Name: a hydrophobic tissue clearing method for rat brain tissue
Uploaded: 2020-12-23T15:00:00
Description: Watch this Scientific Journal Video about A Hydrophobic Tissue Clearing Method for Rat Brain Tissue at JoVE.com

이 작품은 NIH 보조금에 의해 지원되었다: NS100624, DA013137, HD043680, MH106392 및 T32 교육 보조금 5T32GM081740

모든 동물 프로토콜은 사우스 캐롤라이나 대학의 동물 관리 및 사용 위원회에 의해 검토되고 승인되었습니다.
1. 주식 솔루션 준비
<ol><li>용액 1 (1 L): 900 mL의 탈이온화 H2O는 10배 인산완충식식염(PBS)과 트리톤 X-1002mL의 100mL를 추가한다.</li>
	<li>솔루션 2 (1 L): 900 mL의 deionized H2O, 10x PBS의 100 mL, 20 tween-20의 2mL 및 10 mg / mL Heparin 재고 용액의 1 mL을 추가하십시오.</li>
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조직 정리는 기존의 IHC 프로토콜의 한계에 대한 해결책을 제공합니다. 투명한 시료는 빛의 산란과 흡수를 최소화하여,18,19의그대로 조직에 대한 세포 수준 광학 액세스를 제공한다. 조직 클리어링 기술은 용매의 투여와 함께 탈색, 탈색 및 탈화를 통해 조직을 투명하게 돌립니다. 조직 샘플의 굴절률이 선택한 이미징 매체의 굴절률과 일치하면 샘플이 ?...

여러 조직 클리어링 기술은 뇌의 사용을 위해 검증되었습니다: 소수겔, 친수성 및 소수성. 이러한 기술은 용매의 투여를 통해 탈색, 탈색 및 탈화를 통해 조직을 투명하게 전환하는 것을 목표로 합니다. 조직 샘플의 굴절률이 선택한 이미징 매체의 굴절률과 일치하면 시료의 명확한 이미지를 얻을 수 있습니다. CLARITY와 같은 하이드로겔 기반 기술은 아크릴 기반 하이드로겔에 연결하여 조직 내 생체 분자를 확보하여 단백질1의구조적 손상 과 손실을 방지합니다. 그러나 하이드로겔 기술은 더 연약한 조직을 손상시킬 수 있는 가능성이 있는 것보다 가혹한 화학 물질을 이용하며, 조밀한 조직 샘플은 하이드로겔 프로토콜과 호환되지 않을 수 있습니다. 특정 하이드로겔 기술은 고가의 장비가 필요하거나 조직 팽창으로 이어질 수 있습니다. 큐빅과 같은 친수성 기술은 조직2내의 수소 결합 형성을 통해 3D 구조를 보존한다. 조직 확장은 또한 특정 친수성 프로토콜에서 발생할 수 있습니다. 친성 기종의 청산 능력은 종종 소수성 기술이 가지고있는 능력과 일치하지 않으며, 이는 조밀하고 두꺼운 조직에 중요하다3.
소수성 기술은 일반적으로 빠르며 특수 장비가 필요하지 않으며 취급 및 보관이 쉬운 샘플을 생성합니다. iDISCO는 다른 소수성 프로토콜에서 발생할 수 있는 수축을 제거하는 소수성 기술입니다. 원래, iDISCO 조직 청산 기술은 쥐의 배아 및 조밀한, 성인 장기에 대한 Renier 외4에 의해 설명되었다. 이 기술은 초기 탈수 단계에서 조직에서 물을 제거하여 빛 산란을 줄입니다. 조직은 깊은 항체 침투를 허용하기 위하여 전처리 도중 permeabilized됩니다. 극한 스펙트럼에서 알렉사 플루오 염료는 낮은 파장5에서조직의 자가 불화를 피하기 위해 면역 라벨링에 사용된다. 소수성 청산 프로토콜을 거친 조직은 쉽게 처리될 수 있으며 Alexa Fluor 염료의 수명으로 인해 여러 번 이미지화될 수 있습니다. 제대로 저장하면 조직은 초기 처리 후 몇 달에서 1 년 동안 이미지를 제공 할 수 있습니다.
본 프로토콜에서 티로신 하이드록실라제(TH) 항체, 이바1 항체 및 콜레라 톡신 서브유닛 B(CTB)는 남성과 여성 제어 및 HIV-1 형질(Tg) 쥐 뇌 모두에 사용되었다. HIV-1 Tg 랫트는 HIV-1 바이러스 게놈을 구성하는 9개의 유전자 중 7개를 가지고 있으며, 이는 장기 HIV-1 단백질 노출6,7,8의비감염성 모델로 이어진다. 도파민성 변화는 이전에 HIV-1 Tg 랫트에서 입증되었으며, HIV-1 자체는 염증성 질환이므로 항체 선택은 실험 설계9,10,11,12와관련이 있었다. CTB는 신경질 옆 바인딩을 통해 뉴런에 부착하고 뇌의 포퍼런트 프로젝션을 추적하는 데 사용할 수있는 추적자입니다. CTB는 이전에 핵 accumbens에서 실질적인 니그라 영역, 도파민 경로와 크게 관련된 뇌의 두영역(13,14,15)에대한 투영을 연구하는 데 사용되었습니다.
이 프로토콜에서 TH는 도파민 생산을 위한 마커 역할을 하며, Iba1은 활성화된 마이크로글리아를 표시합니다. TH 항체는 티로신 하이드록실라제에 해당하는 약 62kDa에서 단일 대역에 선택적으로 라벨을 부착하는 데 사용되었습니다. Iba1 항체는 Iba1 카복시-말단 서열에 해당한다. 두 항체는 토끼에서 자랐고 폴리클론이었다. CTB는 핵 accumbens 영역에서 실질적인 니그라 영역까지 뉴런의 역행 추적에 사용됩니다. 현재 프로토콜은 또한 두 가지 방법으로 원래 iDISCO 프로토콜의 조정을 위한 지침을 제공합니다: 1) 차단 단계에서 혈청 시약을 변경하여 배경 염색의 전반적인 감소, 그리고 2) 큰 조직 샘플에 적합 하도록 인큐베이션 시간의 스케일링. 전반적으로, 본 프로토콜은 소수성 청산 기술이 쥐의 뇌 조직에서 실현 가능하고, HIV-1 바이러스 성 단백질과 눈에 띄는 해로운 상호 작용이 없으며, TH 항체, Iba1 항체 및 CTB와 호환된다는 지속적인 증거를 제공합니다.

