dopamine d2 receptor
Recently Published Documents


TOTAL DOCUMENTS

1901
(FIVE YEARS 244)

H-INDEX

92
(FIVE YEARS 6)

2022 ◽  
Author(s):  
Estelle Rascol ◽  
Anouk Dufourquet ◽  
Rim Baccouch ◽  
Pierre Soule ◽  
Isabel Alves

Abstract Several biochemical and biophysical methods are available to determine dissociation constants between a biological target and its ligands. Most of them require purification, labelling or surface immobilisation. However, these measurements remain challenging concerning membrane proteins because purification requires their extraction from the native lipid environment using different approaches, a process that may impact receptor conformation and functionality. We have developed a novel experimental procedure to determine binding affinities of a ligand to a membrane protein, the dopamine D2 receptor (D2R), directly from cell membrane fragments, using microscale thermophoresis (MST). Two main challenges had to be overcome: to determine the concentration of dopamine D2R in the crude sample; to find ways to minimize or account for non-specific binding of the ligand to cell fragments. Using MST, we were able to determine the D2R concentration in cell membrane fragments to be about 36.8 ± 2.6 pmol/mg. Then titration curves allowed the determination of a KD about 5.3 ± 1.7 nM, that is very close to the reported value. Important details of the experimental procedure are detailed to allow the transposition of this novel method to various membrane proteins.


Author(s):  
Yuanxi Li ◽  
Rubin Wang ◽  
Tao Zhang

AbstractMajor depressive disorder (MDD) is one of the most serious neuropsychiatric disorders. Exploring the pathogenesis and dynamical coding patterns of MDD can provide new targets for clinical drug treatment and new ideas for the research of other neuropsychiatric and neurodegenerative diseases. We selected the medium spiny neuron (MSN) of nucleus accumbens (NAc) as the research objective. NAc is located in the dopaminergic pathway, regulating rewards, emotions and other behaviors. Abnormalities in these behaviors are considered as the main clinical symptoms of MDD. We simulated the different spike patterns of MSNs in MDD group and control group by dynamical Hodgkin–Huxley model. The simulated results can match the electrophysiological experiments, which occurred due to following reasons: (1) The external stimulus current of MDD group was amplified by the local neural microcircuit; (2) the selective permeability to sodium was abnormally decreased; and (3) the dopamine D2 receptor signaling pathway was abnormal in the MDD group. Furthermore, we proposed a dynamical energy model, and the energy results demonstrated that the energy cost in MDD group was lower, which led to persistent depression in patients with MDD. Simultaneously, the negative-to-total energy ratio of MSN in MDD group was higher than that in control group, and the delay time of the power peak and the potential peak in MDD group was shorter than that in the control group. The results showed that the abnormal firing patterns were the direct cause of abnormal behaviors of MDD and indicated that subthreshold activities of MDD group were more intense.


2022 ◽  
Author(s):  
Su-Ya Ma ◽  
Xu Wang ◽  
Jing Shi

Abstract Along with cognitive deficit, behavioral and psychological symptoms in dementia (BPSD) is another characteration of Alzheimer's disease that hamper clinical management and exacerbate burden for caregivers. However, therapeutic management of BPSD remains challenging. HuanglianJiedu decoction (HLJDD), a traditional Chinese prescription which contains Coptidis rhizome(Huang lian), Scutellariae radix (Huang-qin), Phellodendri chinrnsis cortex (Huang-bai) and Gardeniae fructus (Zhi-zi), is applied to treat BPSD. So elucidating the herbs’ disease-matched pharmacological mechanisms underlying HLJDD, further put forward each herbs’ disease-matched combination are critical to the application of HLJDD. In this study, network pharmacology was used to determine the targets and biological processes regulated by HLJDD in the treatment of BPSD. Moreover, molecular docking was utilized to evaluate the binding activity between the herbs' main active ingredients and neurotransmitter receptors. The results showed that the KEGG signaling pathway of HLJDD in treating BPSD mainly lies in TNF signaling pathway and AGE-RAGE signaling pathway in diabetic complications. Scutellariae radix and Phellodendri chinrnsis cortex exhibited better anti-BPSD effects when compared to Coptidis rhizoma and Gardeniae fructus. Scutellariae radix exhibited superior anti-neuroinflammation functions, with better blood vessel regulation effects. Phellodendri chinrnsis cortex showed a higher binding affinity to the dopamine D2 receptor (DRD2) and 5-hydroxytryptamine receptor 2A (HTR2A). Coptidis rhizoma and Gardeniae fructus were better in neuronal signaling. In conclusion, for treating BPSD, Scutellariae radix and Phellodendri chinrnsis cortex are the principal herbs while Coptidis rhizoma and Gardeniae fructus are the ancillary herbs. Beta-sitosterol, stigmasterol, chelerythrine, campesterol and berberine are the potential effective ingredients in treating BPSD.


