Gene/Protein Disease Symptom Drug Enzyme Compound
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 28,634 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fentanyl is a frequently used and abused opioid analgesic and can cause internalization of mu opioid receptors (MORs). Receptor internalization modulates the signaling pathways of opioid receptors. As changes in dendritic spines and synaptic AMPA receptors play important roles in addiction and memory loss, we investigated how fentanyl affects dendritic spines and synaptic AMPA receptors in cultured hippocampal neurons. Fentanyl at low concentrations (0.01 and 0.1 microM) caused the collapse of dendritic spines and decreased the number of AMPA receptor clusters. In contrast, fentanyl at high concentrations (1 and 10 microM) had opposite effects, inducing the emergence of new spines and increasing the number of AMPA receptor clusters. These dose-dependent bidirectional effects of fentanyl were blocked by a selective MOR antagonist CTOP at 5 microM. In neurons that had been transfected with HA-tagged or GFP-tagged MORs, fentanyl at high concentrations induced persistent and robust internalization of MORs, whereas fentanyl at lower concentrations induced little or transient receptor internalization. The blockade of receptor internalization with the expression of dominant-negative Dynamin I (the K44E mutant) reversed the effect of fentanyl at high concentrations, supporting a role of receptor internalization in modulating the dose-dependent effects of fentanyl. In contrast to morphine, the effects of fentanyl on dendritic spines are distinctively bidirectional and concentration dependent, probably due to its ability to induce robust internalization of MORs at high concentrations. The characterization of the effects of fentanyl on spines and AMPA receptors may help us understand the roles of MOR internalization in addiction and cognitive deficits.
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PMID:Bidirectional effects of fentanyl on dendritic spines and AMPA receptors depend upon the internalization of mu opioid receptors. 1929 8

The purpose of this study was to describe and compare explanations of Alzheimer's disease (AD) of African American, Afro-Caribbean, and European American older adults undergoing cognitive screening. Participants were asked a series of open-ended questions regarding what they knew about AD and if they were experiencing memory problems. Responses were coded and quantized for analysis. Forty percent reported experiencing memory problems. Afro-Caribbeans made significantly more incorrect statements about AD and were less likely to identify memory loss as a symptom. Half the participants said they would seek their physician's advice if the screening was positive; none mentioned a memory disorder center. Misconceptions about AD included the effect of aluminum, brain collapse, relaxed brain, shaking, tremors, and physical illness. More Afro-Caribbeans, all of whom were first generation, had misconceptions about AD. Campaigns to educate the public about AD need to provide culturally sensitive and appropriate information to ethnic minority populations.
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PMID:Explanations of AD in ethnic minority participants undergoing cognitive screening. 2169 41