>>> context weblog
sampling new cultural context
| home | site map | about context | donate | lang >>> español - català |
wednesday :: december 17, 2003
   
 
hippocampal neurogenesis: cell death promotes learning growth

The hippocampal formation has long been associated with the execution of higher-order cognitive functions, and impairment of this structure following severe stress and aging has been linked to cognitive disturbances. In order to understand the involvement of the hippocampal formation in the mediation of normal and pathological behaviors, much attention has recently been devoted to hippocampal neurogenesis. The dentate gyrus of the hippocampal formation has the ability to generate new neurons on a daily basis throughout life. Surviving de novo produced cells develop into granule neurons and integrate into the functional circuitry. Neurogenesis has been proposed to play a role in hippocampal-mediated learning and has been implicated in the appearance of behavioral pathologies associated with the hippocampal formation.

Although evidence suggest that neurogenesis play a role in spatial learning, the effect of learning on cell proliferation remains unclear. The authors demonstrated that the late phase of learning has a multifaceted effect on neurogenesis depending on the birth date of new neurons. The number of newly born cells increased contingently with the late phase and a large proportion of these cells survived for at least 4 weeks and differentiated into neurons. In contrast, the late phase learning decreased the number of newly born cells produced during the early phase. This learning-induced decrease in the number of newly generated cells results most probably from the death of the cells. Strikingly, cell death and not proliferation was positively correlated with performance. Thus, rats with the lowest cell death were less able to acquire and use spatial information than those with the highest cell death.

The results reveal a complex modulation of learning on brain plasticity, which induces death and proliferation of different populations of cells. Most importantly, they introduce the notion that removing neurons from the adult brain can be an important process in learning and memory and a novel mechanism through which neurogenesis may influence normal and pathological behaviors. >from *Cell death promotes learning growth*. November 26, 2003


related context
>
hippocampus.
> differential effects of learning on neurogenesis. Molecular Psychiatry (2003) 8, 974-982. doi:10.1038/sj.mp.4001419
> autumn triggers chickadee's brain expansion. october 3, 2003
> synapses: plasticity and stability. february 19, 2003
> synaptic plasticity: how experiences rewire the brain. january 23, 2003
> neurogenesis observed in human adult brain. march 6, 2002

imago
>
dentate gyrus asymptotic fictional circuitry

| permaLink






> context weblog archive
december 2006
november 2006
october 2006
september 2006
august 2006
july 2006
june 2006
may 2006
april 2006
march 2006
february 2006
january 2006
december 2005
november 2005
october 2005
september 2005
august 2005
july 2005
june 2005
may 2005
april 2005
march 2005
february 2005
january 2005
december 2004
november 2004
october 2004
september 2004
august 2004
july 2004
june 2004
may 2004
april 2004
march 2004
february 2004
january 2004
december 2003
november 2003
october 2003
june 2003
may 2003
april 2003
march 2003
february 2003
january 2003
december 2002
november 2002
october 2002
july 2002
june 2002
may 2002
april 2002
march 2002
february 2002
january 2002
countdown 2002
december 2001
november 2001
october 2001
september 2001
august 2001

more news in
> sitemap

Google


context archives all www
   "active, informed citizen participation is the key to shaping the network society. a new 'public sphere' is required." seattle statement
| home | site map | about context | donate | lang >>> español - català |
03 http://straddle3.net/context/03/en/2003_12_17.html