Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to t...Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to the destabilization of microtubules, is central to the pathogenesis of Alzheimer’s disease. This is accompanied by morphological defects across the somatodendritic compartment, axon, and synapse. However, knowledge of what occurs to the microtubule cytoskeleton and morphology of the neuron during physiological aging is comparatively poor. Several recent studies have suggested that there is an age-related increase in the phosphorylation of the key microtubule stabilizing protein tau, a modification, which is known to destabilize the cytoskeleton in Alzheimer’s disease. This indicates that the cytoskeleton and potentially other neuronal structures reliant on the cytoskeleton become functionally compromised during normal physiological aging. The current literature shows age-related reductions in synaptic spine density and shifts in synaptic spine conformation which might explain age-related synaptic functional deficits. However, knowledge of what occurs to the microtubular and actin cytoskeleton, with increasing age is extremely limited. When considering the somatodendritic compartment, a regression in dendrites and loss of dendritic length and volume is reported whilst a reduction in soma volume/size is often seen. However, research into cytoskeletal change is limited to a handful of studies demonstrating reductions in and mislocalizations of microtubule-associated proteins with just one study directly exploring the integrity of the microtubules. In the axon, an increase in axonal diameter and age-related appearance of swellings is reported but like the dendrites, just one study investigates the microtubules directly with others reporting loss or mislocalization of microtubule-associated proteins. Though these are the general trends reported, there are clear disparities between model organisms and 展开更多
Sparse labeling of neurons contributes to uncovering their morphology, and rapid expression of a fluorescent protein reduces the experiment range. To achieve the goal of rapid and sparse labeling of neurons in vivo, w...Sparse labeling of neurons contributes to uncovering their morphology, and rapid expression of a fluorescent protein reduces the experiment range. To achieve the goal of rapid and sparse labeling of neurons in vivo, we established a rapid method for depicting the fine structure of neurons at 24 h post-infection based on a mutant viruslike particle of Semliki Forest virus. Approximately 0.014 fluorescent focus-forming units of the mutant virus-like particle transferred enhanced green fluorescent protein into neurons in vivo, and its affinity for neurons in vivo was stronger than for neurons in vitro and BHK21(baby hamster kidney) cells. Collectively, the mutant virus-likeparticle provides a robust and convenient way to reveal the fine structure of neurons and is expected to be a helper virus for combining with other tools to determine their connectivity. Our work adds a new tool to the approaches for rapid and sparse labeling of neurons in vivo.展开更多
Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure o...Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure on brain and behavior,little is known about the mechanisms that may underlie those effects,and even less about treatments that might reverse them.Recent studies from our laboratory have indicated that AIE produced enduring changes in astrocyte function and synaptic activity in the hippocampal formation,suggesting the possibility of an alteration in astrocyte-neuronal connectivity and function.We utilized astrocyte-specific,membrane restricted viral labeling paired with immunohistochemistry to perform confocal single cell astrocyte imaging,three-dimensional reconstruction,and quantification of astrocyte morphology in hippocampal area CA1 from adult rats after AIE.Additionally,we assessed the colocalization of astrocyte plasma membrane labeling with immunoreactivity for AMPA-(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)glutamate receptor 1,an AMPA receptor subunit and established neuronal marker of excitatory synapses,as a metric of astrocyte-synapse proximity.AIE significantly reduced the colocalization of the astrocyte plasma membrane with synaptic marker puncta in adulthood.This is striking in that it suggests not only an alteration of the physical association of astrocytes with synapses by AIE,but one that lasts into adulthood-well after the termination of alcohol exposure.Perhaps even more notable,the AIE-induced reduction of astrocyte-synapse interaction was reversed by sub-chronic treatment with the clinically used agent,gabapentin(Neurontin),in adulthood.This suggests that a medication in common clinical use may have the potential to reverse some of the enduring effects of adolescent alcohol exposure on brain function.All animal experiments conducted were approved by the Duke University Institutional Animal Care and Use Committee(Protocol Registry Number A159-18-07)on July 27,2018.展开更多
Therapies that complement free radical scavenging are an important approach for treating aging in the brain. In the present study, two formulations of moxa cone moxibustion were applied at acupoints Zusanfi （ST 36） ...Therapies that complement free radical scavenging are an important approach for treating aging in the brain. In the present study, two formulations of moxa cone moxibustion were applied at acupoints Zusanfi （ST 36） and Xuanzhong （GB 39）, and at acupoints Baihui （DU 20） and Guanyuan （RN 4）, in D-galactose-induced senile mice. The results revealed that moxa cone moxibustion improved total superoxide dismutase and Cu/Zn-superoxide dismutase activity in the homogenates of the cerebral tissue, as well as ameliorating deficits in neuronal morphology and neuronal density in the cerebral cortex and hippocampal CA3. Moxa cone moxibustion also enhanced learning and memory functions of senile mice. Moxa cone moxibustion at Zusanli, Xuanzhong, Baihuiand Guanyuan acupoints can thus be used to complement free radical scavengers, with efficacy that is equal to that of electroacupuncture at Zusanliand Xuanzhong, and superior to that of nimodipine treatment.展开更多
