Masking effect of different durations of forward masker sound on acoustical responses of mouse inferior collicular neurons to probe sound

To study the effects of different durations of forward masker sound on neuronal firing and rate-intensity function(RIF)of mouse inferior collicular(IC)neurons,a tone relative to 5 dB above the minimum threshold(re MT+5 dB)of the best frequency of recorded neurons was used as forward masker sound under free field stimulation condition.The masker durations used were 40,60,80,and 100 ms.Results showed that as masker duration was increased,inhibition in neuronal firing was enhanced(P＜0.0001,n=41)and the latency of neurons was lengthened(P＜0.01,n=41).In addition,among 41 inhibited IC neurons,90.2%(37/41)exhibited narrowed dynamic range(DR)when masker sound duration was increased(P＜0.0001),whereas the DR of 9.8%(4/41)became wider.These data suggest that masking effects of different durations of forward masker sound might be correlated with the amplitude and duration of inhibitory input to IC neurons elicited by the masker sound.     

不同时程弱前掩蔽声对小鼠下丘神经元声反应的选择性抑制

自由声场条件下,以强度为神经元最小阈值阈上5dB,时程分别为40、60、80和100ms的纯音作为前掩蔽声,观察和记录了不同时程弱前掩蔽声对小鼠（Musmusculus Km）下丘神经元发放和声强处理的影响。实验记录到154个神经元,对其中的104个神经元做了不同时程掩蔽声影响的测试。结果发现：掩蔽声对神经元放电率的抑制作用在时间上表现为前抑制（41％）、后抑制（9％）和全抑制（50％）三种类型。改变掩蔽声时程时,大部分神经元（72％）的抑制类型不发生改变,但少部分神经元（28％）随掩蔽声时程的增加,大量的后抑制类型转变为前抑制或全抑制类型。此外,超过一半的神经元（58．06％）其强度．放电率函数曲线随掩蔽声时程的改变而发生转变,主要表现为单调型向饱和型转变及饱和型向非单调型转变,这种转变并不随掩蔽声时程增加表现出规律性的变化。结果表明,前掩蔽作用于下丘神经元声反应的时间域和强度域时具有不均衡性,推测不同时程弱前掩蔽声激活的抑制性输入能分化性调制下丘神经元声反应特性。     

Recent approach to Buchia biostratigraphy from the Tethyan Himalaya area, China

Recent collections from six sections in Lanongla area, Tethyan Himalaya allow the establishment of four buchia assemblages. In ascending order, they are Buchia-Buchia spitiensis, Buchia masquensis-Buchia rugasa, Buchia blanfordiana, Buchia piochii and Buchia subokensis assemblages. These Buchia assemblages first demonstrate that not only the Upper Jurassic strata but also the highest Buchia assemblage-Buchia subokensis, which appeared in Lower Cretaceous strata all over the world are present in Lanongla area. This first records the highest Buchia assemblage in Lanongla area. __________ Translated from Acta Scientiarum Naturalium Universitatis Pekinensis, 2005, 41 (4) [译自: 北京大学学报( 自然科学版), 2005,41(4)]     

抑制性频谱整合对大棕蝠下丘神经元声强敏感性的影响

自由声场条件下 ,采用特定双声刺激方法研究了不同频率通道之间的非线性整合对下丘神经元声强敏感性的调制作用。实验在 1 2只麻醉与镇定的大棕蝠 (Eptesicusfuscus)上进行 ,双电极同步记录 2个配对神经元的声反应动作电位。主要结果如下 :1 )所获 1 1 0个 (5 5对 )配对神经元中 ,85 5 %表现为抑制性频谱整合作用 ,其余 1 4 5 %为易化性频谱整合 ;2 )阈上 1 0dB (SPL)放电率抑制百分比与神经元最佳频率 (BF)及记录深度呈负相关 ;3)抑制效率随声刺激强度升高而逐步下降 ;4 )当掩蔽声分别位于神经元兴奋性频率调谐曲线(FTC)内 (MSin) /外 (MSout)时 ,其抑制效率存在差异。前者的放电率抑制百分比及声反应动力学范围(DR)下降百分比均显著高于后者 ;5 )抑制性频谱整合导致 3类DR改变 :6 1 6 %为下降、 1 0 9%增加、另有2 7 5 %变化小于 1 0 %。本结果进一步支持如下设想 :下丘不同频率通道之间的抑制性频谱整合参与了对强度编码的主动神经调制活动     

Sound-evoked oscillation and paradoxical latency shift in the inferior colliculus neurons of the big fruit-eating bat, <Emphasis Type="Italic">Artibeus jamaicensis</Emphasis>

