A psychophysiological evaluation of female urethral syndrome: Evidence for a muscular abnormality

This is a preliminary investigation into a recently defined urological disorder occurring in a subgroup of women with urethral syndrome suggestive of pelvic floor muscular (PFM) dysfunction. Symptoms include straining to void, urgency, frequency, hesitation, incontinence and/or retention, and subpubic pain. Finding neither bladder nor urological abnormalities, urologists may consider these women emotionally unstable without organic cause for their symptoms. However, their distress may be a consequence rather than a cause of their voiding problems. Sixteen female urological patients were matched with 16 asymptomatic controls to investigate PFM functioning, psychological status, and symptomatology. Results showed heterogeneity of symptomatology and little elevation of depression or anxiety when comparing patients with controls. Hypotheses of muscular abnormality were confirmed. Patients evidenced poor control over tensing and relaxing PFM, elevations of PFM activity under various conditions, and chronic pain as a prominent symptom. Treatment approaches specifically designed to address PFM dysfunction are discussed.     

Scale-invariant superiority of foveal vision in perceptual categorization

The recognition of objects is exceedingly difficult in indirect view. This complication cannot be explained in terms of retino-cortical magnification, as size scaling fails to establish position invariance both for character recognition [Strasburger, H. & Rentschler, I. (1996) Eur. J. Neurosci., 8 1787-1791] and pattern classification [Jüttner, M. & Rentschler, I. (1996) Vision Res., 36, 1007-1021]. Thus we compared, for two tasks of discrimination learning and category learning with respect to a common set of grey-level patterns, how humans perform in foveal and extrafoveal vision. Observers learnt to discriminate (size-scaled) images equally well in foveal and extrafoveal view, whereas they displayed profound deficiencies in extrafoveal category learning for the same patterns. From the behavioural learning data, internal representations of the learning signals were reconstructed by means of computer simulations. For foveal view, these representations were found to be veridical to their physical counterparts for both learning tasks. For extrafoveal view, they were severely distorted for category learning but not for discrimination learning. A variance reduction of the pattern classes by a factor of 100 reduced the dissociation between extrafoveal categorization and discrimination but did not remove it. These observations suggest a scale-invariant superiority of foveal vision for learning object categories. This implies a high degree of space variance of visual cognition which is vastly underestimated by classical measures of visual performance, e.g. acuity, visual field and contrast sensitivity.     

Facilitating effect of histamine on spatial memory deficits induced by dizocilpine as evaluated by 8-arm radial maze in SD rats

AIM: To investigate whether or not histamine is involved in spatial memory deficits induced by dizocilpine (MK-801) as evaluated by 8-arm radial maze of rats. METHODS: 8-Arm (4-arm baited) radial maze was used to measure spatial memory in rats. RESULTS: Bilaterally intrahippocampal (ih) injection of MK-801 (0.3 μg/site) impaired working memory and reference memory in rats. Both histamine (50, 100 ng/site, ih) and intraperitoneal (ip) injection of histidine (100, 200 mg/kg) markedly improved the spatial memory deficits induced by MK-801. On the other hand, the ameliorating effect of histidine (100 mg/kg, ip) was completely antagonized by α-fluoromethylhistidine (α-FMH, 5 μg/site, ih), a potent and selective histidine decarboxylase (HDC) inhibitor, and H_1-antagonist pyrilamine (1 μg/site, ih), but not by H_2-antagonist cimetidine, even at a high dose (2.5 μg/site, ih). CONCLUSION: The hippocampal histamine plays an important role in the ameliorating effect on MK-801-induced spatial memory deficits,     

银杏叶提取物磷脂酰胆碱复合物对缺血大鼠学习记忆障碍的影响

 目的 观察银杏叶提取物磷脂酰胆碱复合物(Gb-PC)对血管性痴呆(VD)大鼠学习记忆功能的影响,并探讨其相关机制。方法 制备VD模型,采用避暗法及水迷宫法评价Gb-PC对VD模型大鼠学习记忆的影响,并测定大鼠海马组织中单胺氧化酶(MAO)及超氧化物歧化酶(SOD)活性,丙二醛(MDA)含量。结果Gb-PC可以明显改善VD大鼠的学习记忆功能,同时可不同程度抑制海马组织中MAO活性,增强SOD活性,减少MDA含量。结论 Gb-PC对VD大鼠学习记忆功能有一定的改善作用,其机制可能与提高脑组织中抗氧化酶活性,减轻生物膜脂质过氧化损伤以及抑制单胺氧化酶活性有关。     

睡眠剥夺对大鼠学习和行为的影响

目的 研究不同时间的睡眠剥夺（ＳＤ）及部分睡眠剥夺（ＰＳＤ）对大鼠行为和学习的影响。方法 采用小平台水环境对照,ＳＤ组有１２,２４,４８,７２,９６ｈ及ＰＳＤ,每组例数为６只,ＣＣ组为５只,测量ＳＤ后动物学会Ｙ型迷宫的总次数、时间。后体质量的变化。结果 ＴＣ组学习成绩、正确反应率优于其他各组,２４ｈ和４８ｈＳＤ组学习成绩 于ＣＣ,其他各组学习成绩不如ＣＣ,随ＳＤ时间的延长,正确反应率下降,同ＣＣ和     

