title: Tissue engineering the mechanosensory circuit of the stretch reflex arc: sensory neuron innervation of intrafusal muscle fibers.
abstract: The sensory circuit of the stretch reflex arc, composed of specialized intrafusal muscle fibers and type Ia proprioceptive sensory neurons, converts mechanical information regarding muscle length and stretch to electrical action potentials and relays them to the central nervous system. Utilizing a non-biological substrate, surface patterning photolithography and a serum-free medium formulation a co-culture system was developed that facilitated functional interactions between intrafusal muscle fibers and sensory neurons. The presence of annulospiral wrappings (ASWs) and flower-spray endings (FSEs), both physiologically relevant morphologies in sensory neuron-intrafusal fiber interactions, were demonstrated and quantified using immunocytochemistry. Furthermore, two proposed components of the mammalian mechanosensory transduction system, BNaC1 and PICK1, were both identified at the ASWs and FSEs. To verify functionality of the mechanoreceptor elements the system was integrated with a MEMS cantilever device, and Ca(2+) currents were imaged along the length of an axon innervating an intrafusal fiber when stretched by cantilever deflection. This system provides a platform for examining the role of this mechanosensory complex in the pathology of myotonic and muscular dystrophies, peripheral neuropathy, and spasticity inducing diseases like Parkinson's. These studies will also assist in engineering fine motor control for prosthetic devices by improving our understanding of mechanosensitive feedback.
authors: NanoScience Technology Center, University of Central Florida, 12424 Research Parkway, Suite 400, Orlando, FL 32826, USA.
authors: John W
authors: JW
authors: Rumsey
authors: Mainak
authors: M
authors: Das
authors: Abhijeet
authors: A
authors: Bhalkikar
authors: Maria
authors: M
authors: Stancescu
authors: James J
authors: JJ
authors: Hickman
mesh_terms: D062565:Acid Sensing Ion Channels; D000818:Animals; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000379:methods*; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels / Q000032:analysis / Q000378:metabolism; D005260:Female; D005727:Ganglia, Spinal / Q000166:cytology; D018485:Muscle Fibers, Skeletal / Q000166:cytology*; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000378:metabolism; D011073:Polyamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D012026:Reflex, Stretch; D011984:Sensory Receptor Cells / Q000166:cytology*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D062565:Acid Sensing Ion Channels; C568425:Asic2 protein, rat; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels; D009419:Nerve Tissue Proteins; D011073:Polyamines; C005391:diethylenetriamine; D011092:Polyethylene Glycols; D002118:Calcium