4 replies to this topic

[Sleepdealer]

Hello brainhealth.

 

I have two questions on things I can't seem to find answers for myself, so I would like to see if anyone knows better...

 

 

1. There are different kinds of dopamine receptors, D1, D2, D3, D4 and D5. How are these related to the four major dopamine pathways? Do you find the largest abundance of D1 receptors in the mesocortical pathway, D2 and D3 in the mesolimbic pathway, etc. or are they more spread out and have different functions in different parts of the brain? If the latter, what does the number tell us, if not for categorizing after each pathway? I'm asking since it would make it easier to know what to look for, if you were looking to alter the levels to maybe get more specific effects if possible.

 

2. About upregulation and downregulation. I have understood that upregulation means an increase in numbers of receptors, and vice versa for dowregulation. However, I haven't as of yet understood the effect of those regulations with the levels of dopamine in your system. I know that if the dopamine system spikes or is hightened over a long period the densities decrease, whereas if you lower the dopamine levels, the dopamine receptors will increase in density. But what I'm wondering is, what does it matter if I have low dopamine, and high receptor densities, or high dopamine, and low receptor densities? To me it sounds moot, unless it is good for avoiding frying the receptors for good. But are there any other benefits rather than that?

 

 

 

Thanks in advance

[Sleepdealer]

Is there anyone who knows about this, that can share his knowledge?

[nuclearz0r]

ill answer the 2nd, up/down regulation is an homeostasis mechanism (meant to preserve a certain steady state by counter-balancing the effect of a certain parameter), lets say a person consumes cocaine, which causes inflation of dopamine to the synapse, in order to prevent the dependence of our consciousness on this experience, upregulation of d2 like receptors takes place meaning more of them start to pop on the synpase where the inflation takes place, these receptors prevent the response of the target neuron to the dopamine inflation thats why theyre considered "inhibitory" receptors, in contrast d1 receptors are excitatory receptors meaning allowing the message to flow forward, there is a certain ratio of d1/d2 receptors on synapses meant to preserve adequte plasticity and not over excitation, buttom line your desired mental effects are achieved through a circuit running with the balance of all these constituents.

[Sleepdealer]

Hmm, that's interesting. There's a lot of threads and talk about upregulating the D2 and D3 receptors, and there's a lot of substances that do, which I in turn thought would increase the dopaminergic effects in the areas they were connected to. But basically, I see now that upregulating them would reduction the dopaminergic signalling. And appearently, that's good, but it's the total opposite of what I had learned.

 

This article says there's a correlation between high D2/D3 receptor density and good social status and social support, while low receptor counts might contribute to drug abuse: http://www.scienceda...00203084254.htm

 

I thought it was the other way around. Anyway. This is sort of hard for me to wrap my head around. I was going to order a batch of Inositol to see how it would affect me, being an extremely asocial individual, thinking that upregulation of receptors would mean more dopamine receptivity but I don't know what inhibiting the signals even more would do. I guess the key word is "impulsecontrol"?

[nuclearz0r]

the brain as a whole is a much greater picture, dopamine plays a role as a modulatory neurotransmitter, translating the actual work it does into mental manifestations is a function of the area youre investigating.

pornography, along with cocaine and and other extremely stimulating sensations, form memories that "hijack" the motivational areas dopamine is affiliated with, they raise the threshold of dopamine excitment to a level that your everyday activities and obligations cant compete with, d2 receptors are upregulated to keep such experiences at bay so that other experiences and intentions would seem joyful and move you forward.