이번 분석을 돕기 위해 Ricardo Dolmetsch 박사 (Stanford University of Medicine, 현재 : Novartis Institute for Biomedical Research)와 Matthew Wood 박사, Aihara Takum, Dongsook Kim에게 감사드립니다.

모든 동물 실험은 쓰쿠바 대학 동물 케어 및 사용위원회 (IACUC)의 승인을 받아 수행되었습니다. 1. 해부 <ol><li> 배아 일 13-14 ICR 또는 C57BL / 6 태아를 준비하기 위해, 자궁 경부 탈구로 임신 생쥐를 안락사. 자궁을 제거하고 행크의 균형 소금 솔루션 (HBSS)와 페트리 접시에 넣어. 혈액을 제거하기 위해 잘 헹구십시오. </li><li> 겸자를 사용하여 70 % 에탄올로 자궁을 새로운 페트리 접시에 옮겨 멸균하십시오. </li><li> 자궁을 HBSS로 새로운 페트리 접시로 옮깁니다. 살균 해부 포셉 및 수술 가위를 사용하여 자궁에서 태아를 제거하십시오. </li><li> 외과 용 가위로 태아를 처치하십시오. HBSS와 함께 새로운 페트리 접시에 그들을 놓으십시오. </li><li> 피부와 두개골을 제거하고 살균 해부 포 셉를 사용하여 두뇌를 꺼내. 그들을 HBSS와 페트리 접시에 넣어. 참고 :이 단계부터 깨끗한 상태에서 절차를 수행하는 것이 가장 좋습니다벤치. </li><li> 입체 현미경으로 멸균 해부 포셉을 사용하여 meninges를 제거합니다. 겸자를 사용하여 기저핵, 해마 및 소뇌를 차단하십시오. 곡선 팁 포셉을 사용하여 HBSS와 함께 새로운 페트리 접시에 cortices를 전송하십시오. </li><li> 일회용 dropper 또는 25mL 피펫을 사용하여 모든 cortices를 수집합니다. 그들을 15 ML 튜브에 넣어 다음 pipetting하여 HBSS를 제거하십시오. </li><li> cortices를 포함하는 튜브에 대뇌 피질 효소 솔루션 3 ML을 추가합니다. 이 튜브를 수조에 넣고 5 분 동안 37 ° C에서 배양하십시오. 참고 : 0.25 % 트립신과 1mM EDTA와 인산염 완충 식염수 (PBS)로 구성된 대뇌 피질 문화 효소를 준비합니다. 0.22 μm 필터로 소독하십시오. </li><li> cortices를 포함하는 튜브에 대뇌 피질 효소 솔루션의 추가 3 ML을 추가하고 추가 5 분 동안 수욕에서 37 ° C에서 품어. </li><li> 5 ML 피펫을 사용하여 대뇌 피질 효소 솔루션을 제거하고 Dulbe 5 ML을 추가10 % 태아 소 혈청 (FBS)이 함유 된 cco &#39;s Modified Eagle Medium (DMEM). </li><li> 멸균 P1000 팁 5 ML 피펫을 사용하여 위아래로 부드럽게 pipetting하여 cortices을 떼어. P200 팁 5 ML 피펫을 사용하여 다시 피펫. </li><li> 40 μm 나일론 셀 스트레이너를 50 mL 튜브에 넣고 현탁액을 여과하여 잔해물을 제거합니다. </li><li> RT에서 5 분 동안 420 XG에서 원심 분리기를 만든 다음 DMEM 배지를 제거합니다. </li><li> 대뇌 피질 배지 5 ML을 추가하고 부드럽게 세포 펠렛을 resuspend. 참고 : 1x B - 27 보충제, 2mM L - 글루타민, 100 U / ML 페니실린 스트렙토 마이신으로 보충 뉴런 기본 미디어로 구성된 대뇌 피질의 문화 매체를 준비합니다. </li><li> hemocytometer를 사용하여 세포를 세고 대뇌 피질 문화 매체를 사용하여 세포 농도를 (원하는대로) 조정합니다. </li><li> 코팅 된 35mm 유리 바닥 접시 당 2.0mL의 플레이트 3.0 × 10 6 피질 뉴런. 참고 : 도금하기 전에Poly-D-Lysine hydrobromide (PDL) 또는 0.01 % Poly-L-Ornithine (PLO)을 함유 한 35mmm 유리 바닥 접시. 37 ° C에서 3 시간 동안 배양하고 적어도 3x PBS로 세척하십시오. </li></ol> 2. 이미징 베 시클 운동성 <ol><li> 각 유형의 소포를 라벨링 할 플라스미드를 준비하십시오. 예를 들어 초기 엔도 솜에는 EGFP-Rab5를, 후기 엔도 솜에는 EGFP-Rab7을, 리소좀에는 LAMP-EGFP를,자가 염색체에는 EGFP-LC3을 사용합니다 8 , 13 . 참고 :이 플라스미드는 tsuruta.fuminori.fn@u.tsukuba.ac.jp에서 ​​요청할 수 있습니다. 전형적으로, 3-5 일 의 시험 관내 (DIV) 뉴런은 형질 전환 시약을 사용하여 이들 플라스미드로 트랜 스펙 션 될 수있다. </li><li> 피펫 팅으로 혈청이없는 배지 200 μL와 4.0 μg의 플라스미드를 섞는다. 별도의 튜브에 혈청이없는 배지 200 μL에 8 μL의 형질 전환 시약 ( 재료 표 참조)을 희석하십시오. RT에서 5 분 동안 품어 둡니다. </li><li> 단계 2.2에서 pipetting하여 플라스미드 솔루션과 transfection 섭정 솔루션을 섞는다. RT에서 20 분 동안 품어 낸다. </li><li> 무 혈청 배지와 단계 2.3에서 얻은 플라스미드 용액 400 μL를 각 코팅 된 유리 바닥 접시에 첨가한다. 37 ° C에서 뉴런을 품어 5 % CO 2 배양기에서 30 분간 항온 처리한다. 