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

Abstract

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.

Effects of single-point acupuncture (HT7) in the prevention of test anxiety: Results of a RCT

“…Acupuncture significantly reduced the extent of orthostatic stress correlates with the change in morning salivary cortisol [ 28 ]. Finally, acupuncture has been shown to decrease the serum cortisol concentration of horses subjected to startle tests, which are stressful conditions for the animals [ 35 ].…”

Individual Differences in Responsiveness to Acupuncture: An Exploratory Survey of Practitioner Opinion

“…Those characteristics/behaviours which were most often considered to impact on treatment outcome ( Table 3 ) included what acupuncture author Bob Flaws once called “the three frees”—relaxation, diet and exercise—but also self-motivation , willingness to follow advice given, general state of health and openness to new experiences. In the HRV literature on acupuncture, parasympathetic activation or an improvement in sympathovagal balance is often found to result from acupuncture treatment [ 56 , 57 , 58 ], so a pre-existing ability to relax could facilitate this. The remaining items are all quite straightforward and easy to interpret in the context of acupuncture, where for instance patients less open to new experiences are presumably less likely to procure treatment in the first place.…”

Laserpuncture Increases Serum Concentration of Insulin-Like Growth Factor–1 in Adolescent Rats

“…Some theories suggest that local stimulation is received by the receptor and transmitted by the nervous system to the visceral organs as a segmental effect and to the brain as a central effect. 19 The visceral organs in this case, the gaster and intestines, have increased motility due to the autonomous system. The nucleus tractus solitarius (NTS) is in the brainstem and is recognized as the primary relay for visceral information from the cardiovascular, respiratory, and gastrointestinal (GI) systems.…”

“…Therefore, acupuncture will maintain balance and improve the efficiency of some organism systems. 19,20 Use of acupuncture also can influence 322 HANDAYANI ET AL.…”

“…Another role of ghrelin is to maintain an energy balance by sending neuroendocrine signals from the gaster to the brain. 19,20 Several sources have reported the effects of acupuncture on ghrelin. Güçel et al studied the effect of ghrelin on obesity, wherein an increase in ghrelin was associated with weight loss in obese women.…”