Central neural correlates of learned heart rate control during exercise: central command demystified

Area of Science:

• Neuroscience
• Cardiovascular Physiology

Background:

• Central command integrates neural signals to modulate cardiovascular and motor functions during exercise.
• Understanding the neural circuitry of central command is essential for comprehending exercise physiology and related disorders.

Purpose of the Study:

• To identify specific brain regions involved in the central command of cardiovascular and motor responses during exercise.
• To characterize different neural control systems influencing heart rate (HR) during physical exertion and voluntary HR modulation.

Main Methods:

• Four monkeys were trained to control their heart rate (tachycardia of exercise).
• Electrical stimulation was applied to 24 different brain sites, primarily in limbic structures, while monitoring HR.
• The effects of stimulation were analyzed during resting conditions, exercise, and operantly controlled HR tasks.

Main Results:

• Four distinct systems modulating HR during exercise and operant control were identified.
• One system consistently increased HR during both exercise and operant control.
• Another system increased HR but abolished operant HR control.
• A third system showed attenuated stimulation effects during exercise.
• The fourth system, crucial for central command, increased HR during both tasks but was significantly attenuated during operant HR control, implicating the mediodorsal nucleus, nucleus ventralis anterior, and cingulate cortex.

Conclusions:

• The study identified distinct neural systems regulating cardiovascular responses during exercise.
• A specific system, including the mediodorsal nucleus, nucleus ventralis anterior, and cingulate cortex, plays a significant role in central command.
• These findings advance our understanding of the neural basis of exercise physiology and autonomic control.