대뇌 피질 문화 매체 2 ML로 매체를 대체하십시오. 1-2 일 동안 5 % CO 2 인큐베이터에서 37 ° C에서 뉴런을 품어. </li><li> transfection 1 ~ 2 일 후, 이미지 수집을 위해 transfected 세포를 선택합니다. 참고 : 7 DIV 미만의 조기 뉴런은 동적 소포 운동성을 나타내는 경향이 있습니다. 고도로 표현하는 뉴런을 선택하면 명확한 이미지를 얻을 수 없기 때문에 형광 프로브를 적당히 표현하는 뉴런을 선택하십시오. 또한 축색 돌기 및 수상 돌기의 확인을 용이하게하기 위해 긴 축삭 및 복잡한 수상 돌기가있는 피라미드 뉴런과 같은 전형적인 연결 형태를 선택하십시오 ( 그림 1A 참조)). </li><li> 저속 영상 시스템을 이용한 영상 획득 : 이미징의 경우 40X Plan Apo 0.95NA 또는 100X Plan Apo VC NA1.4 대물 렌즈가 장착 된 CCD (Charge Coupled Device) 카메라가 장착 된 형광 현미경을 사용하십시오. 부화 시스템을 사용하여 37 ° C에서 온도를 제어하십시오. 이미지 수집 소프트웨어가 제어하는 ​​100 초 동안 한 프레임 / 5 초에서 뉴런 이미지를 수집합니다. 또는 300 초 동안 2 초당 1 프레임과 같이 더 짧은 시간 간격과 더 긴 시간 간격으로 이미지를 수집 할 수 있습니다. 참고 : 순차적 이미지 촬영에는 다양한 응용 프로그램을 사용할 수 있으며 그 중 많은 이미지가이 방법에 적합합니다. 따라서 특정 응용 프로그램을 권장하지 않습니다. 오히려 각 연구원은 사용 가능한 응용 프로그램을 사용해야합니다. </li></ol> 3. 이미지 분석 <ol><li> Manual Tracking 14 로 ImageJ 소프트웨어의 모든 순차 이미지를 엽니 다. 참고 : 현재까지 수동 추적은추적 실험 15 , 16 , 17 , 18 , 19에서 사용 되었습니다. 수동 추적은 Dr. Fabrice Cordelières가 개발했습니다. 자세한 서면 지침은 온라인에서 확인할 수 있습니다 20 . 분석을 위해, 이미징 데이터의 품질은 충분한 수의 이미지로 개선됩니다. 20 장 이상의 이미지를 사용하는 것이 좋습니다. </li><li> 연속 이미지를 결합하려면 &lt;이미지&gt; → &lt;스택&gt; → &lt;스택 할 이미지&gt;를 선택하십시오. &lt;확인&gt;을 클릭하십시오. </li><li> &lt;Plugins&gt; → &lt;Manual Tracking&gt;을 선택하십시오. 추적 창이 열립니다. </li><li> &lt;Show Parameters?&gt; 체크 박스를 클릭하고 매개 변수 섹션에서 추적 매개 변수를 정의하십시오. 참고 : 시간 간격, x / y 보정, z 보정, 중심에 대한 정사각형 크기 검색 등 여러 매개 변수를 설정할 수 있습니다도트 크기, 선 너비 및 글꼴 크기가 포함됩니다. 이 단순화 된 분석에서, 시간 간격 및 x / y 보정 모두가 정의되었다. 다른 실험 환경에서는 다른 매개 변수도 정의해야 할 수 있습니다. 여기에 사용 된 매개 변수는 다음과 같습니다 : 40X Plan Apo 0.95NA 대물 렌즈의 경우 &lt;Time interval&gt;이 5 초이고 &lt;x / y calibration&gt;이 0.26642 μm이거나 100X Plan Apo VC NA1.4의 경우 0.10657 μm입니다. 대물 렌즈. </li><li> 매개 변수가 정의 된 후 &lt;트랙 추가&gt;를 클릭하여 새 트랙을 시작하십시오. </li><li> 관심있는 소낭 ( 예 : 그림 1A (오른쪽 패널)의 파란색과 빨간색 화살촉으로 표시된 소낭)을 결정한 후 순차 이미지에서 신호의 중심을 클릭하여 xy 좌표를 기록합니다. 기록 된 xy 좌표, 거리 및 속도의 결과가 새 창에 표시됩니다. 참고 : 리소좀의 경우, 큰 밝은 형광 신호 ( 예 : Figure 1A (오른쪽 패널), 주황색 화살촉)은 종종 뉴런에서 관찰됩니다. 이 신호들은 때때로 누적 된 소낭이나 병적 정맥류를 나타 내기 때문에 운동성을 정량화하기 위해 이러한 신호를 피해야합니다. </li><li> 모든 순차 이미지에서 vesicles의 xy 좌표를 수집하려면 3.6 단계를 반복하십시오. 각 이미지는 참조 점이 선택된 후 자동으로 연속 이미지로 진행됩니다. </li><li> 이 데이터를 새 테이블 ( 예 : 스프레드 시트)로 내 보냅니다. 적절한 소프트웨어를 사용하여 적절한 그래프를 만듭니다 ( 재료 표 참조). 참고 : 데이터를 분석하려면 &lt;거리&gt; 열을 선택하고이 열의 모든 값을 합한 다음 그림 1B 와 같이 운동 거리를 막대 그래프로 표시합니다. 또한이 단계를 반복하고 전체 운동 거리의 평균을 계산하고 막대 그래프로 표시합니다 ( 그림 1C) . 막대 그래프와 파형 데이터를 생성하는 소프트웨어는자료 표. </li></ol>

