舌慢适应传入纤维终止于三叉神经脊束核和三叉神经感觉主核形成突触的差异

目的：研究舌慢适应传入纤维终止于三叉神经脊束核和三叉神经感觉主核形成突触的类型及突触各组成部分出现频率的差异，为神经生理学研究和神经解剖学研究提供参考资料。方法：用猫作为试验动物，采用确定部位和功能的传入纤维进行细胞内注射，电镜连续切片观察技术。结果：1．猫舌慢适应传入纤维终止于三叉神经脊束核形成的突触以中间型为主；2．猫舌慢适应传入纤维终止于三叉神经感觉主核形成的突触以复杂型为主；3．形成三联体的数目及形成突触的各组成部分出现的频率，三叉神经感觉主核相对较高。结论：三叉神经感觉主核是舌的主要终止核团。     

猫舌快适应传入纤维止于三叉神经脊束核形成轴-树突触分析

目的：研究舌快适应传入纤维终止于三叉神经脊束核核形成的突触类型及与突触后膜—树突的关系，为神经生理学研究和神经解剖学研究提供参考。方法：采用细胞内注射，电镜连续切片技术。结果：猫舌快适应传入纤维投射到三叉神经脊束核形成的突触以中间型为主。与单纯型终扣形成突触的树突较大。与中间型终扣形成突触的树突较小。结论：各种突触类型形成的复杂联系，可能是不同感觉信息传递的形态学基础。     

舌慢适应传入神经终末与三叉神经感觉主核的突触联系

目的：研究舌感觉慢适应传入纤维终止于三叉神经感觉主核形成的突触类型及各类型突触出现的频率，为神经生理学和神经解剖学研究提供参考资料。方法：采用细胞内注射，免疫电镜和连续超薄切片技术。结果：舌感觉传入慢适应纤维投射到三叉神经感觉主核形成的突触类型分单纯型、中间型和复杂型3种，以中间型突触出现率最高。形成突触的各组成部分以轴－树及轴－轴突形形式为主，并有轴－体突轴。结论：中间型突触和轴－树及轴－轴突触是三叉神经感觉主该处理器觉信息的主 要形态学基础。     

舌快反应传入神经终末与三叉神经主核突触联系初步观察

神经系统的各种机能的活动、信息的传送都决定于神经元间的各种不同方式的联系 ,明确人体各不同部位及不同机能信息传送的各种联系方式 ,是深入研究神经生理学及神经性病理学的基础。近年来的一些研究表明 ,三叉神经主感觉核接受面部不同部位直接投射的纤维中 ,由于传入的部位不同 ,机能不同 ,投射到三叉神经主感觉核形成突触的类型及形成突触各种组成部分出现的频率等也不相同[1～ 4 ] 。舌是人体十分重要的器官 ,传送各种不同的感觉 ,各种不同感觉的传送方式的研究将对研究舌的神经生理学及病理学研究提供有价值的形态学资料。见于目前人…     

鸣禽栗巫鸟前脑高级发声中枢及其架区的纤维联系

用ＣＢ－ＨＲＰ顺、逆行追踪的方法,研究了鸣禽栗巫鸟前脑高级发声中枢（ＨＶＣ）及其周围架区（ｓｈｅｌｆ）的传入、传出投射．结果表明,ＨＶＣ接受丘脑葡萄形核（Ｕｖａ）、新纹状体前部巨细胞核内侧部（ｍＭＡＮ）、新纹状体界面核（ＮＩｆ）的传入投射,并发出纤维投射至旁嗅叶的Ｘ区和古纹状体粗核（ＲＡ）;还通过架区间接联系听区复合体（Ｌ区）及脑桥的蓝斑核（Ｌｏｃ）等．     

鸣禽栗Wu前脑高级发声中枢及其架区的纤维联系

用ＣＢ－ＨＲＰ顺、逆行追踪的方法,研究了鸣禽栗Ｗｕ前脑高级发声中枢（ＨＶＣ）及其周围架区的传入,传出投射,结果表明,ＨＶＣ接受丘脑葡萄形核、新纹状体前部巨细胞核内侧部,新纹状体界面核的传入投射,并发出纤维投射至旁嗅叶的Ｘ区和古纹状体粗核（ＲＡ）;还通过架区间接联系听区复合体（Ｌ区）及脑桥的蓝斑核等。     

