Changes in amphetamine stereotypy in cats after electrical stimulation of the caudate nucleus

Two types of behavioral changes arise in cats after repetitive low-frequency stimulation of the head of the caudate nucleus in cats. Behavioral inhibition is more frequently triggered from the dorsomedial zone of the head, whereas activation phenomena precede depression during stimulation of the ventrolateral zone. The assortment and pattern of stereotyped movements following injection of the minimal effective dose of amphetamine vary in different ways against the background of these changes. After stimulation of the dorsomedial zones of the nucleus stereotypy is first disorganized and then weakened, whereas caudate activation is associated with strengthening of stereotypy.Department of Pharmacology, Chita Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 87, No. 6, pp. 518–521, June, 1979.     

Effect of leucine-enkephalin on cerebral cortical unit activity

Experiments on unanesthetized rats immobilized with flaxedil showed that leucineenkephalin (150 g), if injected into the lateral cerebral ventricle, caused heterogeneous changes in the activity of 21 sensomotor cortical units tested. Spike discharges of five neurons were reduced and those of 11 neurons increased. Naloxone (2 mg/kg, intravenously) prevented both the inhibitor and the activating effect of leucine-enkephalin in the case of repeated injections of this pentapeptide. Leucine-enkephalin did not change the activity of five units.Department of Pharmacology, Faculties of Internal Medicine and Hygiene, I. M. Sechenov First Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 42–44, July, 1979.     

A组轮状病毒广州地方株VP7基因序列的比较分析

目的 了解我国轮状病毒G1型广州地方株与标准株及北京G1型地方株VP7基因序列的差异，为我国轮状病毒疫苗的研制提供资料。方法 通过逆转录—聚合酶链反应(RT—PCR)获得了轮状病毒广州地方株R97—196 VP7全基因的cDNA片段，将其克隆入T—A克隆质粒pUCm—T中，构建成重组质粒pUCmT—VP7，对克隆的VP7基因进行序列测定。结果 该地方株的基因核苷酸全长为1062nt，读码框架和以往的研究一致，和北京G1型地方株173的VP7氨基酸序列具有高度同源性(98％)，而与不同血清型标准株间则变异较大(73％—81％)，氨基酸序列中存在的一些高变区和保守功能区与已报道的研究结果一致。从进化角度分析，与轮状病毒标准株Wa株，相距较远。结论 轮状病毒广州地方株R97—196 VP7基因片段属G1型，轮状病毒VP7基因的变异与地域有一定关系。     

Sensation Seeking, Trait and State Anxiety, and the Electrodermal Orienting Response

The relationship between sensation seeking and the orienting reflex (OR) using skin conductance change is investigated in two experiments. In Experiment I, high sensation seekers gave a greater initial OR In novel visual stimuli while not differing in habituation on subsequent trials. In Experiment II. the paradigm was extended to include auditory as well as visual stimuli. Again, high sensation seekers were found to be more arousable with respect to initial ORs while not differing in habituation rates. The results suggest that sensation seekers may be characterized as having strong excitatory CNS processes. In Experiment II, anxiety (trait and state) was also related to the OR. There were no effects due to trait anxiety but state anxiety did yield significant differences. The more highly anxious (state) subjects had weaker initial ORs than lows in both novel tones, but not to repeated tones. The findings with state anxiety are consistent with findings by others using anxiety neurotics as subjects.     

Age-related changes in the cerebrospinal fluid outflow glycosaminoglycans

The glycosaminoglycan distribution patterns of the cerebrospinal fluid (CSF) outflow pathway, dura mater and cerebral cortex of young New Zealand red rabbits and 1-, 3- and 12-week-old C-57 mice were identified by analyses of the glycosaminoglycan moieties and by the use of zone electrophoresis. The glycosaminoglycans were identified by specific degradation procedures, i.e., hyaluronate lyase, chondroitin ABC lyase, endo-gb-D-galactosidase and nitrous acid treatment. The CSF outflow pathway and dura mater glycosaminoglycan components were primarily hyaluronic acid and chondroitin sulfatedermatan sulfate, whereas the cerebral cortex glycosaminoglycan components were hyaluronic acid, chondroitin sulfatedermatan sulfate, keratan sulfate and heparan sulfate. The glycosaminoglycan components of the dura mater and cerebral cortex decreased and those of the CSF outflow pathway increased as a function of age. These results demonstrate the feasibility of analyses of the CSF outflow pathway glycosaminoglycan components and suggest that topographical changes in the glycosaminoglycan distribution profiles may contribute to the pattern of cerebrospinal fluid outflow.     

