Posted by linkadge on March 28, 2006, at 21:44:57
In reply to Re: Neighbor who is a teacher Says SSRI's Cause Memory » Phillipa, posted by Jakeman on March 28, 2006, at 19:44:59
From what I've pieced together, the SSRI's seem to promote the extention of mature hippocampal neurons, but can actually slow the rate of growth of immature neurons. They seem also to affect differentially neurogenesis in certain hippocampal subfeilds. Some studies have hypothesized that SSRI's simply increase hippocampal turnover, see the below study.So, it is not really compleately understood how SSRI's affect the hippocampus overall, longterm.
Additionally, norepinephrine and dopamine also have effects on hippocampal proliferation. in different areas of the hippocampus. Ie mice lacking 5-ht1a receptor still respond to NRI's.
Norepinephrine plays a strong role in the recall of memories of emotional content too.
So, another consideration is that if an SSRI was to lower catecholamines, then it might supress certain forms of neurogenesis or memory recall.A study taken from:
http://www.jneurosci.org/cgi/content/full/25/5/1089
Furthermore, we observed that chronic treatment with imipramine or fluoxetine produced a temporally similar increase in both BrdU-positive and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end-labeled neurons in the dentate gyrus, indicating that these drugs simultaneously increase both neurogenesis and neuronal elimination. These data suggest that antidepressants increase turnover of hippocampal neurons rather than neurogenesis per se and that BDNF signaling is required for the long-term survival of newborn neurons in mouse hippocampus.
Linkadge
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