<ol>
	<li>Nicot, A. S., Laporte, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endosomal+phosphoinositides+and+human+diseases.">Endosomal phosphoinositides and human diseases.</a> Traffic. 9 (8), 1240-1249 (2008).</li><li>De Matteis, M. A., Luini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mendelian+disorders+of+membrane+trafficking.">Mendelian disorders of membrane trafficking.</a> N Engl J Med. 365 (10), 927-938 (2011).</li><li>Lebrand, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Late+endosome+motility+depends+on+lipids+via+the+small+GTPase+Rab7.">Late endosome motility depends on lipids via the small GTPase Rab7.</a> EMBO J. 21 (6), 1289-1300 (2002).</li><li>Chen, C. S., Bach, G., Pagano, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Abnormal+transport+along+the+lysosomal+pathway+in+mucolipidosis,+type+IV+disease.">Abnormal transport along the lysosomal pathway in mucolipidosis, type IV disease.</a> Proc Natl Acad Sci U S A. 95 (11), 6373-6378 (1998).</li><li>Venugopal, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurologic,+gastric,+and+opthalmologic+pathologies+in+a+murine+model+of+mucolipidosis+type+IV.">Neurologic, gastric, and opthalmologic pathologies in a murine model of mucolipidosis type IV.</a> Am J Hum Genet. 81 (5), 1070-1083 (2007).</li><li>Li, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+molecular+mechanism+to+regulate+lysosome+motility+for+lysosome+positioning+and+tubulation.">A molecular mechanism to regulate lysosome motility for lysosome positioning and tubulation.</a> Nat Cell Biol. 18 (4), 404-417 (2016).</li><li>Tsuruta, F., Green, E. M., Rousset, M., Dolmetsch, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PIKfyve+regulates+CaV1.2+degradation+and+prevents+excitotoxic+cell+death.">PIKfyve regulates CaV1.2 degradation and prevents excitotoxic cell death.</a> J Cell Biol. 187 (2), 279-294 (2009).</li><li>Tsuruta, F., Dolmetsch, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=PIKfyve+mediates+the+motility+of+late+endosomes+and+lysosomes+in+neuronal+dendrites.">PIKfyve mediates the motility of late endosomes and lysosomes in neuronal dendrites.</a> Neurosci Lett. 605, 18-23 (2015).</li><li>McCartney, A. J., Zhang, Y., Weisman, L. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphatidylinositol+3,5-bisphosphate:+low+abundance,+high+significance.">Phosphatidylinositol 3,5-bisphosphate: low abundance, high significance.</a> Bioessays. 36 (1), 52-64 (2014).</li><li>Shisheva, A., Sbrissa, D., Ikonomov, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plentiful+PtdIns5P+from+scanty+PtdIns(3,5)P2+or+from+ample+PtdIns?+PIKfyve-dependent+models:+Evidence+and+speculation+(response+to:+DOI+10.1002/bies.201300012).">Plentiful PtdIns5P from scanty PtdIns(3,5)P2 or from ample PtdIns? PIKfyve-dependent models: Evidence and speculation (response to: DOI 10.1002/bies.201300012).</a> Bioessays. 37 (3), 267-277 (2015).</li><li>Chow, C. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutation+of+FIG4+causes+neurodegeneration+in+the+pale+tremor+mouse+and+patients+with+CMT4J.">Mutation of FIG4 causes neurodegeneration in the pale tremor mouse and patients with CMT4J.</a> Nature. 448 (7149), 68-72 (2007).</li><li>Zhang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loss+of+Vac14,+a+regulator+of+the+signaling+lipid+phosphatidylinositol+3,5-bisphosphate,+results+in+neurodegeneration+in+mice.">Loss of Vac14, a regulator of the signaling lipid phosphatidylinositol 3,5-bisphosphate, results in neurodegeneration in mice.</a> Proc Natl Acad Sci U S A. 104 (44), 17518-17523 (2007).</li><li>Mizushima, N., Yamamoto, A., Matsui, M., Yoshimori, T., Ohsumi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+analysis+of+autophagy+in+response+to+nutrient+starvation+using+transgenic+mice+expressing+a+fluorescent+autophagosome+marker.">In vivo analysis of autophagy in response to nutrient starvation using transgenic mice expressing a fluorescent autophagosome marker.</a> Mol Biol Cell. 15 (3), 1101-1111 (2004).</li><li>. Manual Tracking, a plug-in for ImageJ software [Internet] Available from: <a target="_blank" href="https://imagej.nih.gov/ij/plugins/track/track.html">https://imagej.nih.gov/ij/plugins/track/track.html</a> (2017)</li><li>Hu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exopolysaccharide-independent+social+motility+of+Myxococcus+xanthus.">Exopolysaccharide-independent social motility of Myxococcus xanthus.</a> PLoS One. 6 (1), e16102 (2011).</li><li>Tan, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+four+type+IV+pilin+homologues+in+Stigmatella+aurantiaca+DSM17044+by+heterologous+expression+in+Myxococcus+xanthus.">Characterization of four type IV pilin homologues in Stigmatella aurantiaca DSM17044 by heterologous expression in Myxococcus xanthus.</a> PLoS One. 8 (9), e75105 (2013).</li><li>Choi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetic+variant+of+cortactin+linked+to+acute+lung+injury+impairs+lamellipodia+dynamics+and+endothelial+wound+healing.">A genetic variant of cortactin linked to acute lung injury impairs lamellipodia dynamics and endothelial wound healing.</a> Am J Physiol Lung Cell Mol Physiol. 309 (9), L983-L994 (2015).</li><li>Dahirel, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Movement+propensity+and+ability+correlate+with+ecological+specialization+in+European+land+snails:+comparative+analysis+of+a+dispersal+syndrome.">Movement propensity and ability correlate with ecological specialization in European land snails: comparative analysis of a dispersal syndrome.</a> J Anim Ecol. 84 (1), 228-238 (2015).</li><li>Hu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interplay+between+type+IV+pili+activity+and+exopolysaccharides+secretion+controls+motility+patterns+in+single+cells+of+Myxococcus+xanthus.">Interplay between type IV pili activity and exopolysaccharides secretion controls motility patterns in single cells of Myxococcus xanthus.</a> Sci Rep. 6, 17790 (2016).</li><li>. Manual Tracking [Internet] Available from: <a target="_blank" href="https://imagej.nih.gov/ij/plugins/track/Manual">https://imagej.nih.gov/ij/plugins/track/Manual</a> (2017)</li><li>. ImageJ Tracking plug-in [Internet] Available from: <a target="_blank" href="https://imagej.net/Category:Tracking">https://imagej.net/Category:Tracking</a> (2017)</li><li>Tinevez, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TrackMate:+An+open+and+extensible+platform+for+single-particle+tracking.">TrackMate: An open and extensible platform for single-particle tracking.</a> Methods. , (2016).</li><li>Ekvall, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+tracking+of+small+aquatic+organisms+using+fluorescent+nanoparticles.">Three-dimensional tracking of small aquatic organisms using fluorescent nanoparticles.</a> PLoS One. 8 (11), e78498 (2013).</li><li>Jeyakumar, M., Dwek, R. A., Butters, T. D., Platt, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Storage+solutions:+treating+lysosomal+disorders+of+the+brain.">Storage solutions: treating lysosomal disorders of the brain.</a> Nat Rev Neurosci. 6 (9), 713-725 (2005).</li></ol>

