Aged ; Aged, 80 and over ; Alzheimer Disease ; metabolism ; pathology ; Brain ; metabolism ; Dentate Gyrus ; metabolism ; Dynamin I ; metabolism ; Hippocampus ; metabolism ; Humans ; Monomeric Clathrin Assembly Proteins ; metabolism ; Neuropil ; metabolism ; Synaptophysin ; metabolism

Peroxisome proliferator-activated receptor gamma (PPARgamma) has various actions including the regulation of adipocyte differentiation, lipid metabolism and glucose homeostasis. In the present study, we examined the changes of PPARgamma immunoreactivity and protein levels in the gerbil dentate gyrus (DG) after transient global cerebral ischemia using immunohistochemistry and western blot analysis. PPARgamma immunoreactivity was gradually increased from 1 day after ischemia-reperfusion. PPARgamma immunoreactivity, in accordance with protein level, was highest at 2 days after ischemia-reperfusion and was detected in microglia at this time. Thereafter, both PPARgamma immunoreactivity and protein level were decreased with time in the ischemic DG. These results indicate that PPARgamma may be related to the ischemia-induced microglial activation and neuronal damage/death in the DG after transient global cerebral ischemia.
Adipocytes ; Blotting, Western ; Brain Ischemia* ; Dentate Gyrus* ; Gerbillinae* ; Glucose ; Homeostasis ; Immunohistochemistry ; Lipid Metabolism ; Microglia ; Neurons ; PPAR gamma*

Peroxisome proliferator-activated receptor gamma (PPARgamma) has various actions including the regulation of adipocyte differentiation, lipid metabolism and glucose homeostasis. In the present study, we examined the changes of PPARgamma immunoreactivity and protein levels in the gerbil dentate gyrus (DG) after transient global cerebral ischemia using immunohistochemistry and western blot analysis. PPARgamma immunoreactivity was gradually increased from 1 day after ischemia-reperfusion. PPARgamma immunoreactivity, in accordance with protein level, was highest at 2 days after ischemia-reperfusion and was detected in microglia at this time. Thereafter, both PPARgamma immunoreactivity and protein level were decreased with time in the ischemic DG. These results indicate that PPARgamma may be related to the ischemia-induced microglial activation and neuronal damage/death in the DG after transient global cerebral ischemia.
Adipocytes ; Blotting, Western ; Brain Ischemia* ; Dentate Gyrus* ; Gerbillinae* ; Glucose ; Homeostasis ; Immunohistochemistry ; Lipid Metabolism ; Microglia ; Neurons ; PPAR gamma*

OBJECTIVETo investigate the relationship between diabetes and somatostatin (SOM).

METHODSWe established a streptozocin-induced diabetic rats model and studied the changes of SOM mRNA in hippocampi of diabetic and normal rats by using in situ hybridication and computer image analysis. We studied the mechanism of chronic diabetes encephalopathy by observing the changes of somatostatin mRNA in the hippocampus of diabetic rats was studied.

RESULTThe number, light density and average area of positive cells in dentate gyrus area of hippocampus in diabetes model were reduced significantly as compared with normal rats (P < 0.01).

CONCLUSIONA decline in SOM mRNA expression may play a role in chronic diabetes encephalopathy because of SOM effect in brain.

Animals ; Brain Diseases ; etiology ; metabolism ; Dentate Gyrus ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; Diabetic Neuropathies ; metabolism ; Hippocampus ; metabolism ; Male ; RNA, Messenger ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; Somatostatin ; biosynthesis ; genetics

