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Biomedical subjects

K L Davis

Publications and source records attributed to K L Davis.

At least 343 records · Page 19Linked to original sources
PubMed1980

CSF monoamine metabolites in depression and schizophrenia.

The authors report cerebrospinal fluid (CSF) concentrations of five monoamine metabolites before and after probenecid administration in normal subjects and patients with depression and schizophrenia. No differences were found in baseline metabolite concentrations among the three groups. CSF metabolite and CSF probenecid concentrations were significantly correlated in depressed patients for all metabolites, and there was decreased postprobenecid accumulation of homovanillic acid in the CSF of depressed patients compared with schizophrenic patients and with normal subjects. The authors propose a method for correcting for probenecid concentrations. Data from normal subjects should be of value for other investigators using the probenecid technique.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1980

CKholinergic mechanisms and anterior pituitary hormone secretion.

The study of the hypothalamic-pituitary axis has been a useful approach in assessing neurotransmitter function in man. Unfortunately, its utility in exploring cholinergic mechanisms is complicated by the induction of a stress response. However, the possibility that cholinergic transmission is a mediating factor in the stress response perhaps raises a more fundamental consideration.

Acetylcholine↗
PubMed1979

Dimethylaminoethanol (deanol): effect on apomorphine-induced stereotypy and an animal model of tardive dyskinesia.

Dimethylaminoethanol (DMAE) was administered acutely to rats subsequently injected with spomorphine. A dose of 80 mg of DMAE had no effect on the severity of apomorphine-induced stereotypy. However, 160 mg of DMAE significantly diminished the severity of apomorphine-induced stereotypy. This dose of DMAE did not significantly alter spontaneous locomotor activity. DMAE did not reduced apomorphine-induced stereotypy in animals previously exposed to haloperidol and presumed to have postsynaptic dopamine receptor supersensitivity. These results with DMAE are contrasted with the effects of choline chloride, and suggest that choline chloride may be more effective than DMAE at augmenting striatal cholinergic activity.

Animals↗
PubMed1979

Cerebrospinal fluid acetylcholinesterase in neuropsychiatric disorders.

Acetylcholinesterase (AChE) was measured in the cerebrospinal fluid (CSF) of patients with a diagnosis of Huntington's disease, depression, schizophrenia, or mania and also in the CSF of normal subjects. No significant differences in CSF AChE were found between any diagnostic group and normal subjects. Furthermore, the administration of choline chloride, physostigmine, or probenecid did not significantly alter CSF AChE. No diurnal variation in CSF AChE activity was apparent. These findings, combined with the unclear relationship of brain AChE to CSF AChE, suggest that this measurement does not reflect the relative cholinergic underactivity presumed to exist in some neuropsychiatric conditions.

Acetylcholinesterase↗
PubMed1979

EEG effects of physostigmine and choline chloride in humans.

Seventeen normal volunteers received either 0.5 mg, 1.5 mg, or 2.5 mg physostigmine i.v. in a placebo-drug-placebo single-blind design. EEG was recorded simultaneously and analyzed by computerized spectral analysis. Eleven healthy elderly volunteers (mean age = 69.1 years) with mild memory impairment were treated with placebo, followed by oral choline chloride (either 8 g/day for 3 weeks, or 16 g/day for 1 week), and then, again, placebo. Recordings of spontaneous EEG and EEG event-related potentials (contingent negative variation) were obtained during both placebo and choline treatments. The larger doses of physostigmine produced an increase in low frequency activity and a slowing of the peak alpha frequency. Oral choline chloride had no effect on the EEG as measured by spectral analysis, but appears to have differential effects on contingent negative variation (CNV) amplitude and reaction time, depending upon the initial CNV amplitude.

Adult↗
PubMed1979

Choline chloride treatment of memory deficits in the elderly.

Eight elderly patients with mild memory impairment were given choline chloride, a drug that increases brain acetylcholine concentrations. After 16 g/day of choline for 7 days, average memory performance was not different from performance during pre- and postcholine placebo treatment, although the patient with the poorest baseline performance improved considerably on choline.

Aged↗
PubMed1979

Choline chloride in schizophrenia.

The authors investigated the possibility that choline chloride might reduce schizophrenic symptoms by increasing central cholinergic activity. In a single blind crossover study, up to 20 g/day of choline chloride had no significant effect on clinical ratings of nine schizophrenic patients. However, there was some evidence that choline significantly increased symptoms of depression.

Adult↗
PubMed1979

Is there a limbic system equivalent of tardive dyskinesia?

Long-term administration of antipsychotic drugs to animals induces super-sensitive mesolimbic postsynaptic dopamine receptors. It is possible that a similar process can occur in man. Following a reduction in the dose of antipsychotic medications, or their complete discontinuation, mesolimbic dopamine receptor supersensitivity could be reflected in rapid relapse of schizophrenic patients, the development of schizophrenic symptoms in patients with no prior history of schizophrenia, or in the necessity for ever-increasing doses of long-acting depot fluphenazine to maintain a remission.

Animals↗
PubMed1978

Physostigmine: improvement of long-term memory processes in normal humans.

Nineteen normal male subjects received 1.0 milligram of physostigmine or 1.0 milligram of saline by a slow intravenous infusion on two nonconsecutive days. Physostigmine significantly enhanced storage of information into long-term memory. Retrieval of information from long-term memory was also improved. Short-term memory processes were not significantly altered by physostigmine.

Acetylcholine↗