卷烟滤嘴研究进展

本文将卷烟滤嘴分为传统卷烟滤嘴和特殊卷烟滤嘴这两大类别,并简要介绍了包括醋酸纤维滤嘴、聚丙烯纤维滤嘴、纸滤嘴、降焦减害型滤嘴、增香型滤嘴在内的不同类型滤嘴的工作原理、优缺点及其研究发展史。     

福州市不同性别大学生社会适应性的发展研究

目的：考察福州市不同性别大学生社会适应性的发展状况。方法：采用卢谢峰（2003）的《大学生适应性量表》对福州市4所大学的697名大学生展开调查。结果：（1）福州市大学生在社会适应的7个维度上存在发展不均衡的状况,适应水平最高的是生活自理适应性,接着依次是角色适应性、身心症状表现、人际适应性、环境的总体认同和学习适应性,最差的是职业选择适应性;（2）大学生的适应类型可以分为适应性水平较强、适应性水平一般和适应性水平较差三种,且各年级适应类型分布存在显著差异;（3）女大学生的学习适应性显著优于男大学生;（4）男女大学生在社会适应的发展上呈现差异：男大学生在人际适应、角色适应、生活自理适应和身心症状表现上呈现大一强、大二弱、大三强、大四弱的波动态势;而女大学生随着年级增长,在各项适应维度上表现出稳定的发展态势。结论：福州市大学生社会适应性的发展不均衡,不同性别大学生社会适应性呈现不同的发展态势。     

湘西苗族舌运动类型的遗传学研究

对湘西苗族学生555例（男254例,女301例）的舌运动类型（卷舌、叠舌、翻舌、尖舌、三叶舌）进行了调查测试,结果表明：卷舌、叠舌、翻舌、尖舌、三叶舌出现率分别为69.01%,17.30%,19.64%,36.40%,40.36%;5种舌运动类型出现男女性别间均无显著差异（P＞0.05）;5项舌运动类型间相关性较小,仅有2对相关;翻舌基因与叠舌、尖舌基因间存在互作关系.     

γ-氨基丁酸对家鸽(Columba livia)顶盖脑片Ⅲ层神经元电活动的影响

在２５只家鸽的离体顶盖脑片上,用玻璃微电极胞外记录到顶盖Ⅲ层神经元自发放电单位５５个,观察了γ氨基丁酸（ｇａｍｍａａｍｉｎｏｂｕｔｙｒｉｃ,ＧＡＢＡ）及其拮抗剂以及电刺激Ⅱａ～ｆ亚层对Ⅲ层神经元电活动的作用．作用显示：脑片灌流ＧＡＢＡ（１０－６ｍｏｌ／Ｌ,３ｍｉｎ）后,１６／２１个单位（占７６．２％）放电频率减少,１／２１个单位（占４．８％）放电频率增加,４／２１个单位（占１９．６％）放电频率无变化．ＧＡＢＡ的这种减频作用可被１０－６ｍｏｌ／Ｌ荷包牡丹碱（ｂｉｃｕｃｕｌｉｎｅ,ＢＩＣ）逆转．１４个被Ⅱａ～ｆ亚层刺激传入减频的Ⅲ层神经元,其中１１个单位（占７８．６％）的减频作用可被ＢＩＣ阻断,另３个单位则不产生阻遏作用．上述药物的作用具有可逆性和重复性．结果表明：家鸽顶盖Ⅲ层中可能有ＧＡＢＡ能纤维的到达,Ⅲ层内存在ＧＡＢＡ敏感神经元．顶盖Ⅱａ～ｆ亚层与Ⅲ层神经元间的抑制性突触传递过程中有ＧＡＢＡ及其相应的ＧＡＢＡＡ型受体参与     

Ectoenzymes control adenosine modulation of immunoisolated cholinergic synapses

One of the most important inhibitory modulators of synaptic transmission in mammalian brain is adenosine. At some cholinergic terminals, adenosine is known to inhibit further release of acetylcholine. It is unclear whether adenosine is released directly at the synapse or whether ATP is co-released with transmitter and hydrolysed to adenosine in the synaptic cleft. Methods used in the past for isolating nerve terminals have not yielded homogeneous preparations, making it impossible to determine whether sufficient ATP or adenosine is released at specific synapses for inhibition of transmitter release to occur. Immunoaffinity purification techniques have recently permitted the preparation of homogeneous populations of cholinergic nerve terminals, which release ATP upon stimulation. We now report that in immunoisolated cholinergic nerve terminals from the striatum synaptic ectophosphohydrolases convert this ATP to adenosine, which inhibits further acetylcholine release, but this inhibitory effect is not seen in cortical cholinergic terminals lacking the complete ectophosphohydrolase pathway. Therefore the differing adenosine-mediated modulation in different brain areas is controlled by the presence and activity of synaptic ectophosphohydrolases.     

