Related Experiment Video
Updated: Sep 14, 2025

Analysis of Developing Tooth Germ Innervation Using Microfluidic Co-culture Devices
Published on: August 14, 2015
Intradental mechano-nociceptors serve as sentinels that prevent tooth damage
Elizabeth A Ronan1, Akash R Gandhi1, Karin H Uchima Koecklin2
1Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
None:
The trigeminal sensory neurons that innervate the tooth's vital interior-intradental neurons-are expected to drive severe pain, yet their contribution to healthy tooth sensation has not been explored. Here, we uncover a role for myelinated high-threshold mechano-nociceptors (intradental HTMRs) in tooth protection using in vivo Ca2+ imaging, opto-/chemogenetics, and the AI-driven behavioral analysis tool LabGym. Intradental HTMRs innervate the inner dentin through overlapping receptive fields and respond as the external structures of the tooth are damaged in the absence of either PIEZO2 or Nav1.8. Whereas chemogenetic activation of intradental HTMRs results in a pain phenotype marked by facial and postural changes, their transient optogenetic activation triggers a rapid, jaw-opening reflex via contraction of the digastric muscle. Our work indicates that intradental HTMRs not only trigger pain but also protect the teeth by initiating a reflexive movement of the jaws when the teeth experience damage during chewing.
Related Concept Videos
Mechanically-gated Ion Channels
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or...
Sensory Functions of the Skin
There are two main categories of receptors on the skin: capsulated and non-capsulated. The non-capsulated ones are mainly the pain receptors. The capsulated ones can be further categorized based on the...
Nociception
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin...
Cell-matrix's Response to Mechanical Forces
Anchoring junctions mechanically attach a cell to the...

