Axel Shum

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Within the first 2 h after adrenalectomy in rats there is a marked decrease in hypothalamic, brain stem, and hippocampal serotonin (5HT) turnover. This adrenalectomy-induced decrease in brain 5HT turnover was demonstrated in this study using four different methods. These include 1) accumulation of 5HT after monoamine oxidase inhibition with pargyline, 2)(More)
To thrive, the Open Educational Resource (OER) movement, or a given initiative, must make sense of a complex, changing environment. Since " sustainability " is a desirable systemic capacity that our community should display, we consider a number of principles that sharpen the concept: resilience, sensemaking and complexity. We outline how these motivate the(More)
After bilateral adrenalectomy in adult male rats a triphasic change occurs in the plasma concentration of radioimmunoassayable ACTH. Plasma ACTH is markedly elevated at 2 h, returns almost to normal at 20 h, and is again markedly elevated 92 h after adrenalectomy. We have examined brain serotonin (5HT) turnover during this period using two nonsteady state(More)
Exposure to intense sound can damage or kill cochlear hair cells (HC). This loss of input typically manifests as noise induced hearing loss, but it can also be involved in the initiation of other auditory disorders such as tinnitus or hyperacusis. In this study we quantify changes in HC number following exposure to one of four sound damage paradigms. We(More)
The role of PRL in mediating the haloperidol-induced increase in tuberoinfundibular dopamine synthesis rate was assessed by studying the effects of administration of PRL antiserum. Antiserum to PRL generated in rabbits and not cross-reacting with other anterior pituitary hormones was administered IV to adult, male rats which received haloperidol 2.5 mg/kg(More)
Following bilateral adrenalectomy in adult male rats, there occurs a pattern of triphasic change in basal plasma concentration of radioimmunoassayable ACTH. Plasma ACTH is markedly elevated at 2 h, has returned down almost to normal at 20 h and is again markedly elevated 96 h after adrenalectomy. We have examined serotonin (5HT) synthesis rats in several(More)
Catecholamine and serotonin neurons in the hypothalamus regulate the secretion of corticotropin releasing factor (CRF). We considered the possibility that CRF might in turn affect the activity of these aminergic neurons. We examined the effect of intracisternal administration of synthetic CRF on the synthesis turnover rates of dopamine and serotonin in the(More)
Serotonin synthesis, as estimated by the accumulation of 5-hydroxytryptophan 25 min following aromatic-L-amino acid decarboxylase inhibition, was measured in the medulla, pons-midbrain and posterior and anterior hypothalamus of rats subjected to left coronary artery ligation and their sham-operated controls. Left coronary artery ligation led to reduction in(More)
Acute coronary artery ligation in pargyline-treated rats decreased serotonin and increased 5-hydroxyindoleacetic acid in the medulla and posterior hypothalamus. Lidocaine applied topically to the left ventricle completely prevented these alterations. No changes in serotonin were observed in the other brain regions examined. These data suggest a reflex(More)
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