Association of Long-Term Diet Quality with Hippocampal Volume: Longitudinal Cohort Study

BACKGROUND

Diet quality is associated with brain aging outcomes. However, few studies have explored in humans the brain structures potentially affected by long-term diet quality. We examined whether cumulative average of the Alternative Healthy Eating Index 2010 (AHEI-2010) score during adult life (an 11-year exposure period) is associated with hippocampal volume.

电针对老年性痴呆模型大鼠海马线粒体酶活性的影响

目的研究电针对老年性痴呆（AD）模型大鼠海码神经元线粒体酶活性的影响，从能量代谢的角度探讨电针治疗AD的部分作用机制。方法以D-半乳糖腹腔注射和Aβ1-40海马注射诱导形成的AD模型大鼠为研究对象，电针“百会”、“涌泉”穴，每日1次，连续20d。以通道式水迷宫测试学习记忆能力的变化，评价电针对AD的治疗效庸；以生化方法检测海马神经元线粒体琥珀酸脱氢酶、Na^＋ -K^＋ -ATP酶、Ca^2＋ -Mg^2＋ -ATP酶的活性。结果电针能有效改善AD模型大鼠学习记忆能力，提高线粒体琥珀酸脱氢酶、Na^＋ -K^＋ -ATP酶、Ca^2＋ -Mg^2＋ -ATP酶活性。结论电针可促进ATP的合成与分解利用，调节线粒体功能，改善AD能量代谢障碍。     

1H-MRS检测帕金森病伴轻度认知障碍患者后扣带回代谢物

目的 探讨¹H-MRS波谱技术联合线性拟合模型（LCmodel）软件在帕金森病（PD）伴认知障碍中的诊断价值。方法 选取PD患者35例（PD组）和健康体检者22名（对照组）,并根据是否伴有认知功能障碍,将PD组分为PDN亚组和PDMCI亚组。采用¹H-MRS波谱技术联合LCmodel软件获取PD组与对照组后扣带回（PCG）区域的波谱及代谢物的绝对浓度。比较2组各代谢物绝对浓度,并分析各代谢物绝对浓度与认知功能评分的相关性。结果 PDN亚组各代谢物绝对浓度与对照组差异均无统计学意义（P均>0.05）,PDMCI亚组总肌酸（tCr）、N-乙酰天门冬氨酸（NAA）、肌醇（mI）和胆碱复合物（tCho）的绝对浓度均较对照组降低（P均<0.05）;PDMCI亚组tCr绝对浓度较PDN亚组降低（P<0.05）。tCr（r=0.444,P=0.01）、谷胱甘肽（GSH;r=0.393,P=0.024）绝对浓度与MMSE评分存在相关性;tCr（r=0.367,P=0.035）、GSH（r=0.376,P=0.031）及tCho（r=0.375,P=0.031）绝对浓度与MoCA评分存在相关性。结论 ¹H-MRS技术联合LCmodel软件可定量分析PCG区域代谢物变化,有助于评估PD伴认知障碍。     

The clinical and imaging features of cerebrotendinous xanthomatosis: A case report and review of the literature

Rationale:Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid deposition disorder characterized by systemic signs and neurological dysfunction. The radiological features of CTX are infrequently summarized in the literature.Patient concerns:We described a 40-year-old male patient who repeatedly engaged in wrestling matches and presented with progressive difficulty in walking and reduced balance with egg-sized, hard, smooth, and painless masses in both ankles.Diagnosis:Neuroimaging examination showed abnormalities both supra- and infratentorially. Bilateral ankle joint magnetic resonance imaging showed bilateral xanthomata of the Achilles tendon. The diagnosis was confirmed by the detection of a sterol 27-hydroxylase gene mutation.Interventions:The patient was treated with chenodeoxycholic acid (250 mg 3 times per day).Outcomes:To date, the patient''s bilateral xanthomas of the Achilles tendon have begun to diminish, and his neurological impairment has not deteriorated further but has not yet improved.Lessons:We report a rare case of CTX and summarize the clinical and imaging features of this disease. Our findings suggest that the abnormal signals in the dentate nucleus or a long spinal cord lesion involving the central and posterior cord, combined with tendon xanthoma, are important clues for the diagnosis of CTX.     

