AIMIn order to explore the neurobiological mechanism of morphine addiction and treatment methods, the acute and chronic effects of morphine on the intracellular free calcium concentration ([Ca2+]i) in cultured hippocampal neurons were investigated.

METHODSChanges of [Ca2+]i induced by morphine in primarily cultured hippocampal neurons were measured by confocal laser scanning microscopy using Ca(2+) -sensitive dye fluo-4 as the calcium fluorescent probe.

RESULTSMorphine actually induced the increase in [Ca2+]i of hippocampal neurons. This process could be blocked by naltrindole (delta opioid receptor antagonist) pretreatment, but not by CTOP (micro opioid receptor antagonist) pretreatment. Pretreatment of the cells with thapsigargin almost completely blocked morphine-evoked response; while pretreatment of the cells with verapamil partially inhibited this response. After exposure to 100 micromol/L morphine for 24 h, intracellular [Ca2+]i increased and the increase could be intensified after adding 10 micromol/L naloxone to the medium.

CONCLUSIONMorphine induced the release of Ca2+ is mainly from inositol 1, 4, 5-trisphosphate (IP3) sensitive stores in hippocampal neuron of rats through activation of delta2 subtype opioid receptor.

Animals ; Calcium ; metabolism ; Cells, Cultured ; Hippocampus ; cytology ; Male ; Microscopy, Confocal ; Morphine ; pharmacology ; Neurons ; cytology ; drug effects ; Rats ; Rats, Wistar

AIMTo observe the effect and mechanism of scopolamine on morphine(Mor)-induced mice dependence.

METHODSThe Mor-dependent mice model was established by intraperitoneal (ip) administered Mor for seven days. Pain threshold, times of jump and hippocampus intracellular free calcium ion concentration ([Ca2+]i) were determined by the heat plate test, naloxone (Nal)-precipitated jumping response and flow cytometry, respectively.

RESULTSThe pain threshold of Mor-dependent mice decreased significantly while there was a marked increase in times of jump, the rate of jumping animals and hippocampus [Ca2+]i. Co-administered scopolamine, the pain threshold of Mor-dependent mice increased significantly; the number of jump, the rate of jumping animals and hippocampus [Ca2+]i all decreased significantly.

CONCLUSIONScopolamine could antagonize the Mor-induced mice dependence, which could be related to decreasing the levels of brain intracellular free calcium.

Animals ; Calcium ; metabolism ; Hippocampus ; cytology ; drug effects ; metabolism ; Mice ; Mice, Inbred Strains ; Morphine ; pharmacology ; Morphine Dependence ; metabolism ; Scopolamine Hydrobromide ; pharmacology

Animals ; Calcium ; metabolism ; Cell Hypoxia ; Cells, Cultured ; Hippocampus ; cytology ; Neurons ; drug effects ; metabolism ; Rats ; Rats, Wistar ; omega-Conotoxins ; pharmacology

Animals ; Apoptosis ; drug effects ; Cell Hypoxia ; Cells, Cultured ; Hippocampus ; cytology ; Neurons ; cytology ; drug effects ; Propofol ; pharmacology ; Proto-Oncogene Proteins c-fos ; metabolism ; Rats

The possible role of minocycline in microglial activation and neuronal death after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in mice was investigated in this study. The mice were given potassium chloride to stop the heart beating for 8 min to achieve CA, and they were subsequently resuscitated with epinephrine and chest compressions. Forty adult C57BL/6 male mice were divided into 4 groups (n=10 each): sham-operated group, CA/CPR group, CA/CPR+minocycline group, and CA/CPR+vehicle group. Animals in the latter two groups were intraperitoneally injected with minocycline (50 mg/kg) or vehicle (normal saline) 30 min after recovery of spontaneous circulation (ROSC). Twenty-four h after CA/CPR, the brains were removed for histological evaluation of the hippocampus. Microglial activation was evaluated by detecting the expression of ionized calcium-binding adapter molecule-1 (Iba1) by immunohistochemistry. Neuronal death was analyzed by hematoxylin and eosin (H&E) staining and the levels of tumor necrosis factor-alpha (TNF-α) in the hippocampus were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that the neuronal death was aggravated, most microglia were activated and TNF-α levels were enhanced in the hippocampus CA1 region of mice subjected to CA/CPR as compared with those in the sham-operated group (P<0.05). Administration with minocycline 30 min after ROSC could significantly decrease the microglial response, TNF-α levels and neuronal death (P<0.05). It was concluded that early administration with minocycline has a strong therapeutic potential for CA/CPR-induced brain injury.
Animals ; Cardiopulmonary Resuscitation ; Cell Death ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Heart Arrest ; pathology ; Hippocampus ; cytology ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Microglia ; cytology ; drug effects ; Minocycline ; pharmacology ; Neurons ; drug effects ; Tumor Necrosis Factor-alpha ; metabolism

