Guys can you explain what Dopamine D2/3 Receptors mean?
I know there are D2 receptors, D3 receptors (besides D1, D4, D5)
And this D2/3 mean what? 'D2 and D3'. Or 'ratio of D2 to D3'.
If you go through the thread and read a little more carefully, you would understand.
Look at the context of what is written.
D2/D3 is referring them both in the same sentence, because there are comparable / similar effects between both receptors, and they are both considered "D2-Like" receptors...given their similarity in biological function*.
D1 receptors and D5 are both considered D1-like dopamine receptors, because D5 was cloned shortly after and considered like , in structure and function the D1 receptor....both of these receptors are positively coupled to G-proteins and both activate adenylate cyclase which leads to increased cAMP - which then leads to some degree of stimulation and calcium channel activation.
D2-D3-D4 are all D2-like receptors, they all are negatively coupled to G-proteins with similar biological effects but with distribution that densitites that vary and thus effect researchable outcomes.
D2 receptors have autoreceptors which function to decrease dopamine synthesis / neuron activity...two distinct pathways, but the autoreceptors are ONLY the pre-synaptic ones (D2s), whereas D2 L = D-2-"Long" has it's post-synaptic effects and a stronger downstream effect more indicative of a dopaminergic pathway and having more interaction with the D1-like receptors...
D1 and D5 are largely involved in behavioral responses and energy production/expenditure, they both play a role in cocaine induced hyper-excitation and euphoria, and are necessary in the study of anxiety disorders and depression.
D2,D3,D4 have some similar effects; are involved in memory, sexuality, depressive-phases, response to light and affect heart rate via a central mechanisms - they have involvement in addiction as well and tend to play a role in "channeling" neural activity leading to more transient states if excessively activated....
As I've said, the main reason why dopamine drugs have side-effects is because they activate only D2-like, if they activated both families there would be far less side-effects altogether...
The body/mind is not really set up or made to just accept dopaminergic inputs to one family-type, therefore dopamine drugs are seen as very strange to the human body and it only gets balanced out when you find a separate way to re-activate the cyclic adensoine monophosphate symptoms (as would be done by activating D1-D5 complex's)..therefore, I don't recommend dopamine drugs without the use of either forskolin, or more preferably, a histamine H3 antagonist such as conessine or pitolisant.