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Objective To investigate the effect of sad mood to implicit memory of depressed individuals under the condition of percept-driven process. Methods Using the percept-driven implicit paradigm improved by Paller,26 depression subjects and 25 normal subjects completed study-test task and reported the gender of different emotional faces. Results ①There were main effects of time(F = 4.61, P<0.05)and mood state(F= 21.61, P <0.05) ,significant interaction of time and emotion(F = 4. 13, P<0. 05) ,no significant difference of group on visual analogue scale(VAS) mood ratings. ②Among the accuracy rate of subjects' gender judging to different emotional faces,there were significant main effects on time(F = 4.12, P<0.05)and experiment type (F = 20.55, P < 0.05) , and there was significant interaction of time and experiment type (F=31.72,P<0.05). ③Further simple effects analysis showed that the positive((80 ± 13)%vs(92 ± 10)% , F=65.06, P<0.05) ,negative((58 ± 12)%vs(91 ±10)%,F=10.00,P<0.05),neutral((84±16)%vs(88±9)%, F= 12.49, P < 0. 05) faces when the presentation time was 3600ms in experiment type had significant simple effects; the positive ((76 ± 12)%vs(85±10)%,F=54.72, P<0.05) ,neutral((82 ± 10)% vs(80 ± 10)% , F = 54.57, P<0.05)faces when the presentation time was 300 ms in experiment types had significant simple effects, while the accuracy of neutral faces had significant simple effect between the two groups. Conclusion Sad mood enhance the implicit memory of both depressed and normal subjects to positive and negative faces,and the accuracy rate in implicit processing to neutral faces of depressed group were lower than that of normal group.
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To explore the effect of coriaria lactone (CL)-activated astrocyte-conditioned medium on the cerebral TNF-alpha of normal rats, the CL-activated astrocyte-conditioned medium (ACM) was injected into the lateral ventricle of SD rats. The rats were observed for behavioral changes, and the changes of the expression of TNF-alpha in the cerebral cortex and hippocampus were immunohistochemically examined by employing SP method. TNF-alpha level was assessed by means of radioimmunoassay in homogenate of cerebral cortex and hippocampus as well as cerebrospinal fluid. Seizure episodes were observed in ACM group 30 min after the ACM injection, but they were not observed in the control group. Immunohistochemical detection showed that the immunoreaction of TNF-alpha in hippocampus and cerebral cortex of rats were stronger than that of the control group 4 h after the ACM injection (P<0. 05). In this group, the concentrations of TNF-alpha in homogenate of cerebral cortex and hippocampus and cerebrospinal fluid were higher than those of the control group (P<0.05). It is suggested that the ACM activated by CL can enhance the expression of TNF-alpha in normal rats, and is related to epileptogenesis.
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Techniques for functional brain imaging are critical to analyze the information processing of brain and to reveal the advanced functions in brain. These techniques are the hot topics of international research. Great success has been obtained with neuroimaging techniques in the fields of neuroscience research and clinical diagnosis. Existing brain functional imaging such as magnetic resonance imaging (fMRI),positron emission tomography (PET),electroencephalogram (EEG),magnetoencephalography (MEG) and so on,have been successfully used to study brain function. However,these methods have some limitations unavoidably in the temporal or spatial resolution at present. Comparatively,the optical imaging technologies of brain function show their unique charms. Laser speckle imaging (LSI) and intrinsic optical signals imaging (IOSI) stand out because they offer a superior combination of spatial sampling,spatial resolution and temporal resolution; on the other hand,they have no need to use exogenous contrast agents. Great developments also have been obtained in both techniques and applications of brain optical imaging,and they have become powerful tools for in vivo studying functional architecture and pathophysiology in cerebral cortex by monitoring hemodynamics. However,the two optical imaging techniques are confronted with some challenges.
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To explore the effect of coriaria lactone (CL)-activated astrocyte-conditioned medium on the cerebral TNF-α of normal rats, the CL-activated astrocyte-conditioned medium (ACM) was injected into the lateral ventricle of SD rats. The rats were observed for behavioral changes, and the changes of the expression of TNF-α in the cerebral cortex and hippocampus were immunohistochemically examined by employing SP method. TNF-α level was assessed by means of radioimmunoassay in homogenate of cerebral cortex and hippocampus as well as cerebrospinal fluid. Seizure episodes were observed in ACM group 30 min after the ACM injection, but they were not observed in the control group.Immunohistochemical detection showed that the immunoreaction of TNF-α in hippocampus and cerebral cortex of rats were stronger than that of the control group 4 h after the ACM injection (P＜0.05). In this group, the concentrations of TNF-α in homogenate of cerebral cortex and hippocampus and cerebrospinal fluid were higher than those of the control group (P＜0.05). Itis suggested that the ACM activated by CL can enhance the expression of TNF-α in normal rats,and is related to epileptogenesis.