저자는 공개 할 것이 없습니다.

이 프로토콜은 소포 운동성을 정량화하는 절차를 소개합니다. 일차 뉴런에서 엔도 좀과 리소좀은 젊은 뉴런에서 높은 운동성을 나타내는 경향이 있습니다 (4-6 DIV). 뉴런은 신경 프로세스를 길게하기 위해 리딩 에지에 몇 가지 구성 요소를 제공해야한다는 것을 감안할 때 멤브레인 트래 피킹은이 단계에서 동적으로 발생해야합니다. 따라서, 신경 dendrites의 동적 운동을 관찰하기 위해 젊은 뉴런을 ...

Endosome-lysosome trafficking의 정확한 조절은 신경 기능 조절에 필수 불가결합니다. 주목할 만하게,이 vesicles의 동적 인 운동은 신경질 형태학, 발달 및 생존의 규칙의 기초가되는 중요한 요인이다. 이 시스템의 결함은 심한 신경 장애를 유발합니다 1 , 2 . 소포 인신 매매를 신경 질환과 연결시키는 분자 메커니즘은 복잡하다고 여겨지며, 몇몇 그룹에서는이 관련성을 조사하려고 시도해 왔습니다. 예를 들어, 늦은 엔도 솜 운동성을 교란 시키면 리소좀 결함으로 인해 유전되는 신경 퇴행성 질환 인 Niemann-Pick C 질병 3 과 유의 한 연관성이있는 것으로보고되었습니다. 다른 예는 리소좀 운동성을 손상시키는 리소좀 성 Ca 2+ 채널 trpml 1의 돌연변이로 리소좀 성 저장 질환 4 , 5 , </6 . 우리 그룹은 PtdIns (3,5) P 2 turnover의 조절 장애가 뉴런의 엔도 좀과 리소좀 운동성을 억제하여 스트레스 반응에 대한 취약성이 증가한다고보고했다. PtdIns (3,5) P 2의 대사 조절은 후기 엔도 좀과 리소좀에 주로 국한되며, 소포 수송과 융합 분열 과정을 포함한 다양한 세포 기능에 중요한 역할을한다. 손상된 PtdIns (3,5) P 2 turnover가 심한 신경 퇴화를 유발하기 때문에 11,12 endosome-lysosome 운동성의 비정상적인 조절은 신경 퇴행의 발병 기전을 이해하는 중요한 요소가 될 수 있습니다. 소포 운동성의 기초가되는 분자 메커니즘에 대한 연구는 우리의 unde를 깊게 할 수있는 유망한 단서를 제공 할 수 있습니다몇 가지 신경 장애의 견해. 이 논문에서는 수동 추적이라는 무료 소프트웨어 패키지를 사용하여 뉴런의 소포 운동성을 정량화하는 유용한 방법을 소개합니다. 목표는 소포 운동성을 분석하는 빠른 정량화 방법을 개발하는 것이 었습니다. 이 양화는 저속 영화의 각 프레임에서 기준점을 클릭하는 표준 방식을 통해 이루어집니다. 수동 추적 소프트웨어를 사용하면이 방법을 다른 응용 프로그램과 달리 매우 간단하고 폭넓게 사용할 수 있습니다. 또한, 이러한 접근법은 신경 교세포와 같은 다른 세포에도 적용 가능하다. 이 방법은 원시적이지만 세포 운동성 및 형태 학적 변화를 비롯한 다양한 분석에 적용 할 수 있습니다. 예를 들어 일련의 이미지에서 참조 점을 정의한 후 데이터 분석 및 이미지 처리 소프트를 사용하여 순차 이미지에서 참조 지점의 위치 및 각 위치에서의 시간에 대한 정보를 추출 할 수 있습니다제품. 이 방법은 간단하면서도 강력하며, 엔도 좀 - 리소좀 기능을 검사하는 것과 같은 멤브레인 트래 피킹을 기반으로 한 연구의 효율성 향상에 기여합니다.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Neurobasal medium</td>
			<td>Thermo Fisher</td>
			<td>21103-049</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified eagle medium&#160;</td>
			<td>Wako</td>
			<td>044-29765</td>
			<td></td>
		</tr>
		<tr>
			<td>Opti-MEM</td>
			<td>Thermo Fisher</td>
			<td>31985070</td>
			<td>Serum free medium</td>
		</tr>
		<tr>
			<td>Hank&#39;s balanced salt solution</td>
			<td>Thermo Fisher</td>
			<td>14170112</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicilin Streptmycin</td>
			<td>Thermo Fisher</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Glutamine</td>
			<td>Thermo Fisher</td>
			<td>25030081</td>
			<td></td>
		</tr>
		<tr>
			<td>B-27 Supplements</td>
			<td>Thermo Fisher</td>
			<td>17504044</td>
			<td></td>
		</tr>
		<tr>
			<td>2.5% Trypsine</td>
			<td>Thermo Fisher</td>
			<td>15090046</td>
			<td></td>
		</tr>
		<tr>
			<td>poly-D-lysine hydrobromide</td>
			<td>Sigma</td>
			<td>P7280</td>
			<td></td>
		</tr>
		<tr>
			<td>poly-L-ornithine&#160;</td>
			<td>Sigma</td>
			<td>P4957</td>
			<td></td>
		</tr>
		<tr>
			<td>Nylon cell strainer</td>
			<td>Corning</td>
			<td>431750</td>
			<td></td>
		</tr>
		<tr>
			<td>Lipofectamine 2000</td>
			<td>Thermo Fisher</td>
			<td>11668027</td>
			<td>Transfection reagent</td>
		</tr>
		<tr>
			<td>Polyethyleneimine &#34;Max&#34;</td>
			<td>polysciences</td>
			<td>24765</td>
			<td>Transfection reagent. As an alternative to Lipofectamine2000, 0.1mg/ml Polyethyleneimine dissolved in sterilized water is available. But it is low efficiency and high toxicity.</td>
		</tr>
		<tr>
			<td>BIOREVO BZ-9000</td>
			<td>Keyence</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubation system INUG2-K13</td>
			<td>Tokay Hit</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>GraphPad Prism version 6.0</td>
			<td>GraphPad Software</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>Excel version 15</td>
			<td>Microsoft</td>
			<td>NA</td>
			<td></td>
		</tr>
		<tr>
			<td>ImageJ verion 1.47</td>
			<td>NA</td>
			<td>NA</td>
			<td></td>
		</tr>
	</tbody>
</table>

