Electroconvulsive shock (ECS) has been suggested to affect cAMP signaling pathways to exert therapeutic effects. ECS was recently reported to increase the expression of PDE4 isoforms in rat brain, however, these studies were limited to PDE4 family in the cerebral cortex and hippocampus. Thus, for comprehensive understanding of how ECS regulates PDE activity, the present study was performed to determine whether chronic ECS treatment induces differential changes in the expression of all the PDE isoforms in rat brains. We analyzed the mRNA expression of PDE isoforms in the rat hippocampus and striatum using reverse transcription polymerase chain reaction. We found chronic ECS treatment induced differential changes in the expression of PDE isoform 1, 2, 3, 4, 5 and 7 at the rat hippocampus and striatum. In the hippocampus, the expression of PDE1A/B (694%), PDE4A (158%), PDE4B (323 %), and PDE4D (181%) isoforms was increased from the controls, but the expression of PDE2 (62.8%) and PDE7 (37.8%) decreased by chronic ECS treatment. In the striatum, the expression of PDE1A/B (179%), PDE4A (223%), PDE4B (171%), and PDE4D (327%) was increased by chronic ECS treatment with the concomitant decrease in the expression of PDE2 (78.4%) and PDE3A (67.1%). In conclusion, chronic ECS treatment induces differential changes in the expression of most PDE isoforms including PDE1, PDE2, PDE3, PDE4, PDE5, and PDE7 in the rat hippocampus and striatum in an isoform- and brain region-specific manner. Such differential change is suggested to play an important role in regulation of the activity of PDE and cAMP system by ECS.
3',5'-Cyclic-Nucleotide Phosphodiesterase/analysis* ; Animal ; Corpus Striatum/enzymology* ; Electroconvulsive Therapy* ; Gene Expression Regulation, Enzymologic ; Hippocampus/enzymology* ; Isoenzymes/analysis* ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the distribution of neuronal nitric oxide synthase (nNOS)-immunopositive neurons in rat corpus striatum and their ultrastructural features.

METHODSBrain tissue specimens were obtained from normal SD rats, in which nNOS-immunopositive neurons were visualized by ABC immunocytochemistry and observed under immunoelectron microscope with pre-embedding staining.

RESULTSUnder light microscope, nNOS-immunopositive neurons appeared brown with distinct profiles of the cell body and processes. These neurons, mostly medium-sized and small cells, were located mainly in the lateral region of the corpus striatum. Only a few immunopositive neurons were detected in the medial region of the corpus striatum. Immunohistochemistry and transmission electron microscopy identified the nNOS-immunopositive neurons as interneurons possessing large nuclei with small amount of cytoplasma. The immunopositive granules were visualized as black plaques, and the larger ones distributed mainly in the cell bodies, some with monolayer membrane encapsulation. The small granules did not have the encapsulation, scattering in perinuclear regions and under the cell membrane, but not in the cell body. The immunopositive granules were also found in the axons and dendrites, but not in the vesicles of the synapses. In addition, many immunopositive terminals were found close to the blood vessels.

CONCLUSIONSnNOS-immunopositive neurons in rat corpus striatum are mainly medium-sized and small cells as is typical of the interneurons. The immunopositive granules locate in the cytoplasma, axons and dendrites, and larger granules have membrane coating while small ones do not, possibly in relation to their functions.