<table>
	<tbody>
		<tr>
			<td>Cholera Toxin Subunit B (Recombinant), Alexa Fluor 488</td>
			<td>Invitrogen</td>
			<td>C34775</td>
			<td></td>
		</tr>
		<tr>
			<td>DBE</td>
			<td>Sigma-Aldrich</td>
			<td>108014-1KG</td>
			<td></td>
		</tr>
		<tr>
			<td>DCM</td>
			<td>Sigma-Aldrich</td>
			<td>270997-100mL</td>
			<td></td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>Sigma-Aldrich</td>
			<td>472301-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycine</td>
			<td>Fisher Chemical</td>
			<td>G46-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-rabbit Alexa Fluor Plus 647</td>
			<td>Invitrogen</td>
			<td>A32733</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat serum</td>
			<td>Sigma Life Science</td>
			<td>G9023-10mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Acros Organics</td>
			<td>41121-0010</td>
			<td></td>
		</tr>
		<tr>
			<td>Iba1 primary antibody</td>
			<td>FUJIFILM Wako</td>
			<td>019-19741</td>
			<td></td>
		</tr>
		<tr>
			<td>Kwik-sil epoxy</td>
			<td>VWR</td>
			<td>70730-062</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma-Aldrich</td>
			<td>34860-1l-R</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Fisher Bioreagents</td>
			<td>BP2944-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Perfusion machine</td>
			<td>VWR</td>
			<td>70730-062</td>
			<td>mini pump variable flow</td>
		</tr>
		<tr>
			<td>PFA</td>
			<td>Sigma-Aldrich</td>
			<td>158127-3KG</td>
			<td></td>
		</tr>
		<tr>
			<td>TH primary antibody</td>
			<td>Millipore Sigma</td>
			<td>AB152</td>
			<td></td>
		</tr>
		<tr>
			<td>TritonX-100</td>
			<td>Fisher Bioreagents</td>
			<td>BP151-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween-20</td>
			<td>Fisher Bioreagents</td>
			<td>BP337-500</td>
			<td></td>
		</tr>
	</tbody>
</table>

