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1.
Choong Hyun Lee In Koo Hwang Ki-Yeon Yoo Jung Hoon Choi Ok Kyu Park Jae-Chul Lee Young-Gil Jeong In Se Lee Moo-Ho Won 《Cellular and molecular neurobiology》2009,29(5):665-672
The hippocampus is associated with learning and memory function and shows neurochemical changes in aging processes. Calbindin
D-28k (CB) binds calcium ion with a fast association rate. We examined age-related changes in CB immunoreactivity and its
protein level in the gerbil hippocampus during normal aging. In the hippocampal CA1 region (CA1) and CA2, CB immunoreaction
was found in some neurons in the stratum pyramidale (SP) at postnatal month 1 (PM 1). CB immunoreactivity in neurons was markedly
increased at PM 3. Thereafter, CB immunoreactivity was decreased with time: CB-immunoreactive (+) neurons were fewest at PM 24. In the CA3, a few CB+ neurons were found only in the SP at PM 1 and in the stratum radiatum at PM 18 and 24. In addition, mossy fibers were stained
with CB at PM 1. CB immunoreactivity in mossy fibers was markedly increased at PM 3, thereafter it was decreased with time.
In the dentate gyrus, many granule cells (GC) in the granule cell layer were stained with CB at PM 1. CB immunoreactivity
in GC was markedly increased at PM 3, thereafter CB immunoreactivity was decreased with time. In Western blot analysis, CB
protein level in the gerbil hippocampus was highest at PM 3, thereafter CB protein levels were decreased with time. This result
indicates that CB in the gerbil hippocampus is abundant at PM 3 and is decreased with age. 相似文献
2.
Choong Hyun Lee Ki-Yeon Yoo Jung Hoon Choi Ok Kyu Park In Koo Hwang Il-Jun Kang Moo-Ho Won 《Neurochemical research》2010,35(1):99-106
Cyclooxygenases-2 (COX-2) is not only related to inflammation but also plays critical roles in brain development and synaptic
signaling. In the present study, we investigated age-related changes in COX-2 immunoreactivity and protein levels in the gerbil
hippocampus. In the hippocampal CA1 region (CA1) and dentate gyrus (DG), weak COX-2 immunoreactivity was observed at postnatal
month 1 (PM 1), and COX-2 immunoreactivity was markedly increased at PM 18 and 24. In the CA2/3, COX-2 immunoreactivity was
strong at PM 1. COX-2 immunoreactivities in the PM 3, 6 and 12 groups were decreased compared to that in the PM 1 group, and
it was increased at PM 18 and 24. In addition, age-related changes in COX-2 levels were similar with immunohistochemical results
in the CA2/3. These results suggest that COX-2 immunoreactivity and levels were high in the hippocampus of aged gerbils. 相似文献
3.
Hwang IK Yoo KY Yi SS Kwon YG Ahn YK Seong JK Lee IS Yoon YS Won MH 《Neurochemical research》2008,33(5):867-872
In the present study, we investigated age-related changes of newborn neurons in the gerbil dentate gyrus using doublecortin
(DCX), a marker of neuronal progenitors which differentiate into neurons in the brain. In the postnatal month 1 (PM 1) group,
DCX immunoreactivity was detected in the subgranular zone of the dentate gyrus, but DCX immunoreactive neurons did not have
fully developed processes. Thereafter, DCX immunoreactivity and its protein levels in the dentate gyrus were found to decrease
with age. Between PM 3 and PM 18, DCX immunoreactive neuronal progenitors showed well-developed processes which projected
to the granular layer of the dentate gyrus, but at PM 24, a few DCX immunoreactive neuronal progenitors were detected in the
subgranular zone of the dentate gyrus. DCX protein level in the dentate gyrus at PM 1 was high, thereafter levels of DCX were
decreased with time. The authors suggest that a decrease of DCX immunoreactivity and its protein level with age may be associated
with aging processes in the hippocampal dentate gyrus. 相似文献
4.