Animals ; Corpus Striatum ; enzymology ; ultrastructure ; Immunohistochemistry ; Male ; Microscopy, Electron, Transmission ; Neurons ; enzymology ; ultrastructure ; Nitric Oxide Synthase Type I ; metabolism ; Rats ; Rats, Sprague-Dawley

This study was undertaken to observe the biochemical changes in striatum of Parkinson's disease (PD) rat model by modified proton magnetic resonance spectroscopy. 12 SD rats were divided into model (n=7) and control (n=5) groups. At 3 weeks after the injection of 6-hydroxydopamine into right striatum, 1H-MRS on the striatum was taken by modified proton magnetic resonance spectroscopy, and then tyrosine hydroxylase (TH) immunostatining was used to visualize the changes of the neurons in substantia nigra and neurites in striatum. The results showed that TH positive neurons and neurites in the substantia nigra compacts (SNc) and striatum in the normal side of the rat model of PD were decreased (P < 0.05), which proved the successful establishment of PD models. The NAA/Cr ratio of the injected side striatum of model group was lower than that of the normal side (P < 0.05). The ratios of Cho/Cr showed no significant difference between the two sides (P > 0.05). These results indicated that the modified 1.5T 1H-MRS should be a noninvasive technique which could provide useful information about the biochemical metabolites in striatum for the study of PD in rat model.
Animals ; Corpus Striatum ; enzymology ; Female ; Magnetic Resonance Spectroscopy ; methods ; Male ; Oxidopamine ; Parkinson Disease, Secondary ; chemically induced ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tyrosine 3-Monooxygenase ; metabolism

BACKGROUNDParaquat (PQ; 1, 1'-dimethyl-4, 4'-bipyridinium), a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant MPTP (1-methyl-1, 2, 3, 6-tetrahydropyridine), has been suggested as a potential etiologic factor for the development of Parkinson's disease (PD). Aging is an accepted risk factor for idiopathic Parkinson's disease. The aim of this study was to test the hypothesis that paraquat could induce PD-like nigrostriatal dopaminergic degeneration in aging C57BL/6 mice.

METHODSSenile male C57BL/6 mice were intraperitoneally injected with either saline or PQ at 2-day intervals for a total of 10 doses. Locomotor activity and performance on the pole test were measured 7 days after the last injection and animals were sacrificed one day later. Level of dopamine (DA) and its metabolites levels in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD), and numbers of tyrosine hydroxylase (TH) positive neurons were estimated using immunohistochemistry.

RESULTSLocomotor activities were significantly decreased and the behavioral performance on the pole test were significantly impaired in the PQ treated group. Level of DA and its metabolites levels in the striatum were declined by 8 days after the last injection. Immunohistochemical analyses showed that PQ was associated with a reduction in numbers of tyrosine hydroxylase positive neurons.

CONCLUSIONSLong-term repeated exposes to PQ can selectively impair the nigrostriatal dopaminergic system of senile mice, suggesting that PQ could play an important role in the pathogenesis of Parkinson's disease (PD). Our results also validate a novel model of PD induced by exposure to a toxic environmental agent.

Aging ; pathology ; Animals ; Corpus Striatum ; drug effects ; Disease Models, Animal ; Dopamine ; analysis ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Motor Activity ; drug effects ; Paraquat ; toxicity ; Parkinson Disease, Secondary ; chemically induced ; Substantia Nigra ; drug effects ; enzymology ; Tyrosine 3-Monooxygenase ; analysis

OBJECTIVETo study the changes in the microglial cells and the activity of nitric oxide synthase (NOS), inducible nitric oxide synthase (iNOS) and constitutive nitric oxide synthase (cNOS) in the striatum of rats with methamphetamine (METH) treatment.

METHODSThe rats were randomly divided into two groups for injections with METH or saline. Specific antibody against OX-42 was used to detect the changes in the morphology and the number of microglia, and the activities of NOS, iNOS and cNOS were compared between the two groups.

RESULTSThe microglial cells were activated and their number significantly increased in the striatum of rats with METH treatment as compared with those in the saline group. The activated microglial cells showed bushy and amoeboid morphologies in the METH group. METH also significantly enhanced the activities of NOS, iNOS and cNOS in the striatum (P < 0.05).

CONCLUSIONMicroglial activation and increased NOS activity may participate in METH-induced neurotoxicity in rat striatum.

