大鼠胰岛内γ-干扰素样免疫反应阳性物质的表达

In order to study the correlation between the neuroendocrine and immune systems, we observed the distribution and expression of interferon γ(IFN-γ) in cells of SD rat pancreas islets using the streptavidin-perosidase immunohistoche-mical method. A number of IFN-γ-like positive substances were found in the in the cytoplasm of pancreas islet A cells, but the nucleus could not be stained. Most of the IFN-γ-like positive cells were distributed around the periphery of the pan-creas islet, the cells were round or oval in shape and the cell body was relatively large. Results suggest IFN-γ may play a role in the regulation of the function of pancreas islet cells and act as a neuro-immune medium.     

Application of the sodium hyaluronate-CNTF scaffolds in repairing adult rat spinal cord injury and facilitating neural network formation

The present study aimed to explore the potential of the sodium hyaluronate-CNTF (ciliary neurotrophic factor) scaffold in activating endogenous neurogenesis and facilitating neural network re-formation after the adult rat spinal cord injury (SCI). After completely cutting and removing a 5-mm adult rat T8 segment, a sodium hyaluronate-CNTF scaffold was implanted into the lesion area. Dil tracing and immunofluorescence staining were used to observe the proliferation, differentiation and integration of neural stem cells (NSCs) after SCI. A planar multielectrode dish system (MED64) was used to test the electrophysiological characteristics of the regenerated neural network in the lesioned area. Electrophysiology and behavior evaluation were used to evaluate functional recovery of paraplegic rat hindlimbs. The Dil tracing and immunofluorescence results suggest that the sodium hyaluronate-CNTF scaffold could activate the NSCs originating from the spinal cord ependymal, and facilitate their migration to the lesion area and differentiation into mature neurons, which were capable of forming synaptic contact and receiving glutamatergic excitatory synaptic input. The MED64 results suggest that functional synapsis could be established among regenerated neurons as well as between regenerated neurons and the host tissue, which has been evidenced to be glutamatergic excitatory synapsis. The electrophysiology and behavior evaluation results indicate that the paraplegic rats’ sensory and motor functions were recovered in some degree. Collectively, this study may shed light on paraplegia treatment in clinics.     

Comparison of dark- and light-adapted carp retinas with NADPH diaphorase staining

The carp retina was examined by NADPH diaphorase histochemistry to determine if the staining pattern of retinal cells was changed depending on the adaptation state of the retina. When dark-adapted for 5 h, ellipsoids of inner segments of both rods and cones and some horizontal cells were heavily stained. Staining was also found in subpopulations of amacrine cells and ganglion cells. In addition, Muller cells were strongly positive for NADPH diaphorase. When light-adapted for 5h, ellipsoids of photoreceptors and ganglion cells were less intensely stained, whereas Muller cells and horizontal cells became negative for NADPH diaphorase. Furthermore, rod ON-center bipolar cells were clearly stained. The difference of staining of amacrine cells between dark- and light-adapted retinas was not significant. The differences in diaphorase-staining pattern between dark- and light-adapted retinas suggest that Muller cells, some horizontal cells and rod ON-center bipolar cells contain inducible nitric oxide synthase,     

Physiological properties of neurons in superficial layers of superior colliculus of rabbits

Neurons in superficial layers of the superior colliculus of the rabbit are classified into three types by their electrophysiological properties. Among them, two types belong to projecting neurons which send axons to the thalamic pulvinar (N=52) and dorsal lateral geniculate nucleus (N = 54) respectively. All other neurons are pooled into the third type (N=99). Projecting neurons of both types receive monosynaptic visual inputs via optic tract fibers of similar conduction velocity, indicating that in the superior colliculus of the rabbit, there is no difference in conduction velocity between the two pathways. They also receive trisynaptic inhibitory inputs, most likely via recurrent inhibitory circuits. The third type of neurons receives disynaptic optic and trisynaptic inhibitory inputs. The function of neurons of the third type is studied.     

