Long term assessment of axonal regeneration through polyimide regenerative electrodes to interface the peripheral nerve.

Polyimide sieve electrodes were implanted between the severed ends of the sciatic nerve in rats. The degree of axonal regeneration through the electrode was examined by physiological and histological methods from 2 to 12 months postimplantation. Regeneration was successful in the 30 animals implanted.

Behavioral and histological effects of endoneurial administration of nerve growth factor: possible implications in neuropathic pain.

Animal models of neuropathic pain involving incomplete nerve injury result in causalgia-like symptoms, including thermal hyperalgesia and mechanical allodynia. Although current evidence links the overexpression of nerve growth factor (NGF) to peripheral neuropathic pain, the direct effect of NGF inside a nerve has not been evaluated yet. The purpose of this study was to investigate whether a single, low-dose (1-30 ng), endoneurial administration of NGF reproduces behavioral consequences of a partial nerve injury and to analyze the changes on myelinated fibers induced by NGF.

FK506 enhances reinnervation by regeneration and by collateral sprouting of peripheral nerve fibers.

We examined the effects of FK506 administration on the degree of target reinnervation by regenerating axons (following sciatic nerve crush) and by collateral sprouts of the intact saphenous nerve (after sciatic nerve resection) in the mouse. FK506-treated animals received either 0.2 or 5 mg/kg/day, dosages previously found to maximally increase the rate of axonal regeneration in the mouse.

Improvement of regeneration with predegenerated nerve transplants in silicone chambers.

We compared regeneration and reinnervation of target organs after sciatic nerve resection and repair with silicone tubes filled with saline solution or with a peroneal nerve segment as a nerve transplant versus an autologous sciatic nerve graft leaving either 4 mm or 6 mm gaps. The aims of this study were to evaluate the effects of predegeneration and donor immunogenicity of nerve transplants. Functional reinnervation was assessed by noninvasive methods to determine recovery of sweating, sensory and motor functions in the hindpaw after three months postoperation for 4 mm and four months postoperation for 6 mm gap groups.

Alignment of collagen and laminin-containing gels improve nerve regeneration within silicone tubes.

Purpose: Placement of extracellular matrix components has been used as a mean to enhance axonal growth across nerve long gaps repaired by tubulization. However, such matrices may impede axonal regeneration depending on its density and microgeometry.

Methods: Silicone tubes were prefilled with collagen or laminin-containing gels and implanted into a 6 mm gap, a length considered limiting for regeneration, in the mouse sciatic nerve.

Bimodal dose-dependence of FK506 on the rate of axonal regeneration in mouse peripheral nerve.

FK506 has been shown to enhance the rate of axonal regeneration after peripheral nerve lesions. However, quite variable doses of FK506 have been used in different animal studies. We examined the dose-dependence of FK506 on the rate of axonal regeneration after crush lesion of the mouse sciatic nerve.

Morphologic and functional evaluation of peripheral nerve fibers regenerated through polyimide sieve electrodes over long-term implantation.

We evaluated by morphologic and functional analysis the regeneration of peripheral nerve fibers through polyimide regenerative-type electrodes over long-term implantation. Polyimide sieve electrodes were placed in silicone chambers and implanted between the severed ends of the sciatic nerve in rats. The sieve part had 281 round via holes of 40 microm in diameter, with nine integrated recording-stimulating electrodes arranged around the via holes.

Changes in mouse sudomotor function and sweat gland innervation with ageing.

Age-related changes in sudomotor neuroeffector function have been evaluated in mice aged 2 (young), 6, 12 (adult) and 18 (old) months. We evaluated sudomotor function by determining the number of sweat glands reactive to pilocarpine and the sweat output per gland on the plantar surface of the hindpaws with the impression mould technique. Protein gene product 9.