quantification of endosome and lysosome motilities in cultured neurons using fluorescent probes

뇌에서 멤브레인 트래 피킹 시스템은 연결 형태, 시냅스 가소성, 생존 및 신경 교종과 같은 신경 기능을 조절하는 데 중요한 역할을합니다. 지금까지 수많은 연구에서 이러한 시스템의 결함이 다양한 신경 질환을 일으킨다 고보고했습니다. 따라서, 소포 역학의 기저를 이해하는 메커니즘은 여러 가지 신경 질환의 치료에 도움이 될 수있는 영향력있는 단서를 제공 할 수 있습니다. 여기에서는 ImageJ 플랫폼 용 소프트웨어 플러그인을 사용하여 운동 거리 및 이동 속도와 같은 소포 운동을 정량화하는 방법을 설명합니다. 정량화를위한 ​​이미지를 얻기 위해, 우리는 EGFP - 태그 소낭 마커 단백질과 연결 endosome - 리소좀 구조를 표시하고 시간 경과 현미경을 사용하여 소포의 움직임을 관찰했다. 이 방법은 매우 유용하고 축삭 및 수상 돌기와 같은 신경 돌기뿐만 아니라 뉴런 및 신경아 교세포의 소마에서 소포 운동성 측정을 단순화합니다. 추가이 방법은 섬유 아세포 및 내피 세포와 같은 다른 세포주에도 적용될 수있다. 이 접근법은 막 밀매에 대한 우리의 이해를 진전시키는 데 도움이 될 수 있습니다.

이 분석은 체외 배양 에서 소포 역학을 측정하기 위해 고안되었습니다. 이 분석은의 연결 형태 및 생존과 관련된 소포 운동성을 결정하는 데 활용되었습니다. 그림 1A 및 B 는 뉴런의 리소좀 운동성을 보여주는 대표적인 데이터를 표시합니다. 피질 뉴런은 리소좀 마커, LAMP-EGFP로 형질 감염되었고, 표준 형광 현미경을 사용하여 관찰되...

Watch this Scientific Journal Video about Quantification of Endosome and Lysosome Motilities in Cultured Neurons Using Fluorescent Probes at JoVE.com

Quantification of Endosome and Lysosome Motilities in Cultured Neurons Using Fluorescent Probes

막 인신 매매에 대한 조사는 신경 기능을 이해하는 데 중요합니다. 여기서는 뉴런에서 소포 운동성을 정량화하는 방법을 소개합니다. 이것은 신경계에서 막 인신 매매의 정량화에 적용 할 수있는 편리한 방법입니다.

형광 프로브를 이용한 배양 된 뉴런의 엔도 좀과 리소좀 기능의 정량화

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, ...

quantification-endosome-lysosome-motilities-cultured-neurons-using

Research

JoVE Journal

Neuroscience

8.0K 조회수.  University of Tsukuba.  막 인신 매매에 대한 조사는 신경 기능을 이해하는 데 중요합니다. 여기서는 뉴런에서 소포 운동성을 정량화하는 방법을 소개합니다. 이것은 신경계에서 막 인신 매매의 정량화에 적용 할 수있는 편리한 방법입니다. 

비디오: Quantification of Endosome and Lysosome Motilities in Cultured Neurons Using Fluorescent Probes

Dissection and Culture of Commissural Neurons from Embryonic Spinal Cord

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies of these neurons are located in the dorsal spinal cord and their axons follow stereotyped trajectories during embryonic development. Commissural axons initially project ventrally towards the floorplate. After crossing the midline, these axons turn anteriorly and project towards the brain. Each of these steps is regulated by the action of several guidance cues. Cultures highly enriched in commissural neurons are ideally suited for many experiments addressing the mechanisms of axon pathfinding, including turning assays, immunochemistry and biochemistry. Here, we describe a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. First, the spinal cord is isolated and dorsal strips are dissected out. The dorsal tissue is then dissociated into a cell suspension by trypsinization and mechanical disruption. Neurons are plated onto poly-L-lysine-coated glass coverslips or tissue-culture dishes. After 30 hours in vitro, most neurons have extended an axon. The purity of the culture (Yam et al. 2009), typically over 90%, can be assessed by immunolabeling with the commissural neuron markers DCC, LH2 and TAG1 (Helms and Johnson, 1998). This neuronal preparation is a useful tool for in vitro studies of the cellular and molecular mechanisms of commissural axon growth and guidance during spinal cord development.

This video demonstrates a method to dissect and culture commissural neurons from E13 rat dorsal spinal cord. Dissociated commissural neurons are useful to study the cellular and molecular mechanisms of axon growth and guidance.

배아 척수에서 뉴런의 Commissural 해부와 문화

Commissural neurons have been widely used to investigate the mechanisms underlying axon guidance during embryonic spinal cord development. The cell bodies ...