Synapse elimination in neonatal rat muscle is sensitive to pattern of muscle use

The synaptic connections among the cells of the vertebrate nervous system undergo extensive rearrangements early in development. During their initial growth, neurones apparently form synaptic connections with an excessive number of targets, later retracting a portion of these synapses in establishing the adult neural circuits. Because of the profound effects which experience has upon the developing nervous system, a question of considerable interest has been the role which the functional use of these developing synapses might play in determining the final pattern of connectivity. At the neuromuscular junction the early changes in synaptic connections are well documented, and here questions about the importance of function can be relatively easily addressed. Mammalian skeletal muscle fibres experience a perinatal period of synapse elimination so that all but one of several synapses formed on each muscle fibre are lost. This synapse elimination is sensitive to alterations of neuromuscular use or activity. Reduction of muscle use by tenotomy or by paralysis of the muscle with drugs blocking nerve impulse conduction or neuromuscular transmission delays or even prevents synapse loss, while increased use produced by stimulation of the muscle nerve apparently accelerates the rate at which synapses are lost. I report here a further examination of the role of neuromuscular activity in synapse elimination. I show that chronic neuromuscular stimulation accelerates synapse elimination but that this acceleration is dependent on the temporal pattern in which the stimuli are presented: brief stimulus trains containing 100 Hz bursts of stimuli produce this acceleration whereas the same number of stimuli presented continuously at 1 Hz do not. Furthermore, the 100 Hz activity pattern which is effective in altering synapse elimination also alters two other muscle properties: the sensitivity of the muscle fibers to acetylcholine and the 'speed' of muscle contractions. These findings suggest that the ability of muscle fibres to maintain more than one nerve terminal, like other muscle properties, is sensitive to the pattern of muscle use rather than just the total amount of use.     

Dual-component NMDA receptor currents at a single central synapse

Present thinking about the way that the NMDA (N-methyl-D-aspartate) class of glutamate receptor operates at central synapses relies mainly on information obtained from single-channel and whole-cell recordings from cultured neurons stimulated by exogenous NMDA receptor agonists. The mechanisms that operate in the postsynaptic membrane of a normal neuron following release of the natural transmitter are far less clear. An important problem is that most normal neurons receive many excitatory synapses (10(3)-10(5) per cell) and these synapses are located on slender dendritic elements far away from the somatic recording site, making the study of discrete synaptic events difficult. Typically, when populations of synapses are activated, NMDA receptor-mediated synaptic potentials appear as slowly rising, long-lasting waves superimposed on faster, non-NMDA-receptor potentials. Although believed to be critical for NMDA receptor function, this slow time-course would not be predicted from single-channel kinetics and its origin remains puzzling. We have now analysed the events occurring at the level of a single excitatory synapse using a simple, small, neuron--the cerebellar granule cell--which has an unusually simple glutamatergic input. By applying high-resolution whole-cell recording techniques to these cells in situ, we were able to study the nature of elementary NMDA receptor-mediated synaptic currents. Contrary to expectations, the prominent currents are fast but are followed by slow ones. Both types of current are strongly voltage-dependent but differ subtly in this respect. Furthermore, the currents are absent unless glycine is provided.     

Three modes of synaptic vesicular recycling revealed by single-vesicle imaging

Synapses recycle their spent vesicles in order to keep up with on-going neurotransmitter release. To investigate vesicle recycling in the small synapses of hippocampal neurons, we have used an optical recording method that permits us to resolve single-vesicle events. Here we show that an exocytic event can terminate with three modes of vesicle retrieval: a fast (400-860 ms) 'kiss-and-run' mode that has a selective fusion pore; a slow (8-21 s) 'compensatory' mode; and a 'stranded' mode of recycling, in which a vesicle is left on the cell surface until a nerve impulse triggers its retrieval. We have also observed that, in response to a nerve impulse, synapses with low release probability primarily use the kiss-and-run mode, whereas high release probability terminals predominantly use the compensatory mode of vesicle retrieval.     