a hydrophobic tissue clearing method for rat brain tissue

소수성 조직 청산 방법은 변경되지 않은 조직 샘플에 대한 관심 분자의 연구를 허용하는 쉽게 조절 가능하고 빠르며 저렴한 절차입니다. 기존의 면역 라벨링 절차는 샘플을 얇은 섹션으로 절단해야 하므로 손상되지 않은 구조물에 라벨을 부착하고 검사하는 기능이 제한됩니다. 그러나, 뇌 조직이 처리 하는 동안 그대로 남아 있는 경우, 구조 및 회로 분석을 위해 그대로 남아 있습니다. 이전에 확립 된 클리어링 방법은 조직을 완전히 지우는 데 상당한 시간이 걸리며 가혹한 화학 물질은 종종 민감한 항체를 손상시킬 수 있습니다. iDISCO 방법은 조직을 신속하고 완전히 지우고 많은 항체와 호환되며 특별한 실험실 장비가 필요하지 않습니다. 이 기술은 마우스 조직에서 사용하기 위해 처음에 검증되었지만 현재 프로토콜은 이 방법을 제어 및 형질 전환 쥐 뇌의 이미지 반구에 적응시합니다. 이 외에도 현재 프로토콜은 기존 프로토콜을 여러 번 조정하여 배경 염색이 적은 선명한 이미지를 제공합니다. 이바-1 및 티로신 하이드록실라제에 대한 항체는 HIV-1 형질전환 쥐및 F344/N 대조군 쥐에서 현재소수성 조직 청산 방법을 사용하여 검증되었다. 뇌는 서로 분리된 것보다 구조가 더 자주 함께 작동하는 얽힌 네트워크입니다. 개별 조각의 조합반대로 전체 시스템으로 뇌를 분석하는 것은이 전체 뇌 청산 방법의 가장 큰 이점입니다.

F344/N 과 HIV-1 쥐 뇌 조직의 큰 부분을 완전히 지우는 이 변형된 소수성 조직 청산 프로토콜을 사용하여 달성되었다. 도 1은 실질적인 니그라 영역에서 TH에 대한 일반적인 공초점 이미지를 표시한다. 도 1A는 조밀하고 양적인 염색을 나타냅니다. 이와 같은 조밀한 영역은 "Z" 평면을 통해 초점을 맞추어 양성 염색 및 적절한 세포 형태를 확인함으로써 구문...

Watch this Scientific Journal Video about A Hydrophobic Tissue Clearing Method for Rat Brain Tissue at JoVE.com

A Hydrophobic Tissue Clearing Method for Rat Brain Tissue

여기서 우리는 손상되지 않은 뇌 구조의 일환으로 표적 분자의 보기를 허용하는 소수성 조직 청산 방법을 제시합니다. 이 기술은 지금 F344/N 통제 및 두 남녀의 HIV-1 형질전환 쥐를 위해 검증되었습니다.

쥐 뇌 조직을 위한 소수성 조직 청산 방법

Hydrophobic tissue clearing methods are easily adjustable, fast, and low-cost procedures that allows for the study of a molecule of interest in unaltered ...