Mediation by calcium/calmodulin-dependent protein kinase II of suppression of GABA_A receptors by NMDA

Using nystatin-perforated whole-cell recording configuration, the modulatory effect of N-methyl-D-aspartate (NMDA) on γ-aminobutyric acid (GABA)-activated whole-cell currents was investigated in neurons freshly dissociated from the rat sacral dorsal commissural nucleus (SDCN). The results showed that: (i) NMDA suppressed GABA- and muscimol (Mus)-activated currents (IGABA and IMUS), respectively in the Mg2 -free external solution containing 1 μmol/L glycine at a holding potential (VH) of -40 mV in SDCN neurons. The selective NMDA receptor antagonist, D-2-amino-5-phosphonovaleric acid (APV, 100 μmol/L), inhibited the NMDA-evoked currents and blocked the NMDA-induced suppression of IGABA; (ii) when the neurons were incubated in a Ca2 -free bath or pre-loaded with a membrane-permeable Ca2 chelator, BAPTA AM (10 nmol/L), the inhibitory effect of NMDA on IGABA disappeared. Cd2 (10 μmol/L) or La3 (30 μmol/L), the non-selective blockers of voltage-dependent calcium channels, did not affect the suppressio     

Influences of cerebellar interpositus nucleus and fastigial nucleus on neuronal activity of lateral hypothalamic area

Stimulation of cerebellar interpositus nucleus and (astigial nucleus could influence the neuronal activi-ty of lateral hypothalamic area in the cat, and some of the neurons which respond to the cerebellar stimulations are glucose-sensitive neurons. These results suggest that the cerebellum is involved not only in motor control, but also in the regulation of non-somatic functions through the cerebello-hypothalamic pathways.     

Neural correlates of behavioral gap detection in the inferior colliculus of the young CBA mouse

The gap detection paradigm is frequently used in psychoacoustics to characterize the temporal acuity of the auditory system. Neural responses to silent gaps embedded in white-noise carriers, were obtained from mouse inferior colliculus (IC) neurons and the results compared to behavioral estimates of gap detection. Neural correlates of gap detection were obtained from 78 single neurons located in the central nucleus of the IC. Minimal gap thresholds (MGTs) were computed from single-unit gap functions and were found to be comparable, 1–2 ms, to the behavioral gap threshold (2 ms). There was no difference in MGTs for units in which both carrier intensities were collected. Single unit responses were classified based on temporal discharge patterns to steady-state noise bursts. Onset and primary-like units had the shortest mean MGTs (2.0 ms), followed by sustained units (4.0 ms) and phasic-off units (4.2 ms). The longest MGTs were obtained for inhibitory neurons (xˉ = 14 ms). Finally, the time-course of behavioral and neurophysiological gap functions were found to be in good agreement. The results of the present study indicate the neural code necessary for behavioral gap detection is present in the temporal discharge patterns of the majority of IC neurons. Accepted: 6 February 1997     

The studies on neurogenesis indufced by brain injury in adult ring dove

It was the first time demonstrated by us that the number of newborn neurons was increased after making lesion in forebrain of adult ring dove(Streptopelia risoria) by means of autoradiography and imunohistochemistry,Neurogensis in the adult avian is restricted to the telencephalon.In doves with bilateral electrolytic lesion of nucleus ectostriatum(E),the mean mumber of proliferating cells in the lateral ventricular zone(LVZ) and newborn neurons in the forebrain increased by 1.95 times and 2.38 times respectively as compared with that in intact doves.The most remarkable incresase of neurogenesis induced by nucleus ectostriatum lesions was found at the anteriorposterior level 3(L3),where the lesion site was located.These results showed that the electrolytic brain lesion al tered the distribution pattern of proliferating cells in the LVZ and resulted in increase of the number of newborn neureons in the non-VZ areas of forebrain.The changes in number and distribution pattern of proliferating cells in LVZ and newbon neurons in forebrain may be dependent on site of lesion.Studies on the relationship between proliferating cells in LVZ and newly generated neurons in non-VZ aresa may help to understand the mechanism of brain plasticity and development.     

Synaptic organization of substance P, glutamate and GABA-immunoreactive boutons on functionally identified neurons in cat spinal deeper dorsal horn

In order to determine how nociceptive input conveyed by the C-fibers terminating in superficial lam-inae of the spinal cord reaches the wide dynamic range (WDR) cells in deeper dorsal horn, which functions as ascend-ing projection pathway, the morphological features of some WDR cells in the deeper dorsal horn of the cat lumbar spinal cord were studied by intracellular injection of horseradish peroxidase and physiological characterization. One of the fully stained neurons with somata in lamina V and dendrites that entered lamina Ⅱ were examined by electron mi-croscopy. Immunogold staining of ultrathin sections through the labeled proximal dendrites in lamina Ⅱ revealed that these dendrites received numerous synapses from substance P and glutamate immunoreactive (IR) axons, which were considered originating from C-fibers. In addition, many GABA-IR terminals were found presynaptic to the labeled dendrites. The results, therefore, suggest that the information carried by primary afferent can be sent from t     

