Comparison of neurogenesis in the dentate gyrus between the adult and aged gerbil following transient global cerebral ischemia.
In the present study, we compared differences in cell proliferation, neuroblast differentiation and neuronal maturation in the hippocampal dentate gyrus (DG) between the adult and aged gerbil induced by 5 min of transient global cerebral ischemia using Ki-67 and BrdU (markers for cell proliferation), doublecortin (DCX, a marker for neuroblast differentiation) and neuronal nuclei (NeuN, a marker for mature neuron). The number of Ki-67-immunoreactive (⁺) cells in the DG of both the groups peaked 7 days after ischemia/reperfusion (I/R). However, the number in the aged DG was 40.6 ± 1.8% of that in the adult DG. Thereafter, the number decreased with time. After ischemic damage, DCX immunoreactivity and its protein level in the adult and aged DG peaked at 10 and 15 days post-ischemia, respectively. However, DCX immunoreactivity and its protein levels in the aged DG were much lower than those in the adult. DCX immunoreactivity and its protein level in the aged DG were 11.1 ± 0.6% and 34.4 ± 2.1% of the adult DG, respectively. In addition, the number of Ki-67⁺ cells and DCX immunoreactivity in both groups were similar to those in the sham at 60 days postischemia. At 30 days post-ischemia, the number of BrdU⁺ cells and BrdU⁺/NeuN⁺ cells in the adult-group were much higher (281.2 ± 23.4% and 126.4 ± 7.4%, respectively) than the aged-group (35.6 ± 6.8% and 79.5 ± 6.1%, respectively). These results suggest that the ability of neurogenesis in the ischemic aged DG is much lower than that in the ischemic adult DG.
Department of Anatomy, College of Veterinary Medicine, Kangwon National University, Chuncheon 200-701, South Korea.
Jung Hoon
JH
Choi
Ki-Yeon
KY
Yoo
Choong Hyun
CH
Lee
Joon Ha
JH
Park
Bing Chun
BC
Yan
Seung-Hae
SH
Kwon
Jeong Yeol
JY
Seo
Jun Hwi
JH
Cho
In Koo
IK
Hwang
Moo-Ho
MH
Won
D000367:Age Factors; D000375:Aging / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D018891:Dentate Gyrus / Q000378:metabolism* / Q000473:pathology; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000378:metabolism* / Q000473:pathology; D008297:Male; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000378:metabolism / Q000473:pathology