Posted by Larry Hoover on November 16, 2002, at 14:40:26
In reply to Re: prozac/effexor=dendrite shrinkage? » djmmm, posted by Ritch on November 15, 2002, at 9:31:43
> Hi, is this the smae thing as "dendritic 'pruning'"? I remember reading about this a couple of years ago. The speculation was that depressed and suicidal people have excessive serotonin receptors and an "overgrowth" of dendrites as a result. THe author's conclusion was that SSRI's raise the level of extracellular serotonin which reduces the density of serotonin receptors (down-regulation), and "prunes" the overgrown dendrites. Perhaps there is some overpruning going on? Would that be dose related?
>Here's an article showing protective and healing effects of fluoxetine on hippocampal dendrites. The full-text has compelling micrographs.
Acta Pharmacol Sin 2001 Oct;22(10):865-70
Fluoxetine inhibits dendrite atrophy of hippocampal neurons by decreasing nitric oxide synthase expression in rat depression model.Luo L, Tan RX.
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China. rxtan@netra.nju.edu.cn
AIM: To study the effect of fluoxetine on dendrite atrophy of hippocampal neurons in rat depression model. METHODS: CMS (chronic mild stress), mimicking human depression, was used as the animal depression model. The neurons shape and numbers of nitric oxide synthase positive cells in the hippocampal subfields were measured by Nissl staining and histochemical staining of NADPH (nicotinamide adenine dinucleotide phosphate)-diaphorase respectively. RESULTS: CMS deforms neurons in the hippocampal formation, and fluoxetine can renormalize the deformed neurons by inhibiting the nitric oxide synthase catalyzing the over-production of NO, which lead subsequently to the morphological abnormality in the circumscribed area of brain. CONCLUSION: Fluoxetine, an antidepressant, renormalizes dendrite atrophy of hippocampal neurons by inhibiting nitric oxide synthase overexpression in rat chronic mild stress model.
Full-text at:
http://www.chinaphar.com/1671-4083/22/865.pdf
poster:Larry Hoover
thread:127552
URL: http://www.dr-bob.org/babble/20021116/msgs/127936.html