Laryngeal afferent inputs during vocalization in the cat

Area of Science:

• Neuroscience
• Physiology
• Speech Science

Background:

• The larynx plays a crucial role in vocalization.
• Understanding sensory feedback from the larynx is essential for comprehending vocal control mechanisms.

Purpose of the Study:

• To investigate the types of information transmitted by laryngeal afferent nerves to the central nervous system during vocalization.
• To characterize the discharge patterns of laryngeal afferent fibers during vocalization.

Main Methods:

• Electrically induced vocalization was performed in ketamine-anesthetized cats.
• Single fibers of the laryngeal afferent nerve were recorded.
• Fibers were classified into four types based on their discharge patterns relative to vocal fold vibration and movement.

Main Results:

• Four types of laryngeal afferent fibers were identified: Type A (responding to vocal fold vibration), Type B (increased activity without synchronization), Type C (decreased activity), and Type D (responding to vocal fold adduction/abduction onset).
• These distinct patterns suggest differential encoding of laryngeal events.

Conclusions:

• Laryngeal afferent nerves transmit diverse information about vocal fold status during vocalization.
• These afferent inputs may play a significant role in the feedback control of vocalization.