Animals ; Corpus Striatum ; enzymology ; Male ; Methamphetamine ; pharmacology ; Microglia ; metabolism ; Nitric Oxide Synthase ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Random Allocation ; Rats ; Rats, Wistar

The present study is to assess the prophylactic effect of quinacrine (QA) , an anti-malarial drug, against heatstroke in rats. Conscious rats were orally given equal volume normal saline or QA (dissolved in normal saline and final dosage for rats was 4.5, 9.0 and 18 mg x kg(-1)). An hour later rats were put into a warm water circulated hot chamber (41.0 +/- 0.5) degrees C. Rectal temperature (core temperature, T(co)) of rats in hot chamber was continuously monitored by a thermocouple. T(co) and survival time of rats showed that QA pre-treatment postponed the hyperthermia, and increased the survival time of rats in hot chamber. Primary striatum neurons' culture from new born rats was maintained with D-MEM and 10% FBS. After immuno-cytochemistry identification with antibodies against neural specific proteins, culture received 20 micromol x L(-1) QA only for 1 h and followed by 43.0 degrees C heat treatment for another hour, or 20 micromol x L(-1) QA for 1 h followed by 43.0 degrees C heat treatment for another hour. Control culture received heat treatment only. Cultures were labeled with the fluorescent indicator DPH and the relative membrane fluidity of neurons was measured with the help of fluorescent polarized spectrophotometer. [3H] Arachidonic acid (AA) labeled membrane of E. Coli cells was used as substrate to determine cPLA2 activity of neurons. Gas chromatography and mass spectrum were also employed to detect on the level of fatty acids level in rat striatum neurons. Results from cells indicated that inhibition of cPLA2, reduction the release of active fatty acids such as AA, and possibly, stabilization of the cell membrane which was disturbed by hot treatment, may contribute to the mechanism underlying heat protection and heatstroke preventive effects of quinacrine.
Animals ; Cells, Cultured ; Corpus Striatum ; drug effects ; pathology ; Fatty Acids ; metabolism ; Heat Stroke ; metabolism ; physiopathology ; prevention & control ; Hot Temperature ; adverse effects ; Male ; Membrane Fluidity ; drug effects ; Neurons ; enzymology ; metabolism ; physiology ; Phospholipases A2 ; metabolism ; Quinacrine ; pharmacology ; Rats ; Rats, Wistar

OBJECTIVETo investigate the protective effects of Huperzine A, a potent acetylcholinesterase inhibitor, against the hypoxic ischemic brain damage (HIBD) of the cognitive and morphology in the neonatal rats.

METHODSPostnatal 7 days old rats were given vehicle or Huperzine A (0.05 mg/kg or 0.1 mg/kg, i.p.) following HIBD (unilateral carotid artery ligation followed by hypoxia) or sham operation, and then tested the learning ability and memory in the Morris water maze (MWM) from 36 to 40 postnatal days. The performance in MWM (escape latency, probe time) were recorded to evaluate the learning and memory dysfunction. At the end of MWM trials, the rats were decapitated and their brains were histologically analyzed. The tissue loss in different brain regions including striatum, cortex, and hippocampus were analyzed by image analysis system. The CA(1) subfield neurons numbers were counted to evaluate the brain damage. The acetylcholinesterase histochemistry staining was used to determine the activity of acetylcholinesterase in different brain regions.

