Neural control of the circulation with particular interest in the roles of the brain in regulating the sympathetic nervous system, arterial pressure, and fluid intake. My studies utilize a combination of electrophysiological, neuroanatomical, molecular, and behavioral approaches in anesthetized and conscious rats.
The lab is currently pursuing 2 lines of research related to how the brain regulates autonomic control of cardiovascular function in rats.
- We are examining how a specific region of the brain stem (caudal ventrolateral medulla: CVLM) regulates the sympathetic nerve activity (SNA) that maintains blood pressure. The CVLM provides the major restraint to SNA, and reductions in the activity of this region are linked with hypertension and increased reactivity to stress. We use neuroanatomical approaches to discover how the CVLM is connected to other areas of the brain and physiological studies to understand how the CVLM functions, including recording from individual CVLM neurons in anesthetized rats.
- The brain stem is a critical site for integration of regulatory mechanisms for cardiovascular function and respiratory function. Disruptions in these connections may contribute to diseases such as sleep apnea and sudden infant death syndrome. We are mapping how and where these two regulatory systems are linked using electrophysiological approaches and stimuli such as hypoxia.
- Obesity is an epidemic health problem in the US today and is associated with several significant disruptions in cardiovascular regulation. Namely, hypertension, increased risk of stroke, and exaggerated responses to stress. We use the obese Zucker rat as a model of obesity to study how autonomic regulation is altered in obesity.
Go to PubMed
Schreihofer, A.M., D.A. Mandel, S.C. Mobley, and D.W. Stepp. Development of impaired sympathetic baroreceptor reflexes occurs after the onset of obesity in obese Zucker rats, Submitted to Am J Physiol Reg, 2006.
D'Angelo, G.D., J.D. Mintz, J.E. Tidwell,
A. M. Schreihofer, D. M. Pollock, and D. W. Stepp. Impaired b-adrenergic-mediated vasodilation contributes to augmented cardiovascular response to stress in obese Zucker rats. In Press, Hypertension, 2006.
Mobley, S.C., D.A. Mandel, and
A.M. Schreihofer (2006). Cholecystokinin differentially affects baro-activated GABAergic neurons in rat caudal ventrolateral medulla, In press, J Neurophysiol, 2006.
Mandel, D.A. and
A.M. Schreihofer (2006). Central respiratory modulation of baro-activated GABAergic neurons in rat caudal ventrolateral medulla, J Physiol. 572: 881-896.
Schreihofer, A.M., S. Ito, and A.F. Sved (2005). Brain stem control of arterial pressure in chronic arterial baroreceptor denervated rats. Am J Physiol Regulatory Integrative Comp Physiol. 289: R1746-R1755.
Schreihofer, A.M., Clark Hair, and David Stepp (2005). Reduced plasma volume and mesenteric vascular reactivity in obese Zucker rats. Am J Physiol Regulatory Integrative Comp Physiol 288: R253-R261.
Schreihofer, A.M. and P.G. Guyenet (2003). Baro-activated neurons in the caudal ventrolateral medulla (CVLM) with pulse-modulated activity express GAD67 mRNA. J Neurophysiol 89: 1265-1277.
Schreihofer, A.M., and P. G. Guyenet (2002). The baroreflex and beyond: The control of sympathetic vasomotor tone by GABAergic neurons in the caudal ventrolateral medulla. Clin Exper Pharmacol and Physiol 29: 514-421.
Schreihofer, A. M., R. L. Stornetta, and P. G. Guyenet (2000). Regulation of sympathetic tone and arterial pressure by rostral ventrolateral medulla after depletion of C1 cells in rat. J Physiol 529:221-236.
Schreihofer, A. M., and P. G. Guyenet (2000). Sympathetic reflexes after depletion of bulbospinal catecholaminergic neurons with anti-DbH-saporin. Am J Physiol Regulatory Integrative Comp Physiol 279: R729-R742.
