title: Cold pressor stress affects cardiac attenuation of startle.
abstract: Stress may affect cardio-afferent neural traffic. We investigated whether acute autonomic stress has an impact on cardiac modulation of startle (CMS), a 'background' methodology for assessing baro-afferent signal transmission. Therefore, 38 healthy volunteers received acoustic startle stimuli (105 dB) at 6 different latencies relative to the R-wave (R +0, 100, 200, 300, 400, and 500 ms; randomized order), both before and immediately after either a cold pressor (n = 19) or a control intervention (n = 19). Blood pressure was enhance d significantly in the cold pressor group right after the intervention (+13.7/5.7 mmHg), reflecting sustained autonomic activation after the stress procedure. Before stress, startle responses were lowest for latencies of R +200 and +300 ms, corroborating previous findings. After the cold pressor test, startle responsiveness was lowest for earlier latencies (R +0, +100 and +200 ms). Stress facilitation of pre-ejection baro-afferent traffic originating from atrial mechano-sensitive receptors may be associated with this time shift effect. We conclude that the cardiac modulation of startle is sensitive to altered temporal baro-afferent feedback characteristics induced by stress and autonomic activation.
authors.affiliation: Institute of Psychobiology, University of Trier, Trier, Germany. schulza@uni-trier.de
authors.forename: André
authors.initials: A
authors.lastname: Schulz
authors.forename: Debora E
authors.initials: DE
authors.lastname: Plein
authors.forename: Steffen
authors.initials: S
authors.lastname: Richter
authors.forename: Terry D
authors.initials: TD
authors.lastname: Blumenthal
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schächinger
mesh_terms: D000161:Acoustic Stimulation; D001341:Autonomic Nervous System / Q000502:physiology; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D003080:Cold Temperature; D004562:Electrocardiography; D004576:Electromyography; D005260:Female; D006225:Hand / Q000502:physiology; D006321:Heart / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011312:Pressure; D013216:Reflex, Startle / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology*; D055815:Young Adult