猪圆环病毒2型及猪繁殖与呼吸综合症病毒的快速检测

According to the published genome sequences of Porcine circovirus type 2(PCV2)and Porcine reproductive and respiratory syndrome virus(PRRSV),primers were designed and PCR,RT-PCR were set up for the detection of PCV2 and PRRSV,respectively,With the established methods,38 clinical samples from the respiratory disease pigs were detected for the presence of PCV2 and PRRSV. The results demonstrated that 22 samples were positive for PCV2,27 samples were positive for PRRSV and among the above positive samples,18 samples were positive for both viruses,The data obtained in the present study indicated that PCV2 and PRRSV maybe play an important role in the course of the development of respiratiory diseases.     

The role of γ-aminobutyric acid and its receptors in the nucleus of basal optic root in pigeons

The effects of γ-aminobutyric acid (GABA) and its antagonists bicuculline and 2-hydroxysaclofen on neuronal firings in the nucleus of basal optic root (nBOR) in pigeons were studied by using extracellular recording and microiontophoretic techniques. The results suggest that GABA may be an inhibitory neurotransmitter or modulator within nBOR, functioning by means of main mediation of GABAA receptors and of minor mediation of GABAB receptors. Furthermore, GABA and its GABAA receptors are involved in the modulation of directional selectivity in part of nBOR neurons.     

β-EP和胃泌素在大鼠舌下腺的免疫组织化学定位

In order to study the distribution of β-EP and gastrin immunoreactive cells in the sublingual gland, we used the Advidin Biptin-Peroxidase Complex (ABC) immunohistochemical technique to detect the expression of β-EP and gastrin in rat sublingual glands. The results show that the epithelial cells of striated ducts and interlobular ducts appeared β-EP and gastrin positive in immunoreaction and the mucosus and serous acinar cells were immunoreactive negative. The poei-tive substances were distributed in the cytoplasm with negative nuclei. These results suggest that β-EP and gastrin are ex-pressed in the epithelial cells of ducts in the rat sublingual gland, which may play an important role in the secretion and functional regulation of the sublingual gland.     

EFFECTS OF VASOACTIVE INTESTINAL PEPTIDE ON ACTIVITIES OF SUCCINIC DEHYDROGENASE AND ALKALINE PHOSPHATASE IN RAT HEPATOMA CELLS

Using cytochemical method,microspectrophotometry and image analysis,effects of va-soactive intestinal peptide(VIP)on activities of succinic dehydrogenase(SDH)and alkalinephosphatase(ALP)in rat hepatoma cells were studied in vitro.The results showed that thehepatoma cell expressed potent positive reactions of SDH and ALP,the positive positionswere located at the cell membranes and/or cytoplasm.Having been treated with VIP,ALPdecreased obviously in activity(P<0. 01,compared with hepatoma cells untreated by VIP).The sites of ALP activty were chiefly located at the cell membranes,particularly at the cell-cell contacts.Cultured rat hepatoma cells had intensive SDH activity in their cytoplasm.Compared with untreated eclls,there was no marked difference in the intensity of SDH activ-ity in VIP-treated hepatoma cells(P>0.05).     

The facilitatory influence of anterior cingulate cortex on ON-OFF response of tactile neuron in thalamic ventrobasal nucleus

The structures of limbic system have been found to modulate the auditory, visual and pain afferent signals in the related nuclei of thalamus. One of those structures is anterior cingulate cortex (ACC) that influences nocuous response of the pain-sensitive neurons in the ventropos-tero-lateral nucleus of thalamus. Thus, we inferred that ACC would also modulate tactile information at the thalamic level. To test this assumption, single units were recorded extracellularly from thalamic ventrobasal nucleus (VB). Tactile ON-OFF response and the relationship between different patterns of the responses and the parameters of tactile stimulation were examined. Furthermore, the influence of ACC on the tactile ON-OFF response was studied. ACC stimulation was found to produce a facilitatory effect on the OFF-response of ON-OFF neurons. It lowered the threshold of the off-response of that neuron, and therefore changed the response pattern or enhanced the firing rate of the OFF-response of the neuron. The study on rec     

