Long-term changes in neuronal degeneration and microglial activation in the hippocampal CA1 region after experimental transient cerebral ischemic damage.
Delayed neuronal death following transient cerebral ischemia is mixed with apoptosis and necrosis, and the activation of microglia are activated after the ischemic insult. In the present study, we examined the long-term changes in neuronal degeneration and microglial activation in the gerbil hippocampal CA1 region after 5min of transient cerebral ischemia using specific markers for neuronal damage and microliosis. Transient ischemia-induced neuronal death was shown in CA1 pyramidal cells 4days after ischemia/reperfusion (I/R). However, neuronal degeneration of the pyramidal cells were observed up to 45days in the CA1 region after I/R. Microglial activation was also observed in the CA1 region after I/R. Isolectin B4- (IB4) immunoreactive ((+)) microglia appeared in the CA1 region 4days after I/R. On the other hand, ionized calcium-binding adapter molecule 1 (Iba-1)(+) microglia was markedly increased after I/R, and peaked at 15days after I/R. Thereafter, Iba-1 immunoreactivity was decreased with time-dependant manner in the ischemic CA1 region. These results indicate that neuronal degeneration of CA1 pyramidal cells may last about 45days in the CA1 region after ischemic damage, and microglial activation may be diverse according to their function, such as phagocytosis, after I/R.
Lee
Choong Hyun
CH
Department of Anatomy and Neurobiology, and Institute of Neurodegeneration and Neuroregeneration, College of Medicine, Hallym University, Chuncheon 200-702, South Korea.
Moon
Seung Myung
SM
Yoo
Ki-Yeon
KY
Choi
Jung Hoon
JH
Park
Ok Kyu
OK
Hwang
In Koo
IK
Sohn
Youdong
Y
Moon
Joong Bum
JB
Cho
Jun Hwi
JH
Won
Moo-Ho
MH
D000818:Animals; D002545:Brain Ischemia / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D005849:Gerbillinae; D005911:Gliosis / Q000473:pathology* / Q000503:physiopathology; D006624:Hippocampus / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D017628:Microglia / Q000473:pathology*; D009410:Nerve Degeneration / Q000473:pathology* / Q000503:physiopathology; D009474:Neurons / Q000473:pathology*; D013995:Time; D013997:Time Factors