生命1号健脑强身及促骨生长的实验研究

采用水迷宫法、穿梭箱法、避暗法、跳台法观察了生命1号对小鼠学习、记忆、巩固的影响。灌胃给生命1号可改善东莨菪碱、樟柳碱致小鼠记忆获得障碍。生命1号能明显提高单核细胞吞噬功能，显著增加小鼠血清溶血素的含量，促进T淋巴细胞的转化。除此之外，还能明显地增加阳虚大鼠股骨的重量、长度、直径及皮质厚度；提高血清钙、磷水平；降低血清碱性磷酸酶的含量，具有促进骨骼生长的作用。     

Optometry and WebCT: a student survey of the value of web‐based learning environments in optometric education

Purpose : Improvements in information and communication technology and the need for off‐campus delivery have led to the increased use of web‐based learning tools in optometry schools around the world. This study compared student‐reported preferences for traditional lecture‐based learning with their preferences when using a web‐based learning tool. Methods : One hundred and thirteen second and third year students from the School of Optometry and Vision Science at the University of New South Wales were surveyed. All students had worked with WebCT for at least two years. Students were asked to rank a range of learning tools in perceived usefulness and also to state how often they used the particular learning tools. Results : The students rated notes (lecture or WebCT delivered) and clinical laboratory sessions as their most useful learning tools. The use of specific learning tools was more diverse, with students reporting that they often used notes (lecture or WebCT delivered), the WebCT calendar tool and the WebCT discussion tool. This result highlights the valuable contribution of the communication aspect of WebCT to fostering learning communities. The least used learning tools were textbooks, websites mentioned in lectures and library print resources. Interestingly, the purchase of textbooks was high with 77 per cent of students on average reporting they had bought the recommended textbooks. Conclusion : Notes were the preferred learning tool of the optometry students at UNSW, suggesting that passive learning of content was the preferred learning style. It is hoped that the introduction of web‐based learning environments may allow students and staff to reflect on their preferred teaching and learning styles. Web‐based learning tools, such as WebCT, provide a powerful method to facilitate independent deeper learning in students with active learning styles. The current encouragement of student‐based active learning methods should see increased use of independent learning platforms, such as WebCT, in optometry schools.     

Mechanisms of motor learning in the cerebellum

How the elaborate neuronal circuit in the cerebellum operates and is involved in motor learning is a question addressed in earnest in studies on the cerebellum. During the past four decades, experimental studies have revealed circuit and module structures of the cerebellum, established long-term depression (LTD) as a unique and characteristic type of synaptic plasticity in the cerebellum, and analysed signal contents of activates of cerebellar neurons related to motor learning. In the 1990s, these studies were developed to detailed analyses of the signal transduction underlying LTD, and to uncovering the involvement of the cerebellum in cognitive function. On the other hand, theoretical studies yielded epochal Marr-Albus network models of the cerebellum around 1970, and introduced control system principles explaining the essential roles of the cerebellum in motor learning as providing internal models, both forward and inverse. The author maintains the hypothesis that reorganisation of the neuronal circuit by error-driven induction of LTD constitutes the major memory and learning mechanisms of the cerebellum. In this article, we examine the validity of the hypothesis in light of currently available data in recent studies of the cerebellum.     

Phospholipid composition and levels are altered in Down syndrome brain

Individuals chronically exposed to low levels of organophosphate insecticides may present with subtle impairments in cognition. In addition, low level diisopropylflurophosphate (DFP) exposure (0.25 mg/kg per day for 2 weeks) in rats resulted in protracted working memory impairment [29]. The current studies attempt to show a temporal relationship between the DFP-induced impairment in performance of a spatial memory task and the protracted decrease in the expression of cholinergic receptors and acetylcholinesterase in specific brain regions. Cholinergic receptors labeled with the ligands [(3)H]epibatidine and [(3)H]AFDX-384 were affected to a much greater extent and for a longer period of time than were both acetylcholinesterase activities and cholinergic receptors labeled with [(3)H]QNB. Pre-testing administration of nicotine was shown to completely reverse this DFP-induced impairment in memory-related task performance. Additionally, prophylaxis with pyridostigmine bromide (PB) caused DFP-treated animals to exhibit near normal levels of memory-related task performance. These results are consistent with the development of a protracted phase of learning impairment to sub-acute DFP exposure, which may involve the loss of hippocampal nicotinic receptors, and may be prevented or reversed by PB or nicotine, respectively.     

Antioxidant-rich diets improve cerebellar physiology and motor learning in aged rats

The free radical theory of aging predicts that reactive oxygen species are involved in the decline in function associated with aging. The present paper reports that diets supplemented with either spinach, strawberries or blueberries, nutritional sources of antioxidants, reverse age-induced declines in beta-adrenergic receptor function in cerebellar Purkinje neurons measured using electrophysiological techniques. In addition the spinach diet improved learning on a runway motor task, previously shown to be modulated by cerebellar norepinephrine. Motor learning is important for adaptation to changes in the environment and is thus critical for rehabilitation following stroke, spinal cord injury, and the onset of some neurodegenerative diseases. These data are the first to indicate that age-related deficits in motor learning and memory can be reversed with nutritional interventions.