Hippocampal interneurons are local circuit neurons which are responsible for inhibitory activity in the hippocampus. Parvalbumin
(PV) is one of useful markers for GABAergic interneurons, not for principle cells, in the hippocampus. In the present study,
we investigated age-related changes in PV immunoreactive neurons and protein levels in the gerbil hippocampus during normal
aging. PV immunoreactive neurons were detected in all hippocampal subregions of all groups. PV immunoreactive neurons, which
innervated principal neurons, were non-pyramidal neurons in the hippocampal CA1-3 regions, and were polymorphic neurons in
the dentate gyrus. In the hippocampal CA1 region, the number of PV immunoreactive neurons was significantly reduced in the
postnatal month 3 (PM 3) group, which was sustained by PM 18, and, at PM 24, the number of PV immunoreactive neurons was significantly
decreased. In the CA2/3 region and dentate gyrus, the number of PV immunoreactive neurons was significantly decreased at PM
6: Thereafter, the number of PV immunoreactive neurons was sustained until PM 24. In addition, changes in PV protein levels
in the gerbil hippocampus were similar to immunohistochemical changes during normal aging: PV protein levels were significantly
decreased with age by PM 6: Thereafter, PV protein levels were sustained by PM 24. These results suggest that PV immunoreactive
interneurons were decreased in the hippocampus with age in gerbils. 相似文献
5.
Chan Woo Park Ki-Yeon Yoo In Koo Hwang Jung Hoon Choi Choong Hyun Lee Ok Kyu Park Jun Hwi Cho Yun Lyul Lee Hyung-Cheul Shin Moo-Ho Won 《Neurochemical research》2009,34(12):2154-2162
The insulin receptor has been reported to be associated with memory formation via the hippocampus. In this study, we observed
age-related changes in the insulin receptor β immunoreactivity and its protein levels in the hippocampus of gerbils of various
ages in order to identify the correlation between the insulin receptor β and aging processes in the hippocampus. Insulin receptor
β immunoreactivity was mainly detected in the molecular and polymorphic layers of the dentate gyrus, and in mossy fibers,
Schaffer collaterals, alveus and stratum lacunosum-moleculare of the hippocampus proper (CA1-3) of gerbils at postnatal month
1 (PM 1). Insulin receptor β immunoreactivity decreased with age in all of these structures, except for the alveus. Reduction
of the insulin receptor β immunoreactivity was prominent in the molecular layer of the dentate gyrus at PM 6 and in the stratum
lacunosum-moleculare of the CA1 region at PM 12, while insulin receptor β immunoreactivity was decreased in other regions
in the PM 18 groups. In addition, insulin receptor β protein level in the whole hippocampus was slightly increased at PM 3,
and it decreased in an age-dependent manner from PM 6 to PM 24. These reductions of the insulin receptor β in the hippocampus
may be associated with age-related memory deficits in gerbils. 相似文献
6.
Choong Hyun Lee Ki-Yeon Yoo Ok Kyu Park Jung Hoon Choi Il-Jun Kang Eunjoo Bae Sung Koo Kim In Koo Hwang Moo-Ho Won 《Molecules and cells》2010,29(4):373-378
Phosphorylated extracellular signal-regulated kinase (pERK) mediates neuronal synaptic plasticity, long-term potentiation,
and learning and memory in the hippocampus. In this study, we examined pERK1/2 immunoreactivity and its protein level in the
gerbil hippocampus at various ages. In the postnatal month 1 (PM 1) group, very weak pERK1/2 immunoreactivity was detected
in the hippocampus. In the CA1 region, pERK1/2 immunoreactivity was considerably increased in the stratum pyramidale in the
PM 6 group. Thereafter, pERK1/2 immunoreactivity was decreased. In the CA2/3 region, pERK1/2 immunoreactivity increased in
an age-dependent manner until PM 12. Thereafter, numbers of pERK1/2-immunoreactive neurons were decreased. However, in the
mossy fiber zone, pERK1/2 immunostaining became stronger with age. In the dentate gyrus, a few pERK1/2-immunoreactive cells
were observed until PM 12. In the PM 18 and 24 groups, numbers of pERK1/2-immunoreactive cells were increased, especially
in the polymorphic layer. In Western blot analysis, pERK1/2 level in the gerbil hippocampus was increased with age. These
results indicate that total pERK1/2 levels are increased in the hippocampus with age. However pERK1/2 immunoreactivity in
subregions of the gerbil hippocampus was changed with different pattern during normal aging. 相似文献
7.
