Structural development of the feline mental nerve

Area of Science:

• Neuroscience
• Developmental Biology
• Veterinary Anatomy

Background:

• The feline mental nerve (MN) is a crucial branch of the inferior alveolar nerve (IAN).
• Understanding the structural development and aging of the MN is vital for feline neuroanatomy.
• Previous studies noted age-related degeneration in the IAN.

Purpose of the Study:

• To investigate the qualitative and quantitative structural development of the feline mental nerve (MN).
• To compare the MN's structural development and aging with the inferior alveolar nerve (IAN).
• To determine the potential causes of age-related axon degeneration in the IAN.

Main Methods:

• Electron microscopy was used to examine the MN's structure.
• Samples were collected from 40 days postconception (dpc) to 11 years of age.
• Axon myelination, morphology, and size distribution were analyzed.

Main Results:

• Myelination of the MN began at 40-45 dpc and was complete by 2 months post-birth.
• Fully differentiated nodal-paranodal morphology was achieved by 2 months.
• The MN had a higher proportion of unmyelinated axons compared to the IAN.
• No age-related axon degeneration was observed in the MN, unlike in the IAN.

Conclusions:

• The feline mental nerve undergoes significant structural development early in life.
• The MN exhibits resilience to age-related degeneration, contrasting with the IAN.
• IAN degeneration may be linked to dental factors rather than cutaneous branches of the MN.