The D2 dopamine receptor (D2 DAR) is one of the most validated drug targets for neuropsychiatric and endocrine disorders. However, clinically approved drugs targeting D2 DAR display poor selectivity between the D2 and other receptors, especially the D3 DAR. This lack of selectivity may lead to undesirable side effects. Here we describe the chemical and pharmacological characterization of a nove...

introduction: the hippocampus (hip), the primary brain structure related to learning and memory, receives sparse but comprehensive dopamine innervations and contains dopamine d1/d2-like receptors. it is demonstrated that dopamine receptors in dentate gyrus (dg) region of hip have a remarkable function in spatial reward processing. much less is known about the involvement of hip and its d1/d2 do...

Type II deiodinase (D2) activates thyroid hormone by converting thyroxine (T4) to 3,5,3'-triiodothyronine (T3). This allows plasma T4 to signal a negative feedback loop that inhibits production of thyrotropin-releasing hormone (TRH) in the mediobasal hypothalamus (MBH) and thyroid-stimulating hormone (TSH) in the pituitary. To determine the relative contributions of these D2 pathways in the fee...

Let In be the (big) diagonal ideal of (C). Haiman proved that the q, t-Catalan number is the Hilbert series of the graded vector space Mn = ⊕ d1,d2 (Mn)d1,d2 spanned by a minimal set of generators for In. We give simple upper bounds on dim (Mn)d1,d2 in terms of partition numbers, and find all bi-degrees (d1, d2) such that dim (Mn)d1,d2 achieve the upper bounds. For such bi-degrees, we also find...

Given a graph G and integers p, q, d1 and d2, with p > q, d2 > d1 > 1, an L(d1, d2; p, q)-labeling of G is a function f : V (G) → {0, 1, 2, . . . , n} such that | f (u) − f (v)| > p if dG(u, v) 6 d1 and | f (u) − f (v)| > q if dG(u, v) 6 d2. A k-L(d1, d2; p, q)-labeling is an L(d1, d2; p, q)-labeling f such that maxv∈V (G) f (v) 6 k. The L(d1, d2; p, q)-labeling number of G, denoted by λ d1,d2(...

Several dopamine agonists, administered i.m., produced persistent, excessive and non-localized scratching in squirrel monkeys (Saimiri sciureus). Studies were conducted with a series of drugs to determine the pharmacological mechanisms responsible for this effect. All of the dopamine D2 agonists studied produced dose-related increases in scratching, whereas several dopamine D1 receptor agonists...

We provided evidence for the formation of a novel phospholipase C-mediated calcium signal arising from coactivation of D1 and D2 dopamine receptors. In the present study, robust fluorescence resonance energy transfer showed that these receptors exist in close proximity indicative of D1-D2 receptor heterooligomerization. The close proximity of these receptors within the heterooligomer allowed fo...

Background The synthesis of [11C]L-deprenyl-D2 for imaging of astrocytosis with positron emission tomography (PET) in neurodegenerative diseases has been previously reported. [11C]L-deprenyl-D2 radiosynthesis requires a precursor, L-nordeprenyl-D2, which has been previously synthesized from L-amphetamine as starting material with low overall yields. Here, we present an efficient synthesis of L-...

The loss of nigrostriatal dopamine neurons in Parkinson's disease induces a reduction in the number of dendritic spines on medium spiny neurons (MSNs) of the striatum expressing D1 or D2 dopamine receptor. Consequences on MSNs expressing both receptors (D1/D2 MSNs) are currently unknown. We looked for changes induced by dopamine denervation in the density, regional distribution and morphologica...