The overall goal of this clearing technique is to establish a tissue clearing method for the rat brain. This protocol can also be used for the HIV-1 transgenic rat. The main advantage of this technique is that the rat brain tissue can be left intact for clearing thus allowing for full circuit level analysis.Demonstrating the procedure will be Kristin Kirchner, a PhD candidate from my laboratory, and also Hailong Li, a research associate from my lab. After performing transcardial perfusion in a three to six week old rat, remove the brain from the skull using forceps. Then place it in a sagittal position and slice it into four equal three millimeter wide sections using a razor blade and a rat brain matrix.Fix each section in four percent PFA in a sealed five milliliter plastic tube overnight on a shaker at four degrees Celsius. On the next day, continue the fixation at room temperature for one hour. Wash each section three times with PBS for about 30 minutes per wash.Serially incubate the washed sections in 20, 40, 60, 80, and 100%methanol solution for one hour each. Repeat the dehydration with 100%methanol. Then chill the samples in 100%methanol at four degrees Celsius for 10 minutes.Prepare a solution containing 66%DCM and 33%methanol and incubate the chilled sections in this solution overnight at room temperature with shaking. On the next day, wash the sample twice with methanol for 30 minutes and chill it in 100%methanol at four degrees Celsius for 10 minutes. For bleaching, place the sample in fresh five percent hydrogen peroxide in methanol and incubate it overnight at four degrees Celsius.After the overnight incubation, serially incubate the sample in 80, 60, 40, and 20%methanol solutions for one hour each at room temperature. Then incubate the sample in PBS for one hour and wash it twice in solution one for one hour per wash. Fill a one milliliter syringe with 2.5 microliters of one percent biotin-CTB and slowly inject it into the nucleus accumbens site over 20 seconds.Leave the needle tip in place for one minute and remove it slowly over 10 seconds to prevent leakage. Incubate the sample in solution three and then solution four for two days each in a 37 degrees Celsius water bath. Then add the primary antibody and continue the incubation for seven days.Wash the sample five times in solution two for one hour per wash and store it in solution two at room temperature overnight. Incubate the sample with a secondary antibody for seven days in a 37 degrees Celsius water bath. Finally, wash it five times in solution two for one hour per wash and store it in solution two at room temperature overnight in low light.Incubate the sample serially in 20, 40, 60, 80, and 100%methanol for one hour each at room temperature. Then incubate it in fresh 100%methanol overnight. On the next day, incubate the sample in freshly prepared 66%DCM in 33%methanol for three hours at room temperature with shaking.After three hours, incubate the sample in dibenzyl ether without shaking until it is clear. Then store it in dibenzyl ether until imaging. Obtain a 3D printer chamber and secure it to a microscope slide using epoxy.Place the sample in the square space in the middle of the chamber and completely fill the chamber with dibenzyl ether. Place a 0.17 millimeter thick cover slip over the chamber and apply pressure to ensure it is in full contact with the chamber walls. Then seal the edges using epoxy.Make sure to rotate the chamber to allow air bubbles to escape from the filling inlet. Fill the chamber with additional dibenzyl ether. Then seal the filling inlet with epoxy and allow it to cure.Observe the specimen using a confocal microscope system to perform a z-scan at four times magnification. The confocal image of hydrophobically-cleared tissue sample at four times magnification shows dense TH staining in the substantia nigra area, sparse TH neurons adjacent to the substantia nigra, and a dark black area of tissue lacking TH neurons. Typical morphology of a TH-positive neuron at 20 times magnification has a large soma and several branching processes.Whereas IBA1-stained microglia have small cell bodies and shorter extending processes. The ideal confocal image shows positive and dense TH staining in the substantia nigra area with suitable fluorescence gain. Examples of poor confocal images include an improperly focused image with too much fluorescent gain, a false positive staining with bright spots not in focus with the rest of the tissue, and a high background staining as a result of using a blocking serum that does not match with a secondary antibody.Positive CTB staining in the rat brain is shown here. The long thin fibers are afferent projections along the dopaminergic pathway. Colocalization of TH and CTB makes it possible to visualize the injection site in the nucleus accumbens area which appears as a densely fluorescent green circle.Colocalization of TH and CTB in the substantia nigra is shown here. The most important things to remember in attempting this procedure are to allow the sample plenty of time to incubate in all antibody solutions and plenty of time to fully clear before imaging. The sample should have limited exposure to air as this will damage the sample.This technique is highly versatile and can be used to investigate many different proteins of interest throughout different regions of the brain. The present technique helps pave the way for neuroscientists to investigate the rat brain on a circuit level which is essential for the study of brain as a whole system.