AIMTo observe the protective role of pituitary adenylate cyclase activating polypeptide (PACAP) on hippocampal neuronal apoptosis induced by beta amyloid peptide in the culture.

METHODSHippocampal neurons were isolated from 1d old SD rat and neuronal survival and apoptosis were measured by MTT assay and DNA ladder.

RESULTS25 micromol/L Abeta could induce neuron apoptosis while co-treatment with PACAP could increase the survival of hippocampal neurons. The antagonist of PACAP receptor, P6-27, could reverse the effect of PACAP.

CONCLUSIONPACAP could protects cultured neurons from the neurotoxicity of Abeta through the activation of PACAP receptor and may have a bright use in treatment of neurodegenerative disease.

Amyloid beta-Peptides ; toxicity ; Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Hippocampus ; cytology ; Neurons ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide ; metabolism

OBJECTIVETo study the effects of deltamethrin on intracellular free Ca2+ concentration and apoptosis in rat neural cells.

METHODSWister rats were randomly divided into 4 groups(3 treated groups and 1 control). Intracellular free Ca2+ concentration in rat neural cells was measured by using the fluorescent Ca2+ indicator Fura-2/AM. Apopotic rate of neural cells was measured by using FACS420 Flow Cytometer.

RESULTSIntracellular free Ca2+ concentration at 5 h after deltamethrin exposure [hippocampus: (389.94 +/- 43.64) nmol/L, cerebral cortex: (449.33 +/- 23.23) nmol/L], at 24 h[hippocampus: (340.47 +/- 32.36) nmol/L, cerebral cortex: (311.62 +/- 25.48) nmol/L] and at 48 h[hippocampus: (287.13 +/- 24.29) nmol/L, cerebral cortex: (346.55 +/- 36.87) nmol/L] were all higher than those of the control group[hippocampus: (203.24 +/- 18.53) nmol/L, cerebral cortex: (226.85 +/- 14.81) nmol/L, P < 0.01]; Apoptotic rate in neural cells 24 h and 48 h later [hippocampus: (8.45 +/- 1.02)%, (9.44 +/- 1.14)%, cerebral cortex: (7.90 +/- 0.49)%, (8.01 +/- 0.87)%] were also higher than those of the control group[hippocampus: (2.97 +/- 0.36)%, cerebral cortex: (3.50 +/- 0.48)%, P < 0.01)] and increased with time prolonged.

CONCLUSIONExposure to high dose of deltamethrin would interfere with intracellular free Ca2+ concentration and apoptotic rate in rat neural cells, suggesting that there may be certain relation between them.

Animals ; Apoptosis ; drug effects ; Calcium ; metabolism ; Cerebral Cortex ; drug effects ; metabolism ; pathology ; Flow Cytometry ; Hippocampus ; drug effects ; metabolism ; pathology ; Insecticides ; toxicity ; Neurons ; cytology ; drug effects ; metabolism ; Nitriles ; toxicity ; Pyrethrins ; toxicity ; Rats ; Rats, Wistar

OBJECTIVETo investigate the synergistic effect of Schwann cells (SCs) and retinoic acid (RA) on differentiation and synaptogenesis of neural stem cells (NSCs) derived from hippocampus of neonatal rats.

METHODSThe classical method for 2x2 factorial analysis experiment was used to assess synergistic action of SCs and RA. NSCs were treated with RA, SCs, and SCs + RA in DMEM/F12 with 0.5% fetal bovine serum for six days, respectively. Double immunofluorescent staining was used to detect the differentiation of NSCs including nestin, glial fibrillary acidic protein (GFAP) and Map2. The expression of PSD95 was used to demonstrate synaptogenesis.

