Brainstem control of vocalization and its coordination with respiration

Area of Science:

• Neuroscience
• Vocalization research
• Respiratory control

Background:

• Phonation requires precise laryngeal muscle control coordinated with respiration.
• Neural mechanisms for vocal-laryngeal-respiratory coordination are not fully understood.

Purpose of the Study:

• Identify neural circuits controlling vocal cord adduction and ultrasonic vocalizations (USVs) in mice.
• Investigate the role of retroambiguus nucleus (RAm^VOC) neurons in vocal production and respiratory coordination.

Main Methods:

• Identification of vocalization-specific premotor neurons in the retroambiguus nucleus (RAm^VOC) in mice.
• Experimental manipulation of RAm^VOC neuron activity and inhibitory synapses.
• Analysis of vocalization patterns and respiratory phase coordination.

Main Results:

• RAm^VOC neurons are necessary and sufficient for vocal cord closure and USV production.
• RAm^VOC activation duration influences USV syllable length and expiration.
• Inhibitory input from the preBötzinger complex gates RAm^VOC activity during inspiration, ensuring vocal-respiratory coordination.

Conclusions:

• The retroambiguus nucleus contains excitatory premotor neurons crucial for vocalization.
• A neural circuit involving RAm^VOC and its inhibitory inputs governs vocal-respiratory coordination.
• Disruption of inhibitory gating leads to discoordination between vocalization and respiration.