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The effects of chloroquine on glial fibrillary acidic protein (GFAP), proliferation cell nuclear antigen (PCNA) and Cyclin D1 in hippocampus and cerebral cortex of rats with seizures induced by pentylenetetrazole (PTZ) were observed in the present study. Forty-eight male adult Sprague-Dawley (SD) rats were randomly divided into control group, chloroquine intervening group, and PTZ group. The behavior and electroencephalogram (EEG) were observed and recor ded. GFAP and PCNA were examined with immunohistochemistry. The content of Cyclin D1 in hippocampus and cerebral cortex was inspected with Western blot. The results showed no seizure activity in the control group, severe seizure activity in the PTZ group (Ⅳ-Ⅴ degree), and slight seizure activity ( Ⅰ - Ⅲ degree) in the chloroquine intervening group (P＜0. 05). EEG recordings showed no epileptic spikes in the control group, high amplitude with fast frequency in the PTZ group, low-amplitude and slow frequency in the chloroquine intervening group. The expression of GFAP and the positive index of PCNA in the PTZ group were higher than those of control group (P ＜0.05 and P＜0.01, respectively). No differences in GFAP expression and PCNA index were observed between chloroquine intervening and control groups (P＞0.05). The content of Cyclin D1 in hippocampus and cerebral cortex was significantly higher in the PTZ group than in control and chloroquine intervening groups (P＜ 0.05). Therefore, it is considered that chloroquine, by inhibiting the functions and proliferation of glial cells in the hippocampus and cerebral cortex, can alleviate the seizure activities. These results suggest that chloroquine may be an ideal anticonvulsant in preventing and treating epilepsy.
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To explore the mechanism of interleukin-1beta (IL-1beta) in the onset of seizure and the effect of IL-1beta on the expression of adenylyl cyclase (AC) in rats with seizure induced by L-glutamate. Experimental rats were first injected with IL-1beta and then L-glutamate (a dose under the threshold) was injected into the right lateral ventricle. The rats were sacrificed 4 h after the onset of epileptic activity and examined for changes in behavior, immunohistochemistry and compared with those with seizure induced by L-glutamate alone. It was found that the expression of AC in hippocampal and neocortex of rats with seizure induced by IL-1beta and L-glutamate were stronger than that of control group (P<0.05), without significant difference found between the L-glutamate group and IL-1beta plus L-glutamate group in the expression of AC, the latent period and the severity of seizure. When IL-ra were given (i.c.v.) first, there was no epileptic activity and the expression of AC did not increase. There were no differences in the expression of AC of rats with IL-1ra and that of control rats. But when 2-methyl-2-(carboxycyclopropyl) glycine (MCCG) was given (i.c.v.) first, the strongest expression of AC, the shortest latent period and the the most serious seizure activities were observed. The results indicated that IL-1beta could facilitate the onset of epilepsy induced by L-glutamate through IL-1R, metabotropic glutamate receptors might work with IL-1R and the increased expression of AC might be involved in the process.