a-hydrophobic-tissue-clearing-method-for-rat-brain-tissue

Research

JoVE Journal

Neuroscience

Preparation of Mouse Brain Tissue for Immunoelectron Microscopy

Transmission electron microscopy (TEM) is extremely useful for visualizing microglial, oligodendrocytic, astrocytic, and neuronal subcellular compartments (dendrite, dendritic spine, axon, axon terminal, perikaryon), as well as their intracellular organelles and cytoskeleton, in the central nervous system at high spatial resolution. Combined with TEM, pre-embedding immunocytochemistry allows the discrimination of cellular elements with few distinctive features and identification criteria (e.g., microglial perikarya and processes, when using an antibody against the microglia-specific marker Iba1 (ionized calcium binding adaptor molecule 1; as presented here)), identifying the neurotransmitter contents of cellular elements (e.g., serotonergic) and their ultrastructural localization of soluble or membrane-bound proteins (e.g., 5 HT1A and EphA4 receptors). Here, we describe a protocol for transcardiac perfusion of mice with acrolein fixative, removal and sectioning of the brain, as well as immunoperoxidase-diaminobenzidine (DAB) staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with TEM. When rigorously performed, this technique provides an excellent compromise between optimal ultrastructural preservation and immunocytochemical detection.

We describe a protocol for transcardiac perfusion of mice, removal and sectioning of the brain, as well as immunoperoxidase staining, resin embedding, and ultrathin sectioning of the brain sections. Upon completion of these procedures, the immunostained material is ready for examination with transmission electron microscopy.

Immunoelectron 현미경을위한 마우스 뇌 조직의 준비

Transmission electron microscopy (TEM) is extremely useful for visualizing microglial, oligodendrocytic, astrocytic, and neuronal subcellular compartments ...

연구

신경과학

Chromatin Immunoprecipitation from Dorsal Root Ganglia Tissue following Axonal Injury

Axons in the central nervous system (CNS) do not regenerate while those in the peripheral nervous system (PNS) do regenerate 
to a limited extent after injury (Teng et al., 2006). It is recognized that transcriptional programs essential for neurite and axonal outgrowth are 
reactivated upon injury in the PNS (Makwana et al., 2005). However the tools available to analyze neuronal gene regulation in vivo are limited and 
often challenging.
The dorsal root ganglia (DRG) offer an excellent injury model system because both the CNS and PNS are innervated by a 
bifurcated axon originating from the same soma. The ganglia represent a discrete collection of cell bodies where all transcriptional events occur, 
and thus provide a clearly defined region of transcriptional activity that can be easily and reproducibly removed from the animal. Injury of nerve 
fibers in the PNS (e.g. sciatic nerve), where axonal regeneration does occur, should reveal a set of transcriptional programs that are distinct from 
those responding to a similar injury in the CNS, where regeneration does not take place (e.g. spinal cord). Sites for transcription factor binding, 
histone and DNA modification resulting from injury to either PNS or CNS can be characterized using chromatin immunoprecipitation (ChIP). 
Here, we describe a ChIP protocol using fixed mouse DRG tissue following axonal injury. This powerful combination provides a means for characterizing the pro-regeneration chromatin environment necessary for promoting axonal regeneration.

We present a method for chromatin immunoprecipitation from dorsal root ganglia tissue following axonal injury. The approach can be used to identify specific transcription factor binding sites and epigenetic modification of histone and DNA important for the regeneration of injured axons in both the peripheral and central nervous system.

Axonal 상해 다음 도설 루트 신경 조직에서 염색질의 Immunoprecipitation

Axons in the central nervous system (CNS) do not regenerate while those in the peripheral nervous system (PNS) do regenerate 
to a limited extent after ...

Intact Histological Characterization of Brain-implanted Microdevices and Surrounding Tissue

Research into the design and utilization of brain-implanted microdevices, such as microelectrode arrays, aims to produce clinically relevant devices that interface chronically with surrounding brain tissue. Tissue surrounding these implants is thought to react to the presence of the devices over time, which includes the formation of an insulating "glial scar" around the devices. However, histological analysis of these tissue changes is typically performed after explanting the device, in a process that can disrupt the morphology of the tissue of interest.
Here we demonstrate a protocol in which cortical-implanted devices are collected intact in surrounding rodent brain tissue. We describe how, once perfused with fixative, brains are removed and sliced in such a way as to avoid explanting devices. We outline fluorescent antibody labeling and optical clearing methods useful for producing an informative, yet thick tissue section. Finally, we demonstrate the mounting and imaging of these tissue sections in order to investigate the biological interface around brain-implanted devices.

