Spafford, Julia E
Mayo Clinic
Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada.
Citations 2
The role of α 2 -adrenergic mechanisms in sympathetic baroreflex control of human blood pressure
Spafford, Julia, Limberg, Jacqueline K. , Wiggins, Chad C. , Iannarelli, Nathaniel , Senefeld, Jonathon W. , Nicholson, Wayne T. , Shoemaker, J. Kevin , Spafford, Julia E , Harvey, Ronée E , Wiggins, Chad C , Iannarelli, Nathaniel J , Senefeld, Jonathon W , Curry, Timothy B. , Joyner, Michael J , Shoemaker, J Kevin , Baker, Sarah E , Klassen, Stephen A , Harvey, Ronée E. , Joyner, Michael J. , Baker, Sarah E. , Klassen, Stephen A.
American Journal of Physiology-Heart and Circulatory Physiology | September 3, 2025 | Volume: 329 | Issue: 5 | Pages: H1229-H1243
Intravenous dexmedetomidine infusion (selective α 2 -adrenergic receptor agonist) 1) reduced the firing probability and strength of baroreflex control over medium-sized sympathetic action potentials in muscle sympathetic nerve activity (MSNA) and 2) attenuated the transduction of MSNA bursts to changes in blood pressure (BP) by reducing the magnitude of BP responses and increasing the time to peak BP. These data suggest that neural and vascular α 2 -adrenergic mechanisms contribute to sympathetic baroreflex regulation of human BP.
Human sympathetic neuronal discharge and recruitment patterns regulate neuropeptide Y bioavailability
Limberg, Jacqueline K. , Wiggins, Chad C. , Spafford, Julia, Iannarelli, Nathaniel , Senefeld, Jonathon W. , Nicholson, Wayne T. , Joyner, Michael J. , Shoemaker, J. Kevin , Klassen, Stephen A , Limberg, Jacqueline K , Harvey, Ronée E , Wiggins, Chad C , Senefeld, Jonathon W , Curry, Timothy B. , Joyner, Michael J , Shoemaker, J Kevin , Baker, Sarah E , Spafford, Julia E , Klassen, Stephen A. , Harvey, Ronée E. , Baker, Sarah E.
American Journal of Physiology-Heart and Circulatory Physiology | October 25, 2024 | Volume: 327 | Issue: 6 | Pages: H1599-H1605
The purpose of sympathetic neuronal discharge and the recruitment of neuronal subpopulations for human circulatory homeostasis remains unknown. This study tested the hypothesis that sympathetic neuronal discharge and recruitment patterns regulate neuropeptide Y (NPY) bioavailability. Across baseline and an intravenous dexmedetomidine infusion (α2-adrenergic agonist) sympathetic action potential (AP) frequency and total sympathetic AP clusters were associated with NPY bioavailability. This is the first study to report that sympathetic neuronal discharge and recruitment patterns regulate NPY bioavailability to support circulatory homeostasis in humans.