Meta-analysis of brain structural changes after electroconvulsive therapy in depression

BackgroundIncreases in the volume of the amygdala and hippocampus after electroconvulsive therapy (ECT) are among the most robust effects known to the brain-imaging field. Recent advances in the segmentation of substructures of these regions allow for novel insights on the relationship between brain structure and clinical outcomes of ECT.ObjectiveWe aimed to provide a comprehensive synthesis of evidence available on changes in brain structure after ECT, including recently published data on hippocampal subfields.MethodsA meta-analysis of published studies was carried out using random-effects models of standardized mean change of regional brain volumes measured with longitudinal magnetic resonance imaging of depressive patients before and after a series of ECT.ResultsData from 21 studies (543 depressed patients) were analysed, including 6 studies (118 patients) on hippocampal subfields. Meta-analyses could be carried out for seven brain regions for which data from at least three published studies was available. We observed increases in left and right hippocampi, amygdalae, cornua ammonis (CA) 1, CA 2/3, dentate gyri (DG) and subicula with standardized mean change scores ranging between 0.34 and 1.15. The model did not reveal significant volume increases in the caudate. Meta-regression indicated a negative relationship between the reported increases in the DG and relative symptom improvement (−0.27 (SE: 0.09) per 10%).ConclusionsECT is accompanied by significant volume increases in the bilateral hippocampus and amygdala that are not associated with treatment outcome. Among hippocampal subfields, the most robust volume increases after ECT were measured in the dentate gyrus. The indicated negative correlation of this effect with antidepressant efficacy warrants replication in data of individual patients.     

角类动物药DNA提取方法研究

目的建立角类动物药材的DNA提取方法,使提取的DNA质量满足PCR及测序要求,同时可用于陈旧动物角类样品的DNA提取。方法为避免取骨塞部位用EDTA脱钙造成DNA提取不完全或DNA被破坏,取角质层部位,采用二硫苏糖醇(DTT)结合化学试剂盒中的细胞裂解液及蛋白酶K处理角质层样本,其余按试剂盒操作提取DNA。考察了取样量、DTT用量对角质部位DNA质量的影响。结果确定了取样量为25 mg,DTT用量为20μL,角质细胞裂解完全,所有样品的DNA质量均可满足PCR要求。结论建立的DNA提取方法,提取DNA完全,可标准化操作,可应用于多种动物角的提取。     

Studies on the hippocampal formation: From basic development to clinical applications: Studies on schizophrenia

The hippocampal formation plays a critical role in cognitive function. The developmental events that shape the hippocampal formation are continuing to be elucidated and their implications for brain function are emerging as well as applying those advances to interventions that have important possibilities for the treatment of brain dysfunction. The story told in this chapter is about the use of the in oculo transplant method to illuminate intrinsic and extrinsic features that underlie the development of the dentate gyrus and adjacent hippocampus and the role of one molecule in the hippocampus and schizophrenia. Schizophrenia, originally conceptualized as a dysfunction in dopaminergic neurotransmission, is now known to involve multiple neuronal systems. Dysfunction of hippocampal neurons is emerging as one of its signature pathological features. Basic insights into the development and function of hippocampal interneurons form the basis of a new treatment initiative for this illness. Evidence for the role of the alpha 7-nicotinic acetylcholine receptor in the development and function of these neurons in rodents has led to human trials of nicotinic agonists for cognitive dysfunction in schizophrenia and the possibility of improving hippocampal development in children at risk for schizophrenia by perinatal supplementation with choline, which can act as an alpha 7-nicotinic acetylcholine receptor agonist.     

角类动物药质量控制模式与方法的创新和发展

通过述评角类动物药质量控制模式与方法 的现状,针对角类动物药本身的特点进行分析,探索从生物鉴定的角度建立角类动物药质量控制模式和方法 的可行性,并提出基于外观鉴别-物性鉴定-化学组分分析-生物效价检测序贯分析的角类动物药质量控制模式,为从根本上解决长期制约角类动物药发展的瓶颈问题,创建一套有效的内在质量控制方法 提供新的理论依据与技术支撑.     

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.     