Ki-Yeon Yoo Ok Kyu Park Jiatian Yu Bingchun Yan Hua Li Choong Hyun Lee Jung Hoon Choi Dae Won Kim In Koo Hwang Moo-Ho Won 《Cellular and molecular neurobiology》2009,29(3):413-421
Oxidative stress is one of predisposing factors to age-related neurodegeneration in the brain. In particular, thiol-containing
groups are susceptible to oxidative stress, which induces the formation of the disulfide bond and/or hyperoxidized form of
thiol-containing proteins. We observed the protein thiol levels in the hippocampal homogenates and also investigated changes
in hyperoxidized form of peroxiredoxin (Prx–SO3) immunoreactivity and proteins levels in the gerbil hippocampal subregions during normal aging. Levels of total thiol, non-protein
thiol, and protein thiol were decreased in the hippocampal homogenates with age. At post-natal month 1 (PM 1), pyramidal and
non-pyramidal cells in the hippocampal CA1 region (CA1) showed Prx–SO3 immunoreactivity. Prx–SO3 immunoreactivity in the cells was decreased by PM 12, thereafter, Prx–SO3 immunoreactivity in the cells increased again with age. In the CA2/3, Prx–SO3 immunoreactivity in pyramidal cells was not significantly changed; however, the immunoreactivity in pyramidal cells was very
low at PM 12. Prx–SO3 immunoreactivity in the dentate gyrus (DG) was distinctly changed during aging. At PM 1, Prx–SO3 immunoreactivity in granule and polymorphic cells was weak and strong, respectively. The immunoreactivity in the neurons
was decreased with age, not shown in any neurons at PM 12. Thereafter, Prx–SO3 immunoreactivity increased again with age. In addition, Prx–SO3 protein level in the hippocampus was lowest at PM 12. These results suggest that thiol-containing proteins are changed during
aging and Prx–SO3 immunoreactivity was different according to cells in the hippocampal subregion during aging. 相似文献
8.
Choi JH Hwang IK Lee CH Chung DW Yoo KY Li H Won MH Seong JK Yoon YS Lee IS 《Neurochemical research》2008,33(3):562-568
Corticosteroids are important factors in the maintenance of homeostasis in the brain. They are regulated via the interaction
with two corticosteroid receptor systems—the mineralocorticoid (MR) and glucocorticoid receptor (GR). In the present study,
we observed age-related changes in serum cortisol levels, and immunoreactivities and protein levels of MR and GR in the hippocampal
CA1 region and dentate gyrus. The serum cortisol levels were significantly high (about twofold) in the aged group compared
to that in the adult group. In the adult dog (2–3 years old), MR and GR immunoreactivity was detected in neurons in the pyramidal
layer of the CA1 region, and in the granular and multiform layers of the dentate gyrus. In the aged dog (10–12 years old),
MR immunoreactivity in the CA1 region was significantly decreased, especially, in the dentate multiform layer. In contrast,
GR immunoreactivity in the aged dog was slightly decreased in the CA1 region and dentate gyrus. In the Western blot analysis,
MR protein level in the aged dog was significantly lower compared to that of the adult dog; GR protein level in the aged dog
was not significantly decreased. This result indicates that the reduction of MR immunoreactivity and protein level in the
hippocampus of the aged dog may be associated with neural dysfunction in the aged hippocampus. 相似文献
9.