Chronic oleoylethanolamide treatment improves spatial cognitive deficits through enhancing hippocampal neurogenesis after transient focal cerebral ischemia

Oleoylethanolamide (OEA) has been shown to have neuroprotective effects after acute cerebral ischemic injury. The aim of this study was to investigate the effects of chronic OEA treatment on ischemia-induced spatial cognitive impairments, electrophysiology behavior and hippocampal neurogenesis. Daily treatments of 30 mg/kg OEA significantly ameliorated spatial cognitive deficits and attenuated the inhibition of long-term potentiation (LTP) in the middle cerebral artery occlusion (MCAO) rat model. Moreover, OEA administration improved cognitive function in a manner associated with enhanced neurogenesis in the hippocampus. Further study demonstrated that treatment with OEA markedly increased the expressions of brain-derived neurotrophic factor (BDNF) and peroxisome proliferator-activated receptors α (PPARα). Our data suggest that chronic OEA treatment can exert functional recovery of cognitive impairments and neuroprotective effects against cerebral ischemic insult in rats via triggering of neurogenesis in the hippocampus, which supports the therapeutic use of OEA for cerebral ischemia.     

Reduced plasticity and mild cognitive impairment-like deficits after entorhinal lesions in hAPP/APOE4 mice

Mild cognitive impairment (MCI) is a clinical condition that often precedes Alzheimer disease (AD). Compared with apolipoprotein E-ε3 (APOE3), the apolipoprotein E-ε4 (APOE4) allele is associated with an increased risk of developing MCI and spatial navigation impairments. In MCI, the entorhinal cortex (EC), which is the main innervation source of the dentate gyrus, displays partial neuronal loss. We show that bilateral partial EC lesions lead to marked spatial memory deficits and reduced synaptic density in the dentate gyrus of APOE4 mice compared with APOE3 mice. Genotype and lesion status did not affect the performance in non-navigational tasks. Thus, partial EC lesions in APOE4 mice were sufficient to induce severe spatial memory impairments and synaptic loss in the dentate gyrus. In addition, lesioned APOE4 mice showed no evidence of reactional increase in cholinergic terminals density as opposed to APOE3 mice, suggesting that APOE4 interferes with the ability of the cholinergic system to respond to EC input loss. These findings provide a possible mechanism underlying the aggravating effect of APOE4 on the cognitive outcome of MCI patients.     

The hippocampal formation of two carnivore species: The feliform banded mongoose and the caniform domestic ferret

Employing cyto‐, myelo‐, and chemoarchitectural staining techniques, we analyzed the structure of the hippocampal formation in the banded mongoose and domestic ferret, species belonging to the two carnivoran superfamilies, which have had independent evolutionary trajectories for the past 55 million years. Our observations indicate that, despite the time since sharing a last common ancestor, these species show extensive similarities. The four major portions of the hippocampal formation (cornu Ammonis, dentate gyrus, subicular complex, and entorhinal cortex) were readily observed, contained the same internal subdivisions, and maintained the topological relationships of these subdivisions that could be considered typically mammalian. In addition, adult hippocampal neurogenesis was observed in both species, occurring at a rate similar to that observed in other mammals. Despite the overall similarities, several differences to each other, and to other mammalian species, were observed. We could not find evidence for the presence of the CA2 and CA4 fields of the cornu Ammonis region. In the banded mongoose the dentate gyrus appears to be comprised of up to seven lamina, through the sublamination of the molecular and granule cell layers, which is not observed in the domestic ferret. In addition, numerous subtle variations in chemoarchitecture between the two species were observed. These differences may contribute to an overall variation in the functionality of the hippocampal formation between the species, and in comparison to other mammalian species. These similarities and variations are important to understanding to what extent phylogenetic affinities and constraints affect potential adaptive evolutionary plasticity of the hippocampal formation.     

