Adult hippocampal neurogenesis is coupled to angiogenesis in the dentate gyrus in rodent studies and is increased by antidepressants. The authors of this study investigated whether antidepressants also increase neural progenitor cells and capillaries in the dentate gyrus of human subjects suffering from major depressive disorder (MDD).
Neural progenitor cells and capillaries were quantified in post-mortem brain tissue from matched untreated MDD patients (n = 12), MDD patients treated with selective serotonin reuptake inhibitors (SSRIs) (n = 6) or tricyclic antidepressants (n = 6), and nonpsychiatric control subjects (n = 12).
MDD patients treated with SSRI antidepressants had a larger capillary area and more neural progenitor cells in the whole dentate gyrus compared to untreated MDD or control subjects. No neural progenitor cells or antidepressant-related angiogenesis were observed in the CA1 or parahippocampal gyrus. The dentate gyrus volume correlated positively with neural progenitor cell number and capillary area. There was a negative correlation between age and neural progenitor number/capillary area.
The study concluded that antidepressants selectively increased human hippocampal neural progenitor cells and angiogenesis in the anterior and mid dentate gyrus. A causal relationship between angiogenesis and neurogenesis, as well as a possible role in the mechanism of action of antidepressants was suggested.
Boldrini M, Hen R, Underwood MD, Rosoklija GB, Dwork AJ, Mann JJ, Arango V: Hippocampal Angiogenesis and Progenitor Cell Proliferation Are Increased with Antidepressant Use in Major Depression. Biological Psychiatry [Epub ahead of print, May 30, 2012; http://dx.doi.org/10.1016/j.biopsych.2012.04.024 ]