Subject(s)
Animals , Male , Rats , Adenylyl Cyclases , Genetics , Glutamic Acid , Hippocampus , Metabolism , Interleukin-1 , Pharmacology , Neocortex , Metabolism , SeizuresABSTRACT
Objective To explore the effects of astrocytes on the N-ethylmaleimide-sensitive fusion protin,(NSF) and AMPA receptor of the neurons as well as their function in epileptogenesis. Methods ACM was injected into lateral ventricle of SD rats and the behaviour changes were observed; Immunohistochemical method was used to assess the changes of the expression of NSF in the cerebral cortex and hippocampus; The cultured neurons were divided into control group, ACM group and CNQX+ACM group at random, immunocytochemistry was used to assess the changes of the expression of NSF, Western blotting was used to assess the changes of the content of NSF of the cultured neurons. Results Seizure was observed in ACM group 30 min after injecting ACM. the immunoreaction of NSF in hippocampus and cerebral cortex of rats were depressed than those of the control group 2h, 4h after injecting ACM (P
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In order to explore the roles of different neurotransmitters in epileptic pathogenesis,the synaptic connections between glutamic acid (Glu) neurons and GABA neurons in normal rat hippocampus were studied by pre-embedding double labeling immunoelectron microscopy. The GABA immunoreaction was first demonstrated by chromogen DAB, then the Glu immunoreaction was demonstrated by molybdic acid-TMB method. After being stabilized by DAB-cobalt chloride,the sections were processed for electron microscopic embedding. Under electron microscope, there were many Glu immunoreaction-positive neurons in the pyramidal layer of hippocampal CA1 area and some GABA immunoreaction-positive neurons with pyramidal or polygonal perikarya in the pyramidal, polymorphic and radiant layer of CA1 area. There were also symmetric dendro-axonic synapses formed by GABA-positive dendrites and Glu-positive axons in the polymorphic layer and symmetric axo-dendritic synapses formed by GABA-positive axons and Glu-positive dendrites in the radiant layer. In addition, there were symmetric autoregulatory axo-dendritic synapses between Glu-positive axons and dendrites and autoregulatory axo-axonic synapses (both symmetric and asymmetric) between GABA-positive axons. Above mentioned results, for the first time,showed that there were complex synaptic regulatory relationships between excitatory Glu neurons and inhibitory GABA neurons in the hippocampal CA1 area, thereby, providing ultrastructural evidence for different neurotransmitters participating in epileptic pathogenesis.
ABSTRACT
In order to explore the roles of different neurotransmitters in epileptic pathogenesis,the synaptic connections between glutamic acid (Glu) neurons and GABA neurons in normal rat hippocampus were studied by pre-embedding double labeling immunoelectron microscopy. The GABA immunoreaction was first demonstrated by chromogen DAB, then the Glu immunoreaction was demonstrated by molybdic acid-TMB method. After being stabilized by DAB-cobalt chloride,the sections were processed for electron microscopic embedding. Under electron microscope, there were many Glu immunoreaction-positive neurons in the pyramidal layer of hippocampal CA1 area and some GABA immunoreaction-positive neurons with pyramidal or polygonal perikarya in the pyramidal, polymorphic and radiant layer of CA1 area. There were also symmetric dendro-axonic synapses formed by GABA-positive dendrites and Glu-positive axons in the polymorphic layer and symmetric axo-dendritic synapses formed by GABA-positive axons and Glu-positive dendrites in the radiant layer. In addition, there were symmetric autoregulatory axo-dendritic synapses between Glu-positive axons and dendrites and autoregulatory axo-axonic synapses (both symmetric and asymmetric) between GABA-positive axons. Above mentioned results, for the first time,showed that there were complex synaptic regulatory relationships between excitatory Glu neurons and inhibitory GABA neurons in the hippocampal CA1 area, thereby, providing ultrastructural evidence for different neurotransmitters participating in epileptic pathogenesis.
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The chemical nature of spinal ganglionic neurons, the peripheral processes of which project divergently to the somatic and visceral areas, has been identified by means of tri-labeling method of combining fluorescein tracing and immunocytochemistry. Ten rats were used. First, 2?l of 2% fast blue (FB) were injected into the left coeliac ganglion. Two days later, 2% nuclear yellow (NY) was injected into left 9-11th intercostal nerves(l?l for each). On the 4th day, animal was perfused with 10% formalin in 0.1mol/L phosphate buffer.The left Th9-11 spinal ganglia were removed and cut into sections by cryostat. The sections were observed under fluorescence microscope and photographed. The results showed that there were three kinds of neurons in the spinal ganglia: (1) single FB labeled cells with blue fluorescent cytoplasm accounted for 38.8% of total labeled cells; (2) single NY labeled cells with yellow fluorescent nuclei accounted for 52,7%; (3) FB and NY double labeled cells accounted for 8.5% and mostly were small or medium in size. Then, the double labeled cells-containing sections were further processed by substance P-demonstrating PAP immunocytochemical staining. The immunostain and fluorescent photographs in the same section were compared and identified each other. We have found that the labeling ratio of SP/NY was 1.4%; SP/FB was 7% and SP/NY+FB was 28.8%. Present study has not only identified the convergence of somato-vesceral sensation in spinal ganglia but also detected the chemical nature of these neurons(substance P) for the first time. In addition, this result has provided a morphological basis for the mechanisma of referred pain and somato-visceral reflection.
