Salivary nerve growth factor reactivity to acute psychosocial stress: a new frontier for stress research.
OBJECTIVE
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.


METHODS
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.


RESULTS
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).


CONCLUSIONS
This study is the first to document sNGF as a marker that responds to stress in humans.
Psychology Department, University of Oregon, 1227, Eugene, OR 97403. hlaurent@uoregon.edu.
Heidemarie K
HK
Laurent
Sean M
SM
Laurent
Douglas A
DA
Granger
D000208:Acute Disease; D000704:Analysis of Variance; D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D003220:Conflict, Psychological; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007124:Immunoenzyme Techniques; D016014:Linear Models; D008297:Male; D020932:Nerve Growth Factor / Q000378:metabolism* / Q000502:physiology; D010913:Pituitary-Adrenal System / Q000502:physiology; D012463:Saliva / Q000378:metabolism; D012747:Sexual Partners / Q000523:psychology; D013315:Stress, Psychological / Q000378:metabolism*; D055815:Young Adult; D000516:alpha-Amylases / Q000378:metabolism*
D015415:Biomarkers; D020932:Nerve Growth Factor; D000516:alpha-Amylases; D006854:Hydrocortisone
ANS; HPA; cortisol; nerve growth factor; stress; α-amylase