Lee CH Yoo KY Ryu PD Park JH Choi JH Kim S Hwang IK Kim YM Won MH 《Cellular and molecular neurobiology》2011,31(3):345-350
In this study, we investigated age-related changes in glucagon-like peptide-1 receptor (GLP-1R) immunoreactivity and its protein
levels in the gerbil hippocampus during normal aging. In the postnatal month 3 (PM 3) group, GLP-1R immunoreaction was well
observed in neurons, especially pyramidal and non-pyramidal cells in the hippocampus proper, and granule and polymorphic cells
in the dentate gyrus. In the hippocampus proper, GLP-1R immunoreactivity in neurons was maintained until PM 24. In the dentate
gyrus, however, GLP-1R immunoreactivity in granule cells, not polymorphic cells, was hardly detected from PM 6. Western blot
analysis also showed that age-dependent change patterns in GLP-1R protein levels in the gerbil hippocampus were similar to
the immunohistochemical changes. These results indicate that GLP-1R immunoreactivity was markedly decreased in dentate granule
cells from PM 6, showing that GLP-1R immunoreactivity and its protein levels were decreased in the adult and aged gerbil hippocampus. 相似文献
10.
Comparison of Ionized Calcium-binding Adapter Molecule 1 Immunoreactivity of the Hippocampal Dentate Gyrus and CA1 Region in Adult and Aged Dogs 总被引:1,自引:1,他引:0
Hwang IK Lee CH Li H Yoo KY Choi JH Kim DW Kim DW Suh HW Won MH 《Neurochemical research》2008,33(7):1309-1315
Similarities between age-related changes in the canine and human brain have resulted in the general acceptance of the canine brain as a model of human brain aging. The hippocampus is essentially required for intact cognitive ability and appears to be particularly vulnerable to the aging process. We observed changes in ionized calcium-binding adapter molecule 1 (Iba-1, a microglial marker) immunoreactivity and protein levels in the hippocampal dentate gyrus and CA1 region of adult (2-3 years) and aged (10-12 years) dogs. We also observed the interferon-gamma (IFN-gamma), a pro-inflammatory cytokine, protein levels in these groups. In the dentate gyrus and CA1 region of the adult dog, Iba-1 immunoreactive microglia were well distributed and their processes were highly ramified. However, in the aged dog, the processes of Iba-1 immunoreactive microglia were hypertrophied in the dentate gyrus. Moreover, Iba-1 protein level in the dentate gyrus in the aged dog was higher than in the adult dog. IFN-gamma expression was increased in the dentate gyrus homogenates of aged dogs than adult dogs. In addition, we found that some neurons were positive to Fluoro-Jade B (a marker for neuronal degeneration) in the dentate polymorphic layer, but not in the hippocampal CA1 region in the aged dog. These results suggest that Iba-1 immunoreactive microglia are hypertrophied in the dentate gyrus in the aged dog. 相似文献
11.
Hwang IK Yi SS Yoo KY Park OK Yan B Song W Won MH Yoon YS Seong JK 《Neurochemical research》2011,36(2):281-287
Abnormal excess of glucocorticoid is one of feature characteristics in type 2 diabetes. In the present study, we investigated
the effect of treadmill exercise at chronic diabetic stages on glucocorticoid receptor (GR) immunoreactivity in the hippocampal
CA1 region and dentate gyrus, which are very vulnerable to diabetes. For this study, we used Zucker diabetic fatty (ZDF) rats
and Zucker lean control (ZLC) rats. Twenty-three-week-old ZLC and ZDF rats were put on the treadmill with or without running
for 7 weeks and sacrificed at 30 weeks of age. Treadmill exercise significantly decreased diabetes-induced blood glucose and
serum corticosteroid levels although they did not drop to control levels. In sedentary ZLC rats, GR immunoreactivity was detected
in pyramidal cells of the CA1 region as well as in granule cells of the dentate gyrus. In the sedentary ZDF rats, GR immunoreactivity
was significantly increased in these regions. However, treadmill exercise significantly decreased GR immunoreactivity in these
regions. These results indicate that treadmill exercise in chronic diabetic rats significantly decreased GR immunoreactivity
in the hippocampal CA1 region and dentate gyrus, although blood glucose and serum corticosteroid levels did not fully recover
to normal state. 相似文献
12.