Author(s):  
Xiao-Yu Liu ◽  
Li-Fei Zheng ◽  
Yan-Yan Fan ◽  
Qian-Ying Shen ◽  
Yao Qi ◽  
...  

In vivo administration dopamine (DA) receptor (DR)-related drugs modulates gastric pepsinogen secretion. However, DRs on gastric pepsinogen-secreting chief cells and DA D2 receptor (D2R) on somatostatin-secreting D cells were subsequently acquired. In this study, we aimed to further investigate the local effect of DA on gastric pepsinogen secretion through DRs expressed on chief cells or potential D2Rs expressed on D cells. To elucidate the modulation of DRs in gastric pepsinogen secretion, immunofluorescence staining, ex vivo incubation of gastric mucosa isolated from normal and D2R-/- mice were conducted, accompanied by measurements of pepsinogen or somatostatin levels using biochemical assays or enzyme-linked immunosorbent assays. D1R, D2R, and D5R-immunoreactivity (IR) were observed on chief cells in mouse gastric mucosa. D2R-IR was widely distributed on D cells from the corpus to the antrum. Ex vivo incubation results showed that DA and the D1-like receptor agonist SKF38393 increased pepsinogen secretion, which was blocked by the D1-like receptor antagonist SCH23390. However, D2-like receptor agonist quinpirole also significantly increased pepsinogen secretion, and D2-like receptor antagonist sulpiride blocked the promotion of DA. Besides, D2-like receptors exerted an inhibitory effect on somatostatin secretion, in contrast to their effect on pepsinogen secretion. Furthermore, D2R-/- mice showed much lower basal pepsinogen secretion but significantly increased somatostatin release and an increased number of D cells in gastric mucosa. Only SKF38393, not quinpirole, increased pepsinogen secretion in D2R-/- mice. DA promotes gastric pepsinogen secretion directly through D1-like receptors on chief cells and indirectly through D2R-mediated suppression of somatostatin release.


2022 ◽  
Author(s):  
Marie-Lise Jobin ◽  
Veronique De Smedt-Peyrusse ◽  
Fabien Ducrocq ◽  
Asma Oummadi ◽  
Rim Baccouch ◽  
...  

The heterogenous and dynamic constitution of the membrane fine-tunes signal transduction. In particular, the polyunsaturated fatty acid (PUFA) tails of phospholipids influence the biophysical properties of the membrane, production of second messengers, or membrane partitioning. Few evidence mostly originating from studies of rhodopsin suggest that PUFAs directly modulate the conformational dynamic of transmembrane proteins. However, whether such properties translate to other G protein-coupled receptors remains unclear. We focused on the dopamine D2 receptor (D2R), a main target of antipsychotics. Membrane enrichment in n-3, but not n-6, PUFAs potentiates ligand binding. Molecular dynamics simulations show that the D2R preferentially interacts with n-3 over n-6 PUFAs. Furthermore, even though this mildly affects signalling in heterologous systems, in vivo n-3 PUFA deficiency blunts the effects of D2R ligands. These results suggest that n-3 PUFAs act as allosteric modulators of the D2R and provide a putative mechanism for their potentiating effect on antipsychotic efficacy.


Author(s):  
Daniel Pulido ◽  
Verònica Casadó-Anguera ◽  
Marc Gómez-Autet ◽  
Natàlia Llopart ◽  
Estefanía Moreno ◽  
...  

