6,789 research outputs found
Roles for the Uptake\u3csub\u3e2\u3c/sub\u3e Transporter OCT3 in Regulation of Dopaminergic Neurotransmission and Behavior
Transporter-mediated uptake determines the peak concentration, duration, and physical spread of released monoamines. Most studies of monoamine clearance focus on the presynaptic uptake1 transporters SERT, NET and DAT. However, recent studies have demonstrated the expression of the uptake2 transporter OCT3 (organic cation transporter 3), throughout the rodent brain. In contrast to NET, DAT and SERT, OCT3 has higher capacity and lower affinity for substrates, is sodium-independent, and is multi-specific, with the capacity to transport norepinephrine, dopamine, serotonin and histamine. OCT3is insensitive to inhibition by cocaine and antidepressant drugs but is inhibited directly by the glucocorticoid hormone corticosterone. Thus, OCT3 represents a novel, stress hormone-sensitive, monoamine transport mechanism. Incorporating this transporter into current models of monoaminergic neurotransmission requires information on: A) the cellular and subcellular localization of the transporter; B) the effects of OCT3 inhibitors on monoamine clearance; and C) the consequences of decreased OCT3-mediated transport on physiology and/or behavior. This review summarizes studies describing the anatomical distribution of OCT3, its cellular and subcellular localization, its contribution to the regulation of dopaminergicsignaling, and its roles in the regulation of behavior. Together, these and other studies suggest that both Uptake1 and Uptake2 transporters play key roles in regulating monoaminergic neurotransmission and the effects of monoamines on behavior
Radiative Semileptonic Kaon Decays
We evaluate the matrix elements for the radiative kaon decays , and \ () to next-to-leading order in chiral perturbation theory. We calculate
total rates and rates with several kinematical cuts and confront the results
with existing data. Measurements at future kaon facilities will allow for a
more detailed comparison between theory and experiment.Comment: LaTeX, 40 pages, 5 figures (not included), CERN-TH 6625/92,
BUTP-92/3
Isospin dependence of the three-nucleon force
We classify --nucleon forces according to their isospin dependence and
discuss the most general isospin structure of the three--nucleon force. We
derive the leading and subleading isospin--breaking corrections to the
three--nucleon force using the framework of chiral effective field theory.Comment: 21 pages, 6 figure
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