연구

신경과학

Fluorescence Recovery After Photobleaching (FRAP) of Fluorescence Tagged Proteins in Dendritic Spines of Cultured Hippocampal Neurons

FRAP has been used to quantify the mobility of GFP-tagged proteins. Using a strong excitation laser, the fluorescence of a GFP-tagged protein is bleached in the region of interest. The fluorescence of the region recovers when the unbleached GFP-tagged protein from outside of the region diffuses into the region of interest. The mobility of the protein is then analyzed by measuring the fluorescence recovery rate. This technique could be used to characterize protein mobility and turnover rate.
In this study, we express the (enhanced green fluorescent protein) EGFP vector in cultured hippocampal neurons. Using the Zeiss 710 confocal microscope, we photobleach the fluorescence signal of the GFP protein in a single spine, and then take time lapse images to record the fluorescence recovery after photobleaching. Finally, we estimate the percentage of mobile and immobile fractions of the GFP in spines, by analyzing the imaging data using ImageJ and Graphpad softwares.
This FRAP protocol shows how to perform a basic FRAP experiment as well as how to analyze the data.

Fluorescence Recovery After Photobleaching FRAP of Fluorescence Tagged Proteins in Dendritic Spines of Cultured Hippocampal Neurons

FRAP has been used to quantify the mobility of Green Fluorescence Protein (GFP)-tagged proteins in cultured cells. We examined the mobile/immobile fractions of the GFP by analyzing the fluorescence recovery percentage after photobleaching. In this study, FRAP was performed at spines of hippocampal neurons.

교양 Hippocampal 뉴런의 돌기 쪽이에서 형광 단백질의 태그 Photobleaching 후 형광 복구 (FRAP)

FRAP has been used to quantify the mobility of GFP-tagged proteins. Using a strong excitation laser, the fluorescence of a GFP-tagged protein is bleached ...

Analysis of Dendritic Spine Morphology in Cultured CNS Neurons

Dendritic spines are the sites of the majority of excitatory connections within the brain, and form the post-synaptic 
compartment of synapses. These structures are rich in actin and have been shown to be highly dynamic. In response to classical Hebbian plasticity 
as well as neuromodulatory signals, dendritic spines can change shape and number, which is thought to be critical for the refinement of neural 
circuits and the processing and storage of information within the brain. Within dendritic spines, a complex network of proteins link extracellular 
signals with the actin cyctoskeleton allowing for control of dendritic spine morphology and number. Neuropathological studies have demonstrated that 
a number of disease states, ranging from schizophrenia to autism spectrum disorders, display abnormal dendritic spine morphology or numbers. 
Moreover, recent genetic studies have identified mutations in numerous genes that encode synaptic proteins, leading to suggestions that these 
proteins may contribute to aberrant spine plasticity that, in part, underlie the pathophysiology of these disorders. In order to study the potential 
role of these proteins in controlling dendritic spine morphologies/number, the use of cultured cortical neurons offers several advantages. Firstly, 
this system allows for high-resolution imaging of dendritic spines in fixed cells as well as time-lapse imaging of live cells. Secondly, this in 
vitro system allows for easy manipulation of protein function by expression of mutant proteins, knockdown by shRNA constructs, or pharmacological 
treatments. These techniques allow researchers to begin to dissect the role of disease-associated proteins and to predict how mutations of these 
proteins may function in vivo.

Numerous recent studies have identified mutations in synaptic proteins associated with brain pathologies. Primary cultured cortical neurons offer great flexibility in examining the effects of these disease-associated proteins on dendritic spine morphology and motility.

교양 CNS의 뉴런의 돌기 스파인 형태론 분석

Dendritic spines are the sites of the majority of excitatory connections within the brain, and form the post-synaptic 
compartment of synapses. These ...

Quantitative Analysis of Synaptic Vesicle Pool Replenishment in Cultured Cerebellar Granule Neurons using FM Dyes

After neurotransmitter release in central nerve terminals, SVs are rapidly retrieved by endocytosis. Retrieved SVs are then refilled with neurotransmitter and rejoin the recycling pool, defined as SVs that are available for exocytosis1,2. The recycling pool can generally be subdivided into two distinct pools - the readily releasable pool (RRP) and the reserve pool (RP). As their names imply, the RRP consists of SVs that are immediately available for fusion while RP SVs are released only during intense stimulation1,2. It is important to have a reliable assay that reports the differential replenishment of these SV pools in order to understand 1) how SVs traffic after different modes of endocytosis (such as clathrin-dependent endocytosis and activity-dependent bulk endocytosis) and 2) the mechanisms controlling the mobilisation of both the RRP and RP in response to different stimuli.
FM dyes are routinely employed to quantitatively report SV turnover in central nerve terminals3-8. They have a hydrophobic hydrocarbon tail that allows reversible partitioning in the lipid bilayer, and a hydrophilic head group that blocks passage across membranes. The dyes have little fluorescence in aqueous solution, but their quantum yield increases dramatically when partitioned in membrane9. Thus FM dyes are ideal fluorescent probes for tracking actively recycling SVs. The standard protocol for use of FM dye is as follows. First they are applied to neurons and are taken up during endocytosis (Figure 1). After non-internalised dye is washed away from the plasma membrane, recycled SVs redistribute within the recycling pool. These SVs are then depleted using unloading stimuli (Figure 1). Since FM dye labelling of SVs is quantal10, the resulting fluorescence drop is proportional to the amount of vesicles released. Thus, the recycling and fusion of SVs generated from the previous round of endocytosis can be reliably quantified.
Here, we present a protocol that has been modified to obtain two additional elements of information. Firstly, sequential unloading stimuli are used to differentially unload the RRP and the RP, to allow quantification of the replenishment of specific SV pools. Secondly, each nerve terminal undergoes the protocol twice. Thus, the response of the same nerve terminal at S1 can be compared against the presence of a test substance at phase S2 (Figure 2), providing an internal control. This is important, since the extent of SV recycling across different nerve terminals is highly variable11.
Any adherent primary neuronal cultures may be used for this protocol, however the plating density, solutions and stimulation conditions are optimised for cerebellar granule neurons (CGNs)12,13.