RESULTSCompared with sham-operated group, HIBD rats with the vehicle treatment displayed significant tissue losses in the hippocampus (including CA(1) neurons), cortex, and striatum, as well as severe spatial memory deficits (escape latency: 44 s vs 30 s, P < 0.05, probe time: 14 s vs 40 s, P < 0.01). Huperzine A treatment (0.1 mg/kg) resulted in significant protection against both HI-induced brain tissue losses and spatial memory impairments (mean escape latency: 34 s vs 44 s, P < 0.05, probe time: 35 s vs 14 s,P < 0.01). However, Huperzine A treatment (0.05 mg/kg) did not show any significant improvement of spatial memory impairments (mean escape latency: 45 s vs 44 s, P > 0.05, probe time: 17 s vs 14 s, P > 0.05), but moderate to severe brain tissue losses. There was a pronounced reduction of CA(1) neuron density in ipsilateral hemisphere of vehicle-treated group and 0.05 mg/kg Huperzine A group compared with contralateral hemisphere or ipsilateral hemisphere of sham-operated group and 0.1 mg/kg Huperzine A group (72 vs 232, P < 0.01, 72 vs 229, P < 0.01, respectively). There was a close linear correlation between the CA(1) neurons cell number and the mean escape latency for 5 d acquisition trials (r = 0.777, P < 0.01).

CONCLUSIONThe unilateral HI brain injury in a neonatal rat model was associated with cognitive deficits, and that Huperzine A treatment may be protective against both brain injury and spatial memory impairment. Huperzine A showed a therapeutic potential for the treatment of hypoxic-ischemic encephalopathy (HIE) caused by the perinatal asphyxia.

Acetylcholinesterase ; metabolism ; Alkaloids ; Animals ; Animals, Newborn ; Cerebral Cortex ; drug effects ; enzymology ; pathology ; Cognition Disorders ; drug therapy ; physiopathology ; Corpus Striatum ; drug effects ; enzymology ; pathology ; Female ; Hippocampus ; drug effects ; enzymology ; pathology ; Hypoxia-Ischemia, Brain ; drug therapy ; Male ; Maze Learning ; drug effects ; Neuroprotective Agents ; administration & dosage ; therapeutic use ; Rats ; Rats, Sprague-Dawley ; Sesquiterpenes ; administration & dosage ; therapeutic use ; Treatment Outcome

The characteristic pathological changes of Parkinson s disease (PD) include a severe loss of dopamine neurons in the substantia nigra and a severe decrease in dopamine in the striatum. Since the expression of tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC) in the biosynthetic pathway for dopamine are low, a promising approach to the gene therapy of PD is to augment the gene expression of the enzymes in the biosynthetic pathway for dopamine. In the present study, human TH and AADC genes were reconstructed into retrovirous vectors pLHCX and pLNCX(2) respectively. Then pLHCX/TH and pLNCX(2)/AADC were transfected into packaging cell line PA317 with liposome. PA317/TH and PA317/AADC were selected by different antibiotics. Gene expression was examined by methods of immunohistochemistry and in situ hybridization. The catalytic activity of two cloned gene enzymes was assessed in vitro by HPLC-EC. Immunocytochemical staining showed that TH and AADC were expressed efficiently in vitro. Both TH and AADC mRNA were transcripted in PA317 cell lines by using in situ hybridazation. HPLC-EC experiments revealed that the transfected cells produced a significantly higher level of dopamine and L-dopa than the untransfected cells. The two genetically modified cells could improve the production of L-dopa and dopamine in response to suitable substrate. The present results suggest that not only recombinant TH and AADC genes are successfully expressed in vitro, but also the enzymes have respective functional activities. These results have set up a way for in vivo gene therapy of PD with TH and AADC genes.
Aromatic-L-Amino-Acid Decarboxylases ; biosynthesis ; genetics ; metabolism ; Cell Line ; Corpus Striatum ; enzymology ; Dopamine ; biosynthesis ; Gene Expression ; Genetic Therapy ; Genetic Vectors ; Humans ; Levodopa ; biosynthesis ; Parkinson Disease ; enzymology ; genetics ; RNA, Messenger ; biosynthesis ; Substantia Nigra ; metabolism ; Transfection ; Tyrosine 3-Monooxygenase ; biosynthesis ; genetics ; metabolism