Frequency tuning, temporal response pattern and latency properties of inferior colliculus neurons were investigated in the big fruit-eating bat, Artibeus jamaicensis. Neurons having best frequencies between 48–72 kHz and between 24–32 kHz are overrepresented. The inferior colliculus neurons had either phasic (consisting in only one response cycle at all stimulus intensities) or long-lasting oscillatory responses (consisting of multiple response cycles). Seventeen percent of neurons displayed paradoxical latency shift, i.e. their response latency increased with increasing sound level. Three types of paradoxical latency shift were found: (1) stable, that does not depend on sound duration, (2) duration-dependent, that grows with increasing sound duration, and (3) progressive, whose magnitude increases with increasing sound level. The temporal properties of paradoxical latency shift neurons compare well with those of neurons having long-lasting oscillatory responses, i.e. median inter-spike intervals and paradoxical latency shift below 6 ms are overrepresented. In addition, oscillatory and paradoxical latency shift neurons behave similarly when tested with tones of different durations. Temporal properties of oscillation and PLS found in the IC of fruit-eating bats are similar to those found in the IC of insectivorous bats using downward frequency-modulated echolocation calls.     

Drought resistance of four grasses using pressure-volume curve

Pressure-volume curve (PV curve) technique is a major method for studying critical plant water potential and critical tissue water content when plasmolysis takes place. In the present study, a mathematical solution method is put forward to obtain parameters based on the PV curve. The calculated results for the parameters of Lolium perenne, Festuca arundinacea, Leymus chinensis and Stipa krylovii indicated that the mathematical solution method is convenient for actual research compared with the graphical method. Further analysis of the calculations suggested that drought resistance decreased in the following order: S. krylovii > F. arundinacea and L. chinensis > L. perenne. __________ Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2006, 39(3): 16–22 [译自: 南开大学学报 (自然科学版)]     

Intra-specific relationships among Tibetan Eared-pheasants based on randomly amplified polymorphic DNA (RAPD) analysis

The Tibetan Eared-pheasant Crossoptilon harmani is a rare species native to China. A captive population has been established in the Beijing Zoo since 1999. In order to determine the kinship of the offsprings in 2001, randomly amplified polymorphic DNA (RAPD) was used to examine the parenthood of seven Tibetan Eared-pheasants in the Beijing Zoo. To amplify the genomic DNA of each individual, 53 arbitrary primers were selected. The results of amplifications showed that 14 primers had clear and distinct RAPD patterns. Totally, 226 amplified fragments were generated by RAPD in this study. Cluster analysis of the seven Tibetan Eared-pheasants indicated that all the four young birds had the same father (No.5 male). This study provides a practical method to determine the relationship of offsprings whose parents are unknown in birds. __________ Translated from Journal of Beijing Normal University (Natural Science), 2005, 41(5): 507–509 [译自: 北京师范大学学报 (自然科学版), 2005, 41(5): 507–509]     

Analysis of sparteines in the seeds of Ammopiptanthus mongolica

Seven alkaloids were isolated from the seeds of Ammopiptanthus mongolica by thin layer chromatography and silica gel column chromatography, and the chemical structures of five alkaloids, 17-oxosparteine, β-isosparteine, 3α-hydroxysparteine, sparteine, and 3β-hydroxysparteine were identified by ¹H nuclear magnetic resonance (NMR) and electron ionization mass spectrum (EIMS). __________ Translated from Journal of Lanzhou University (Natural Sciences), 2007, 43(2): 43–46 [译自: 兰州大学学报(自然科学版)]     

Encoding of sound duration by neurons in the auditory cortex of the little brown bat, Myotis lucifugus

Responses of 117 single- or multi-units in the auditory cortex (AC) of bats (Myotis lucifugus) to tone bursts of different stimulus durations (1– 400 ms) were studied over a wide range of stimulus intensities to determine how stimulus duration is represented in the AC. 36% of AC neurons responded more strongly to short stimulus durations showing short-pass duration response functions, 31% responded equally to all pulse durations (i.e., all-pass), 18% responded preferentially to stimuli having longer durations (i.e., long-pass), and 15% responded to a narrow range of stimulus durations (i.e., band-pass). Neurons showing long-pass and short-pass duration response functions were narrowly distributed within two horizontal slabs of the cortex, over the rostrocaudal extent of the AC. The effects of stimulus level on duration selectivity were evaluated for 17 AC neurons. For 65% of these units, an increase in stimulus intensity resulted in a progressive decrease in the best duration. In light of the unusual intensity-dependent duration responses of AC neurons, we hypothesized that the response selectivities of AC neurons is different from that in the brainstem. This hypothesis was validated by results of study of the duration response characteristics of single neurons in the inferior colliculus. Accepted: 8 November 1996     

