A novel reticular node in the brainstem synchronizes neonatal mouse crying with breathing

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Developmental Neuroscience

Background:

• Mammalian vocalizations, including human speech and animal calls, exhibit rhythmic temporal patterns.
• The underlying cellular and molecular mechanisms governing vocalization tempo and the specific neural circuits involved remain largely unknown.
• Understanding vocalization control is crucial for fields ranging from speech pathology to comparative biology.

Purpose of the Study:

• To identify the neural substrates responsible for the temporal patterning of neonatal mammalian vocalizations.
• To elucidate the cellular and molecular mechanisms that dictate the rhythm and tempo of vocalizations.
• To investigate the relationship between vocalization control and respiratory circuitry.

Main Methods:

• Recording and analysis of neonatal mouse vocalizations.
• Optogenetic and chemogenetic manipulation of identified brainstem neural populations.
• In vivo electrophysiological recordings to assess neural activity.
• Anatomical tracing to determine neural connectivity.

Main Results:

• Identified rhythmically timed neonatal mouse vocalizations occurring within single breaths.
• Discovered a specific brainstem node, the intermediate reticular oscillator (iRO), essential for structuring these vocalizations.
• Demonstrated that the iRO autonomously paces and patterns vocalizations, coordinating them with breathing via direct inputs to respiratory and motor circuits.

Conclusions:

• A novel mammalian brainstem oscillator, the iRO, embedded within the respiratory network, is critical for neonatal vocalization production.
• The iRO acts as a central pattern generator for vocalizations, integrating respiratory and motor control.
• This research provides fundamental insights into the neural control of vocal timing and rhythm in mammals.