Acetylcholine Measurement of Cerebrospinal Fluid by In Vivo Microdialysis in Freely Moving Rats

Abstract

Acetylcholine (ACh) and choline (Ch) levels in rat cerebrospinal fluid (CSF) were determined by in vivo microdialysis (CSF microdialysis) in both halothane-anesthetized and freely-moving rats. The Ch/ACh ratio in CSF perfused with Ringer's solution (30 ail/30 min) containing 10-5 M physostigmine, a centrally active cholinesterase inhibitor, was significantly lower than that in unprocessed CSF due to significantly higher ACh levels in the former. The successive measurement on the 2nd and 7th day after the guide cannula implantation demonstrated the feasibility of the CSF microdialysis method for repetitive monitoring of CSF ACh and Ch levels in freely moving rats without extensive tissue damage. Intra peritoneal administration of physostigmine caused an increase in CSF ACh levels, whereas administra tion of neostigmine, which cannot penetrate into the blood brain barrier, did not. Furthermore, a centrally active acetylcholinergic M,-receptor agonist, AF102B, produced an increase in CSF ACh and Ch levels. Thus, the present study demonstrates that CSF microdialysis is a useful method for evaluating overall cen tral cholinergic activity and investigating the pharmacological effects of various drugs that act via the central cholinergic system.

Synthesis of fluorescent Molecularly Imprinted Polymer Nanoparticles Sensing Small Neurotransmitters with High Selectivity Using Immobilized Templates with Regulated Surface Density

“…The lowest concentration of the detection would be higher than 1 µM. Several papers have reported acetylcholine concentrations in brain plasma fluid in the tens of pM [ 27 , 28 , 29 ]. Unfortunately, this fMIP-NP has limited sensitivity to acetylcholine, though the concentrations of acetylcholine around the neurons may be higher.…”

Therapeutic Issues in Vascular Dementia: Studies, Designs and Approaches

“…The pathological interplay of AD and VaD is further underlined by emerging evidence of shared cardiovascular risk factors, such as hypertension, hypercholesterolemia and diabetes, and of cognitive benefits from treatment interventions, such as for hypertension. [61][62][63] There is accumulating evidence for cholinergic system compromise in VaD, both from animal 64 and human studies. 65 In a clinical dementia cohort, 60% of patients with VaD and 30% with AD had hyperintensities involving the cholinergic projections, and more severe involvment correlated with worse executive function.…”