Hwang IK Yoo KY Yoo DY Choi JW Lee CH Choi JH Yoon YS Won MH 《Cellular and molecular neurobiology》2011,31(5):669-674
Cyclic AMP (cAMP) response element-binding protein (CREB) is involved in memory, learning, and synaptic transmission. In this
study, we observed changes of phosphorylated CREB (pCREB) immunoreactivity and its protein levels as well as brain-derived
neurotrophic factor (BDNF) levels in the hippocampal dentate gyrus at postnatal (P) 1, 7, 14, and 21 in mice. In addition,
we also investigated pCREB expression in doublecortin (DCX, a marker for neuronal progenitors) immunoreactive neuroblasts
at P21. pCREB immunoreaction at P1 was detected in most of cells in the dentate gyrus, thereafter pCREB immunoreactivity was
decreased in all the layers of the dentate gyrus with time, however, strong pCREB immunoreactivity was shown in cells confined
to the subgranular zone of the dentate gyrus at P21. In this group, many pCREB immunoreactive cells were co-localized with
DCX immunoreactive neuroblasts. In addition, pCREB protein levels were decreased with age, showing that their levels were
very low at P21, while BDNF protein levels were increased with age. These results suggest that pCREB may play important roles
in functional maturity of granule cells in mice. 相似文献
13.
Sara A. Westgate Jean Brown Jaroslaw Aronowski M. Neal Waxham 《Journal of neurochemistry》1994,63(6):2217-2224
Abstract: Both CA1 and dentate gyrus regions of the hippocampal slice exhibit an irreversible loss of synaptic transmission after exposure to in vitro ischemic conditions (buffer without oxygen and glucose). However, after shorter durations of ischemia (8–10 min) the CA1 region shows an irreversible loss of synaptic responses, whereas the dentate gyrus region completely recovers synaptic responses upon reoxygenation. To determine biochemical mechanisms underlying this differential susceptibility, we have examined changes in Ca2+ /calmodulin-dependent protein kinase II (CaM-KII) and cyclic AMP-dependent protein kinase activities in homogenates from CA1 and dentate gyrus regions of the hippocampal slice after increasing durations of in vitro ischemia. Time-dependent changes in CaM-KII activities were correlated with changes in electrophysiological responses. CA1 homogenates from slices exposed to 1 min of ischemia showed significant increases in CaM-KII activity, whereas there was no significant change in kinase activity in dentate homogenates after 1 min of ischemia. However, after longer durations of ischemia (5, 10, and 20 min) we found a time-dependent reduction in CaM-KII activity in both CA1 and dentate gyrus regions, whereas no change was detected in cyclic AMP-dependent protein kinase activity. Irreversible depression of CaM-KII activity was seen at shorter durations of ischemia (10 min) in the CA1 region than in dentate region (20 min), which correlated with irreversible effects on synaptic responses. Immunoblot analysis showed that the decrease in CaM-KII activity was not due to degradation of CaM-KII protein. However, the microtubule-associated protein MAP2, known to be a substrate for the Ca2+ -dependent proteases (calpains), showed extensive proteolysis evident after 90 min of reoxygenation after ischemia. 相似文献
14.
