Newborn granule cells in the ageing dentate gyrus.

LOMBARDI GABRIELA; MORGENSTERN NICOLÁS; SCHINDER ALEJANDRO

THE JOURNAL OF PHYSIOLOGY

The Physiological Society and Blackwell Publishing publish

Lugar: London ; Año: 2008 vol. 586 p. 3751 - 3757

0022-3751

The dentate gyrus of the hippocampus generates neurons throughout life, but adult neurogenesis exhibits a marked age-dependent decline. Although the decrease in the rate of neurogenesis has been extensively documented in the ageing hippocampus, the specific characteristics of dentate granule cells born in such a continuously changing environment have received little attention. We have used retroviral labelling of neural progenitor cells of the adult mouse dentate gyrus to study morphological properties of neurons born at different ages. Dendritic spine density was measured to estimate glutamatergic afferent connectivity. Fullymature neurons born at the age of 2 months display ¡­2.3 spines ¥ìm−1 and maintain their overall morphology and spine density in 1-year-old mice. Surprisingly, granule cells born in 10-month-oldmice, at which time the rate of neurogenesis has decreased by ¡­40-fold, reach a density of dendritic spines similar to that of neurons born in young adulthood. Therefore, in spite of the sharp decline in cell proliferation, differentiation and overall neuronal number, the ageing hippocampus presents a suitable environment for new surviving neurons to reach a high level of complexity, comparable to that of all other dentate granule cells.¡­2.3 spines ¥ìm−1 and maintain their overall morphology and spine density in 1-year-old mice. Surprisingly, granule cells born in 10-month-oldmice, at which time the rate of neurogenesis has decreased by ¡­40-fold, reach a density of dendritic spines similar to that of neurons born in young adulthood. Therefore, in spite of the sharp decline in cell proliferation, differentiation and overall neuronal number, the ageing hippocampus presents a suitable environment for new surviving neurons to reach a high level of complexity, comparable to that of all other dentate granule cells.