Neurotrophins such as nerve growth factor (NGF) may represent a stress-responsive system complementing the better known neuroendocrine (hypothalamic-pituitary-adrenal axis) and autonomic nervous system, but there is little evidence for NGF response to acute stress in humans because noninvasive measures have not been available. We investigated salivary NGF (sNGF) in 40 healthy young adults confronting a romantic conflict stressor.
Five saliva samples—two collected before and three after the conflict—were assayed for sNGF, cortisol (hypothalamic-pituitary-adrenal marker), and α-amylase (sAA; ANS marker). In addition, a control group (n = 20) gave saliva samples at the same time intervals to determine whether sNGF changes were specific to the conflict stressor.
sNGF showed significant reactivity from entry to the first poststress sample among study participants (β = .13, p = .001), with nonsignificant change across poststress samples. Control participants showed no change in sNGF across the same period. Within-person changes in sNGF were generally aligned with both cortisol (β = .17, p = .003) and sAA (β = .17, p = .021) responses. Preconflict negative emotion predicted lower sNGF reactivity (β = −.08, p = .009) and less alignment with sAA (β = −.09, p = .040), whereas positive emotion predicted less alignment with cortisol (β = −.10, p = .019).
This study is the first to document sNGF as a marker that responds to stress in humans.
From the Psychology Department (H.K.L., S.M.L.), University of Wyoming, Laramie, Wyoming; Institute for Interdisciplinary Salivary Bioscience Research (H.K.L., D.A.G.), Arizona State University, Phoenix, Arizona; and School of Nursing, Public Health and Medicine (D.A.G.), Johns Hopkins University, Baltimore, Maryland.
Address correspondence and reprint requests to Heidemarie K. Laurent, PhD, Psychology Department, University of Oregon, 1227, Eugene, OR 97403. E-mail: email@example.com
Current address of H.K. Laurent: Psychology Department, University of Oregon, Eugene, Oregon.
Received for publication April 11, 2013; revision received July 17, 2013.