Retrotrapezoid nucleus, respiratory chemosensitivity and breathing automaticity

Area of Science:

• Neuroscience
• Respiratory Physiology

Background:

• Breathing automaticity and CO2 regulation are critical, interconnected neural processes.
• The retrotrapezoid nucleus (RTN), a cluster of Phox2b-expressing glutamatergic neurons, is a potential key regulator.
• Understanding RTN function is vital for respiratory control research.

Purpose of the Study:

• To review and update the role of the RTN in breathing automaticity and CO2 homeostasis.
• To present evidence for RTN neurons' central respiratory chemoreceptor properties.
• To analyze RTN neuron control over the downstream respiratory pattern generator.

Main Methods:

• Literature review and analysis of existing research on the RTN.
• Examination of evidence regarding RTN neuron inputs and outputs.
• Synthesis of data on RTN's role in respiratory control.

Main Results:

• RTN neurons possess central respiratory chemoreceptor properties, but their activity is influenced by multiple inputs.
• RTN neurons receive significant regulation from carotid bodies and other synaptic inputs.
• Evidence suggests RTN neurons innervate the ventral respiratory column, controlling both inspiration and expiration.

Conclusions:

• The RTN is a critical control center for breathing automaticity and CO2 regulation.
• RTN neurons integrate various signals to modulate respiratory output.
• RTN neurons are proposed as the adult counterpart to the neonatal parafacial respiratory group.