Detection of Nitric Oxide Release from Single Neurons in the Pond Snail, Lymnaea stagnalis

Abstract

Multiple film-coated nitric oxide sensors have been fabricated using Nafion and electropolymerized polyeugenol or o-phenylenediamine on 30-microm carbon fiber disk electrodes. This is a rare study that utilizes disk electrodes rather than the widely used protruding tip microelectrodes in order to measure from a biological environment. These electrodes have been used to evaluate the differences in nitric oxide release between two different identified neurons in the pond snail, Lymnaea stagnalis. These results show the first direct measurements of nitric oxide release from individual neurons. The electrodes are very sensitive to nitric oxide with a detection limit of 2.8 nM and a sensitivity of 9.46 nA microM-1. The sensor was very selective against a variety of neurochemical interferences such as ascorbic acid, uric acid, and catecholamines and secondary oxidation products such as nitrite. Nitric oxide release was measured from the cell bodies of two neurons, the cerebral giant cell (CGC) and the B2 buccal motor neuron, in the intact but isolated CNS. A high-Ca2+/high-K+ stimulus was capable of evoking reproducible release. For a given stimulus, the B2 neuron released more nitric oxide than the CGC neuron; however, both cells were equally suppressed by the NOS inhibitor l-NAME.

Peripheral sensory cells in the cephalic sensory organs of Lymnaea stagnalis

“…The unipolar cells are corroborated by both methods, and the balance of evidence from NADPHd controls and anti-NOS immunoreactivity is consistent with the hypothesis that NOS is present. If they are NOS-containing, then NO is likely produced by these cells, as direct measurements of NO and metabolites involved in its production have been shown in an NADPHd-R cell in the CNS of L. stagnalis (Moroz et al, 2005;Patel et al, 2006). We found no NADPHd-R counterpart to the bipolar NOS-IR PSCs, but they are corroborated by bipolar NADPHd-R PSCs in sectioned lip tissues, and neurophysiological assays further support their nitrergic character (Elphick et al, 1995).…”

An electrochemical functional assay for the sensing of nitric oxide release induced by angiogenic factors

“…They are also amenable to mass production and can be quickly integrated into larger electronic architectures. For instance, several electrochemical investigations of NO have been carried out (17,18) using platinum modified electrodes (19)(20)(21), or chemically modified electrodes (22)(23)(24)(25). Additionally, several array designs have been proposed (24,26,27).…”

Designing sensitive and selective polymer/enzyme composite biosensors for brain monitoring in vivo

“…The use of poly-ortho-phenylenediamine (PPD) as a permselective membrane in the fabrication of implantable sensors and biosensors has been reported by a number of laboratories [59][60][61][62][63][64]. Indeed, PPD has been used in the construction of biosensors for a range analytes in different target media [63,[65][66][67][68][69][70][71].…”