A live fluorescence imaging technique to quantify the replenishment and mobilisation of specific synaptic vesicle (SV) pools in central nerve terminals is described. Two rounds of SV recycling are monitored in the same nerve terminals providing an internal control.

FM 염료를 사용하여 양식 소뇌 과립 뉴런에서 시냅틱 소포 풀 보충의 정량 분석

After neurotransmitter release in central nerve terminals, SVs are rapidly retrieved by endocytosis.  Retrieved SVs are then refilled with ...

Inducing Dendritic Growth in Cultured Sympathetic Neurons

The shape of the dendritic arbor determines the total synaptic input a neuron can receive 1-3, and influences the types and distribution of these inputs 4-6. Altered patterns of dendritic growth and plasticity are associated with impaired neurobehavioral function in experimental models 7, and are thought to contribute to clinical symptoms observed in both neurodevelopmental disorders 8-10 and neurodegenerative diseases 11-13. Such observations underscore the functional importance of precisely regulating dendritic morphology, and suggest that identifying mechanisms that control dendritic growth will not only advance understanding of how neuronal connectivity is regulated during normal development, but may also provide insight on novel therapeutic strategies for diverse neurological diseases.
Mechanistic studies of dendritic growth would be greatly facilitated by the availability of a model system that allows neurons to be experimentally switched from a state in which they do not extend dendrites to one in which they elaborate a dendritic arbor comparable to that of their in vivo counterparts. Primary cultures of sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rodents provide such a model. When cultured in defined medium in the absence of serum and ganglionic glial cells, sympathetic neurons extend a single process which is axonal, and this unipolar state persists for weeks to months in culture 14,15. However, the addition of either bone morphogenetic protein-7 (BMP-7) 16,17 or Matrigel 18 to the culture medium triggers these neurons to extend multiple processes that meet the morphologic, biochemical and functional criteria for dendrites. Sympathetic neurons dissociated from the SCG of perinatal rodents and grown under defined conditions are a homogenous population of neurons 19 that respond uniformly to the dendrite-promoting activity of Matrigel, BMP-7 and other BMPs of the decapentaplegic (dpp) and 60A subfamilies 17,18,20,21. Importantly, Matrigel- and BMP-induced dendrite formation occurs in the absence of changes in cell survival or axonal growth 17,18.
Here, we describe how to set up dissociated cultures of sympathetic neurons derived from the SCG of perinatal rats so that they are responsive to the selective dendrite-promoting activity of Matrigel or BMPs.

We describe a protocol for using bone morphogenetic protein-7 (BMP-7) or Matrigel to selectively induce dendritic growth in primary sympathetic neurons dissociated from the superior cervical ganglia (SCG) of perinatal rats.

교양 공감 뉴런의 돌기 성장을 유도

The shape of the dendritic arbor determines the total synaptic input a neuron can receive 1-3, and influences the types and distribution of these inputs ...

Large-scale Recording of Neurons by Movable Silicon Probes in Behaving Rodents

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of neurons and circuits requires methods with the spatial selectivity and temporal resolution appropriate for mechanistic analysis of neural ensembles in the behaving animal, i.e. recording of representatively large samples of isolated single neurons. Ensemble monitoring of neuronal activity has progressed remarkably in the past decade in both small and large-brained animals, including human subjects1-11. Multiple-site recording with silicon-based devices are particularly effective because of their scalability, small volume and geometric design.
Here, we describe methods for recording multiple single neurons and local field potential in behaving rodents, using commercially available micro-machined silicon probes with custom-made accessory components. There are two basic options for interfacing silicon probes to preamplifiers: printed circuit boards and flexible cables. Probe supplying companies (<a href="http://www.neuronexustech.com/" >http://www.neuronexustech.com/</a>; <a href="http://www.sbmicrosystems.com/">http://www.sbmicrosystems.com/</a>; <a href="http://www.acreo.se/">http://www.acreo.se/</a>) usually provide the bonding service and deliver probes bonded to printed circuit boards or flexible cables. Here, we describe the implantation of a 4-shank, 32-site probe attached to flexible polyimide cable, and mounted on a movable microdrive. Each step of the probe preparation, microdrive construction and surgery is illustrated so that the end user can easily replicate the process.

We describe methods for large-scale recording of multiple single units and local field potential in behaving rodents with silicon probes. Drive fabrication, probe attachment to the drive and probe implantation processes are illustrated in sufficient details for easy replication.

설치류를 행동에 이동 가능한 실리콘 프로브에 의한 뉴런의 대규모 녹화

A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of ...

Lateral Diffusion and Exocytosis of Membrane Proteins in Cultured Neurons Assessed using Fluorescence Recovery and Fluorescence-loss Photobleaching

Membrane proteins such as receptors and ion channels undergo active trafficking in neurons, which are highly polarised and morphologically complex. This directed trafficking is of fundamental importance to deliver, maintain or remove synaptic proteins.
Super-ecliptic pHluorin (SEP) is a pH-sensitive derivative of eGFP that has been extensively used for live cell imaging of plasma membrane proteins1-2. At low pH, protonation of SEP decreases photon absorption and eliminates fluorescence emission. As most intracellular trafficking events occur in compartments with low pH, where SEP fluorescence is eclipsed, the fluorescence signal from SEP-tagged proteins is predominantly from the plasma membrane where the SEP is exposed to a neutral pH extracellular environment. When illuminated at high intensity SEP, like every fluorescent dye, is irreversibly photodamaged (photobleached)3-5. Importantly, because low pH quenches photon absorption, only surface expressed SEP can be photobleached whereas intracellular SEP is unaffected by the high intensity illumination6-10. 
FRAP (fluorescence recovery after photobleaching) of SEP-tagged proteins is a convenient and powerful technique for assessing protein dynamics at the plasma membrane. When fluorescently tagged proteins are photobleached in a region of interest (ROI) the recovery in fluorescence occurs due to the movement of unbleached SEP-tagged proteins into the bleached region. This can occur via lateral diffusion and/or from exocytosis of non-photobleached receptors supplied either by de novo synthesis or recycling (see Fig. 1). The fraction of immobile and mobile protein can be determined and the mobility and kinetics of the diffusible fraction can be interrogated under basal and stimulated conditions such as agonist application or neuronal activation stimuli such as NMDA or KCl application8,10. 
We describe photobleaching techniques designed to selectively visualize the recovery of fluorescence attributable to exocytosis. Briefly, an ROI is photobleached once as with standard FRAP protocols, followed, after a brief recovery, by repetitive bleaching of the flanking regions. This 'FRAP-FLIP' protocol, developed in our lab, has been used to characterize AMPA receptor trafficking at dendritic spines10, and is applicable to a wide range of trafficking studies to evaluate the intracellular trafficking and exocytosis.

