Introducing the brain: control of heart rate (Introduction)

by David Turell , Friday, June 21, 2024, 17:09 (7 days ago) @ David Turell

From cortex to brain stem:

https://www.science.org/doi/10.1126/science.adl3353?utm_source=sfmc&utm_medium=emai...

"Editor’s summary
Voluntary control of one’s heart rhythm can be achieved through feedback training. This technique is practiced in areas such as free diving and meditation, and offers the promise of future applications in therapy for arrhythmias, pain, and depression. However, the neural circuits underlying this biofeedback remain poorly understood. Using biofeedback-based operant learning, Yoshimoto et al. developed a rat model of self-regulated heart rate control. Neuronal activity in the anterior cingulate cortex was central to the development of bradycardia. Electrophysiology, calcium imaging, and synaptic tracing techniques revealed the complete neuronal pathway from the anterior cingulate cortex to the heart through several relay stations. —Peter Stern.

"Heart rate (HR) can be voluntarily regulated when individuals receive real-time feedback. In a rat model of HR biofeedback, the neocortex and medial forebrain bundle were stimulated as feedback and reward, respectively. The rats reduced their HR within 30 minutes, achieving a reduction of approximately 50% after 5 days of 3-hour feedback. The reduced HR persisted for at least 10 days after training while the rats exhibited anxiolytic behavior and an elevation in blood erythrocyte count. This bradycardia was prevented by inactivating anterior cingulate cortical (ACC) neurons projecting to the ventromedial thalamic nucleus (VMT). Theta-rhythm stimulation of the ACC-to-VMT pathway replicated the bradycardia. VMT neurons projected to the dorsomedial hypothalamus (DMH) and DMH neurons projected to the nucleus ambiguus, which innervates parasympathetic neurons in the heart."

A science writer's view:

https://mail.google.com/mail/u/0/#inbox/FMfcgzQVxHfCQbBSxKbhsjngjwrtCchQ

"You may think about intentionally making your heart beat faster or slower, but some professional free divers and seasoned meditators seem to be able to control the rhythm of their hearts using nothing but willpower. Indeed, scientists have found that providing people with real-time information about their bodies—a technique known as biofeedback training—can help them take charge of processes usually considered involuntary. And it even works in rodents!

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"When the authors of a new study used this approach in rats, the animals learned to slow their heart rate within just 30 minutes and were able to maintain a level of reduction even after the training period had ended. The researchers also discovered that a region of the brain called the anterior cingulate cortex is anatomically connected to the heart and plays an integral role in slowing its rhythm. The team notes that, in humans, this same area appears to light up during meditation."

Comment: just another example of how the brain tracks and controls all of our internal organs. It is all a numbers game, whether it is pulse rate or how many molecules in a production system or in solution in the blood or the urine as examples. This degree of control complexity requires design, not chance mutations.