We have previously shown that both acute and chronic ethanol treatment depresses neural activity, specifically in the cingulate cortex. Minor influences were found in the motor cortex. The acute effect of ethanol in t...We have previously shown that both acute and chronic ethanol treatment depresses neural activity, specifically in the cingulate cortex. Minor influences were found in the motor cortex. The acute effect of ethanol in the hippocampus was intermediate to those in the cingulate and motor cortices. In the present study, we concentrate on the chronic effects of ethanol on the hippocampus. We demonstrate how the neuronal activity underlying food-acquisition behavior is modified after chronic ethanol treatment, and how the hippocampus subserves formation of newly-formed alcohol-acquisition behavior. Neuronal activity in CA1 was more sensitive to chronic ethanol than the Dg area. Acute administration of ethanol had a normalizing effect on the chronically-treated animals: their performance and the hippocampal neural activity approached a normal range. The sets of neurons involved in food-acquisition behavior formed before chronic ethanol treatment, and those involved in alcohol-acquisition behavior formed after treatment significantly overlapped supporting the view that the neuronal mechanisms of pre-existing behavior provide the basis for the formation of new behavior. Additionally, we also discovered alcohol-acquisition selective neurons. Assuming that the formation of new neuronal specializations underlies learning, we believe that alcohol-selective neurons are specialized during the formation of alcohol-acquisition behavior. Our data demonstrate several new findings on the effect of acute and chronic ethanol on hippocampus activity, and how the neuronal activity relates to behavior before and after ethanol treatment.展开更多
基金funded by the Gerald Kerkut Charitable Trust (GKT)(to BR)
文摘Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to the destabilization of microtubules, is central to the pathogenesis of Alzheimer’s disease. This is accompanied by morphological defects across the somatodendritic compartment, axon, and synapse. However, knowledge of what occurs to the microtubule cytoskeleton and morphology of the neuron during physiological aging is comparatively poor. Several recent studies have suggested that there is an age-related increase in the phosphorylation of the key microtubule stabilizing protein tau, a modification, which is known to destabilize the cytoskeleton in Alzheimer’s disease. This indicates that the cytoskeleton and potentially other neuronal structures reliant on the cytoskeleton become functionally compromised during normal physiological aging. The current literature shows age-related reductions in synaptic spine density and shifts in synaptic spine conformation which might explain age-related synaptic functional deficits. However, knowledge of what occurs to the microtubular and actin cytoskeleton, with increasing age is extremely limited. When considering the somatodendritic compartment, a regression in dendrites and loss of dendritic length and volume is reported whilst a reduction in soma volume/size is often seen. However, research into cytoskeletal change is limited to a handful of studies demonstrating reductions in and mislocalizations of microtubule-associated proteins with just one study directly exploring the integrity of the microtubules. In the axon, an increase in axonal diameter and age-related appearance of swellings is reported but like the dendrites, just one study investigates the microtubules directly with others reporting loss or mislocalization of microtubule-associated proteins. Though these are the general trends reported, there are clear disparities between model organisms and
基金supported by the National Natural Science Foundation of China(31771197,31830035 and 91732304)the National Basic Research Development Program(973 Program)of China(2015CB755600)+2 种基金the Strategic Priority Research Program(B)Chinese Academy of Sciences,China(XDBS01030200)the Major Research Plan of the National Natural Science Foundation of China(91632303)
文摘Sparse labeling of neurons contributes to uncovering their morphology, and rapid expression of a fluorescent protein reduces the experiment range. To achieve the goal of rapid and sparse labeling of neurons in vivo, we established a rapid method for depicting the fine structure of neurons at 24 h post-infection based on a mutant viruslike particle of Semliki Forest virus. Approximately 0.014 fluorescent focus-forming units of the mutant virus-like particle transferred enhanced green fluorescent protein into neurons in vivo, and its affinity for neurons in vivo was stronger than for neurons in vitro and BHK21(baby hamster kidney) cells. Collectively, the mutant virus-likeparticle provides a robust and convenient way to reveal the fine structure of neurons and is expected to be a helper virus for combining with other tools to determine their connectivity. Our work adds a new tool to the approaches for rapid and sparse labeling of neurons in vivo.