Competition favouring inactive over active motor neurons during synapse elimination

During normal postnatal maturation, mammalian muscles undergo an orderly process of synapse elimination, whereby each muscle fibre loses all but one of the multiple inputs with which it is endowed at birth. Experimental perturbations that increase or decrease the overall activity of nerve and/or muscle cause a corresponding increase or decrease in the overall rate of neuromuscular synapse elimination. On other grounds it has been suggested that competition among motor neurons is important in determining which synapses survive and which are eliminated. Would a difference in activity among the terminals at the same endplate affect the outcome of the competition and not just its rate? We investigated this issue by blocking activity for four days in a small fraction of the motor neurons innervating the neonatal rabbit soleus muscle. Twitch tensions of motor units were subsequently measured for both the active and inactive populations of neurons to assess whether the inactive neurons had lost fewer or more synapses than is normal. We found that inactive motor neurons have a significant advantage compared to active counterparts in control experiments, a finding opposite to that expected if the neuromuscular junction operated by classical 'Hebbian' rules of competition.     

High-fidelity transmission of sensory information by single cerebellar mossy fibre boutons

Understanding the transmission of sensory information at individual synaptic connections requires knowledge of the properties of presynaptic terminals and their patterns of firing evoked by sensory stimuli. Such information has been difficult to obtain because of the small size and inaccessibility of nerve terminals in the central nervous system. Here we show, by making direct patch-clamp recordings in vivo from cerebellar mossy fibre boutons-the primary source of synaptic input to the cerebellar cortex-that sensory stimulation can produce bursts of spikes in single boutons at very high instantaneous firing frequencies (more than 700 Hz). We show that the mossy fibre-granule cell synapse exhibits high-fidelity transmission at these frequencies, indicating that the rapid burst of excitatory postsynaptic currents underlying the sensory-evoked response of granule cells can be driven by such a presynaptic spike burst. We also demonstrate that a single mossy fibre can trigger action potential bursts in granule cells in vitro when driven with in vivo firing patterns. These findings suggest that the relay from mossy fibre to granule cell can act in a 'detonator' fashion, such that a single presynaptic afferent may be sufficient to transmit the sensory message. This endows the cerebellar mossy fibre system with remarkable sensitivity and high fidelity in the transmission of sensory information.     

Gastric vagal afferent inputs reach the glycemia-sensitive neurons of lateral hypothalamic area in the rat

The glycemia-sensitive neuron in lateral hypothalamic area (LHA) is one of the important central neural events involved in the feeding control.Electrophysio-logical studies have demonstrated that gastrointestinal vagal afferent inputs could convey the meal-related infomation of gastrointestinal tract to the hypothalamus,In this study ,we examined whether the gastric vagal afferent inputs could reach the glycemia-sensitive neurons of the LHA by using in vivo extracelluar recording technique in the rat.The results showed that stimulation of gastric vagal nerves elictied two types of the LHA neurons responses:the phasic response (93/116,80.2%),and the change in cell‘s firing pattern (23/116,19.3%) ,Within the 93 cells that responded to the gastric vagal stimulation with a phasic response ,67(72.0%) showed an inhibition in the cell‘s firing rate 26(27.4%) were excited,Of the 23 cells that showed a change in the firing pattern 13 responded to the gastric vagal stimulation with a long-lasting increase or decrease in firing rate,the remaining 10 cells turned thier discrete spiking to the bust discharging .In addition ,of 101 LHA neurons including the ypes of responsive neurons,73(72.3%)were identified to be glycemia-sensitive neurons,These results demonstrated that the gastric vagal afferent inputs could reach the LHA and predominaltly reach those glycemia-seach neurons in the LHA ,Presumably,the modulation of glycemia-sensitive neurons of LHA by the gastric vagal afferent inputs may play an important role in the short-term regulation of feeding behavior.     

Gastric vagal afferent inputs reach the glycemia-sensitive neurons of lateral hypothalamic area in the rat

The lateral hypothalamic area (LHA) is one of the most important central areas in the regulation of feeding behavior[1]. The glycemia-sensitive neurons within the LHA sense the blood glucose level and subsequently trig-ger various visceral and somatic responses for maintaining the homeostasis of blood glucose concentration. Some electrophysiological studies have demonstrated that the gastric vagal afferent inputs could reach the LHA in the cat[2,3], but the studies did not reveal whether th…