The fluorescence brightener Rylux BSU induces dimorphism inBasidiobolus ranarum

The fluorescence brightener Rylux BSU (RBSU) showed an affinity for polysaccharide components of cell walls and accumulated in the extension zones of hyphal apices inBasidiobolus ranarum. It inhibited the polarized growth of mycelial hyphae and induced isotropic growth resulting in spherical thick-walled cells up to 456 μm in diameter. On the inner cell wall surface, massive protuberances were formed. The cell wall and protuberances were positive in PAS and the Grocott method and stained with fluorochromes Blankophor BA, Calcofluor, Uvitex 2B, Rylux BSU and FITC-labeled WGA- and ConA-lectins. The WGA-FITC fluorescence intensity of the wall’s outermost layer, if not connected with neighbouring cells, and the fluorescence intensity of the innermost layer and of some protuberances mainly in their apical parts were on the average twice higher than the fluorescence intensity of the remaining wall material. RBSU binding to the cell wall material was stable. The process of converting from polarized to isotropic growth was reversible, depending upon contact with RBSU-containing medium. Repeated transfers of cells from RBSU-containing medium to an RBSU-free medium resulted in the development of apical swollen dumbbell-shaped cells.     

Modulation of dragon’s blood on tetrodotoxin-resistant sodium currents in dorsal root ganglion neurons and identification of its material basis for efficacy

To clarify the modulation of dragon's blood on the tetrodotoxin-resistant (TTX-R) sodium currents in dorsal root ganglion (DRG) neurons and explore its corresponding material basis for the efficacy, using whole-cell patch clamp technique, the effects of dragon's blood and the combined effects of three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from dragon's blood on the TTX-R sodium currents in acute-isolated DRG neurons of rats were observed. According to the operational definition of material basis for the efficacy of TCM established, the material basis of the modulation on the TTX-R sodium currents in DRG neurons of dragon's blood was judged from the experimental results. The drug interaction equation of Greco et al. was used to assess the interaction of the three components extracted from dragon's blood. This investigation demonstrated that dragon's blood suppressed the peak TTX-R sodium currents in a dose-dependent way and affected the activations of TTX-R sodium currents. The effects of the combination of cochinchinenin A, cochinchinenin B, and loureirin B were in good agreement with those of dragon's blood. Although the three components used alone could modulate TTX-R sodium currents, the concentrations of the three components used alone were respectively higher than those used in combination when the inhibition rates on the TTX-R sodium currents of them used alone and in combination were the same. The combined effects of the three components were synergistic. These results suggested that the interference with pain messages caused by the modulation of dragon's blood on TTX-R sodium currents in DRG neurons may explain some of the analgesic effect of dragon's blood and the corresponding material basis for the efficacy is the combination of cochinchinenin A, cochinchinenin B, and loureirin B.     

Modulation of dragon''''s blood on tetrodotoxin-resistant sodium currents in dorsal root ganglion neurons and identification of its material basis for efficacy

To clarify the modulation of dragon's blood on the tetrodotoxin-resistant (TTX-R) sodium currents in dorsal root ganglion (DRG) neurons and explore its corresponding material basis for the efficacy, using whole-cell patch clamp technique, the effects of dragon's blood and the combined effects of three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from dragon's blood on the TTX-R sodium currents in acute-isolated DRG neurons of rats were observed. According to the operational definition of material basis for the efficacy of TCM established, the material basis of the modulation on the TTX-R sodium currents in DRG neurons of dragon's blood was judged from the experimental results. The drug interaction equation of Greco et al. was used to assess the interaction of the three components extracted from dragon's blood. This investigation demonstrated that dragon's blood suppressed the peak TTX-R sodium currents in a dose-dependent way and affected the activations of TTX-R sodium currents. The effects of the combination of cochinchinenin A, cochinchinenin B, and loureirin B were in good agreement with those of dragon's blood. Although the three components used alone could modulate TTX-R sodium currents, the concentrations of the three components used alone were respectively higher than those used in combination when the inhibition rates on the TTX-R sodium currents of them used alone and in combination were the same. The combined effects of the three components were synergistic. These results suggested that the interference with pain messages caused by the modulation of dragon's blood on TTX-R sodium currents in DRG neurons may explain some of the analgesic effect of dragon's blood and the corresponding material basis for the efficacy is the combination of cochinchinenin A, cochinchinenin B, and loureirin B.     

