Neural pathways from thalamus associated with regulation of aggressive behavior

Small electrolytic lesions were made through electrodes in the thalamus of cats at sites where electrical stimulation elicited attack on a rat. Staining by modified Nauta reduced silver methods revealed that significant degeneration passed caudally from the lesions and entered the midbrain dorsal central gray region. Electrical stimulation of this dorsal midbrain region elicited attack on a rat, and destruction of this region suppressed the attack elicited by thalamic stimulation.     

Unit activity: motiviation-dependent responses from midbrain neurons

Single neurons in the midbrain tegmentum of rats showed clear discriminatory responses to three tones announcing either food or water or no reinforcement. Subjects were required to press a single lever and remain motionless for 2 seconds during which time unit activity from several brain sites was recorded. One of the tones, randomly designated, was sounded halfway through this period. Manipulation of drive states revealed that the highest activity was associated with tones announcing the reinforcement for which the animal was most strongly motivated. Thus, from a hungry animal sustained or increased firing rates were elicited by a " food" tone and differentially lowered rates by the other tones.     

北京鸭脑干网状脊髓束的起源及其细胞构筑：HRP逆行追踪法研究

采用HRP法,对54例北京鸭分别在脊髓的颈中部、颈膨大部、腰膨大部单侧注射或包埋HRP,兰色反应显色。逆行追踪了54例北京鸭,对脑干网状脊髓束的起源及其细胞构筑进行了研究。发现网状脊髓束不仅起于延髓和脑桥内侧网状结构的大细胞部,同时还起于外侧网状结构的小细胞部和中脑网状结构。标记细胞呈双侧性分布,同侧多于对侧。其结果为生理学研究提供了可靠的形态学依据。     

北京鸭脑干网状脊髓束的起源及其细胞构筑:HRP逆行追踪法研究

采用HRP法,分别在北京鸭脊髓的颈中部、颈膨大部、腰膨大部单侧注射或包埋HRP,蓝色反应显色。逆行追踪了54例北京鸭,对脑干网状脊髓束的起源及其细胞构筑进行了研究。发现网状脊髓束不仅起于延髓和脑桥内侧网状结构的大细胞部,同时还起于外侧网状结构的小细胞部和中脑网状结构。标记细胞呈双侧性分布,同侧多于对侧。其结果为生理学和药理学提供了可靠的形态依据。     

Neural pathways associated with hypothalamically elicited attach behavior in cats

Small electrolytic lesions were made in cats through electrodes, which, when stimulated, elicited either quiet biting attack or affective paw strike attack upon rats. The Nauta method for impregnating degenerating axoplasm was used to reveal that degeneration resulting from lesions at quiet attack sites followed largely along the course of the medial forebrain bundle, while the degeneration after lesions of affective attack sites was concentrated more heavily in the periventricular system.     

Activation of pontine cholinergic sites implicated in unconsciousness following cerebral concussion in the cat

Low levels of cerebral concussion in the cat produce reversible behavioral suppression presumably associated with unconsciousness. This injury is also associated with increased rates of glucose utilization in regions within the dorsomedial pontine tegmentum. Microinjection of carbachol into these regions produced behavioral suppression resembling that following concussion. These data, together with previously published observations on cholinergic responses to brain injury, suggest that concussive unconsciousness may be attributable in part to activation of cholinergic pontine sites.     

Cells related to fighting behavior recorded from midbrain central gray neuropil of cat

Cells were recorded in the midbrain central gray neuropil of the cat that responded with action potentials only during fighting behavior and not while the cat was resting or while control manipulations were performed. Some other cells in the same region responded maximally during fighting, and all cells responded to at least one manipulation. Brain stimulation at sites of cells related to fighting caused the animals to hiss.     

Neuronal correlates of behavior in freely moving rats

Firing patterns of single neurons in the hypothalamus, preoptic area, midbrain reticular system, and hippocampus of awake, freely moving female rats were temporally correlated with exploratory sniffing and vibrissa twitching, feeding, lordosis, locomotion, and (or) arousal. These relationships were remarkably stable during continuous observations lasting many hours. During extended periods when certain of these movements were not performed, the correlated neurons showed no action potentials for minutes at a time. Electrical stimulation at certain recording sites elicited behavior patterns whose spontaneous occurrence was accompanied by neuronal activation. Self-stimulation was elicited from sites spontaneously activated during exploratory behavior.     

Generation of torsional and vertical eye position signals by the interstitial nucleus of Cajal

The neural integrator, which converts eye velocity signals into position signals, is central to oculomotor theory. Similar integrators are probably necessary in any neural system that changes and maintains muscular tension. The integrator for horizontal eye position is in the pons, but the locations of the vertical and torsional integrators have not been clearly defined. Recording three-dimensional eye movements in alert monkeys during microstimulation and pharmacological inactivation of midbrain sites showed that the interstitial nucleus of Cajal generates both the torsional and vertical eye position signals. Up and down signals are linked with clockwise signals in the right brain and counterclockwise signals in the left brain. This three-dimensional coordinate system achieves orthogonality and bilateral symmetry without redundancy and optimizes energy efficiency for horizontal visual scanning.     

Midbrain control of three-dimensional head orientation

Little is known about the neural mechanisms controlling head posture and why they fail in clinical syndromes like torticollis. It is well established, however, that the brain controls eye position by integrating eye velocity commands. By electrically stimulating and reversibly inactivating midbrain sites in the head-free (nonimmobilized) monkey, we found that the interstitial nucleus of Cajal functions as a neural integrator for head posture. We suggest that a bilateral imbalance in this structure, through either direct damage or inappropriate input, could be one of the mechanisms underlying torticollis.     