Nonlinear structural and material properties and models: The pulmonary trunk

General models are developed for static and dynamic geometric and material passive responses. The models are applied to data obtained from the main pulmonary arteries of calves and dogs. The structural model predicts distortions by simultaneous stretching and bending in a concise manner. Parameters are obtained by a fiveelement material model. This latter predicts static and dynamic, nonlinear, frequency-dependent, viscoelastic responses observed in biomaterials over the entire strain range irrespective of the nature of loading. Validity and baseline parameter values are investigated for the inactivated state, developed by poisoning the smooth muscle with potassium cyanide. Complexities, related to nonlinear (strain-dependent) and colloidal (thixotropic) properties of tissues, are analyzed. These properties enter into functional responses in a complex manner that can modify substantially concepts of material components and vary appreciably between physiologic circumstances and laboratory evaluations. We propose that, in general, evaluations of material responses must account for these properties.     

Quantitative Characterization of the Cellular Elements of Human Cerebellar Nuclei at Different Ages

A quantitative assessment of the cellular elements present in the nuclei of the human cerebellum was performed using subjects aged 22-90 years. A series of horizontal sections of cerebellar nuclei was studied. stained with hematoxylin and eosin. The numbers of neurons and gliocytes per unit area were measured on sections, with subsequent calculation of their ratios (the glial index). These experiments showed that aging is associated with decreases in the content of neurons and increases in the content of gliocytes. The extent of these changes increases as ontogenesis proceeds.     

大学生网络成瘾影响因素分析

目的探讨大学生网络成瘾的原因。方法采用中文网络成瘾量表、自尊量表、孤独量表、大学生日常生活压力调查表、自编大学生网络使用行为调查问卷，对1450名大学生进行了调查，回收有效问卷1038份。结果对大学生网络成瘾的现状、网络使用特征及心理特征进行调查，建立大学生网络成瘾影响因素模型。结论①大学生网络成瘾呈轻度、重度两种水平，这两种水平总流行率达到14．84％；②网络使用时间、娱乐上网、交易上网、人际上网与网络成瘾存在着显著正相关关系；③自尊、孤独、大学生日常生活压力对网络成瘾有很好的预测作用；④网络成瘾是特定的个体心理特征与特定的网络使用行为、外部环境交互作用的结果。     

Latency of adaptive vergence eye movements induced by vergence-vestibular interaction training in monkeys

Clear vision of objects that move in depth toward or away from an observer requires vergence eye movements. The vergence system must interact with the vestibular system to maintain the object images on the foveae of both eyes during head movement. Previous studies have shown that training with sinusoidal vergence-vestibular interaction improves the frequency response of vergence eye movements during pitch rotation: vergence eye velocity gains increase and phase-lags decrease. To further understand the changes in eye movement responses in this adaptation, we examined latencies of vergence eye movements before and after vergence-vestibular training. Two head-stabilized Japanese monkeys were rewarded for tracking a target spot moving in depth that required vergence eye movements of 10°/s. This target motion was synchronized with pitch rotation at 20°/s. Both target and chair moved in a trapezoidal waveform interspersed with random inter-trial intervals. Before training, pitch rotation in complete darkness without a target did not induce vergence eye movements. Mean latencies of convergence and divergence eye movements induced by vergence target motion alone were 182 and 169 ms, respectively. After training, mean latencies of convergence and divergence eye movements to a target synchronized with pitch rotation shortened to 65 and 53 ms, and vergence eye velocity gains (relative to vergence target velocity) at the normal latencies were 0.68 and 1.53, respectively. Pitch rotation alone without a target induced vergence eye movements with similar latencies after training. These results indicate that vestibular information can be used effectively to initiate vergence eye movements following vergence-vestibular training.