Posted by Shawn. T. on August 27, 2003, at 21:53:14
In reply to question regarding receptors, posted by linkadge on August 27, 2003, at 10:50:05
The answer to your question probably depends on whether we're dealing with presynaptic 5-HT1A receptors (autoreceptors) or postsynaptic 5-HT1A receptors. My opinion is that having more postsynaptic 5-HT1A receptors in the hippocampus would be beneficial; however, the truly important factor is how often these receptors are activated. Also, it's important to consider the sensitivity of these receptors. Several different antidepressant drugs enhance the tonic activation of 5-HT1A receptors in the hippocampus (see http://www.jneurosci.org/cgi/content/full/18/23/10150 ). Furthermore, 5-HT1A activation in the hippocampus has been linked to the induction of neurogenesis (see http://jpet.aspetjournals.org/cgi/content/abstract/299/2/401 and http://www.sciencemag.org/cgi/content/abstract/301/5634/805 ). I'm less sure about postsynaptic 5-HT1A receptors in other regions of the brain; their "beneficial" effects probably vary depending on where they're located.
I'm not sure that the upregulation of presynaptic 5-HT1A autoreceptors has been shown to exhibit clear benefits; the matter is debatable. Again, the regularity of activation and sensitivity factors are probably as important or more important than the number of receptors. My personal opinion is that having a greater number 5-HT1A autoreceptors would be desirable in a person not taking a serotonergic drug like an SSRI; see http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12684476&dopt=Abstract for some support for my point of view.
Shawn
poster:Shawn. T.
thread:254679
URL: http://www.dr-bob.org/babble/20030823/msgs/254894.html