An electrochemical investigation into the effects of local and systemic administrations of sodium nitroprusside in brain extracellular fluid of mice.

Sodium nitroprusside (SNP) is a nitric oxide (NO)-donor drug used clinically to treat severe hypertension, however, there are limitations associated with its mechanism of action that prevent widespread adoption. In particular, its impact on cerebral hemodynamics is controversial and direct evidence on its effects are lacking. Electrochemical methods provide an attractive option to undertake real time neurochemical measurements in situ using selective microsensors.

A platinum oxide-based microvoltammetric pH electrode suitable for physiological investigations.

Attempts to develop miniaturised pH electrodes for in vivo monitoring have received much attention in recent years. Continuous real-time pH measurements may be predictive of potentially dangerous deviations in metabolic events that could improve patient prognosis. Herein, we report the in vitro investigation of a physiologically relevant, Pt oxide-based microvoltammetric pH electrode.

In vitro development and in vivo application of a platinum-based electrochemical device for continuous measurements of peripheral tissue oxygen.

Acute limb ischaemia is caused by compromised tissue perfusion and requires immediate attention to reduce the occurrence of secondary complications that could lead to amputation or death. To address this, we have developed a novel platinum (Pt)-based electrochemical oxygen (O) device for future applications in clinical monitoring of peripheral tissue ischaemia. The effect of integrating a Pt pseudo-reference electrode into the O device was investigated in vitro with an optimum reduction potential of -0.

Real-Time Amperometric Recording of Extracellular H₂O₂ in the Brain of Immunocompromised Mice: An In Vitro, Ex Vivo and In Vivo Characterisation Study.

We detail an extensive characterisation study on a previously described dual amperometric H₂O₂ biosensor consisting of H₂O₂ detection (blank) and degradation (catalase) electrodes. In vitro investigations demonstrated excellent H₂O₂ sensitivity and selectivity against the interferent, ascorbic acid. Ex vivo studies were performed to mimic physiological conditions prior to in vivo deployment.

Long Term Amperometric Recordings in the Brain Extracellular Fluid of Freely Moving Immunocompromised NOD SCID Mice.

We describe the in vivo characterization of microamperometric sensors for the real-time monitoring of nitric oxide (NO) and oxygen (O₂) in the striatum of immunocompromised NOD SCID mice. The latter strain has been utilized routinely in the establishment of humanized models of disease e.g.

Continuous real-time in vivo measurement of cerebral nitric oxide supports theoretical predictions of an irreversible switching in cerebral ROS after sufficient exposure to external toxins.

Background: Mathematical models of the interactions between alphasynuclein (αS) and reactive oxygen species (ROS) predict a systematic and irreversible switching to damagingly high levels of ROS after sufficient exposure to risk factors associated with Parkinson's disease (PD).

Objectives: We tested this prediction by continuously monitoring real-time changes in neurochemical levels over periods of several days in animals exposed to a toxin known to cause Parkinsonian symptoms.

Methods: Nitric oxide (NO) sensors were implanted in the brains of freely moving rats and the NO levels continuously recorded while the animals were exposed to paraquat (PQ) injections of various amounts and frequencies.

An investigation of hypofrontality in an animal model of schizophrenia using real-time microelectrochemical sensors for glucose, oxygen, and nitric oxide.

Glucose, O2, and nitric oxide (NO) were monitored in real time in the prefrontal cortex of freely moving animals using microelectrochemical sensors following phencyclidine (PCP) administration. Injection of saline controls produced a decrease in glucose and increases in both O2 and NO. These changes were short-lived and typical of injection stress, lasting ca.

Brain nitric oxide: regional characterisation of a real-time microelectrochemical sensor.

A reliable method of directly measuring endogenously generated nitric oxide (NO) in real-time and in various brain regions is presented. An extensive characterisation of a previously described amperometric sensor has been carried out in the prefrontal cortex and nucleus accumbens of freely moving rats. Systemic administration of saline caused a transient increase in signal from baseline levels in both the prefrontal cortex (13 ± 3pA, n=17) and nucleus accumbens (12 ± 3pA, n=8).

Nitric oxide monitoring in brain extracellular fluid: characterisation of Nafion-modified Pt electrodes in vitro and in vivo.

A Nafion(5 pre-coats/2 dip-coats)-modified Pt sensor developed for real-time neurochemical monitoring has now been characterised in vitro for the sensitive and selective detection of nitric oxide (NO). A potentiodynamic profile at bare Pt established +0.9 V (vs.

Calibration of NO sensors for in-vivo voltammetry: laboratory synthesis of NO and the use of UV-visible spectroscopy for determining stock concentrations.

The increasing scientific interest in nitric oxide (NO) necessitates the development of novel and simple methods of synthesising NO on a laboratory scale. In this study we have refined and developed a method of NO synthesis, using the neutral Griess reagent, which is inexpensive, simple to perform, and provides a reliable method of generating NO gas for in-vivo sensor calibration. The concentration of the generated NO stock solution was determined using UV-visible spectroscopy to be 0.