Dopamine agonist / antagonist

[anacleta]

http://www.utexas.edu/research/asrec/dopamine.html


Neurons can become sensitized or desensitized to dopamine

One important aspect of drug addiction is how cells adapt to previous drug exposure.

For example, long-term treatment with dopamine antagonists increases the number of dopamine receptors. This happens as the nervous system tries to make up for less stimulation of the receptors by dopamine itself. Likewise, the receptors themselves become more sensitive to dopamine. Both are examples of the same process, called sensitization.

An opposite effect occurs after dopamine or dopamine agonists repeatedly stimulate dopamine receptors. Here overstimulation decreases the number of receptors, and the remaining receptors become less sensitive to dopamine. This process is called desensitization.

Desensitization is better known as tolerance, where exposure to a drug causes less response than previously caused. Tolerance reflects the actions of the nervous system to maintain homeostasis -a constant degree of cell activity in spite of major changes in receptor stimulation. The nervous system maintains this constant level in an attempt to keep the body in a state of equilibrium, even when foreign chemicals are present.

Sensitization and desensitization do not take place only after long-term understimulation or overstimulation of dopamine receptors. Both sensitization and desensitization can occur after only a single exposure to a drug. In fact, they may develop within a few minutes.

[Ghost]

http://www.utexas.edu/research/asrec/dopamine.html


Neurons can become sensitized or desensitized to dopamine

One important aspect of drug addiction is how cells adapt to previous drug exposure.

For example, long-term treatment with dopamine antagonists increases the number of dopamine receptors. This happens as the nervous system tries to make up for less stimulation of the receptors by dopamine itself. Likewise, the receptors themselves become more sensitive to dopamine. Both are examples of the same process, called sensitization.

An opposite effect occurs after dopamine or dopamine agonists repeatedly stimulate dopamine receptors. Here overstimulation decreases the number of receptors, and the remaining receptors become less sensitive to dopamine. This process is called desensitization.

Desensitization is better known as tolerance, where exposure to a drug causes less response than previously caused. Tolerance reflects the actions of the nervous system to maintain homeostasis -a constant degree of cell activity in spite of major changes in receptor stimulation. The nervous system maintains this constant level in an attempt to keep the body in a state of equilibrium, even when foreign chemicals are present.

Sensitization and desensitization do not take place only after long-term understimulation or overstimulation of dopamine receptors. Both sensitization and desensitization can occur after only a single exposure to a drug. In fact, they may develop within a few minutes.

Could this logic also be applied to Serotonin, where post-synaptic antagonists could help re-sensitize 5ht1a? Or increase their numbers?

Also, in order for these effects to be permanent, they must cause gene expression changes...do these drugs do that?