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Biomedical subjects

D E Moss

Publications and source records attributed to D E Moss.

40 records · Page 3Linked to original sources
PubMedDate not supplied

Methanesulfonyl fluoride (MSF) blocks scopolamine-induced amnesia in rats.

Cholinesterase inhibitors, such as physostigmine and tetrahydroaminoacridine, have been found to alleviate some of the memory deficits characteristic of senile dementia of the Alzheimer's type (SDAT). Many toxic side effects, however, have been associated with the use of these compounds. Recently, a cholinesterase inhibitor, methanesulfonyl fluoride (MSF), was discovered to have low toxicity, central nervous system (CNS) selectivity, and a long therapeutic duration. The purpose of this research was to determine if MSF (1.5 mg/kg) would be effective in reducing or blocking amnesia induced by various doses of scopolamine (0.2, 0.6, and 2.0 mg/kg). One hundred and twenty-two female Sprague-Dawley albino rats were trained and retention tested in a Y-maze brightness discrimination task. MSF was highly effective in reducing scopolamine-induced amnesia.

Amnesia↗
PubMedDate not supplied

Chronic methanesulfonyl fluoride enhances one-trial per day reward learning in aged rats.

Aged (24-month-old) rats were treated chronically with methanesulfonyl fluoride (MSF), an acetylcholinesterase (AChE) inhibitor with selectivity for central nervous system AChE, or with injection vehicle alone. Twelve 0.22 mg/kg IP injections were given over 4 weeks. MSF rats showed significantly greater speed and accuracy on a 1 trial/day discriminative reward learning task. The chronic MSF treatment resulted in a 56% decrease in brain AChE activity but no discernable locomotor side effects and no liver damage as indicated by aspartate transferase activity.

Acetylcholinesterase↗
PubMedDate not supplied

Age-impaired impulse flow from nucleus basalis to cortex.

Recent studies have renewed interest in the role of acetylcholine (ACh) in the cognitive changes associated with ageing and dementia. Deficits in cortical choline acetyltransferase (ChAT) in Alzheimer's disease have been consistently demonstrated, while other research has suggested a connection between deterioration of cortical ACh fibres and dementia. However, despite clear biochemical and anatomical evidence for a fall in ACh in dementia, results of therapeutic trials with cholinergic agonists, precursors and cholinesterase inhibitors have been inconsistent. Such findings suggest that cortical cholinergic disorders are not wholly a function of simple biochemical change; alterations of impulse flow along cholinergic fibres could well be as debilitating. An important extrinsic source of cortical ACh innervation derives from neurones diffusely located in rat basal forebrain, denoted the nucleus basalis (NB). We have now investigated the impulse conduction properties of cortically projecting, putatively cholinergic NB axons in adult and aged rats and have found that conduction latencies from NB to frontal cortex are significantly longer (by 51%) in aged animals. In addition, systematic analysis varying cortical stimulation depth revealed that these longer latencies are due entirely to decreased conduction velocities in the subcortical fibre projections. Indeed, intracortical velocities were virtually identical in the two groups. Our results indicate that ageing occasions a decrease in the temporal fidelity of impulse flow in the cholinergic input to the cortex from the NB, a previously overlooked but potentially important element in cognitive deficits that occur with age.

Aging↗