Hiroki Kimoto Risa Eto Manami Abe Hiroyuki Kato Tsutomu Araki 《Cellular and molecular neurobiology》2009,29(8):1181-1189
We investigated the postnatal alterations of neurons, astrocyte, oligodendrocyte, and microglia in the mouse hippocampal CA1
sector and dentate gyrus under the same conditions using immunohistochemistry. Neuronal nuclei (NeuN), Glial fibrillary acidic
protein (GFAP), 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase), and ionized calcium binding adaptor molecule 1 (Iba
1) immunoreactivity were measured in 1-, 2-, 4-, and 8-week-old mice. Total number of NeuN-positive neurons was unchanged
in the mouse hippocampal CA1 sector and dentate gyrus from 1 to 8 weeks of birth. In contrast, a significant increase in the
number of GFAP-positive astrocytes was observed only in the hippocampal CA1 sector of 1-week-old mice when compared with 8-week-old
animals. Thereafter, total number of GFAP-positive astrocytes was unchanged in the hippocampal CA1 sector and dentate gyrus
from 2 to 8 weeks of birth. For microglia, a significant increase in the number of Iba 1-positive microglia was observed in
the hippocampal CA1 sector and dentate gyrus of 1-, 2-, and 4-week-old mice as compared with 8-week-old animals. On the other
hand, a significant decrease in the area of expression of CNPase-positive fibers was observed in the hippocampal CA1 sector
of 1- and 2-week-old mice as compared with 8-week-old animals. In dentate gyrus, a significant decrease in the area of expression
of CNPase-positive fibers was found in 1-, 2-, and 4-week-old mice. Furthermore, our double-labeled immunostaining showed
that brain-derived neurotrophic factor (BDNF) immunoreactivity was observed in GFAP-positive astrocytes and Iba 1-positive
microglia in the hippocampal CA1 sector and dentate gyrus of 1- and 2-week-old mice. These results show that glial cells may
play some role in the maintenance and neuronal functions of hippocampal CA1 pyramidal neurons and granule cells of dentate
gyrus during postnatal development. Furthermore, our results demonstrate that glial BDNF may play an important role in the
maturation of oligodendrocyte in the hippocampal CA1 sector and dentate gyrus during postnatal development. Thus, our findings
provide valuable information on the developmental processes. 相似文献
15.
Redd1, also known as RTP801/Dig2/DDIT4, is a stress-induced protein and marked changes of Redd1 expression occurs in response to hypoxia or cerebral ischemia. In the present study, we examined the time-course changes in Redd1 protein expressions in the rat hippocampal CA1 region following chronic cerebral hypoperfusion (CCH) induced by permanent bilateral common carotid arteries occlusion (2VO). Redd1 immunoreactivity in the pyramidal neurons of the hippocampal CA1 region was increased at 7 days after 2VO surgery, and then the immunoreactivity was decreased with time. Especially, very weak Redd1 immunoreactivity was observed in the hippocampal CA1 region at 28 days after 2VO surgery. Western blot analysis showed that Redd1 level in the hippocampal CA1 region was significantly increased at 7 days following CCH and significantly decreased at 28 days after 2VO surgery, compared with that of the sham-operated group. These results indicate that Redd1 expressions is markedly changed in the hippocampal CA1 region following CCH and that change of Redd1 expression may be associated with the CCH-induced neuronal damage in the hippocampal CA1 region. 相似文献
16.
Yoshitaka Furuta Masaaki Kobayashi Tamotsu Masaki Ken Takamatsu 《Neurochemical research》1999,24(5):651-658
Expression of hippocalcin and neural visinin-like calcium-binding protein 2 (NVP2) in aging rat brain was investigated by immunoblot and immunohistochemical analyses. In 3-month old rats, hippocalcin and NVP2 were present at high concentrations in hippocampal and cerebral pyramidal cells and dentate granule cells, with hippocalcin protein levels being five to ten times higher than NVP2 levels. Hippocalcin levels in hippocampus and cerebral cortex decreased by approximately 20% at 24 months. While the number of hippocalcin-positive cells in CA3, dentate gyrus and cerebral cortex were preserved, staining intensity decreased. In contrast, the number and staining intensity of hippocalcin-positive cells in CA1 were maintained. NVP2 levels in hippocampus and cerebral cortex decreased by approximately 30% at 24 months. In cerebral cortex, the number and intensity of NVP2-positive cells decreased. In CA1 through CA3 and in dentate gyrus, NVP2-positive cell numbers were preserved, but staining intensity decreased. In summary, the loss of hippocalcin and NVP2 in aging rat brain may be associated with age-related impairment of postsynaptic functions. 相似文献
17.