Neural modelling of the semantic predictability gain under challenging listening conditions

When speech intelligibility is reduced, listeners exploit constraints posed by semantic context to facilitate comprehension. The left angular gyrus (AG) has been argued to drive this semantic predictability gain. Taking a network perspective, we ask how the connectivity within language‐specific and domain‐general networks flexibly adapts to the predictability and intelligibility of speech. During continuous functional magnetic resonance imaging (fMRI), participants repeated sentences, which varied in semantic predictability of the final word and in acoustic intelligibility. At the neural level, highly predictable sentences led to stronger activation of left‐hemispheric semantic regions including subregions of the AG (PGa, PGp) and posterior middle temporal gyrus when speech became more intelligible. The behavioural predictability gain of single participants mapped onto the same regions but was complemented by increased activity in frontal and medial regions. Effective connectivity from PGa to PGp increased for more intelligible sentences. In contrast, inhibitory influence from pre‐supplementary motor area to left insula was strongest when predictability and intelligibility of sentences were either lowest or highest. This interactive effect was negatively correlated with the behavioural predictability gain. Together, these results suggest that successful comprehension in noisy listening conditions relies on an interplay of semantic regions and concurrent inhibition of cognitive control regions when semantic cues are available.     

Probing the role of the right inferior frontal gyrus during Pain‐Related empathy processing: Evidence from fMRI and TMS

Recent studies have suggested that the right inferior frontal gyrus (rIFG) may be involved in pain‐related empathy. To verify the role of the rIFG, we performed a functional magnetic resonance imaging (fMRI) experiment to replicate previous research and further designed a noninvasive repetitive transcranial magnetic stimulation (rTMS) experiment to probe the causal role of the rIFG in pain‐related empathy processing. We assigned 74 volunteers (37 females) to three groups. Group 1 (n = 26) performed a task in which participants were required to perceive pain in others (task of pain: TP) and we used fMRI to observe the activity of the rIFG during pain‐related empathy processing. Then, we applied online rTMS to the rIFG and the vertex site (as reference site) to observe the performance of Group 2 (n = 24; performing TP) and Group 3 (n = 24; performing a control task of identifying body parts; task of body: TB). fMRI experiment demonstrated stronger activation in the rIFG than in the vertex during the perception of pain in others (p < .0001, Bonferroni‐corrected). rTMS experiment indicated that when the rIFG was temporarily disrupted, participants perceived pain in others significantly more slowly (p < .0001, Bonferroni‐corrected) than when the vertex was disrupted. Our results provide evidence that the rIFG is involved in pain‐related empathy processing, which yields insights into how the brain perceives pain in others.     

海马微环境对细胞分化和极性化的影响

目的 观察海马脑片微环境对不同分化程度细胞的极性和分化的影响。方法 将小鼠的海马脑片与5种不同分化程度的细胞（肝癌细胞、正常肝脏细胞、PC12细胞、正常神经细胞和骨髓间充质干细胞）进行共同培养,观察细胞的分化和极性产生情况。结果 与对照组相比,与海马脑片共培养的细胞数量明显减少。共培养的细胞在海马脑片上的分布有一定的规律,主要集中锥体细胞层和颗粒细胞层,其他地方分布均匀,类似于脑片片层化的构筑。海马微环境下低分化的细胞受海马脑片微环境的影响可以产生极性并分化,高分化的细胞不能产生极性。 结论 海马微环境对细胞的极性和分化有促进作用,对生长和分裂有抑制作用,细胞的极性变化与自身和所处的微环境有关,特别对低分化的细胞极性和分化的影响较大。