Acupuncture Affects Autonomic and Endocrine but Not Behavioural Responses Induced by Startle in Horses

• Published in: Evidence-based complementary and alternative medicine 2015-01, Vol.2015 (2015), p.1-9
• Main Authors: de Almeida, Fernando Queiroz, Almeida, Norma Aparecida dos Santos, Trigo, Pablo Ignacio, Dias, Daniel Penteado Martins, Villas-Boas, Julia Dias, de Medeiros, Magda Alves
• Format: Article
• Language: English
• Subjects: Acupuncture; Analysis; Animals; Corticosteroids; Heart beat; Homeostasis; Horse sports; Horses; Physiology; Rodents; Studies; T cells; Veterinary medicine
• ISSN: 1741-427X; 1741-4288
• DOI: 10.1155/2015/219579

Startle is a fast response elicited by sudden acoustic, tactile, or visual stimuli in a variety of animals and in humans. As the magnitude of startle response can be modulated by external and internal variables, it can be a useful tool to study reaction to stress. Our study evaluated whether acupuncture can change cardiac autonomic modulation (heart rate variability); and behavioural (reactivity) and endocrine (cortisol levels) parameters in response to startle. Brazilian Sport horses ( n = 6 ) were subjected to a model of startle in which an umbrella was abruptly opened near the horse. Before startle, the horses were subjected to a 20-minute session of acupuncture in acupoints GV1, HT7, GV20, and BL52 (ACUP) and in nonpoints (NP) or left undisturbed (CTL). For analysis of the heart rate variability, ultrashort-term (64 s) heart rate series were interpolated (4 Hz) and divided into 256-point segments and the spectra integrated into low (LF; 0.01–0.07 Hz; index of sympathetic modulation) and high (HF; 0.07–0.50 Hz; index of parasympathetic modulation) frequency bands. Acupuncture (ACUP) changed the sympathovagal balance with a shift towards parasympathetic modulation, reducing the prompt startle-induced increase in LF/HF and reducing cortisol levels 30 min after startle. However, acupuncture elicited no changes in behavioural parameters.