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6-OHDA was injected into the third cerebroventricle of rats.24 hours later,thanimals were sacrificed and the degeneration of catecholaminergic (CA) nerve term-inals were studied by electron microscopic cytochemical method.The results showedthat there were a number of degenerated nerve terminals in the arcuate nucleus.Thecharacteristics of these terminals were as follows:enhanced axoplasmic electron opa-sity,destroyed mitochondria and synaptic vesicles and the formation of dense bodies.The multilocular forms were commonly encountered.Most of degenerated terminalswere surrouded by processes of glial cells.The degnerated perikarya of the neuronsin arcuate nucleus with decreased RER,destroyed mitochondria and dense bodieswere also observed.Based on the characteristics of degenerated features the authorsbelieved that these damaged terminals should mainly belong to DA fibers.Theymight regulate or control the function of the arcuate nucleus by means of differentkinds of synaptic mechanisms.The source of DA nerve fibers may originate from A_(12)A_(14) or A_(15) cell groups of the hypothalamus.
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Origin and ultrastructural characteristics of serotonergic fibers of the spinal dorsal horn in the rat have been confirmed by means of a combined method of HRP and immunocytochemistry and immunoelectron microscopic observation. The results showed that serotonergic axonal terminals in the spinal dorsal horn come mainly from nucleus raphe magnus and the ventral part of the reticular formation of medulla oblongata. Serotonin immunoreactive positive structures of the spinal dorsal horn have been found in lamina Ⅰ (marginal zone) and lamina Ⅱ (substantia gelatinosa) as fine myelinated and unmylinated fibers. There were mainly axo-axonic synapses between the labeled and nonlabeled terminals. The labeled terminals were presynaptic or postsynaptic element. Axo-dendritic synapses were rarely found. The non-synaptic releasing figures have not been found. Based on the ultrastructural characteristics the authors suggest that in performing analgesia role the serotonergic system in the spinal dorsal horn might influence directly or indirectly the excitability of interneurons and inhibit directly the nerve impulses of primary afferents by means of synaptic connections instead of non-synaptic releasing manner.
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Ultrastructures of the neurohypophysis in the rats have been studied by means of electron microscopy. Besides identifying the fact that the neurosecretory substances store in the nerve terminals and release into the blood, there are also axo-axonic synaptoid structures existed between neurosecretory terminals and neuro-glial synaptoid contacts between neurosecretory terminals and pituicytes. The characteristics of these contacts mentioned above are as follows: (1) the pre-and postsynaptic membranes are insignificantly thickened; (2) clustered microvesicles are close to and attach to the presynaptic membrane; (3) the synaptic cleft is about 20 nm wide and contains various amount of electron dense materials. The authors suggest that the two kinds of synaptoid structures and pituicytes are all involved in the regulation for the releasing of the neurosecretory substances.
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The distribution of somatostatin (SRIF) in substantia gelatinosa of the rat spinal cord was studied by means of immuno-electron microscopy. The ultrastructural features showed that nerve terminals containing SRIF take part in forming presynap- tie elements of axe-somatic, axe-dendritic and axo-axonic synapses. The immune- reactive products locatl at the external membrane of mitochondria, around the small clear synaptie vesicles and in the large granular vesicles. Most of synaptic vesicles are round or ovoid in shape. Only a few of them are flattened. Based on the ultrastructural characteristics mentioned above and related experimental results the authors believe that SRIF in substantia gelatinosa of the rat spinal cord is probably involved as a neurotransmitter instead of neuromodulator.
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In order to clarify the regulatory mechanism of the neurohormone releasing in the neurohypophysis, the immunohistochemical and chemical lesion method were combined to demonstrate the vasopressin (VP)-and catecholamine (CA)-containing nerve terminals, and their distribution and relationship were observed under electron microscopic level. The results showed that in the rat neurohypophysis there were not only widely distributed VP nerve terminals, but also there were many 6-OHDA induced degenerated nerve endings. The close relationship even synapse-like contacts existed between the CA-ergic endings and pituicytes as well as microglial cells. It was very interesting that the CA-ergic boutons formed axoaxonic synapses with VP-containing boutons. In this case, the CA-bouton was presynaptic element whereas the VP-bouton served as postsynaptic element. The above mentioned results probably provided ultrastructural evidence for the regulatory mechanism of the neurohormone releasing in the neurohypophysis for the first time.