RESULTSAfter NSCs were treated with RA or SCs, the expression of nestin and GFAP was significantly decreased while the expression of Map2 and PSD95 was significantly increased in comparison with the control. Factorial ANOVA showed that interactions between SCs and RA could induce the expression of Map2 and PSD95.

CONCLUSIONSCs and RA could promote synergistically the neuronal differentiation and synaptogenesis of hippocampal neural stem cells in vitro while they decreased the astrocytes and nestin positive NSCs.

Animals ; Animals, Newborn ; Astrocytes ; cytology ; metabolism ; Cell Differentiation ; drug effects ; physiology ; Cells, Cultured ; Drug Synergism ; Fluorescent Antibody Technique ; Glial Fibrillary Acidic Protein ; metabolism ; Hippocampus ; cytology ; drug effects ; ultrastructure ; Intermediate Filament Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Nestin ; Neurons ; cytology ; drug effects ; ultrastructure ; Rats ; Rats, Sprague-Dawley ; Schwann Cells ; metabolism ; Stem Cells ; cytology ; drug effects ; ultrastructure ; Synapses ; drug effects ; physiology ; Tretinoin ; pharmacology

Rat hippocampal precursor cells isolated from hippocampi of embryonic day 16.5 (E16.5) rat embryos were found to proliferate in the presence of basic fibroblast growth factor. Addition of soluble neural cell adhesion molecule (NCAM) to these precursor cells reduced cell proliferation in a dose dependent manner and enhanced the induction of precursor cells' differentiation to the neuronal lineage. Given these findings that NCAM induces the differentiation of hippocampal precursor cells, we investigated possible effects of NCAM on the expression of basic helix-loop-helix (bHLH) transcription factors during the differentiation. Soluble NCAM upregulated the transcription of bHLH transcription factors, neurogenin1 and NeuroD, but decreased HES5. Western blot analysis showed that NCAM increased the expression levels of CaMKII, p-MAPK, GluR1 and NR1 but decreased p-STAT3. These results support a role for NCAM in the inhibition of proliferation and the induction of neural differentiation of hippocampal neural precursor cells, and act as developmental regulators of the bHLH families, ultimately leading to the generation of glutamatergic neural cell types in the differentiation of hippocampal precursor cells.
Animals ; Apoptosis/drug effects ; Cell Differentiation/*drug effects ; Cell Division/drug effects ; Cell Lineage/drug effects ; Cells, Cultured ; Helix-Loop-Helix Motifs ; Hippocampus/*cytology/*drug effects ; Neural Cell Adhesion Molecules/*pharmacology ; Neurons/cytology/*drug effects/metabolism ; RNA, Messenger/genetics/metabolism ; Rats ; Receptors, Glutamate/*metabolism ; Signal Transduction ; Stem Cells/cytology/*drug effects ; Transcription Factors/genetics/metabolism

OBJECTIVETo investigate the effect of aluminum exposure on neuronal apoptosis of rats hippocampus and the correlation of and synaptic plasticity.

METHODSThere were 40 SPF grade SD rats which were randomly divided into four groups: the control group, the low dose group, the medium dose group and the high dose group, 10 rats in each group. The rats were daily gavaged with aluminum lactate for 30 days. The hippocampal fEPSPs in rat was measured by electrophysiological grapher and the neuronal apoptosis in hippocampus was detected by Flow cytometer. In addition, the relative expression of gene which includes caspase-3, 8, 9 was measured by Real-time PCR.

RESULTSCompared to the control group, the average of fEPSPs which after HFS 10, 20, 30, 40, 50, 60 min was decreased at different time point in the low dose group, the medium dose group and the high dose group (P < 0.05). Compared with the control group, the rate of apoptosis was significantly increased in the medium dose group and the high dose group (P < 0.05). Compared to the control group, the relative expression of caspase-3 in the medium dose group and the high dose group was significantly increased in Real-time PCR (P < 0.05), and the relative expression of caspase-8 in the high dose group was significantly increased (P < 0.05).

CONCLUSIONAluminum exposure may induced neuronal apoptosis in rats, and then affect hippocampal synaptic plasticity.

Aluminum ; toxicity ; Aluminum Compounds ; toxicity ; Animals ; Apoptosis ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Hippocampus ; cytology ; drug effects ; Lactates ; toxicity ; Neuronal Plasticity ; drug effects ; Neurons ; cytology ; drug effects ; Rats ; Rats, Sprague-Dawley