Electroconvulsive Seizure Treatment Increases Cell Proliferation in Rat Frontal Cortex

Abstract

Recent studies have demonstrated increased neurogenesis in adult hippocampus in response to electroconvulsive seizure (ECS) or antidepressant drug treatment. Adult neurogenesis in the subgranular zone of the hippocampus and the subventricular zone is well established, whereas neuronal proliferation outside of these areas under unstimulated conditions is not observed. Since mood disorders are likely to involve brain regions in addition to hippocampus, particularly the frontal cortex, it is likely that antidepressant treatments produce cellular changes in these brain regions as well. In this study, we have investigated the effect of repeated ECS administration on the proliferation of cells in the frontal cortex, and we have examined the phenotype of these cells 4 weeks after labeling with a cell division marker. We found that ECS treatment increases the number of newly divided cells in the frontal cortex and that these new cells express markers of either endothelial cells or oligodendrocytes, but not neurons. It is possible that increased proliferation of these cell types in the frontal cortex could reverse the loss of glial cell number and the reduced volume that has been reported in the frontal cortex of depressed patients.

Chronic Social Stress Inhibits Cell Proliferation in the Adult Medial Prefrontal Cortex: Hemispheric Asymmetry and Reversal by Fluoxetine Treatment

“…We tested several other cellular markers, but the NG2 and RECA-1 phenotypic markers labeled the largest population of BrdU-positive cells in the mPFC. Similar findings were reported earlier by Kodama et al (2004) and Madsen et al (2005). In the present study, we could not observe any newborn cells in the neocortex that acquired a neuronal phenotype.…”

“…This observation agrees with recent reports showing that fluoxetine or ECS treatment can stimulate the genesis of endothelial cells in both the hippocampus and the mPFC (Hellsten et al, 2004;Kodama et al, 2004;Madsen et al, 2005). Furthermore, this ECSinduced increase in endothelial cell proliferation is accompanied by increased angiogenesis in the hippocampus (Hellsten et al, 2005;Newton et al, 2006).…”

“…It has recently been reported that antidepressant treatment with fluoxetine or electroconvulsive seizure modulates cell proliferation not only in the dentate gyrus, but also in the medial PFC (mPFC) in adult rats (Kodama et al, 2004;Madsen et al, 2005). Unlike the hippocampal studies, the effects of antidepressant treatment on cytogenesis in the PFC have been investigated only in healthy animals (Kodama et al, 2004;Madsen et al, 2005).…”

“…Unlike the hippocampal studies, the effects of antidepressant treatment on cytogenesis in the PFC have been investigated only in healthy animals (Kodama et al, 2004;Madsen et al, 2005). This approach is in contrast to clinical practice in which treatment is restricted to sufferers of affective disorders, and antidepressant medication or electroconvulsive stimulation in nondepressed individuals almost certainly does not produce the same neural changes as when these treatments are applied to depressed patients.…”

Methamphetamine Self-Administration and Voluntary Exercise Have Opposing Effects on Medial Prefrontal Cortex Gliogenesis

“…Medial prefrontal cortex (mPFC) precursors are mostly gliogenic, and their neurogenic capacity is uncertain and unconfirmed (Gould et al, 1999b;Magavi et al, 2000;Nowakowski and Hayes, 2000;Kornack and Rakic, 2001;Bernier et al, 2002;Ehninger and Kempermann, 2003;Koketsu et al, 2003;Kodama et al, 2004;Dayer et al, 2005;Madsen et al, 2005;Czeh et al, 2007;Ongur et al, 2007). However, evidence suggests that glia (astrocytes and oligodendrocytes) are necessary to maintain the structure and proper functioning of neurons and may in certain enriched environments support neurogenesis of neural stem cells (AlvarezBuylla et al, 2000;Kondo and Raff, 2000;Alvarez-Buylla and Lim, 2004;Sanai et al, 2004;Benarroch, 2005).…”