I came across this article last week while browsing on Pubmed. Two things jumped out at me. One, it's a Nature paper and, two, the first author used to be Harry Goshgarian's PhD. student. I gave it a look and here's what I learned.
Spinal cord injuries are terrible. In particular though, injuries which occur above the motor neurons innervating the diaphragm (phrenic motor neurons, PMNs in C3-C6) are imminently life-threatening and the prognosis is very poor. The first obvious problem is that PMNs no longer recieve input from higher centers. In addition, inflammation due to degeneration of afferent fibers leads to upregulation of extracellular matrix molecules which potentially inhibit re-innervation. The authors hypothesized that enzymatic digestion of these molecules would improve recovery from injury. They injected the enzyme chondroitinase ABC into the phrenic motor nucleus at the same time as recieving a hemisection at C2. With the enzyme alone, the treated animals showed improved recovery of breathing, but the authors took it one step further. In another group of animals, they grafted a section of the tibial nerve from the site of the lesion (C2) to C4. Remarkably, animals in this group showed near-normal breathing activity 12 weeks after the lesion. Immunohistochemistry showed that fiber regeneration was robust and extensive at the lesion site and at the distal graft site. If this procedure works with fiber tracts to other skeletal muscles, then WOW.
Posted by Nick
No comments:
Post a Comment