Objective To explore the temporal and spatial distribution of CCAAT/enhancer-binding protein homologous protein (CHOP) and calnexin (CNX) in the dentate gyrus of mesial temporal lobe epilepsy (mTLE) mouse model. Methods We used kainic acid (KA) to induce acute phase (12 h and 24 h) mTLE mouse models and performed Western blotting and immunofluorescence to detect the different expressions and distribution pattern of CHOP and CNX in CA3 of the hippocampus. Results Compared with the controls,the expressions of CHOP(F=1.136,P=0.4069) and CNX (F=2.378,P=0.2087) did not increase in CA3 of hippocampus 12 h following KA injection in the acute phase of mTLE mouse models,whereas the expressions in CA1 and CA3 of hippocampus 24 h after injection were significantly higher (F=8.510,P=0.0362;F=6.968,P=0.0497,respectively). As shown by immunofluorescence analysis,CHOP was expressed mainly in CA3 of hippocampus 12 h after KA injection,and increased in CA1 and CA3 24 h after KA administration. Compared with the controls,the expressions of CHOP(F=24.480,P=0.0057) and CNX (F=7.149,P=0.0478) were significantly higher 24 h after KA injection.Conclusions The expression of CHOP increases along with the progression of seizures,indicating the increased level of endoplasmic reticulum stress. An increasing number of CNX,which serves as molecular chaperone,may be needed to facilitate the unfolded protein to complete the folding process.
Animals ; Calnexin ; metabolism ; Dentate Gyrus ; metabolism ; Disease Models, Animal ; Epilepsy, Temporal Lobe ; chemically induced ; metabolism ; Kainic Acid ; Mice ; Seizures ; chemically induced ; metabolism ; Transcription Factor CHOP ; metabolism

OBJECTIVETo explore the temporal and spatial distribution of growth-associated protein 43(GAP-43)and phosphorylated growth-associated protein 43(p-GAP-43)in the dentate gyrus of mesial temporal lobe epilepsy(MTLE)mouse model.

METHODSMTLE mouse model was established by using the kainic acid(KA)induction. Immunohistochemistry and Western blotting were applied to detect the expressions of GAP-43 and p-GAP-43 in different stages of epileptogenesis.

RESULTSBoth in the epileptic and control mice, high GAP-43 expression level was detected in the dentate gyrus, hilus, and inner molecular layer of hippocampus. Decreased p-GAP-43 expression was detected 5 days, 2 weeks, and 5 weeks after KA-induced seizures.

CONCLUSIONThe decreased p-GAP-43 expression in the duration of seizure may play an important role in the synaptic reorganization of the sclerotic hippocampus.

Animals ; Dentate Gyrus ; metabolism ; Disease Models, Animal ; Epilepsy ; Epilepsy, Temporal Lobe ; metabolism ; GAP-43 Protein ; metabolism ; Hippocampus ; metabolism ; Kainic Acid ; Mice ; Seizures

OBJECTIVETo observe the expression of p38 MAPK and HSP 70 in CA3 and dentate gyrus (DG) regions of the hippocampus of rats induced by limb ischemic preconditioning (LIP).

METHODSNinety-six rats were randomly divided into sham and LIP groups. And the animals in the LIP group were further divided into LIP 6 h, LIP 12 h, LIP 1 d, LIP 2 d, LIP 3 d, LIP 4 d and LIP 5 d subgroups according to the time of reperfusion after LIP. Immunohistochemical staining and Western blot were used to observe the expression of p38 MAPK and HSP 70 in CA3 and DG regions of the hippocampus.

RESULTSThe results of the immunohistochemical staining and Western blot were consistent, which indicated that there were fluctuation in the p-p38 MAPK and HSP 70 expression in CA3 and DG regions after LIP compared with those of the sham group. The expression of p-p38 MAPK began to be up-regulated 1d after LIP and reached its peak at 3 d and lasted for 4 d after LIP. However, the expression of HSP 70 was significantly up-regulated 2 d after LIP compared to the sham group, reached its peak at 3 d and lasted until the 4 d after LIP.

CONCLUSIONLIP up-regulates the expression of p38 MAPK and HSP 70 in the CA3 and DG regions of the hippocampus of rats.

