Molecular mechanism of touch sensitivity in the Schnauzenorgan of the Elephant Nose Fish

This research focuses on the sense of touch – a fundamental physiological capacity present in all animals, including humans, which endows them with the ability to sense the physical world through the skin. The sense of touch is essential for navigation in the environment, for handling tools, manipulating objects, detecting the texture of food, for sensing a mother’s caring touch or the bite of a predator.

Even though the sense of touch is important for every aspect of an animal’s existence, it remains one of the least well understood senses. Indeed, we know very little about how touch is detected, and how this ability changes in different species during evolution. This project aims to fill the gap in our knowledge about the sense of touch by studying Elephant Nose Fish (Gnathonemus petersii).

G. petersii is a tactile specialist animal who uses its flexible chin appendage, called the Schnauzenorgan, in a manner similar to a finger in order to find food in the bed of murky rivers. The fascinating ability of G. petersii to find food by touch rather than through vision or smell lends a unique opportunity to study this sense from the perspective of a tactile champion.

This project will obtain mechanistic insights into the process of touch detection by sensory neurons of the peripheral nervous system of vertebrates. To achieve broader impact, results from this research will be disseminated through an extracurricular outreach program. By combining in-person lectures and experiments with online classes, this outreach program will disseminate scientific knowledge in the area of physiology among students of different ages, with an emphasis on the ethnic and socioeconomic groups traditionally underrepresented among scientists.

The scientific and outreach components of this project will provide fundamental training for graduate students to foster their development as researchers and educators.

This project will investigate how G. petersii achieves mechanosensory specialization at cellular and molecular levels. The Schnauzenorgan of G. petersii is innervated by myelinated trigeminal touch receptors, which terminate in the skin as bare nerve endings, without forming a complex with corpuscular structures. The goal of this project is to perform functional and histological investigation of the novel type of mechanoreceptors from the Schnauzenorgan of G. petersii, and identify the molecular mechanism of its touch sensitivity.

The project will test whether the trigeminal ganglia of G. petersii contains an expanded population of mechanoreceptors, investigate whether mechanoreceptors innervating the Schnauzenorgan of G. petersii have augmented ability to sense touch, and reveal molecules that convert touch into excitation. To achieve this, the project will utilize a multidisciplinary approach, combining electrophysiology, histology and bioinformatics.

Results from this proposal will be essential for understanding molecular evolution of mechanosensitivity in vertebrates.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.