Here we present a histological method for capturing, labeling, optically clearing, and imaging the intact brain tissue interface around chronically implanted microdevices in rodent brain tissue. Results from the techniques comprising this method are useful for understanding the impact of various penetrating brain-implants on their surrounding tissue.

뇌 이식 Microdevices과 주변 조직의 손상 조직 학적 특성

Research  into the design and utilization of brain-implanted microdevices, such as  microelectrode arrays, aims to produce clinically relevant devices ...

Immunohistochemical Analysis in the Rat Central Nervous System and Peripheral Lymph Node Tissue Sections

Immunohistochemistry (IHC) provides highly specific, reliable and attractive protein visualization. Correct performance and interpretation of an IHC-based multicolor labeling is challenging, especially when utilized for assessing interrelations between target proteins in the tissue with a high fat content such as the central nervous system (CNS).
Our protocol represents a refinement of the standard immunolabeling technique particularly adjusted for detection of both structural and soluble proteins in the rat CNS and peripheral lymph nodes (LN) affected by neuroinflammation. Nonetheless, with or without further modifications, our protocol could likely be used for detection of other related protein targets, even in other organs and species than here presented.

We here present an optimized, detailed protocol for double immunostaining in formalin-fixed, paraffin-embedded rat central nervous system (CNS) and peripheral lymph node (LN) tissue sections.

쥐 중추 신경계에서 면역 조직 화학 분석 및 주변 림프절 조직 섹션

Immunohistochemistry (IHC) provides highly specific, reliable and attractive protein visualization. Correct performance and interpretation of an IHC-based ...

Primer for Immunohistochemistry on Cryosectioned Rat Brain Tissue: Example Staining for Microglia and Neurons

Immunohistochemistry is a widely used technique for detecting the presence, location, and relative abundance of antigens in situ. This introductory level protocol describes the reagents, equipment, and techniques required to complete immunohistochemical staining of rodent brain tissue, using markers for microglia and neuronal elements as an example. Specifically, this paper is a step-by-step protocol for fluorescent visualization of microglia and neurons via immunohistochemistry for Iba1 and Pan-neuronal, respectively. Fluorescence double-labeling is particularly useful for the localization of multiple proteins within the same sample, providing the opportunity to accurately observe interactions between cell types, receptors, ligands, and/or the extracellular matrix in relation to one another as well as protein co-localization within a single cell. Unlike other visualization techniques, fluorescence immunohistochemistry staining intensity may decrease in the weeks to months following staining, unless appropriate precautions are taken. Despite this limitation, in many applications fluorescence double-labeling is preferred over alternatives such as 3,3&#39;-diaminobenzidine tetrahydrochloride (DAB) or alkaline phosphatase (AP), as fluorescence is more time efficient and allows for more precise differentiation between two or more markers. The discussion includes troubleshooting tips and advice to promote success.

This introductory level protocol describes the reagents, equipment, and techniques required to complete immunohistochemical staining of rodent brains, using markers for microglia and neuronal elements as an example.

미세 아교 세포와 신경 세포에 대한 예 염색 : 저온 절단 된 쥐의 뇌 조직에서 면역 조직 화학에 대한 입문서

Immunohistochemistry is a widely used technique for detecting the presence, location, and relative abundance of antigens in situ. This introductory level ...

Using Fluorescence Activated Cell Sorting to Examine Cell-Type-Specific Gene Expression in Rat Brain Tissue

