Posted by Cam W. on January 29, 2000, at 22:16:08
In reply to Re: What is an autoreceptor?, posted by Sam on January 29, 2000, at 16:22:55
> Is this the same as reuptake?
Sam - No an autoreceptor is different from a reuptake transporter. The autoreceptor increase the neurotransmitter (NT) in the synaptic cleft by turning off the feedback mechanism that turns off the release of NT from the nerve cell.
A reuptake transporter is a conservation mechanism that the body has so it doesn't have to keep making more NT all of the time. After the NT is released into the synaptic cleft from the nerve cell and binds to the receptors on the adjacent nerve cell (carrying the electrical signal across the synaptic cleft) the NT releases from the receptor and the reuptake transporter draws a portion of the NT back into the nerve cell it was released from. The rest of the NT (if it is a monoamine) is metabolized by monoamine oxidase (MAO). In this way the body does not have to make as much NT as it reuses the NT that is taken up back into the cell by the transporter.
In depression, we know that some NTs are in lower quantities than is seen in non-depressed people. Serotonin is observed to be lower so the SSRIs (selective serotonin reuptake inhibitors) block the nerve cell from taking up the serotonin back into the cell. In essence, this is raising the amount of serotonin in the synaptic cleft (which has lower amounts present in a depressed person) and forces the body to begin to produce more serotonin, thus it is thought that this is one way (of possibly many more) that SSRIs relieve the symptoms of depression. I know this is quite detailed & I hope it is clear. _ Cam W.
poster:Cam W.
thread:19944
URL: http://www.dr-bob.org/babble/20000128/msgs/20041.html