Learn More
Nicotine obtained from tobacco can improve learning and memory on various tasks and has been linked to arousal, attention, rapid information processing, working memory, and long-term memories that can cause craving years after someone has stopped smoking. One likely target for these effects is the hippocampus, a centre for learning and memory that has rich(More)
Although the hippocampus expresses nicotinic acetylcholine receptors (nAChRs) and receives cholinergic innervation, the functional roles of these receptors are not completely understood. Our results indicated that presynaptic nAChRs mediated a calcium influx that enhanced the release of both glutamate and GABA. Fura-2 detection of calcium in single mossy(More)
We conducted a series of 10 feeding trials involving over 36,000 broilers. The effects of various dietary levels of cholecalciferol (vitamin D3) or 25-hydroxycholecalciferol (25-OH-D3) were compared using a "basal" dosage level of 69 micrograms/kg feed, as well as levels ranging from .5 to 1.5 times the basal level. For all 10 studies, average body weight(More)
We observed that plasma 1,25-(OH)2-D concentrations average 87 +/- 30 SD pmol/l in 48 healthy adults without a personal or family history of kidney stones. Plasma 1,25-(OH)2-D concentrations were significantly elevated among 26 patients with recurrent calcium-containing renal stones and hypophosphatemia: 150 +/- 74 pmol/l; P less than 0.001, and among 9(More)
Vitamin D is a complex of secosteroids that must undergo metabolic alterations to reach optimal biological activity. The parent compounds 1) ergocalciferol (D2) and 2) cholecalciferol (D3) can be synthesized in the leaves of many plants or in the skin of most animals, respectively. Transport of vitamin D steroids after absorption is associated with vitamin(More)
X-linked hypophosphatemic (Hyp) mice are a model for human sex-linked vitamin D-resistant rickets. We have reported intestinal malabsorption of calcium in young Hyp mice, and in this report we have explored the mechanism for it. To test for resistance of the intestine to 1,25(OH)2 vitamin D3, this hormone was continually infused via osmotic minipumps into(More)