Effects of Meditation on Mental Health and Cardiovascular Balance in Caregivers

Background: Caring for a loved one can be rewarding but is also associated with substantial caregiver burden, developing mental outcomes and affecting happiness. The aim of this study was to determine the effects of a four-week, 16-h presential meditation program on physiological and psychological parameters and vagal nerve activity in high-burden caregivers, as compared to a control group. Methods: A non-randomized repeated-measures controlled clinical trial was conducted. Results: According to the ANCOVA results, the global happiness score (F = 297.42, p < 0.001) and the scores for all subscales were significantly higher in the experimental group than in the control group at 5 weeks. Anxiety levels were also significantly reduced in the experimental group (F = 24.92, p < 0.001), systolic (F = 16.23, p < 0.001) and diastolic blood (F = 34.39, p < 0.001) pressures, and the resting heart rate (F = 17.90, p < 0.05). HRV results revealed significant between-group differences in the HRV Index (F = 8.40, p < 0.05), SDNN (F = 13.59, p < 0.05), and RMSSD (F = 10.72, p < 0.05) in the time domain, and HF (F = 4.82 p < 0.05)) in the frequency domain, which were all improved in the experimental group after the meditation program. Conclusions: Meditation can be a useful therapy to enhance the mental health and autonomic nervous system balance of informal caregivers, improving symptoms of physical and mental overload.

Effects of Meditation on Mental Health and Cardiovascular Balance in Caregivers

Background: Caring for a loved one can be rewarding but also associated with substantial caregiver burden, developing mental outcomes and affecting happiness. Eventually, these physical and psychological disorders can lead to an imbalance of the autonomic nervous system. Meditation has been found to offer multiple benefits to relieve these disorders and reduce the risk of cardiovascular disease. The aim of this study was to determine the effects of a four-week 16-hour presential meditation program on physiological and psychological parameters and vagal nerve activity in high-burden caregivers, comparing the results with those not receiving this program. Methods: A non-randomized repeated-measures controlled clinical trial was conducted, dividing participants between intervention and control groups by convenience allocation because random assignment was ethically inappropriate. Results: After the meditation program, the experimental group showed a significant reduction in anxiety levels (F= 24.92, p&lt;0.001), a non-significant amelioration of depression levels (F= 1.75, p=0.19), and significantly improved heart rate variability (F= 8.40, p&lt;0.05) and SDNN (F=15.59, p&lt;0.05). Conclusions: Meditation can be a useful therapy to enhance the mental health and autonomic nervous system balance of informal caregivers, improving symptoms of physical and mental overload.

Intraneural Recordings in Rat Vagus Nerves Using Carbon Fiber Microelectrode Arrays v1

This protocol is for obtaining physiological action potential recordings in rat vagus nerves using carbon fiber microelectrode arrays (CFMAs) in spontaneous and blood glucose and breathing modulated conditions. The rats were anesthetized with isoflurane, which maintained consistent and stable depth of anesthesia for recording vagal nerve activity with ultra-small carbon fibers. Blood glucose levels were modulated by intraperitoneal (IP) injection of glucose, insulin, or 2-deoxy-D-glucose (2-DG). Breathing was modulated by increasing anesthesia depth. Carbon fiber microelectrode arrays are available through the Multimodal Integrated Neural Technologies (MINT) technology hub (https://mint.engin.umich.edu/), which is supported by the National Science Foundation (Award 1707316). This research was also supported by the National Institute of Health SPARC Program (Award OT2OD024907).

Cardiac interaction between mother and infant: enhancement of heart rate variability

The vagal activity of infants is represented by heart rate variability (HRV) and associated with both growth and socioemotional development. The enhancement of an infant’s vagal tone activity might be beneficial for development. This study explored whether HRV in infants aged 3–8 months can be enhanced by influencing HRV in mothers (40 dyads). The power of the low frequency (LF) component of maternal HRV was facilitated using slow-paced breathing. We investigated whether the change in maternal HRV affected the LF component in infants held by their mothers. In older infants (N = 14, 6–8 months) the LF power showed an increase during maternal paced breathing, whereas a delayed increase occurred after termination of maternal paced breathing in younger infants (N = 16, 3–5 months). These results show that the effects of maternal cardiac activity on the infant’s HRV are age-dependent. This age-dependent reactivity of the infant’s HRV could be due to the development of the inner model in infants which regulates physiological functions, including cardiac activity. This finding might help develop efficient methods for enhancing vagal nerve activity in infants.

Anaphylaxis stimulates afferent vagal nerve activity and efferent sympathetic nerve activity in the stomach of anesthetized rats

Systemic anaphylaxis is a life-threatening and allergic reaction that affects various organs. We previously reported that, in the stomach, gastric vasoconstriction occurring at the late phase (15–55 min after injection of ovalbumin antigen) was observed in anesthetized rats sensitized with ovalbumin. In addition, anaphylaxis enhances gastric motility and delays emptying. However, the role of extrinsic autonomic nervous system on antigen-induced gastric alterations was not known. Thus, using the same rat anaphylaxis model, we aimed to determine the changes in the efferent and afferent autonomic nerve activities in the stomach during anaphylactic hypotension. The findings showed that injection of ovalbumin antigen caused substantial systemic hypotension in all sensitized rats. The efferent gastric sympathetic nerve activity (ef-GSNA), but not the efferent vagal nerve activity, increased only at the early phase (1–10 min after injection of ovalbumin antigen) and showed baroreceptor reflex, as evidenced by a stimulatory response to sodium nitroprusside-induced hypotension. In general, excitation of ef-GSNA could induce pylorus sphincter contraction and gastric vasoconstriction. In the present study, we found that sympathectomy attenuated the anaphylaxis-induced decrease in gastric flux but not the increase in gastric vascular resistance. Thus, the increase in ef-GSNA may cause anaphylactic pylorus sphincter contraction but not anaphylactic gastric vasoconstriction. On the other hand, the afferent gastric vagal nerve activity, but not the afferent sympathetic nerve activity, increased during the early phase of anaphylactic hypotension. However, vagotomy produced no effects on the anaphylactic gastric dysfunction. In conclusion, the gastric sympathetic nerves partly modulate stomach function during systemic anaphylaxis.