramming of glia; how immunometabolism modifies feedback regulation of synaptic function and finally how metabolic reprogramming promotes astrocyte support of microglia immunosurveillance and promotes neuronal survival. The relevance to glial involvement in Alzheimer’s dementia will be discussed.

Lab Bio: Dr. MacVicar’s research has focused on the interactions between nerve cells and the surrounding support cells of the brain called glia in the maintenance of brain function and neurodegeneration. In 1984 he was the first to show that astrocytes, previously thought to be passive, can display neuronal-like active voltage gated calcium and potassium ion currents and responses to transmitters . Since then his work has shown that that glia including astrocytes and microglia are not just support cells but are active participants in brain activity, both responding to and altering activity of nerve cells and directly modifying cerebrovascular responses. His work has been published in Science, Nature, Cell, J Neuroscience, Glia.

Seminar: Microvascular Resilience, Injury, and Regeneration (July 4)

Synopsis: Dr. Segal illustrates how a background in exercise physiology led to a career of studying mechanisms of blood flow control with an emphasis on microcirculation. Ensuing studies of resistance arteries that control blood flow to skeletal muscle and to the brain differentiate the resilience of endothelial cells vs. smooth muscle cells to injury from oxidative stress and illuminate how these interactions are affected by sex, advanced age, and diet. Exploring how microvessels and myofibers regenerate following acute injury is providing insight into contrasting outcomes while identifying future studies.

Lab Bio: Research in the Segal laboratory centers on understanding blood flow regulation as exemplified by skeletal muscle in response to exercise. Studies have centered on elucidating the nature of signaling between skeletal muscle fibers and microvessels as well as between microvascular endothelium and smooth muscle cells in light of how these interactions are modulated by autonomic, sensory and somatic innervation. Ascending vasodilation describes the ability of signals initiated within the smallest microvessels (capillaries and terminal arterioles) to spread upstream into arteriolar networks and feed arteries that control the distribution and magnitude of tissue blood flow. Defining the morphology and physiology of microvascular networks is now being applied towards understanding how myofibers, microvessels, and peripheral nerves interact during regeneration and reinnervation following acute injury. Current studies focus on how “crosstalk” between these critical components of intact skeletal muscle affect each other’s ability to recover structure and function. Complementary studies center on understanding how vascular smooth muscle cells and endothelial cells of the vascular wall are differentially protected from acute oxidative stress in light of their ability to adapt to chronic oxidative stress, as occurs during advanced age or consuming a western-style diet. Gaining new insight into cellular mechanisms of regeneration and survival will translate into improving the ability to restore and protect tissue blood flow, organ function, and the quality of life in patients following traumatic injury.