Effect of long-term Se deficiency on the antioxidant capacities of rat vascular tissue

Selenium (Se) is an essential micronutrient in human health and Se deficiency has been incriminated in the etiology of cardiovascular diseases. However, the effect of long-term Se deficiency on the antioxidant capacities of vascular tissue has not been elucidated. This study was to determine whether long-term Se deficiency might affect the antioxidant capacity of rat vascular tissue and whether the diet Se might affect the activities of glutathione peroxidase (GPx) and thioredoxin reductase (TR) in rat vascular tissue. Weanling male Wister rats were fed Se-deficient and Se-adequate diets for 12 mo. Se was supplemented in drinking water (1 μg Se/mL) for 1 mo. The arterial walls isolated from various groups were used in the assay. In comparison with the control, Se-deficient rats exhibited significant decreases of GPx activity and total antioxidant capacity in the arterial wall. Similar decreases appeared in the heart, liver, and kidney. The superoxide dismutase activity was also decreased in the Se-deficient rat’s arterial wall. Followed by Se supplementation, they were restored to different extent. TR activity was decreased in the heart, liver, and kidney, but increased in the arterial wall. The content of malondialdehyde was increased markedly in Se-deficient rats. In conclusion, a positive correlation exists between dietary Se and antioxidant capacity of rat vascular tissue except TR. It seems that the activities of GPx and TR in the rat arterial wall were mediated in different pathways by the Se status.     

Leptin receptor of the hind brain nuclei is involved in the conditioned taste preference of rats

Objective: Conditioned taste preference(CTP) is a taste learning reflex by which an animal learns to prefer a substance which tastes not well and has been studied with much interest in recent years. However, the neural substrates of CTP are less known. This study aimed to determine the possible neural pathways of CTP and whether serum leptin level and the leptin receptor(OB-Rb) in the hind brain are involved following CTP formation. Methods: We established CTP of quinine in rats with a 2-bottle preference test. The serum leptin concentrations were detected, the expression of c-fos in the rat brain was tested to determine the nuclei in relation with establishment of CTP. Finally, the OB-Rb m RNA expression was examined by RT-q PCR assay in parabrachial nucleus(PBN) and the nucleus of the solitary tract(NST) of the hind brain. Results: Compared with control group, the level of serum leptin was higher in the CTP group(4.58 ± 0.52 vs 1.67 ± 0.25 μg/L, P0. 01); increased c-fos positive cells were found in the anterior hypothalamus(AH, 221.75 ± 4.96 vs. 178.50±6.63 cells/mm~2, P0.05), the basal lateral amygdala(BLA, 70.75±6.17 vs 56.50±3.62 cells/mm~2, P0.05) and the nucleus of the solitary tract(NST, 41.25±1.32 vs 32.50±1.02 cells/mm~2, P0.05). But in ventromedial nucleus of the hypothalamus(VMH, 20.75±2.73 vs 38.5±1.54 per 1 mm~2, P005), PBN(21.50 ±2.24 vs 36.25±1.49 cells/mm~2, P0.05) and the central nucleus of the amygdala(Ce A, 22.25±1.53 vs 35.50 ±2.11 cells/mm~2, P0.05), the number of c-fos positive cells was decreased in the CTP group. In addition, we found OB-Rb m RNA expression in PBN of CTP group rats was higher than that of control group(0.95±0.055 vs 0.57± 0.034, P0.05), while there was no significant difference of OB-Rb m RNA expression in NST between the two groups. Conclusion: Nuclei AH, BLA, NST, VMH, PBN and Ce A participate in the formation of CTP. Leptin and its receptor in PBN may be involved in the formation and maintenance of CTP.     

Adhesion, orientation, and movement of cells cultured on ultrathin fibronectin fibers

Summary This study examined the behavior of rat tendon fibroblasts, baby hamster kidney fibroblasts, macrophage-like P388D1 cells, and neurons from rat dorsal root ganglia, cultured on fibronectin strands 0.2–5 μm in diameter. We investigated cell spreading, orientation, formation of focal contacts, the speed of cell movement, and the speed of neurite outgrowth in cells cultured on fibronectin strands, glass covered with fibronectin, and plain, nontreated glass. Fibronectin strands significantly promoted cell spreading and caused a marked alignment of all kinds of cells to the direction of the fiber. The fibers caused the alignment of actin filaments in fibroblasts and focal contacts in fibroblasts and macrophages and increased polymerization of F-actin in cells. Fibronectin fibers also increased the speed and persistence of cell movement and the rate of neurite outgrowth. Macrophages grown on fibronectin fibers produced numerous actin-rich microspikes and adopted a polarized, migratory phenotype. These findings indicate that fibronectin strands, resembling natural components of the extracellular matrix, are more effective in activating various types of cells than two-dimensional, fibronectin-covered substrata. The results also confirm the suitability of the three-dimensionally oriented fibronectin form for use in clinical practice.