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 101
Author(s):  
Gubbi Govindaiah ◽  
Rong-Jian Liu ◽  
Yanyan Wang

The striatum contains several types of neurons including medium spiny projection neurons (MSNs), cholinergic interneurons (ChIs), and fast-spiking interneurons (FSIs). Modulating the activity of these neurons by the dopamine D2 receptor (D2R) can greatly impact motor control and movement disorders. D2R exists in two isoforms: D2L and D2S. Here, we assessed whether alterations in the D2L and D2S expression levels affect neuronal excitability and synaptic function in striatal neurons. We observed that quinpirole inhibited the firing rate of all three types of striatal neurons in wild-type (WT) mice. However, in D2L knockout (KO) mice, quinpirole enhanced the excitability of ChIs, lost influence on spike firing of MSNs, and remained inhibitory effect on spike firing of FSIs. Additionally, we showed mIPSC frequency (but not mIPSC amplitude) was reduced in ChIs from D2L KO mice compared with WT mice, suggesting spontaneous GABA release is reduced at GABAergic terminals onto ChIs in D2L KO mice. Furthermore, we found D2L deficiency resulted in reduced dendritic spine density in ChIs, suggesting D2L activation plays a role in the formation/maintenance of dendritic spines of ChIs. These findings suggest new molecular and cellular mechanisms for causing ChIs abnormality seen in Parkinson’s disease or drug-induced dyskinesias.


Author(s):  
Dorota Frydecka ◽  
Eid Abo Hamza ◽  
Ahmed Helal ◽  
Ahmed A. Moustafa

Abstract There is great body of evidence showing a relationship between childhood adversity and psychosis onset. Genetic factors moderate the association between childhood adversity and psychosis risk potentially by influencing biological and/or psychological reaction following exposure to adversity. In this review, we discuss studies identifying the specific genetic variants known to affect dopamine levels involved in this interaction. Our review shows that the catechol-O-methyltransferase (COMT), dopamine D2 receptor (DRD2), AKT1 gene play a key role in mediating the relationship between childhood adversity and development of psychosis. We have also found conflicting findings on the impact of dopamine genes on the relationship between childhood adversity and development of psychosis, suggesting that other genetic and environmental factors should be taken into account. We here discuss the implications of our findings and future directions.


Biomedicines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 22
Author(s):  
Richard Ågren ◽  
Kristoffer Sahlholm

SB269,652 has been described as the first negative allosteric modulator (NAM) of the dopamine D2 receptor (D2R), however, the binding mode and allosteric mechanism of action of this ligand remain incompletely understood. SB269,652 comprises an orthosteric, primary pharmacophore and a secondary (or allosteric) pharmacophore joined by a hydrophilic cyclohexyl linker and is known to form corresponding interactions with the orthosteric binding site (OBS) and the secondary binding pocket (SBP) in the D2R. Here, we observed a surprisingly low potency of SB269,652 to negatively modulate the D2R-mediated activation of G protein-coupled inward-rectifier potassium channels (GIRK) and decided to perform a more detailed investigation of the interaction between dopamine and SB269,652. The results indicated that the SB269,652 inhibitory potency is increased 6.6-fold upon ligand pre-incubation, compared to the simultaneous co-application with dopamine. Mutagenesis experiments implicated both S193 in the OBS and E95 in the SBP in the effect of pre-application. The present findings extend previous knowledge about how SB269,652 competes with dopamine at the D2R and may be useful for the development of novel D2R ligands, such as antipsychotic drug candidates.


2021 ◽  
Author(s):  
A. J. Rybicki ◽  
S. L. Sowden ◽  
B. A. Schuster ◽  
J. L Cook

SummarySome theories of human cultural evolution posit that humans have social-specific learning mechanisms that are adaptive specialisations moulded by natural selection to cope with the pressures of group living. However, the existence of neurochemical pathways that are specialised for learning from social information and from individual experience is widely debated. Cognitive neuroscientific studies present mixed evidence for social-specific learning mechanisms: some studies find dissociable neural correlates for social and individual learning whereas others find the same brain areas and, dopamine-mediated, computations involved in both. Here we demonstrate that, like individual learning, social learning is modulated by the dopamine D2 receptor antagonist haloperidol when social information is the primary learning source, but not when it comprises a secondary, additional element. Two groups (total N = 43) completed a decision-making task which required primary learning, from own experience, and secondary learning from an additional source. For one group the primary source was social, and secondary was individual; for the other group this was reversed. Haloperidol affected primary learning irrespective of social/individual nature, with no effect on learning from the secondary source. Thus, we illustrate that neurochemical mechanisms underpinning learning can be dissociated along a primary-secondary but not a social-individual axis. These results resolve conflict in the literature and support an expanding field showing that, rather than being specialised for particular inputs, neurochemical pathways in the human brain can process both social and non-social cues and arbitrate between the two depending upon which cue is primarily relevant for the task at hand.


Sign in / Sign up

Export Citation Format

Share Document