基金supported by the National Institute on Alcohol Abuse and Alcoholism(NIAAA)Neurobiology of Adolescent Drinking In Adulthood(NADIA)Grant#2U01AA019925(to HSS)the National Institute on Alcohol Abuse and Alcoholism(NIAAA)R00AA022651(to TAW)the National Institute on Drug Abuse(NIDA)R01DA041455(to KJR)
文摘Adolescent alcohol abuse is a substantive public health problem that has been the subject of intensive study in recent years.Despite reports of a wide range of effects of adolescent intermittent ethanol(AIE)exposure on brain and behavior,little is known about the mechanisms that may underlie those effects,and even less about treatments that might reverse them.Recent studies from our laboratory have indicated that AIE produced enduring changes in astrocyte function and synaptic activity in the hippocampal formation,suggesting the possibility of an alteration in astrocyte-neuronal connectivity and function.We utilized astrocyte-specific,membrane restricted viral labeling paired with immunohistochemistry to perform confocal single cell astrocyte imaging,three-dimensional reconstruction,and quantification of astrocyte morphology in hippocampal area CA1 from adult rats after AIE.Additionally,we assessed the colocalization of astrocyte plasma membrane labeling with immunoreactivity for AMPA-(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)glutamate receptor 1,an AMPA receptor subunit and established neuronal marker of excitatory synapses,as a metric of astrocyte-synapse proximity.AIE significantly reduced the colocalization of the astrocyte plasma membrane with synaptic marker puncta in adulthood.This is striking in that it suggests not only an alteration of the physical association of astrocytes with synapses by AIE,but one that lasts into adulthood-well after the termination of alcohol exposure.Perhaps even more notable,the AIE-induced reduction of astrocyte-synapse interaction was reversed by sub-chronic treatment with the clinically used agent,gabapentin(Neurontin),in adulthood.This suggests that a medication in common clinical use may have the potential to reverse some of the enduring effects of adolescent alcohol exposure on brain function.All animal experiments conducted were approved by the Duke University Institutional Animal Care and Use Committee(Protocol Registry Number A159-18-07)on July 27,2018.
基金Scientific Research Projects of Education Bureau of Guangxi Zhuang Autonomous Region,No.200710LX022the Natural Science Foundation of Guangxi Zhuang Autonomous Region,No.0832170
文摘Therapies that complement free radical scavenging are an important approach for treating aging in the brain. In the present study, two formulations of moxa cone moxibustion were applied at acupoints Zusanfi （ST 36） and Xuanzhong （GB 39）, and at acupoints Baihui （DU 20） and Guanyuan （RN 4）, in D-galactose-induced senile mice. The results revealed that moxa cone moxibustion improved total superoxide dismutase and Cu/Zn-superoxide dismutase activity in the homogenates of the cerebral tissue, as well as ameliorating deficits in neuronal morphology and neuronal density in the cerebral cortex and hippocampal CA3. Moxa cone moxibustion also enhanced learning and memory functions of senile mice. Moxa cone moxibustion at Zusanli, Xuanzhong, Baihuiand Guanyuan acupoints can thus be used to complement free radical scavengers, with efficacy that is equal to that of electroacupuncture at Zusanliand Xuanzhong, and superior to that of nimodipine treatment.
文摘We have previously shown that both acute and chronic ethanol treatment depresses neural activity, specifically in the cingulate cortex. Minor influences were found in the motor cortex. The acute effect of ethanol in the hippocampus was intermediate to those in the cingulate and motor cortices. In the present study, we concentrate on the chronic effects of ethanol on the hippocampus. We demonstrate how the neuronal activity underlying food-acquisition behavior is modified after chronic ethanol treatment, and how the hippocampus subserves formation of newly-formed alcohol-acquisition behavior. Neuronal activity in CA1 was more sensitive to chronic ethanol than the Dg area. Acute administration of ethanol had a normalizing effect on the chronically-treated animals: their performance and the hippocampal neural activity approached a normal range. The sets of neurons involved in food-acquisition behavior formed before chronic ethanol treatment, and those involved in alcohol-acquisition behavior formed after treatment significantly overlapped supporting the view that the neuronal mechanisms of pre-existing behavior provide the basis for the formation of new behavior. Additionally, we also discovered alcohol-acquisition selective neurons. Assuming that the formation of new neuronal specializations underlies learning, we believe that alcohol-selective neurons are specialized during the formation of alcohol-acquisition behavior. Our data demonstrate several new findings on the effect of acute and chronic ethanol on hippocampus activity, and how the neuronal activity relates to behavior before and after ethanol treatment.
基金国家自然科学基金委员会创新研究群体科学基金(61721092)国家自然科学基金(81327802+4 种基金81771913)国家重点基础研究发展计划(973)(2015CB7556003)湖北省中青年创新研究群体科学基金(T201520)武汉光电国家研究中心主任基金(Wuhan National Laboratory for OptoelectronicsWNLO)资助项目~~