PURPOSE: The purpose of this study was to determine the effect of dehydroepiandrosterone (DHEA) on recovery of muscle atrophy induced by Parkinson's disease. METHODS: The rat model was established by direct injection of 6-hydroxydopamine (6-OHDA, 20 microg) into the left striatum using stereotaxic surgery. Rats were divided into two groups; the Parkinson's disease group with vehicle treatment (Vehicle; n=12) or DHEA treatment group (DHEA; n=22). DHEA or vehicle was administrated intraperitoneally daily at a dose of 0.34 mmol/kg for 21 days. At 22-days after DHEA treatment, soleus, plantaris, and striatum were dissected. RESULTS: The DHEA group showed significant increase (p<.01) in the number of tyrosine hydroxylase (TH) positive neurons in the lesioned side substantia nigra compared to the vehicle group. Weights and Type I fiber cross-sectional areas of the contralateral soleus of the DHEA group were significantly greater than those of the vehicle group (p=.02, p=.00). Moreover, extracellular signal-regulated kinase (ERK) phosphorylation significantly decreased in the lesioned striatum, but was recovered with DHEA and also in the contralateral soleus muscle, Akt and ERK phosphorylation recovered significantly and the expression level of myosin heavy chain also recovered by DHEA treatment. CONCLUSION: Our results suggest that DHEA treatment recovers Parkinson's disease induced contralateral soleus muscle atrophy through Akt and ERK phosphorylation.
Animals ; Corpus Striatum/drug effects/metabolism ; Dehydroepiandrosterone/*pharmacology/therapeutic use ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Male ; Muscle Fibers, Slow-Twitch/drug effects ; Muscle, Skeletal/drug effects/metabolism ; Muscular Atrophy/drug therapy/*etiology/*pathology ; Myosins/metabolism ; Neurons/drug effects/enzymology ; Oxidopamine/toxicity ; Parkinson Disease, Secondary/*chemically induced/*complications ; Phosphorylation ; Proto-Oncogene Proteins c-akt/metabolism ; Rats ; Rats, Sprague-Dawley ; Tyrosine 3-Monooxygenase/metabolism

OBJECTIVETo examine the neuroprotective effects of a novel manganese porphyrin, manganese (III) meso-tetrakis (N,N'-diethylimidazolium-2-yl) porphyrin (MnTDM), in the mouse model of Parkinson's disease (PD) induced by paraquat (PQ).

METHODSMale C57BL/6 mice were subcutaneously injected with either saline or PQ at 2-day intervals for a total of 10 doses, MnTDM was subcutaneously injected with the PQ 2 h before treatment. Performance on the pole and swim test were measured 7 days after the last injection and animals were sacrificed one day later. Levels of dopamine (DA) and its metabolites in the striatum were measured by high-performance liquid chromatography with an electrochemical detector (HPLC-ECD). Thiobarbituric acid (TBA) method was used to assay the lipid peroxidation product, malondialdehyde (MDA), and the number of tyrosine hydroxylase (TH) positive neurons was estimated using immunohistochemistry.

RESULTSPretreatment with MnTDM significantly attenuated PQ-impaired behavioral performance, depleted dopamine content in striata, increased MDA, and dopaminergic neuron loss in the substantia nigra.

CONCLUSIONSOxidative stress plays an important role in PQ-induced neurotoxicity which can be potentially prevented by manganese porphyrin. These findings also propose a possible therapeutical strategy for neurodegenerative disorders associated with oxidative stress such as PD.

Animals ; Antioxidants ; therapeutic use ; Antiparkinson Agents ; therapeutic use ; Behavior, Animal ; drug effects ; Catalysis ; Corpus Striatum ; drug effects ; metabolism ; Dopamine ; metabolism ; Male ; Malondialdehyde ; metabolism ; Metalloporphyrins ; therapeutic use ; Mice ; Mice, Inbred C57BL ; Neuroprotective Agents ; therapeutic use ; Paraquat ; Parkinson Disease ; drug therapy ; metabolism ; physiopathology ; Substantia Nigra ; drug effects ; enzymology ; Tyrosine 3-Monooxygenase ; metabolism