I have been disturbed lately by the number of issues on which people
take extreme positions...
Inhibitors Are Neither Necessary nor Desirable for Microdialysis Studies
of Brain Acetylcholine (329k)
Acetylcholine (ACh), one of the major neurotransmitters in brain, has
an important role in various types of cognition, including attention
and memory. ACh is critical to the neurocognitive dysfunction in Alzheimer’s
disease and possibly other psychiatric disorders such as schizophrenia.
Furthermore, the development of drugs which increase the availability
of brain ACh is a major research goal. Thus, direct measurement of brain
ACh release under physiological conditions, using in vivo microdialysis,
in laboratory animals is of great importance. Because of the low concentration
of ACh, many of the microdialysis studies published to date required
Acetylcholinesterase (AChE) inhibitors in the perfusion medium to increase
basal ACh. However, the artificially increased concentration exerts
a significant influence on the cholinergic system, thereby making interpretation
of drug effects problematic. We have recently developed a highly sensitive
method of ACh measurement, which requires no AChE inhibitors. Advantages
of the new method are discussed.
of Cyclic Voltammetry Using Finite Difference Methods (46k)
This article discusses the application of finite difference methods
to the simulation of cyclic voltammograms with particular reference
to the BAS simulation software DigiSim®.
Electrochemistry of Thiol Self-Assembled Monolayers (SAMs) on a Hanging
Mercury Drop Electrode (HMDE) (71k)
electrochemistry of functionalized self-assembled monolayers on Hg is
studied by cyclic voltammetry and AC voltammetry. The results suggest
that thiols can be adsorbed either chemically or physically depending
on the Hg potential. The transformation between these two states occurs
via an oxidation-reduction process. While a multi-layer of short chemisorbed
thiols is formed under positive potentials than the oxidation-reduction
process, a dense monolayer is self-assembled under more negative potentials.
of Pump-Switching Step Gradients for Bioanalytical LC/MS/MS
separate isocratic LC pumps were configured to perform fast, step gradients
for bioanalytical LC/MS/MS assays, simultaneously reducing analysis time
and ion suppression, and improving peak shape. Although the technique
offers significant advantages for bioanalytical LC/MS/MS assays, it
also presents some practical challenges. A newly designed LC pump, the
BAS PM-92, is shown to be ideally suited for pump-switching step gradients.
In the EC Literature, In the MD Literature, Miscellany (79k)
In the EC Literature: Adrian Bott, BAS, discusses papers on a
special fullerene derivative, reagentless biosensors and much more.
In the LC Literature: Bruce Solomon of BAS reviews discussions
on use of a dual-mode electrochemical detector to determine 3-nitrotyrosine
by high-pressure LC and several other recent papers.
In the MD Literature: James Gitzen of BAS looks at articles on:
the possible reduction in certain behaviors by mGlu2/3 agonists due
to changes in dopaminergic activity; the delivery of ondansetron HCI
via transdermal microdialysis probes; and microdialysis to separate
inorganic anions for analysis in wastewater clean-up.
Miscellany: Upcoming conferences and symposia, faculty vacancies,
the new Indiana Instrumentation Institute and a discussion of available
tools and services for CNS research.