Selective impairment of paired associate learning after administration of a centrally-acting adrenergic agonist (clonidine)

Eight normal volunteers had IV infusions of 200 g clonidine (a centrally-acting adrenergic agonist which reduces noradrenaline release), and saline in a double-blind cross-over design. Clonidine reduced subjective estimates of arousal but did not affect performance on the Digit Symbol Substitution Test. Clonidine impaired pairedassociate learning, but it did not affect performance on a number of measures of short and long term memory. The findings suggest either 1) that there is a specific (adrenergic) mechanism involved in the acquisition of novel associations, but not in other types of learning, or 2) that paired associate learning is more vulnerable than other learning tasks to disruption of adrenergic transmission.     

Attenuation of ethanol tolerance by a novel stimulus

A Pavlovian conditioning model of tolerance emphasizes that an association between predrug cues and the systemic effects of the drug contributes to tolerance. On the basis of this model, established tolerance should be attenuated by external inhibition, i.e., by presentation of a novel, extraneous stimulus. This prediction was evaluated in the present experiment. Rats that were so tolerant to the hypothermic effect of ethanol that they evidenced no drug-induced decrease in temperature were presented with a bright strobe light following ethanol administration. The light precipitated a large decrease in temperature in these rats. These results provide further evidence that tolerance to the hypothermic effect of ethanol is, in part, mediated by learning.     

Central mediation of the conditioned taste aversion induced in rats by harmaline

The assumption that drugs used as unconditioned stimuli in conditioned taste aversion (CTA) studies act centrally was tested by comparing the effects of systemic and intracerebral injections of harmaline hydrochloride (H) in 340 rats. Intraperitoneal injection of 5–20 mg/kg but not of 2.5 mg/kg H administered 5 min after 15-min saccharin (0.1%) drinking decreased saccharin-water preference in a two-choice retention test, performed 48 h later, from 55% to 20%. Since CTA was not diminished when H (10 mg/kg) was injected into rats anesthetised immediately after saccharin drinking by pentobarbital (40 mg/kg), H (1.7–50 g) was administered intracerebrally to anesthetised rats fixed in the stereotaxic apparatus. Injection of 3–6 g H into the inferior olive elicited CTA comparable to that of systemic injection of 10 mg/kg H. Injections of 6 and 50 g H into cerebellum and bulbar reticular formation elicited weaker CTA while neocortical, hypothalamic and mesencephalic applications were ineffective. CTA could also be elicited when 50 g but not 6 g H was injected into the inferior olive 1 or 2 h after saccharin drinking. This delay-dependent effect and failure of non-contingent H administration to change saccharin preference indicates that the H-induced CTA is not contaminated by a non-specific increase in neophobia. It is concluded that H probably elicits CTA by activation of caudal bulbar structures, including the nucleus of the solitary tract, area postrema and lateral reticular formation.     

Resecciones pulmonares anatómicas por vía robótica: análisis de la curva de aprendizaje

IntroductionRobotic surgery has become a safe and effective approach for the treatment of pulmonary surgical pathology. However, the adoption of new surgical techniques requires the evaluation of the learning curve. The objective of this study is to analyze the learning curve of robotic anatomical lung resections.MethodsRetrospective analysis of all robotic anatomical lung resections performed by the same surgeon between June 2018 and March 2020. The learning curve was evaluated using CUSUM charts to estimate trend changes in surgical time, surgical failure and the occurrence of post-operative cardiorespiratory complications throughout the sequence of cases.ResultsThe study included a total of 73 cases. The median duration of all complications was 120 min (interquartile range: 90-150 min), the prevalence of surgical failure was 23.29%, while 4/73 patients had any postoperative cardiorespiratory complication. Based on the CUSUM analysis, the learning curve was divided into 3 different phases: phase i (from the first to the 14th intervention), phase ii (between the 15th and 30th intervention) and phase iii (from the 31st intervention).ConclusionsThe learning curve for robotic anatomical lung resections can be divided into 3 phases. The technical competence that guarantees satisfactory perioperative outcomes was achived in phase iii from the 31st intervention.     

电针肾俞、膈俞、百会穴对拟血管性痴呆学习记忆障碍小鼠水迷宫实验的影响

目的　观察电针肾俞、膈俞、百会穴对拟血管性痴呆小鼠学习记忆障碍的影响。方法　复制脑缺血再灌注拟血管性痴呆小鼠模型 ,并电针肾俞、膈俞、百会穴 ,分别于术后 7天、15天、30天 ,与药物喜德镇对照 ,采用水迷宫法 ,记录游全程时间、错误次数。结果　造模导致了小鼠学习与记忆能力下降 ,表现为游全程时间延长 ,错误次数增加 ,且随着观察时间的延长 ,这种改变逐渐加重。电针和喜德镇均可使模型小鼠的游全程时间缩短 ,错误次数减少 ,但电针组于 7天和 30天时 ,成绩显著优于药物组。结论　电针肾俞、膈俞、百会穴对模型小鼠学习与记忆能力下降有改善和提高作用     