The brain is comprised of four primary cell types including neurons, astrocytes, microglia and oligodendrocytes. Though they are not the most abundant cell type in the brain, neurons are the most widely studied of these cell types given their direct role in impacting behaviors. Other cell types in the brain also impact neuronal function and behavior via the signaling molecules they produce. Neuroscientists must understand the interactions between the cell types in the brain to better understand how these interactions impact neural function and disease. To date, the most common method of analyzing protein or gene expression utilizes the homogenization of whole tissue samples, usually with blood, and without regard for cell type. This approach is an informative approach for examining general changes in gene or protein expression that may influence neural function and behavior; however, this method of analysis does not lend itself to a greater understanding of cell-type-specific gene expression and the effect of cell-to-cell communication on neural function. Analysis of behavioral epigenetics has been an area of growing focus which examines how modifications of the deoxyribonucleic acid (DNA) structure impact long-term gene expression and behavior; however, this information may only be relevant if analyzed in a cell-type-specific manner given the differential lineage and thus epigenetic markers that may be present on certain genes of individual neural cell types. The Fluorescence Activated Cell Sorting (FACS) technique described below provides a simple and effective way to isolate individual neural cells for the subsequent analysis of gene expression, protein expression, or epigenetic modifications of DNA. This technique can also be modified to isolate more specific neural cell types in the brain for subsequent cell-type-specific analysis.

The goal of this protocol is to use the fluorescence activated cell sorting (FACS) technique to sort specific types of neural cells for subsequent analysis of cell-type-specific gene expression, epigenetic markers, and or protein expression.

쥐 뇌 조직 검사 정렬 형광 활성 셀을 사용하여 셀 타입 별 유전자 발현

The brain is comprised of four primary cell types including neurons, astrocytes, microglia and oligodendrocytes. Though they are not the most abundant ...

A Rat Model of Mild Intrauterine Hypoperfusion with Microcoil Stenosis

Intrauterine hypoperfusion/ischemia is one of the major causes of intrauterine/fetal growth restriction, preterm birth, and low birth weight. Most studies of this phenomenon have been performed in either models with severe intrauterine ischemia or models with gradient degree of intrauterine hypoperfusion. No study has been performed in a model on uniform mild intrauterine hypoperfusion (MIUH). Two models have been used for studies of MIUH: a model based on suture ligation of either side of the arterial arcade formed with the uterine and ovarian arteries, and a transient model based on clipping the bilateral ovarian arteries and aorta having patency. Those two rodent models of MIUH have some limitations, e.g., not all fetuses are subjected to MIUH, depending on their position in the uterine horn. In our MIUH model, all fetuses are subjected to a comparable level of intrauterine hypoperfusion. MIUH was achieved by mild stenosis of all four arteries feeding the uterus, i.e., the bilateral uterine and ovarian arteries.
Arterial stenosis was induced by metal microcoils wrapped around the feeding arteries. Producing arterial stenosis with microcoils allowed us to control, optimize, and reproduce decreased blood flow with very little inter-animal variability and a low mortality rate, thus enabling accurate evaluation. When microcoils with an inner diameter of 0.24 mm were used, the blood flow in both the placenta and fetus was mildly decreased (approximately 30% from the pre-stenosis level in the placenta). The offspring of our MIUH model clearly demonstrates long-lasting alterations in neurological, neuroanatomical and behavioral test results.

Mild intrauterine hypoperfusion was produced by artery stenosis with metal microcoils wrapped around the uterine and ovarian arteries in rats at embryonic day 17. This procedure produced prenatal hypoperfusion and intrauterine growth restriction.

Microcoil 협와 가벼운 자궁내 Hypoperfusion의 쥐 모델

Intrauterine hypoperfusion/ischemia is one of the major causes of intrauterine/fetal growth restriction, preterm birth, and low birth weight. Most studies ...

Novel Passive Clearing Methods for the Rapid Production of Optical Transparency in Whole CNS Tissue

Since the development of CLARITY, a bioelectrochemical clearing technique that allows for three-dimensional phenotype mapping within transparent tissues, a multitude of novel clearing methodologies including CUBIC (clear, unobstructed brain imaging cocktails and computational analysis), SWITCH (system-wide control of interaction time and kinetics of chemicals), MAP (magnified analysis of the proteome), and PACT (passive clarity technique), have been established to further expand the existing toolkit for the microscopic analysis of biological tissues. The present study aims to improve upon and optimize the original PACT procedure for an array of intact rodent tissues, including the whole central nervous system (CNS), kidneys, spleen, and whole mouse embryos. Termed psPACT (process-separate PACT) and mPACT (modified PACT), these novel techniques provide highly efficacious means of mapping cell circuitry and visualizing subcellular structures in intact normal and pathological tissues. In the following protocol, we provide a detailed, step-by-step outline on how to achieve maximal tissue clearance with minimal invasion of their structural integrity via psPACT and mPACT.

