The significance of the dopamine receptor D2

[Mauritio]

Striatal dopamine D2 receptor sensitivity is negatively correlated with obesity and positively correlated with insulin sensitivity. [1][2]

Causality also seems likely, since activation of the dopamine D2 receptor enhances lifespan via known longevity pathways such as AMPK in C. elegans. [3]

Interestingly, there is a correlation between social status and dopamine D2/D3 receptor availability, where higher-status individuals show higher receptor levels. [4]

In contrast, serotonin appears to reduce social status, likely by decreasing dopamine signaling. [5]

Caffeine increases striatal dopamine D2/D3 receptor availability. [6]

Fish oil supplementation decreases dopamine D1 and D2 receptor expression. [7]

References

[1] PMID:11210998
[2] PMID:18598772
[3] PMID:35317792
[4] PMID:19811777
[5] PMID:11275287
[6] PMID:25871974
[7] PMID:30951972

[lobotomize]

Dopamine (D_{2}) receptors are inhibitory. When dopamine binds to them, they act as a negative feedback loop to decrease further dopamine release and suppress excitability.;

https://bioenergetic.forum/post/56042
""The dopamine system of healthy, highly creative people is similar to that found in people with schizophrenia" lower d2 in creative people and schizos

low D2 receptor density (not to be mistaken with D3) is correlated to creativity
low protein high carb diet decreases D2 receptor densitya

antipsychotic medicine increases D2 density and lowers dopamine, so one can argue that high baseline dopamine reduces D2 density ""

@mauritio

[Mauritio]

Combined inhibition of dopamine D1/D2 receptors induces cognitive and emotional dysfunction through oxidative stress and dopaminergic neuron damage

Results: Low-dose co-DR1/2I significantly increased MAO-B and ROS levels (p < 0.01) and decreased SOD activity (p < 0.01) in the substantia nigra, striatum, and hippocampus. MAO-B activity positively correlated with ROS (r = 0.916, p < 0.001) and negatively correlated with SOD (r = −0.685, p < 0.001), whereas ROS negatively correlated with SOD (r = −0.661, p < 0.001) in co-DR1/2I-treated mice. The medium- and high-dose groups exhibited spatial memory impairment (longer escape latency, p < 0.05) in the water maze and more anxiety-like behavior (reduced central zone time, p < 0.01) in the open field test; however, no abnormalities in motor coordination were observed in the rotarod test (p > 0.05). Immunofluorescence and WB confirmed a reduction in the dopaminergic neuron count after co-DR1/2I.