Experimental cloning of embryos through human-rabbit inter-species nuclear transfer

Therapeutic cloning, which is based on human somatic cell nuclear transfer, is one of our major research objectives. Though inter-species nuclear transfer has been introduced to construct human somatic cell cloned embryos, the effects of type, passage, and preparation method of donor cells on embryo development remain unclear. In our experiment, cloned embryos were reconstructed with different passage and preparation methods of ossocartilaginous cell, skin fibroblast, and cumulus cells. The cumulus cell embryos showed significantly higher development rates than the other two (P < 0.05). The development rate of embryos reconstructed with skin fibroblasts of different passage number and somatic cells of different chilling durations showed no significant difference. Also, fluorescence in situ hybridization (FISH) was conducted to detect nuclear derivation of the embryos. The result showed that the nuclei of the inter-species cloned embryo cells came from human. We conclude that (1) cloned embryos can be constructed through human-rabbit interspecies nuclear transfer; (2) different kinds of somatic cells result in different efficiency of nuclear transfer, while in vitro passage of the donor does not influence embryo development; (3) refrigeration is a convenient and efficient donor cell preparation method. Finally, it is feasible to detect DNA genotype through FISH. Translated from Zoological Research, 2005, 26(4): 416–421 [译自: 动物学研究]     

Identification of sympatric bat species by the echolocation calls

One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species (Rhinolophus ferrumequinum, Myotis formosus, Myotis ikonnikovi, Myotis daubentoni and Murina leucogaster) were recorded (by ultrasonic bat detector (D980)) in Zhi’an village of Jilin Province, China. According to the frequency-time spectra, these calls were categorized into two types: FM/CF (constant frequency) / FM (R. ferrumequinum) and FM (frequency modulated) (M. formosus, M. ikonnikovi, M. daubentoni and M. leucogaster). Sonograms of the calls of R. ferrumequinum could easily be distinguished from those of the other four species. For the calls of the remaining four species, six echolocation call parameters, including starting frequency, ending frequency, peak frequency duration, longest inter-pulse interval and shortest inter-pulse interval, were examined by stepwise discriminant analysis. The results show that 84.1% of calls were correctly classified, which indicates that these parameters of echolocation calls play an important role in identifying bat species. These parameters can be used to test the accuracy of general predictions based on bats’ morphology in the same forest and can provide essential information for assessing patterns of bat habitat use. __________ Translated from Journal of Northeast Normal University (Natural Science Edition), 2006, 38 (3): 109–114 [译自: 东北师范大学学报(自然科学版)]     

Cytokines mRNA in bone marrow-derived dendritic cells in asthmatic mouse

By inducing and amplifying dendritic cells (DCs) derived from the bone marrow of asthma murine in vitro, cytokines mRNA were expressed, and the functions of DCs were investigated. Cells isolated from murine bone marrow have been cultured with rmGM-CSF and rmIL-4, and the expression of cytokines mRNA was determined by ribonuclease protection assay combined with multi-probe templates. Large numbers of DCs have been obtained from bone marrow, and they expressed interleukin-13 (IL-13), interleukin-9 (IL-9), and interleukin-3 (IL-3) mRNA. Moreover, the level of IL-13 mRNA and IL-9 mRNA expressed by DCs in asthmatic mice was significantly higher than those in the control groups (P<0.05). But, the level of IL-3 mRNA showed no discrepancy between the two groups (P>0.05). DCs are very important in the forming and developing of asthma, which implies that the therapy targeted at DCs will possibly become a new goal. __________ Translated from Journal of Nanjing Normal University (Natural Science), 2005, 28(2): 96–100 [译自: 南京师范大学学报 (自然科学版), 2005, 28(2): 96–100]     

A comparison of in vitro anticancerous activity and mechanism of ethanolic extracts from different Ganoderma genus

Five ethanolic extracts from the mycelia of Ganoderma lucidum, G. tsugae, G. oerstedii, G. subamboinense, and G. resinaceum were respectively studied on their anticancerous activities against leukemic HL-60 cell line in vitro. Results showed that all five extracts potently inhibited HL-60 proliferation. The extract from G. lucidum mycelia exerted the highest activity. Annexin V/PI bivariate flow cytometric analysis further revealed that the five extracts significantly induced early apoptosis in HL-60 cells. The results illustrate that not only G. lucidum but also other Ganoderma species can inhibit cancer cells, and their mechanisms are related to induction of apoptosis. __________ Translated from Journal of Shanghai Normal University (Natural Sciences), 2005, 34(2): 77–81 [译自: 上海师范大学学报 (自然科学版), 2005, 34(2): 77–81]     