Here, we present two novel methodologies, psPACT and mPACT, for achieving maximal optical transparency and subsequent microscopic analysis of tissue vasculature in the intact rodent whole CNS.

소설 수동 전체 CNS 조직에 광학 투명도의 급속 한 생산을 위한 방법 삭제

Since the development of CLARITY, a bioelectrochemical clearing technique that allows for three-dimensional phenotype mapping within transparent tissues, ...

Isolation of Cerebral Capillaries from Fresh Human Brain Tissue

Understanding blood-brain barrier function under physiological and pathophysiological conditions is critical for the development of new therapeutic strategies that hold the promise to enhance brain drug delivery, improve brain protection, and treat brain disorders. However, studying the human blood-brain barrier function is challenging. Thus, there is a critical need for appropriate models. In this regard, brain capillaries isolated from human brain tissue represent a unique tool to study barrier function as close to the human in vivo situation as possible. Here, we describe an optimized protocol to isolate capillaries from human brain tissue at a high yield and with consistent quality and purity. Capillaries are isolated from fresh human brain tissue using mechanical homogenization, density-gradient centrifugation, and filtration. After the isolation, the human brain capillaries can be used for various applications including leakage assays, live cell imaging, and immune-based assays to study protein expression and function, enzyme activity, or intracellular signaling. Isolated human brain capillaries are a unique model to elucidate the regulation of the human blood-brain barrier function. This model can provide insights into central nervous system (CNS) pathogenesis, which will help the development of therapeutic strategies for treating CNS disorders.

Isolated brain capillaries from human brain tissue can be used as a preclinical model to study barrier function under physiological and pathophysiological conditions. Here, we present an optimized protocol to isolate brain capillaries from fresh human brain tissue.

신선한 인간의 뇌 조직에서 뇌 모세 혈관의 절연

Understanding blood-brain barrier function under physiological and pathophysiological conditions is critical for the development of new therapeutic ...

Preparation of Newborn Rat Brain Tissue for Ultrastructural Morphometric Analysis of Synaptic Vesicle Distribution at Nerve Terminals

Our laboratory and many others have exploited the high resolving power of transmission electron microscopy to study the morphology and spatial organization of synaptic vesicles. In order to obtain high-quality electron micrographs that can yield the degree of morphological detail necessary for quantitative analysis of pre-synaptic vesicle distribution, optimal specimen preparation is critical. Chemical fixation is the first step in the process of specimen preparation, and of utmost importance to preserve fine ultrastructure. Vascular fixation with a glutaraldehyde-formaldehyde solution, followed by treatment of vibratome-sectioned specimens with osmium tetroxide, stabilizes the maximum number of molecules, especially proteins and lipids, and results in superior conservation of ultrastructure. Tissue is then processed with counterstaining, sequential dehydration and resin-embedding. En bloc staining with uranyl acetate (i.e., staining of vibratome-sectioned tissue before resin embedding) enhances endogenous contrast and stabilizes cell components against extraction during specimen processing. Contrast can be further increased by applying uranyl acetate as a post-stain on ultrathin sections. Double-staining of ultrathin sections with lead citrate after uranyl acetate treatment also improves image resolution, by intensifying electron-opacity of nucleic acid-containing structures through selective binding of lead to uranyl acetate. Transmission electron microscopy is a powerful tool for characterization of the morphological details of synaptic vesicles and quantification of their size and spatial organization in the terminal bouton. However, because it uses fixed tissue, transmission electron microscopy can only provide indirect information regarding living or evolving processes. Therefore, other techniques should be considered when the main objective is to study dynamic or functional aspects of synaptic vesicle trafficking and exocytosis.

We describe procedures for processing newborn rat brain tissue to obtain high-resolution electron micrographs for morphometric analysis of synaptic vesicle distribution at nerve terminals. The micrographs obtained with these methods can also be used to study the morphology of a number of other cellular components and their dimensional structural relationships.