G-protein coupled receptors interact to provide additional regulatory mechanisms for neurotransmitter signaling. Adenosine A(2A) receptors are expressed at a high density in striatal neurons, where they closely interact with dopamine D₂ receptors and modulate effects of dopamine and responses to psychostimulants. A(2A) receptors are expressed at much lower densities in other forebrain neurons but play a more prominent yet opposing role to striatal receptors in response to psychostimulants in mice. It is, therefore, possible that A(2A) receptors expressed at low levels elsewhere in the brain may also regulate neurotransmitter systems and modulate neuronal functions. Dopamine D₂ receptors play an important role in autoinhibition of neuronal firing in dopamine neurons of the ventral tegmental area (VTA) and dopamine release in other brain areas. Here, we examined the effect of A(2A) receptor deletion on D₂ receptor-mediated inhibition of neuronal firing in dopamine neurons in the VTA. Spontaneous activity of dopamine neurons was recorded in midbrain slices, and concentration-dependent effects of the dopamine D₂ receptor agonist, quinpirole, was compared between wild-type and A(2A) knockout mice. The potency of quinpirole applied in single concentrations and the expression of D₂ receptors were not altered in the VTA of the knockout mice. However, quinpirole applied in stepwise escalating concentrations caused significantly reduced maximal inhibition in A(2A) knockout mice, indicating an enhanced agonist-induced desensitization of D₂ receptors in the absence of A(2A) receptors. The A(2A) receptor agonist, CGS21680, did not exert any effect on dopamine neuron firing or response to quinpirole, revealing a novel non-pharmacological interaction between adenosine A(2A) receptors and dopaminergic neurotransmission in midbrain dopamine neurons. Altered D₂ receptor desensitization may result in changes in dopamine neuron firing rate and pattern and dopamine release in other brain areas in response to persistent dopamine release and administration of psychostimulants.
Pharmacology, Toxicology and Pharmaceutical Science
2
9%
Nursing and Health Professions
1
5%
Other
0
0%
Unknown
2
9%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 5. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 08 April 2020.
All research outputs
#6,929,388
of 25,373,627 outputs
Outputs from Neuroscience
#2,080
of 7,821 outputs
Outputs of similar age
#37,837
of 123,940 outputs
Outputs of similar age from Neuroscience
#17
of 62 outputs
Altmetric has tracked 25,373,627 research outputs across all sources so far. This one has received more attention than most of these and is in the 72nd percentile.
So far Altmetric has tracked 7,821 research outputs from this source. They typically receive a little more attention than average, with a mean Attention Score of 5.6. This one has gotten more attention than average, scoring higher than 73% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 123,940 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 69% of its contemporaries.
We're also able to compare this research output to 62 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 72% of its contemporaries.