盐酸林可霉素的萃取与结晶提纯

为了降低盐酸林可霉素粗品中的B组分含量,采用萃取与结晶相结合的方法,分别研究了萃取结晶过程中萃取剂种类、用量、原料浓度、溶液pH等条件以及溶析结晶过程中的混合速率对产品纯度的影响。结果表明：丁醇或氯仿有较高的萃取效率;降低原料浓度或在萃取、反萃时分别保持溶液pH为11和5均有利于提高产品中的A组分含量;结晶过程中提高搅拌速率有利于提高产品纯度。以氯仿为萃取剂,经过单级萃取,结晶后产品中A组分纯度最高可达97.86%。     

Post-ischemic administration of nimodipine following focal cerebral ischemic-reperfusion injury in rats alleviated excitotoxicity, neurobehavioural alterations and partially the bioenergetics

The present study focuses on the temporal calcium significance in middle cerebral artery occluded (2 h ischemia)-reperfused (70 h reperfusion) rats treated with nimodipine (NM) through concurrent measurements of excitotoxicity, bioenergetics and neurobehavioural paradigms. Further, the suitable therapeutic time window of calcium channel antagonism in stroke was also ascertained. NM (5 mg/kg, i.p.) was administered at pre (30 min before the induction of ischemia), during (1 h following occlusion of MCA) and post-ischemic (3 h after begin of reperfusion) states. The magnitude of neuroprotection in terms of excitotoxicity (glutamate, glutamine synthetase, Na⁺K⁺ATPase), bioenergetics (ATP, NAD⁺) and neurobehavioural paradigms (neurological score and open field exploratory behaviour) were measured and compared to ensure the therapeutic time-window of NM in stroke. Middle cerebral artery occlusion-reperfusion (MCAO/R) was found to elevate glutamate, glutamine synthetase levels and deplete Na⁺K⁺ATPase activity in the vehicle treated group (IR group). Significant decrease in bioenergetics such as ATP and NAD⁺ levels was also observed. Further, IR group demonstrated grievous oxidative stress (increase in lipid peroxidation, protein carbonyl content, nitrite/nitrate levels and decrease in superoxide dismutase and glutathione levels) along with anxiogenic behaviour, neurological deficits and neuronal damage and decreased nuclear to cytoplasm ratio in CA1 hippocampal region. Post-ischemic NM administration reversed the excitotoxicity, neurobehavioural and histopathological alterations significantly, but it restored bioenergetics level in MCAO/R rats only partially.These findings were further confirmed with the combination treatment (CT) of post-ischemic NM and pre-ischemic memantine (MN) administration, since MN showed protective effect in the pre-ischemic administration (Babu and Ramanathan, 2009). The failure of NM to forefend the neurodegeneration on pre- and during-ischemic administration suggests that the initial phase damages in ischemic-reperfusion (IR) might be mediated through other mechanism(s) such as glutamergic overstimulation or reverse operation of glutamate transporters. From the present study, it is concluded that calcium plays a crucial role in post-ischemic status and the suitable therapeutic time window of calcium antagonism is the post-ischemic state.     

Beyond faithful conduction: short-term dynamics, neuromodulation, and long-term regulation of spike propagation in the axon

Most spiking neurons are divided into functional compartments: a dendritic input region, a soma, a site of action potential initiation, an axon trunk and its collaterals for propagation of action potentials, and distal arborizations and terminals carrying the output synapses. The axon trunk and lower order branches are probably the most neglected and are often assumed to do nothing more than faithfully conducting action potentials. Nevertheless, there are numerous reports of complex membrane properties in non-synaptic axonal regions, owing to the presence of a multitude of different ion channels. Many different types of sodium and potassium channels have been described in axons, as well as calcium transients and hyperpolarization-activated inward currents. The complex time- and voltage-dependence resulting from the properties of ion channels can lead to activity-dependent changes in spike shape and resting potential, affecting the temporal fidelity of spike conduction. Neural coding can be altered by activity-dependent changes in conduction velocity, spike failures, and ectopic spike initiation. This is true under normal physiological conditions, and relevant for a number of neuropathies that lead to abnormal excitability. In addition, a growing number of studies show that the axon trunk can express receptors to glutamate, GABA, acetylcholine or biogenic amines, changing the relative contribution of some channels to axonal excitability and therefore rendering the contribution of this compartment to neural coding conditional on the presence of neuromodulators. Long-term regulatory processes, both during development and in the context of activity-dependent plasticity may also affect axonal properties to an underappreciated extent.