A method package for electrophysiological evaluation of reconstructed or regenerated facial nerves in rodents

Tactile information is actively acquired and processed in the brain through concerted interactions between movement and sensation. Somatosensory input is often the result of self-generated movement during the active touch of objects, and conversely, sensory information is used to refine motor control. There must therefore be important interactions between sensory and motor pathways, which we chose to investigate in the mouse whisker sensorimotor system. Voltage-sensitive dye was applied to the neocortex of mice to directly image the membrane potential dynamics of sensorimotor cortex with subcolumnar spatial resolution and millisecond temporal precision. Single brief whisker deflections evoked highly distributed depolarizing cortical sensory responses, which began in the primary somatosensory barrel cortex and subsequently excited the whisker motor cortex. The spread of sensory information to motor cortex was dynamically regulated by behavior and correlated with the generation of sensory-evoked whisker movement. Sensory processing in motor cortex may therefore contribute significantly to active tactile sensory perception.

Striated muscles of the mystacial region of the common albino mouse have been described. They were divided into two categories: extrinsic and intrinsic. The four extrinsic muscles (m. levator labii superioris, m. maxillolabialis, m. transversus nasi, m. nasalis) belong to the facial muscles. They originate on the skull and insert into the corium between the mystacial vibrissae. Their contraction moves the whole mystacial region in directions dependent on their origins. Intrinsic (follicular) muscles are associated solely with the vibrissal follicles and have no bony attachment. They were found around follicles alpha, beta, gamma, delta, around all follicles of rows A and B, and around the first six follicles of rows C, D and E. The form of the follicular muscle is a sling connecting two adjacent follicles of the same row. The arc of the sling surrounds the inferior part of the rostral follicle and the two extremities insert to the conical body of the caudal follicle and to the neighbouring corium. They are the protractors of the vibrissae. The inferior parts of the vibrissal follicles of a given row are fixed in a fibrous band which inserts in the anterior part of the muzzle. It is proposed that these bands become stretched during the protraction of vibrissae and contract, by their elasticity, immediately upon the end of the follicular muscles' contraction, executing the fast return of vibrissae to their resting, retracted position.

Dental pulp tissue contains Schwann and neural progenitor cells. Tissue-engineered nerve conduits with dental pulp cells promote facial nerve regeneration in rats. However, no nerve functional or electrophysiologic evaluations were performed. This study investigated the compound muscle action potential recordings and facial functional analysis of dental pulp cell regenerated nerve in rats.