18.
Dae Young Yoo Hyun Jung Kwon Kwon Young Lee Hyo Young Jung Jong Whi Kim Joon Ha Park 《Animal cells and systems.》2016,20(5):237-245
Transient forebrain ischemia promotes a robust increase in neuroblast differentiation in the hippocampal dentate gyrus that peaks 7–15 days after the surgery. In this study, we compared the glucose transporter 3 (GLUT3)-dependent glucose utilization and the dynamin-1 (DNM1)-dependent neurite growth in the hippocampus of Mongolian gerbils 15 days after the induction of transient forebrain ischemia. The animals were subjected to a 5 min transient ischemia protocol and sacrificed 15 days after the surgery. Both doublecortin (DCX) immunoreactive neuroblasts and DCX total protein levels were abundantly increased in the ischemic group compared to the levels observed in the control group. In addition, animals in the ischemic group showed elevated GLUT3 immunoreactivity in the subgranular zone of the dentate gyrus compared to animals in the control group. Based on the double immunofluorescent study, increased DCX-immunoreactive neuroblasts were co-localized with GLUT3-immunoreactive components in the dentate gyrus. However, both the immunoreactivity and the total protein levels of DNM1 were significantly decreased in the dentate gyrus and hippocampal CA1 regions of the ischemic group. These results suggest that the regeneration process such as neurite growth is lacking in the hippocampus 15 days after ischemia/reperfusion although neuroblasts production and glucose utilization increased in the hippocampus. 相似文献
19.
Hwang IK Yoo KY Li H Choi JH Kwon YG Ahn Y Lee IS Won MH 《Neurochemical research》2007,32(9):1604-1609
Doublecortin (DCX), a microtubule-associated protein, specifically expresses in neuronal precursors. This protein has been
used as a marker for neuronal precursors and neurogenesis. In the present study, we observed differences in DCX immunoreactivity
and its protein levels in the hippocampal dentate gyrus between adult and aged dogs. In the adult dog, DCX immunoreactive
cells with well-stained processes were detected in the subgranular zone of the dentate gyrus. Numbers of DCX immunoreactive
cells in the dentate gyrus of the aged dog were significantly decreased compared to those in the adult dog. DCX immunoreactive
cells in both adult and aged dog did not show NeuN (a marker for mature neurons) immunoreactivity. NeuN immunoreactivity in
the aged dog was poor compared to that in the adult dog. DCX protein level in the aged dentate gyrus was decreased by 80%
compared to that in the adult dog. These results suggest that the reduction of DCX in the aged hippocampal dentate gyrus may
be involved in some neural deficits related to the hippocampus. 相似文献
20.
Human global ischaemia was simulated in adult rats by inducing 20 min brain ischaemia and 60 min post-ischaemic recirculation.
Immunohistochemical expression of MMP-9, TIMP-3, Bax and Bcl-2, and DNA fragmentation (with the TUNEL reaction) were investigated.
The morphological data showed different neuronal responses in the hippocampus compared with the cerebral and cerebellar cortices.
MMP-9 immunoreactivity was different in the hippocampus, particularly in dentate gyrus and the CA1 region, compared with these
cortices. Negative TIMP-3 staining in ischaemic hippocampal neurons may indicate a loss of its inhibitory activity on MMP-9
that could enhance cell death. Bcl-2 down regulation, Bax positivity and TUNEL+ type II cells in the dentate gyrus granular
layer could be responsible for induction of apoptotic death in CA1 hippocampal pyramidal cells via loss of fibre input. Results
suggest differential behaviours of neural cells after 60 min reperfusion. 相似文献