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Biomedical subjects

T J Crow

Publications and source records attributed to T J Crow.

At least 325 records · Page 18Linked to original sources
PubMed1981

The relationships between clinical response, psychophysiological variables and plasma levels of amitriptyline and diazepam in neurotic outpatients.

In a 4 week study of the response of neurotic outpatients to treatment with amitriptyline, diazepam, amitriptyline and diazepam, or placebo clinical and psychophysiological variables and plasma levels of the drug were assessed. Clinical improvements were substantial in all treatment groups but clear relationships between clinical change, psychophysiological change and plasma levels of the drugs were not established. There was no relationship between plasma levels of the drugs and cigarette smoking. It is concluded that neither plasma levels of amitriptyline and diazepam nor change in skin conductance responsivity offer a useful guide to clinical response to drug treatment.

Adult↗
PubMed1981

3H-Flupenthixol binding in post-mortem brains of schizophrenics: evidence for a selective increase in dopamine D2 receptors.

The binding of 3H-cis flupenthixol (3H-FPT) to dopamine receptors in membrane preparations from control subjects and schizophrenics was studied. Using a fixed concentration of 3H-FPT, no differences were observed between controls and all schizophrenics, although 3H-FPT binding was increased in schizophrenics who apparently were drug-free at the time of death. Scatchard analysis of 3H-FPT binding revealed that in drug-treated schizophrenics both the number of binding sites (BM) and the dissociation constant (KD) were increased, whilst in drug-free schizophrenics only the BM was increased. Using domperidone to differentiate 3H-FPT binding to D1 and D2 dopamine sites, it was found that only D2 sites were increased in drug-free schizophrenics. The results are discussed with reference to previous studies on dopamine receptors in schizophrenia, and the effects of neuroleptic treatment. It is suggested that a selective increase in D2 receptors may be associated with the disease process in schizophrenia.

Binding, Competitive↗
PubMed1981

Neuropathological and biochemical observations on the noradrenergic system in Alzheimer's disease.

Abnormalities of the noradrenergic system in Alzheimer's disease have been investigated by comparing quantitative histological and biochemical components of this transmitter system (locus coeruleus neuron counts and cortical dopamine beta-hydroxylase (DBH) activity, respectively) in a series of demented and non-demented cases. Cortical activities of the noradrenergic enzyme, DBH, did not correlate significantly with the number of locus coeruleus neurons, a finding which contrasts with the previous observations in animal brains of reductions in cortical DBH following locus coeruleus lesions. The extent of Alzheimer-type abnormalities, assessed from either morphological measures (mean plaque counts) or clinical measures (Mental Test Scores) of severity, was not significantly related to the cortical activity of DBH in the present series of cases, although non-significant trends were apparent. In contrast the activity of the cholinergic enzyme choline acetyltransferase did, as previously reported, correlate significantly with the extent of Alzheimer-type abnormalities, suggesting that abnormalities of the cholinergic system are more closely associated with specific aspects of the Alzheimer disease process than those of the noradrenergic system.

Alzheimer Disease↗
PubMed1981

A new approach to the role of noradrenaline in learning: problem-solving in the marmoset after alpha-noradrenergic receptor blockade.

Nine marmosets (Callithrix jacchus) were tested on a variety of visual discrimination learning tasks in a Wisconsin General Test Apparatus with or without alpha-noradrenergic receptor blockade achieved by the administration of aceperone. After aceperone, animals were found to be severely and consistently impaired at learning the first task of each test session and to be impaired on new and repeated reversal learning. They were, however, unimpaired on learning another similar task in each test session and on performance of a well-learnt task. Results were interpreted as evidence for defective association formation which can be compensated for by suitable priming or practice.

Adrenergic alpha-Antagonists↗
PubMed1981

Neurotensin: first report of a cortical pathway.

Neurotensin is one of a growing number of putative peptidergic neurotransmitters common to both gut and brain. It has been localised in many areas of the central nervous system including the amygdala, hypothalamus and brain stem, although its physiological significance is unknown. Using a specific antiserum to neurotensin and immunocytochemical techniques, we have investigated the distribution of neurotensin and neurotensin containing pathways in the rat limbic system. Immunoreactive neurotensin was found in all areas of the limbic system and within the limbic cortex. In addition a previously unreported group of neurotensin-containing cell bodies was found in the subicular region of the hippocampus.. In serial sections we were able to trace a pathway which appears to be the first peptide-containing pathway to be reported in the cerebral cortex from the dorsal hippocampus to the anterior cingulate cortex, following the path of the cingulate bundle. The presence of neurotensin (a putative excitatory transmitter) in this new hippocampal efferent pathway indicates that it may have an important role in cortical "association" mechanisms and limbic cortex functions.