Mechanically induced wall appositions of plant cells can prevent penetration by a parasitic fungus

Localized, paramural wall appositions resembling appositions commonly induced by fungal attack, were induced in kohlrabi (Brassica oleracea L. gongyloides) by mechanical wounding (bending) of the root hairs before the hairs were inoculated with zoospores of a compatible parasitic fungus. The appositions were effective in preventing fungal penetration at the wound sites, which shows that wall appositions can prevent fungal ingress into plant cells.     

Serotonin: release in the forebrain by stimulation of midbrain raphé

Electrical stimulation of the midbrain raphé, an area in which neuronal perikarya containing serotonin are aggregated, produces an increase in 5-hydroxyindoleacetic acid and a decrease in serotonin in the forebrain. These changes indicate that serotonin in the brain can be released via a specific neural pathway, namely, the system of axons projecting into the forebrain from serotonin-containing neurons in the midbrain raphé.     

密码体制攻击模型的分析与研究

文章对密码学中的几种主要形式化攻击模型进行了讨论与分析对比，并举例说明了不可区分选择明文攻击模型、不可区分选择密文攻击模型和不可区分适应性选择密文攻击模型的具体应用，为可证明安全性理论设计和分析密码协议提供了理论基础．     

A neural map of auditory space in the owl

Auditory units that responded to sound only when it originated from a limited area of space were found in the lateral and anterior portions of the midbrain auditory nucleus of the owl (Tyto alba). The areas of space to which these units responded (their receptive fields) were largely independent of the nature and intensity of the sound stimulus. The units were arranged systematically within the midbrain auditory nucleus according to the relative locations of their receptive fields, thus creating a physiological map of auditory space.     

黄河流域生态空间网络特征

  目的  黄河流域在生态环境保护中有着举足轻重的地位,为了有效地应对城市快速发展所带来的生态环境问题,本文针对黄河流域构建了生态空间网络,以保护生物多样性、减缓景观格局破碎化。  方法  以黄河流域为研究对象,基于土地利用数据、生态斑块面积周长、归一化植被指数(NDVI)、改进的归一化水体指数(MNDWI)和平均斑块分维数,选取了生态源地;利用GIS空间分析和MCR模型算法构建最小累积生态阻力面,提取出潜在生态廊道和生态节点;最终得到由生态源地和潜在生态廊道组成的黄河流域潜在生态空间网络并对其进行鲁棒性分析。  结果  （1）黄河流域潜在生态空间网络由294块生态源地和369条潜在生态廊道组成。（2）生态源地主要土地利用类型为林地、草地和水域,主要分布在东北部和西南部,东南部也有零星分布。（3）生态廊道在东北部和西南部密度较大,生态空间网络结构复杂,在小块生态源地之间长度较长,对研究区生态环境发挥关键作用。（4）网络中共提取125个生态节点并使用matlab进行模拟攻击测试其鲁棒性,总体上随机攻击下生态空间网络的恢复鲁棒性优于恶意攻击,连接鲁棒性在攻击一定数量的节点后呈现大幅度上涨,网络结构崩溃。  结论  本文基于MCR模型构建黄河流域的潜在生态空间网络并对其进行了拓扑结构分析,为生态空间网络优化提供重要借鉴意义,为促进黄河流域高质量发展、提高黄河流域的生态文明建设水平提供理论指导。      

Brain receptors sensitive to indole compounds: function in control of luteinizing hormone secretion

The placement of melatonin and of 5-hydroxytryptophol in the median eminence of castrated male rats is followed 5 days later by a significant decrease in pituitary stores of luteinizing hormone. Pituitary reserve of this hormone is also depleted after the implantation of melatonin, 5-hydroxytryptophol, and 5-methoxytryptophol in the reticular formation of the midbrain. It is suggested that these indole compounds, which are normally synthesized in the pineal gland, may intervene in the control of the secretion of luteinizing hormone, possibly by acting on specific receptors localized in the median eminence and in the midbrain.     

Electrical stimulation of the midbrain mediates metastatic tumor growth

Pulmonary metastases were counted 10 days after female rats received tail-vein injections of Walker-256 carcinosarcoma cells. Previous observations that halothane anesthesia plus hind-limb amputation increases the number of metastases were confirmed. Amputation under the analgesia of electrical stimulation of the midbrain was found to increase metastatic activity. However, the stimulus-produced analgesia alone also increased the number of metastases. Systemically administered naloxone blocked the analgesic effect of midbrain stimulation but did not block the increase in the number of pulmonary metastases.     

Stepwise quenching of exciton fluorescence in carbon nanotubes by single-molecule reactions

Single-molecule chemical reactions with individual single-walled carbon nanotubes were observed through near-infrared photoluminescence microscopy. The emission intensity within distinct submicrometer segments of single nanotubes changed in discrete steps after exposure to acid, base, or diazonium reactants. The steps were uncorrelated in space and time and reflected the quenching of mobile excitons at localized sites of reversible or irreversible chemical attack. Analysis of step amplitudes revealed an exciton diffusional range of about 90 nanometers, independent of nanotube structure. Each exciton visited about 10,000 atomic sites during its lifetime, providing highly efficient sensing of local chemical and physical perturbations.     

Hippocampal correlates of aversive mibdrain stimulation

Hippocampal synchronization during aversive dorsal midbrain stimulation was observed in rats both in a conditioning procedure and under d-tubo-curarine paralysis. The results restrict the generality of previous reports which correlated hippocampal synchronization and desynchronization with approach and withdrawal behavior, respectively. Relative to the condition of free movement, curarization reduced the frequency of both "spontaneous" and dorsal midbrain-evoked synchronization, thus suggesting possible direct and indirect effects of d-tubocurarine on subcortical structures.