5-HT system and cognition

The study of 5-hydroxytryptamine (5-HT) system has benefited from the identification, classification and cloning of multiple 5-HT receptors (5-HT₁ to 5-HT₇). Growing evidence suggests that 5-HT is important in learning and memory and all its receptors might be implicated in this. Actually, 5-HT pathways, 5-HT reuptake site/transporter complex and 5-HT receptors show regional distribution in brain areas implicated in learning and memory. Likewise, the stimulation or blockade of presynaptic 5-HT_1A, 5-HT_1B, 5-HT_2A/2C and 5-HT₃ receptors, postsynaptic 5-HT_2B/2C and 5-HT₄ receptors and 5-HT uptake/transporter sites modulate these processes. Available evidence strongly suggests that the 5-HT system may be important in normal function, the treatment and/or pathogenesis of cognitive disorders. Further investigation will help to specify the 5-HT system nature involvement in cognitive processes, pharmacotherapies, their mechanisms and action sites and to determine under which conditions they could operate. In this regard, it is probable that selective drugs with agonists, neutral antagonist, agonists or inverse agonist properties for 5-HT_1A, 5-HT_1B/1D, 5-HT_2A/2B/2C, 5-HT₄ and 5-HT₇ receptors could constitute a new therapeutic opportunity for learning and memory alterations.     

学习投入对农村订单定向医学生核心能力的影响及专业承诺的调节作用

目的：探索学习投入、专业承诺对农村订单定向医学生核心能力的影响,为提升基层卫生人才队伍的质量提供理论参考。方法：通过多阶段整群抽样方法,抽取S省两所医学院校的520名农村订单定向医学生作为研究对象进行调查。采用分层回归法分析学习投入对农村订单定向医学生核心能力的影响,简单斜率检验分析专业承诺对前述两者关系的调节效应。结果：S省农村订单定向医学生核心能力总体平均得分为(3.39±0.549);学习投入对农村订单定向医学生核心能力存在显著正向影响(β=0.358),且专业承诺对前述两者关系存在调节效应,该调节效应使得学习投入对核心能力的影响变强(β=0.206)。结论：完善农村订单定向医学生培养政策,严把录取质量,加大基层基地的建设与投入,重视学生职业素质教育,提升核心能力。     

Inhibitory Effects of Eucommia ulmoides Oliv. Bark on Scopolamine-Induced Learning and Memory Deficits in Mice

Eucommia ulmoides Oliv. Bark (EUE) is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia as well as to promote longevity. In this study, we tested the effects of EUE aqueous extract in graded doses to protect and enhance cognition in scopolamine-induced learning and memory impairments in mice. EUE significantly improved the impairment of short-term or working memory induced by scopolamine in the Y-maze and significantly reversed learning and memory deficits in mice as measured by the passive avoidance and Morris water maze tests. One day after the last trial session of the Morris water maze test (probe trial session), EUE dramatically increased the latency time in the target quadrant in a dose-dependent manner. Furthermore, EUE significantly inhibited acetylcholinesterase (AChE) and thiobarbituric acid reactive substance (TBARS) activities in the hippocampus and frontal cortex in a dose-dependent manner. EUE also markedly increased brain-derived neurotrophic factor (BDNF) and phosphorylation of cAMP element binding protein (CREB) in the hippocampus of scopolamine-induced mice. Based on these findings, we suggest that EUE may be useful for the treatment of cognitive deficits, and that the beneficial effects of EUE are mediated, in part, by cholinergic signaling enhancement and/or protection.     

消旋-3-正丁基苯酞对血管性痴呆大鼠学习记忆能力的影响

目的 探讨消旋-3-正丁基苯酞(NBP)对血管性痴呆大鼠学习记忆的影响.方法 用两血管法(2VO)建立血管性痴呆(vascular dementia,VD)模型,将60只3月龄雄性Wistar大鼠随机分成VD组、假手术组和NBP组,NBP组以丁苯酞灌胃1个月,VD组和假手术组给予等量的植物油,以Morris水迷宫测试各组大鼠的学习记忆能力,HE染色观察大鼠海马区脑组织形态.结果 NBP组和假手术组和VD组的隐蔽平台逃避潜伏期[分别为(38.34±2.46)s,(14.83±3.77s),(75.74±6.33)s];原平台象限时间[分别为(26.45±4.66)s,(35.21±3.78)s,(18.67±5.39)s].与VD组相比,NBP组明显缩短隐蔽平台逃避潜伏期,增加原平台象限时间,并在HE染色中减少神经元坏死.结论 NBP能显著改善VD大鼠的学习记忆能力.

Abstract：

Objective To investigate the effect of 3-n-butylphthalide (NBP) on learning and memory abilities in vascular demensia (VD) rats. Methods VD model rats was established by two-vessel method. 60 3-month-old Wistar male rats were randomly divided into VD group, sham-operate group and NBP group. Rats in NBP group were given NBP 120 mg · kg-1 · d-1 ,VD and sham-operate group were given equal quality vegetable oil.Morris water maze was used to assess the learning and memory abilities in each group and HE staining was used to observe the hippocampus morphology of the rats. Results The escape latency in hidden plat test was( (38.34 ±2.46 ) s, ( 14.83 ± 3.77s ), ( 75.74 ± 6.33 ) s ) and the original platform quadrant time was ( ( 26.45 ± 4.66 ) s,(35.21 ±3.78)s, ( 18.67 ±5.39)s) in NBP group,sham-operate group and VD group respectively. Compared to VD group, NBP group had obviously decreased escape latency in hidden plat test, increased original platform quadrant time and distinctly decreased the necrosis of the neurons in HE dyeing. Conclusion NBP can improve the learning and memory deficits in VD rats.