Animals ; CA3 Region, Hippocampal ; metabolism ; Dentate Gyrus ; metabolism ; Extremities ; blood supply ; HSP70 Heat-Shock Proteins ; metabolism ; Ischemic Preconditioning ; Male ; Rats ; Rats, Wistar ; p38 Mitogen-Activated Protein Kinases ; metabolism

MicroRNA-132 (miR-132), a small RNA that regulates gene expression, is known to promote neurogenesis in the embryonic nervous system and adult brain. Although exposure to psychoactive substances can increase miR-132 expression in cultured neural stem cells (NSCs) and the adult brain of rodents, little is known about its role in opioid addiction. So, we set out to determine the effect of miR-132 on differentiation of the NSCs and whether this effect is involved in opioid addiction using the rat morphine self-administration (MSA) model. We found that miR-132 overexpression enhanced the differentiation of NSCs in vivo and in vitro. Similarly, specific overexpression of miR-132 in NSCs of the adult hippocampal dentate gyrus (DG) during the acquisition stage of MSA potentiated morphine-seeking behavior. These findings indicate that miR-132 is involved in opioid addiction, probably by promoting the differentiation of NSCs in the adult DG.
Animals ; Cell Differentiation ; Cell Line, Tumor ; Dentate Gyrus ; metabolism ; Gene Expression Regulation ; Male ; MicroRNAs ; metabolism ; Neural Stem Cells ; metabolism ; Opioid-Related Disorders ; metabolism ; Rats, Sprague-Dawley

OBJECTIVEDivision of the CA1, CA3 and dentate gyrus (DG) regions of the hippocampus of Wistar rat under the stereomicroscope.

METHODSTwenty-four Wistar rats were randomly assigned to three groups. (1) The brain was sectioned coronally (n = 6). The sections were stained with thionin and the morphology of cells in each region of the hippocampus was observed under microscopy. (2) The hippocampus was dissected out and observed on the whole. Then, the CA1, CA3 and DG regions of the hippocampus were divided. Every region divided was sectioned, and the morphology of cells was observed. (3) Rats with brain ischemia or not were also decapitated and the HSP 70 expressions were observed in CA1, CA3 + DG regions by Western blot and immunohistochemical staining (n = 12).

RESULTS(1) The CA1, CA3 and DG regions of the hippocampus could be clearly observed in coronal section of the brain stained by thionin. (2) Under the stereomicroscope, the CA1 and DG regions of the hippocampus could be separated along the hippocampal fissure between them in ventral surface of the hippocampus. The CA3 and DG regions of the hippocampus could be separated along a fissure between them. The appearance of cells in the sections of the divided CA1, CA3 and DG specimens is consistent with that in the brain coronal sections, respectively. (3) The results of Western blot indicated that the HSP 70 expression of the brain ischemia group was up-regulated significantly in CA3 + DG regions compared with the sham group. However, HSP 70 expression has no significant changes in CA1 region. The above results were consistent with those of the immunohistochemical staining.

CONCLUSIONThe CA1, CA3 and DG regions of the hippocampus of Wistar rat could be divided under stereomicroscope, and the divided each region was sensible for detection of protein using Western blot.

Animals ; CA1 Region, Hippocampal ; anatomy & histology ; metabolism ; CA3 Region, Hippocampal ; anatomy & histology ; metabolism ; Dentate Gyrus ; anatomy & histology ; metabolism ; Male ; Rats ; Rats, Wistar

OBJECTIVETo explore the effects of retinol acid (RA) and triiodothyronine (T3) on alleviating the impairment of cognitive function by sleep deprivation (SD).

METHODSMale Wistar rats were divided into 4 groups: control group (C group), sleep deprivation group (SD group), sleep deprivation + RA group (SD + RA group) and sleep deprivation + T3 group (SD + T3 group). Open field test (OFT) was used to observe the nervous behavior of the rats after SD and electrophysiological brain stereotactic method was used to test long-term potentiation (LTP) in dentate gyrus (DG) of the rats. Ng protein expression was determined by Western blot.

RESULTSCompared with the SD group, the number of crossing in OFT, the changes of amplitude of population spike (PS) and the expression of Ng protein in hippocampus were higher significantly in the SD + RA and SD + T3 groups. All of these had not significant difference comparing with the C group.

CONCLUSIONRA and T3 may alleviate the restrain state of neural system after SD by augmenting the expression of Ng protein in hippocampus.

Animals ; Cognition ; drug effects ; Dentate Gyrus ; metabolism ; Long-Term Potentiation ; Male ; Neurogranin ; metabolism ; Rats ; Rats, Wistar ; Sleep Deprivation ; metabolism ; psychology ; Triiodothyronine ; pharmacology ; Vitamin A ; pharmacology