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The ultrastructural localization of peptide substances——VP,SP,ENK,SRIFand distribution of peptidergic nerves in rat neurohypophysis were studied by elect-ron microscopy.The results showed that VP,SP,ENK and SRIF immunoreactiveproducts located in large granular vesicles(110-150 nm in diameter),at the surfaceof microvesicles and outer membrane of mitochondria.The VP-,SP-,ENK- andSRIF-containing nerve fibers distributed at periphery of capillaries and vicinity ofpituicytes.VP- and ENK- positive nerve terminals formed axo-axonic synapses withnegative terminals.Axo-axonic synapses also existed between two SRIF-positive ter-minals.In addition,ENK- and SP-positive terminals formed synaptoid structureswith pituicytes.The authors have discovered the VP-positive pituicytes for the firsttime.The scientific significances of present paper are as follows:(1)Several kinds ofpeptide such as VP,SP,ENK and SRIF have been identified in neurohypophysis atultrastructural level;(2)The discovery of VP-positive pituicytes and their peptide-rgic innervation imply that these structures probably participate in the regulation ofneurohormone releasing;(3)New morphological bases have been provided for theregulation of neurohormone releasing.
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Objective To explore the relationship between interleukin-1?(IL-1?) and group Ⅱ metabotropic glutamate receptors(mGluR2/3). Methods The rats were randomly divided into five groups:1
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Using the immunohistochemical and immunoelectron microscopic methods, the localization and pattern of vasoactive intestinal polypeptidergic nerves in the wall of cerebral vessels were investigated. The results revealed that the VIP-like immunoreactive (VIPLI) fibres were located in the adventitia or at the adventitia-media border. No synaptic contacts were identified among the nerve terminals or between nerve terminal and smooth muscle cell. VIPLI terminals directly apposed to the smooth muscle cells with a distance of 100 nm.The observations mentioned above indicate that there is peptidergic innervation in the wall of the cerebral vessels besides traditional adrenergic and cholinergic innervations. The regulatory function of VIP-containing nerves to the cerebral vessels may be performed by affecting the smooth muscle directly through the nonsynaptic release. In addition, present study identified and discussed the distribution and function of substance P(SP) in the cerebral vessels.
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The ultrastructural characteristics of the arcuate and median eminence in the rat have been studied by means of folmaldehyde-osmic acid fixation method. The observations showed that there are two kinds of neurons (dark and light) in the arcuate nucleus which might be responsible for producing both dopamine and releasing hormones. The tanycytes of the ependyma of the third ventricle run longitudinally through various zones of the median eminence and reach the perivascular space of the portal capillaries. The neurosecretory substance-containing nerve terminals may travel between ependymal cells or end around the basal membrane of the capillaries of the median eminence, even keep close to the endothelial fenestrae of "open-type capillary". The axo-somatie and axo-dendritic synapses are formed at the soma and dendrites of neurons of the arcuate nucleus. Both agranular type and granular type axo-axonic synapses are encountered in the fibrous zone of the median eminence. There are also synaptic connections between the basic processes and the large granular vesicles containing nerve terminals in the palisade zone of the median eminence. The ultrastructural characteristics mentioned above suggest that (1) the releasing (or inhibiting) hormones of the hypothalamus might be released into the portal capillaries from nerve terminals directly or into the cerebro-spinal fluid of the third ventricle and then uptaken by the tanycytes, and transported to the portal capillaries by their processes. (2) each step of synthesis, storage, transport and release of the releasing (or inhibiting) hormones could be regulated by nervous mechanism
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The divergent projections in the bulbo-cerebellar system of rats were studied by double fluorescein labeling method. 2 ?1 of 2％ Fast blue (FB)were injected into the cerebellar cortex of left anterior lobe, 32 hours later, 2 ?l of 2％ Nuclear yellow (NY)were injected into the cerebellar cortex of right anteior lobe. The animals were allowed to survive 16 hours thereafter. Intracardiac perfusion were performed with 10％ formalin in 0.1 mol/L phosphate buffer. The cerebellum and medulla oblongata were removed and serial sections at 20 ?m were cut by cryostat. One of every two sections was preserved for fluorescence microscopic observation. The results identified that there was no intereonnection between the anterior lobes of two cerebellar hemispheres and the anterior lobe of cerebellum received afferent projections from much more nuclei of the medulla oblongata than previous description. The FB or NY single labeled and FB/NY double labeled cells were observed in the nucleus reticularis lateralis, subnucleus reticularis ventralis, nucleus raphe obscurus, nucleus prepositus hypoglossi, nucleus cuneatus lateralis, nucleus spinalis nervi trigemini and nucleus olivaris aceessorius dorsalis. The double labeled cells accounted for 23％ of total labeled cells except the nucleus olivaris inferior. The results mentioned above suggested that the cerebellum receive multiple afferent connections originated from the medulla oblongata, and the divergent projections further amplify the information-receiving areas in the cerebellum, and synchronize the activities of both cerebellar hemispheres.