Animals↗
PubMed1981

Neurochemical activities in human temporal lobe related to aging and Alzheimer-type changes.

Activities relating to 3 neurotransmitter and 4 neuropeptide systems have been examined in human temporal lobe (post mortem) for their relationships with age and Alzheimer-type changes (senile plaques and cognitive function). Significant alterations with increasing age (from 61 to 92 years) in a series of non-demented cases included a reduction of the cholinergic enzyme, choline acetyltransferase, and an increase in vasoactive intestinal peptide immunoreactivity. In cases of alzheimer's disease the only neurochemical activity investigated which correlated significantly with cognitive impairment (assessed from a Mental Test Score obtained shortly before death) and with the severity of Alzheimer-type abnormalities (senile plaques density) was choline acetyltransferase. Further analyses of the data in relation to the severity of plaque formation suggest that alterations in other neurochemical activities including reductions in dopamine-beta-hydroxylase activity, cholecystokinin octapeptide (aqueous extracted) and somatostatin immunoreactivities and an increase in substance P immunoreactivity, may occur at later stages of the disease process. These comparative data suggest that biochemical changes in this brain area associated with age and earlier stages of Alzheimer's disease may be relatively selective.

Aged↗
PubMed1981

Neurotransmitter receptors in brain in schizophrenia.

The binding of the dopamine agonist ADTN and of ligands for the serotonin, muscarinic cholinergic, GABA, and benzodiazepine receptors was studied in 18 schizophrenic and 19 control brains. By contrast with the previously reported increase in binding of the dopamine antagonist spiperone, ADTN binding was not increased, and there was no consistent change in binding of ligands for receptors of substances other than dopamine. The findings suggest that the increase in dopamine receptors (assessed by spiperone binding) in schizophrenia is related to the disease process rather than to previous neuroleptic medication, and may be limited to the type of dopamine receptors that bind butyrophenones.

Brain↗
PubMed1981

Platelet monoamine oxidase activity in acute schizophrenia: relationship to symptomatology and neuroleptic medication.

Platelet MAO activity was assessed in 35 schizophrenics during a trial of the isomers of flupenthixol. Enzyme activity was unrelated to severity of symptoms, the presence of delusions, hallucinations or thought disorder or to negative symptoms. In a few patients MAO activity fluctuated widely with time, but in the group of patients on medication there was a slow decrease in enzyme activity which was significant after 28 days of treatment. Enzyme activity after 14 days' drug treatment was still correlated with activity before treatment, but after 28 days this significant correlation disappeared. Slow effects of neuroleptic drugs on platelet MAO activity may explain previous findings of reduced activity of the enzyme in schizophrenia.

Acute Disease↗
PubMed1981

Institutionalization and the defects of schizophrenia.

Patients conforming to the Feighner criteria for schizophrenia who had been discharged from hospital were traced after 5-9 years. They were assessed in terms of mental state and cognitive, behavioural and neurological functioning; the results of these assessments were related to information obtained from casenotes. The findings of this study of 120 discharged patients were compared with those of an earlier study of 510 in-patients with schizophrenia. When factors of age and duration of illness were taken into account, there was no difference between the two groups in terms of positive or negative schizophrenic features or behavioural performance, although the in-patients performed less well on cognitive tests. This study indicates that the deficits of chronic schizophrenia are an integral feature of the disease process, and that any effects of institutionalisation are relatively small.

Adult↗
PubMed1980

VIP in the rat brain: evidence for a major pathway linking the amygdala and hypothalamus via the stria terminalis.

We report here on the detailed distribution of VIP-like immunoreactivity in the rat brain by a combined immunological approach using immunocytochemistry and radioimmunoassay. VIP-like immunoreactivity was widely distributed. Cell bodies and and fibres were noted principally in the cortex, hippocampus, amygdala, suprachiasmatic nucleus and brain stem. In addition dense areas of immunoreactive fibres and terminals were seen in the stria terminalis and its bed nucleus. The fibres appear to form a major VIP-containing pathway which links the amygdaloid complex with the hypothalamus. Although the functional significance of VIP in the brain is unknown, its presence in the amygdala, the hypothalamus and their linking pathway, as well as its pharmacological actions suggest that it may play a role in neuroendocrine regulation and the modulation of hypothalamic function.

Amygdala↗