Bianca Gonzales Cerqueira1, Glenn M. Toney2, Timothy O. Duong3
1Research Imaging Institute, Univ. of TX Health Science Center, San Antonio, TX, United States; 2Physiology, Univ. of TX Health Science Center, San Antonio, TX, United States; 3Research Imaging Institute, UT Health Science Center at San Antonio, San Antonio, TX, United States
Rat brain BOLD fMRI response to an infusion of alternating isotonic and hypertonic saline was studied. Previous studies have demonstrated that osmosensitive areas of the brain such as the organum vasculosum laminae terminalis can detect small changes in plasma osmolarity and project to the hypothalamic paraventricular nucleus which is involved in sympathetic activation. Increased sympathetic activation is of interest due to its role in many forms of hypertension. There was an significant (p=0.029) increase in average percent change of hypertonic saline (13.79%) compared to isotonic saline (-0.85%) in the anterior medial hypothalamus, which includes osmosensitive areas of the brain. This study demonstrates that non-invasive functional imagining can translated to longitudinal studies of sympathetic activation and hypertension.