偏离最佳频率的声信号对几内亚长翼蝠下丘神经元的前掩蔽

为探讨偏离神经元最佳频率(best frequency,BF)的声刺激对下丘神经元的前掩蔽效应,实验选用5只听力正常的几内亚长翼蝠(Miniopterus magnater),记录它们的下丘神经元对偏离BF的掩蔽声和探测声(BF)的反应.结果发现,当掩蔽声向高或低频方向偏离神经元的BF时,掩蔽效应逐渐降低.根据计算出的...     

Fine mapping of an Arabidopsis thaliana male sterile mutant EC2-157

An Arabidopsis thaliana male sterile mutant EC2-157 has been isolated using an EMS mutagenesis strategy. Genetic analysis indicated that it was controlled by a single recessive gene called ms157. No pollen grains have been observed in mutant anthers. ms157 Has been mapped to a region of 74kb located in BAC clone T6K22 on chromosome IV using a map-based cloning strategy. As no male sterile genes have been reported in this region, ms157 could be a novel gene related to fertility. The further molecular cloning and functional analysis on this gene should facilitate our understanding of A. thaliana another development. __________ Translated from Journal of Shanghai Normal University (Natural Sciences), 2005, 34(1): 58–63 [译自: 上海师范大学学报 (自然科学版), 2005, 34(1): 58–63]     

A preliminary study on designing ecological corridors in Xishuangbanna National Nature Reserve with 3S techniques

This paper is based on the fieldwork in Xishuangbanna Natioanl Nature Reserve in Yunnan Province of China. GPS data of Asian elephants were collected and analyzed with the remote sensing satellite photos of the region to estimate the landform physiognomy of different colors. We also analyzed a series of ecological factors including altitude, landform, relief, villages and roads which affected the distribution and movement of Asian elephants. The results suggested the possibility of designing and establishing corridors in Xishuangbanna National Nature Reserve to protect the population of wild elephants in the region. __________ Translated from Journal of Beijing Normal University (Natural Science) 2006, 42(4): 405-C409 [译自: 北京师范大学学报 (自然科学版)]     

Role of magpie in bird community formation in secondary forest

We analyzed a bird community in a secondary forest and the results show that the magpie was one of the key groups in the secondary forest. The key group is identified based on the nests used by other birds at a rate of 25%–40.17%. The size of the community is different and the number of these key groups is not certain. __________ Translated from Journal of Northeast Normal University (Natural Science Edition), 2006, 38 (3): 644-651 [译自: 东北师大学报(自然科 学版)]     

Biological characteristics of wild Cycas fairylakea population in Guangdong Province, China

There are five wild populations of Cycas fairylakea in Guangdong Province, China, three of which are newly found. A study of the biological characteristics of C. fairylakea populations showed that this species had a narrow colonization area within 300 hm², and an island pattern of distribution. Because of the overexploitation, urbanization, environment pollution, plant diseases, and insect pests, the wild populations and individuals of C. fairylakea decreased markedly in the past decades. All five populations have an opposite pyramid age structure, few coning plants, few seed production, and low level of seed germination rate or sterility. In conclusion, C. fairylakea in Guangdong Province was threatened seriously and an urgent need to take effective efforts to protect the plants and habitats in its location sites was required. __________ Translated from Acta Scientiarum Naturalium Universitatis Sunyatseni, 2005, 44(6): 97–100 [译自: 中山大学学报 (自然科学版), 2006, 44(6): 97–100]     

Effects of intercropping with persimmon on the rhizosphere environment of tea

The rhizosphere environment of tea (Camellia sinensis Kuntze) intercropped with persimmon (Diospyros kaki) differs from monocultures of tea. A trial was conducted to determine the effects of intercropping with persimmon on root exudates and soil nutrient condition of tea. Amino acid exuded in intercropping was three times higher than that in monoculture. Phenol, phenol/amino acid ration, dissolved sugar, and total organic acid were also lower in intercropping. The value of pH in soil was higher, and soil nutrient condition of rhizosphere, especially available nutrient, was not as well in intercropping as that in tea grown alone. While soil nutrient of non-rhizosphere was better than that in monoculture, tea quality and soil nutrient condition were better in intercropping ecosystem. __________ Translated from Journal of Southwest China Normal University (Natural Science), 2005, 30(4): 715–718 [译自: 西南师范大学学报 (自然科学版), 2005, 30(4): 715–718]