It is well understood that the different regions of the body have cortical representations in proportion to the degree of innervation. Our current understanding of the rat upper extremity has been enhanced using functional MRI (fMRI), but these studies are often limited to the rat forepaw. The purpose of this study is to describe a new technique that allows us to refine the sensory and motor representations in the cerebral cortex by surgically implanting electrodes on the major nerves of the rat upper extremity and providing direct electrical nerve stimulation while acquiring fMRI images. This technique was used to stimulate the ulnar, median, radial, and musculocutaneous nerves in the rat upper extremity using four different stimulation sequences that varied in frequency (5 Hz vs. 10 Hz) and current (0.5 mA vs.
Peripheral nerve injury is a common and complicated traumatic disease in clinical neurosurgery. With the rapid advancement and development of medical technologies, novel tissue engineering provides alternative therapies such as nerve conduit transplantation. It has achieved significant outcomes. The scaffold surface modification is vital to the reconstruction of a pro-healing interface. Polydopamine has high chemical activity, adhesion, hydrophilicity, hygroscopicity, stability, biocompatibility, and other properties. It is often used in the surface modification of biomaterials, especially in the peripheral nerve regeneration. The present review discusses that polydopamine can promote the adhesion, proliferation, and differentiation of neural stem cells and the growth of neuronal processes. Polydopamine is widely used in the surface modification of nerve conduits and has a potential application prospect of repairing peripheral nerve injury. Polydopamine-modified scaffolds are promising in the peripheral nerve tissue engineering.
A functional muscle free flap with multiple muscle segments that could be oriented independently to produce different force vectors would be beneficial in facial reanimation and upper extremity reconstruction. The serratus anterior muscle has this potential because two or more individual muscle slips can be transferred on a single vascular pedicle. Although serratus anterior muscular anatomy has been studied previously, little attention has been given to the intramuscular anatomy. Muscle slips 5 through 9 (and 10, if present) in 50 specimens from 27 cadavers were studied following intraarterial latex injection. Eight specimens were injected with a radiopaque material (latex/diatrizoate/lead mixture) for x-ray delineation of the intramuscular vascular pattern. Slips 5 through 9 are consistently supplied by a single dominant branch of the thoracodorsal artery and innervated by the long thoracic nerve. Dissection revealed that the long thoracic nerve and its branches invariably follow the artery and divide proximal to the corresponding arterial division. There is a consistent vascular pattern to each muscle slip, in which the serratus artery gives rise to common slip arteries, each of which supplies adjacent muscle slips. The mean length of a muscle slip from its origin on the rib periosteum to the division of the common slip artery is 9.6 cm. These findings imply that the slips may be separated to the level of these common slip arteries, with up to five slips transferred on a single neurovascular pedicle and each slip oriented independently to provide multiple muscle force vectors. With these possibilities, the reconstructive surgeon may be able to restore more natural facial animation and better intrinsic muscle function in the upper extremity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.