While "researching" for a post/comment over at HU, I came across some interesting text related to a levodopa/carbidopa product called Syndopa.

Here is part of what it said: "There are two types of responses seen with the administration of Syndopa Plus Tablet: The short-duration response which is related to the half-life of the drug. The long-duration response depends directly on the accumulation of effects over at least a two week course, during which ΔFosB accumulates in nigrostriatal neurons. When used in the treatment of Parkinson's disease, this response is seen only in early therapy, as at that stage the inability of the brain to store dopamine is not yet a concern."

This was of great interest to me because it explained something that I experienced recently. A couple of months ago my neuro increased my levodopa dose. For the next 2 or 3 weeks nothing happened, and then suddenly my tremor virtually disappeared, and has remained that way since then.

I was already aware of my ability to store dopamine for short periods of time. For example, when I wake up in the morning I have no tremor, even though it has been about 12 hours since my last dose of levodopa. But the "accumulation of effects over at least a two week course" was something that I had never heard of before.

I'm going to spend some time "researching" this further, starting with the protein ΔFosB. When I first saw it I thought it was a misprint, but when I googled it I found that it was real. And there is a lot of information about it, so it's probably going to take me a while to try to get on top of it.

Is anyone already familiar with all this, and if so, can you point me to an article/paper that explains it all?

I've done a search of neurotalk and found something potentially interesting [1], but it's not at the more introductory level that I'm hoping to start with.

Thanks.

[1] Impact of grafted serotonin and dopamine neurons on development of L-DOPA-induced dyskinesias in parkinsonian rats is determined by the extent of dopamine neuron degeneration, T Carlsson et al. Brain, Feb 2009.