Lakshmi Sangameswaran

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Dorsal root ganglion neurons express a wide repertoire of sodium channels with different properties. Here, we report the cloning from rat, dorsal root ganglia (DRG), cellular expression, and functional analysis of a novel tetrodotoxin-sensitive peripheral sodium channel (PN), PN1. PN1 mRNA is expressed in many different tissues. Within the rat DRG, both the(More)
Small neurons of the dorsal root ganglia (DRG) are known to play an important role in nociceptive mechanisms. These neurons express two types of sodium current, which differ in their inactivation kinetics and sensitivity to tetrodotoxin. Here, we report the cloning of the alpha-subunit of a novel, voltage-gated sodium channel (PN3) from rat DRG. Functional(More)
Neurons of the dorsal root ganglia (DRG) express a diversity of voltage-gated sodium channels. From rat DRG we have cloned and functionally expressed a tetrodotoxin-sensitive sodium channel alpha subunit, NaCh6/Scn8a/rPN4, and a splice variant, rPN4a. Primary structure analysis shows NaCh6/Scn8a/rPN4 to be highly homologous (99%) to NaCh6 and most likely(More)
The novel sodium channel PN3/alpha-SNS, which was cloned from a rat dorsal root ganglion (DRG) cDNA library, is expressed predominantly in small sensory neurons and may contribute to the tetrodotoxin-resistant (TTXR) sodium current that is believed to be associated with central sensitization in chronic neuropathic pain states. To assess further the role of(More)
Voltage-gated sodium channels underlie the generation of action potentials in excitable cells. Various sodium channel isoforms have been cloned, functionally expressed and distinguished on the basis of their biophysical properties or differential sensitivity to tetrodotoxin (TTX). In the present study, we have investigated the immunolocalization of the(More)
Alterations in sodium channel expression and function have been suggested as a key molecular event underlying the abnormal processing of pain after peripheral nerve or tissue injury. Although the relative contribution of individual sodium channel subtypes to this process is unclear, the biophysical properties of the tetrodotoxin-resistant current, mediated,(More)
Previous studies have been directed at the elucidation of neuron-specific gene expression in the mammalian central nervous system. In particular, we have identified a series of marker molecules that are expressed in cerebellar Purkinje cells with varying degrees of specificity. Here, we show by light microscopic immunocytochemistry and Northern transfer and(More)
Immunochemical and immunohistochemical techniques were used to map the tissue distribution and cellular localization of a rat brain-specific polypeptide, termed PEP-19. PEP-19 was found to be abundant in the cerebellum and olfactory bulbs but was present at much lower levels in other gross brain regions. It was undetectable in all nonneural tissues examined(More)
By comparing the HPLC profiles of cerebellar extracts from adult and neonatal rats, a developmentally regulated polypeptide, termed PEP-19, was identified. The concentration of PEP-19 rose from 0.1 nmol/g of cerebellum at birth to 2 nmol/g at 20 days postpartum. The polypeptide could also be detected at lower levels in olfactory bulbs of adult rats but was(More)
Two tetrodotoxin-resistant voltage-gated sodium channels, SNS/PN3 and SNS2/NaN, have been described recently in small-diameter sensory neurones of the rat, and play a key role in neuropathic pain. Using region-specific antibodies raised against different peptide sequences of their alpha subunits, we show by Western blot evidence for the presence of these(More)