In an effort to determine whether the "growth state" and the "mature state" of a neuron are differentiated by different programs of gene expression, we have compared the rapidly transported (group I) proteins in growing and nongrowing axons in rabbits. We observed two polypeptides (GAP-23 and GAP-43) which were of particular interest because of their apparent association with axon growth. GAP-4...

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual...

PURPOSE The signaling of retinal ganglion cell (RGC) death after axotomy is partly dependent on the generation of reactive oxygen species. Shifting the RGC redox state toward reduction is protective in a dissociated mixed retinal culture model of axotomy. The hypothesis for the current study was that tris(2-carboxyethyl)phosphine (TCEP), a sulfhydryl reductant, would protect RGCs in a rat optic...

Objective: To investigate the effect of exogenous Glial cell derived neurotrophic factor (GDNF) on the expression of retinal excitatory amino acid transporter-1 (EAAT-1) and glutamine synthetase (GS) of rats after optic nerve axotomy. Methods: Right unilateral optic nerve crush (ONA) model of Sprague-Dawley rats (56) was established, and divided into 4 groups randomly. Right eyes of each group ...

Peripheral axotomy-induced sprouting of thick myelinated afferents (A-fibers) from laminae III-IV into laminae I-II of the spinal cord is a well-established hypothesis for the structural basis of neuropathic pain. However, we show here that the cholera toxin B subunit (CTB), a neuronal tracer used to demonstrate the sprouting of A-fibers in several earlier studies, also labels unmyelinated affe...

Penetrating limb injuries are common and usually heal without long-lasting effects, even when nerves are cut. However, rare nerve-injury patients develop prolonged and disabling chronic pain (neuralgia). When pain severity is disproportionate to severity of the inciting injury, physicians and insurers may suspect exaggeration and limit care or benefits, although the nature of the relationship b...

To facilitate an understanding of injury-induced changes within the nervous system, we used a single-cell, in vitro model of axonal injury. Sensory neurons were individually dissociated from the CNS of Aplysia and placed into cell culture. The major neurite of some neurons was then transected (axotomized neurons). Axotomy in hemolymph-containing culture medium produced long-term hyperexcitabili...

Optic nerve transection results in the apoptotic cell death of the majority of retinal ganglion cells by 14 days. The neurotrophin brain-derived neurotrophic factor (BDNF) enhances survival of retinal ganglion cells. In addition, the small heat shock protein Hsp27, with its anti-apoptotic effects, may be important for neuron survival following axotomy or trophic factor withdrawal. We recently r...

Two TTX-resistant sodium channels, SNS and NaN, are preferentially expressed in c-type dorsal root ganglion (DRG) neurons and have been shown recently to have distinct electrophysiological signatures, SNS producing a slowly inactivating and NaN producing a persistent sodium current with a relatively hyperpolarized voltage-dependence. An attenuation of SNS and NaN transcripts has been demonstrat...