This report describes the use of live cell imaging and photobleach techniques to determine the surface expression, transport pathways and trafficking kinetics of exogenously expressed, pH-sensitive GFP-tagged proteins at the plasma membrane of neurons.

교양 뉴런의 막 단백질의 측면 보급과 Exocytosis은 형광 복구 및 형광 손실 Photobleaching를 사용하여 평가

Membrane proteins such as receptors and ion channels undergo active trafficking in neurons, which are highly polarised and morphologically complex. This ...

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from individual neurons are critical for understanding how neural circuits function under natural conditions. Traditionally, these recordings have been performed 'blind', meaning the identity of the recorded cell is unknown at the start of the recording. Cellular identity can be subsequently determined via intracellular1, juxtacellular2 or loose-patch3 iontophoresis of dye, but these recordings cannot be pre-targeted to specific neurons in regions with functionally heterogeneous cell types. Fluorescent proteins can be expressed in a cell-type specific manner permitting visually-guided single-cell electrophysiology4-6. However, there are many model systems for which these genetic tools are not available. Even in genetically accessible model systems, the desired promoter may be unknown or genetically homogenous neurons may have varying projection patterns. Similarly, viral vectors have been used to label specific subgroups of projection neurons7, but use of this method is limited by toxicity and lack of trans-synaptic specificity. Thus, additional techniques that offer specific pre-visualization to record from identified single neurons in vivo are needed. Pre-visualization of the target neuron is particularly useful for challenging recording conditions, for which classical single-cell recordings are often prohibitively difficult8-11. The novel technique described in this paper uses retrograde transport of a fluorescent dye applied using tungsten needles to rapidly and selectively label a specific subset of cells within a particular brain region based on their unique axonal projections, thereby providing a visual cue to obtain targeted electrophysiological recordings from identified neurons in an intact circuit within a vertebrate CNS.
The most significant novel advancement of our method is the use of fluorescent labeling to target specific cell types in a non-genetically accessible model system. Weakly electric fish are an excellent model system for studying neural circuits in awake, behaving animals12. We utilized this technique to study sensory processing by "small cells" in the anterior exterolateral nucleus (ELa) of weakly electric mormyrid fish. "Small cells" are hypothesized to be time comparator neurons important for detecting submillisecond differences in the arrival times of presynaptic spikes13. However, anatomical features such as dense myelin, engulfing synapses, and small cell bodies have made it extremely difficult to record from these cells using traditional methods11, 14. Here we demonstrate that our novel method selectively labels these cells in 28% of preparations, allowing for reliable, robust recordings and characterization of responses to electrosensory stimulation.

Retrograde Fluorescent Labeling Allows for Targeted Extracellular Single-unit Recording from Identified Neurons In vivo

Retrograde transport of fluorescent dye labels a sub-population of neurons based on anatomical projection. Labeled axons can be visually targeted in vivo, permitting extracellular recording from identified axons. This technique facilitates recording when neurons cannot be labeled through genetic manipulation or are difficult to isolate using 'blind' in vivo approaches.

역행 형광 라벨이 확인 된 신경 세포의 표적 세포 외 단일 단위 기록을 허용<em&gt; 생체 내</em

The overall goal of this method is to record single-unit responses from an identified population of neurons. In vivo electrophysiological recordings from ...

Detection of Protein Palmitoylation in Cultured Hippocampal Neurons by Immunoprecipitation and Acyl-Biotin Exchange (ABE)

Palmitoylation is a post-translational lipid modification involving the attachment of a 16-carbon saturated fatty acid, palmitate, to cysteine residues of substrate proteins through a labile thioester bond [reviewed in1]. Palmitoylation of a substrate protein increases its hydrophobicity, and typically facilitates its trafficking toward cellular membranes. Recent studies have shown palmitoylation to be one of the most common lipid modifications in neurons1, 2, suggesting that palmitate turnover is an important mechanism by which these cells regulate the targeting and trafficking of proteins. The identification and detection of palmitoylated substrates can therefore better our understanding of protein trafficking in neurons.
Detection of protein palmitoylation in the past has been technically hindered due to the lack of a consensus sequence among substrate proteins, and the reliance on metabolic labeling of palmitoyl-proteins with 3H-palmitate, a time-consuming biochemical assay with low sensitivity. Development of the Acyl-Biotin Exchange (ABE) assay enables more rapid and high sensitivity detection of palmitoylated proteins2-4, and is optimal for measuring the dynamic turnover of palmitate on neuronal proteins. The ABE assay is comprised of three biochemical steps (Figure 1): 1) irreversible blockade of unmodified cysteine thiol groups using N-ethylmaliemide (NEM), 2) specific cleavage and unmasking of the palmitoylated cysteine's thiol group by hydroxylamine (HAM), and 3) selective labeling of the palmitoylated cysteine using a thiol-reactive biotinylation reagent, biotin-BMCC. Purification of the thiol-biotinylated proteins following the ABE steps has differed, depending on the overall goal of the experiment.
Here, we describe a method to purify a palmitoylated protein of interest in primary hippocampal neurons by an initial immunoprecipitation (IP) step using an antibody directed against the protein, followed by the ABE assay and western blotting to directly measure palmitoylation levels of that protein, which is termed the IP-ABE assay. Low-density cultures of embryonic rat hippocampal neurons have been widely used to study the localization, function, and trafficking of neuronal proteins, making them ideally suited for studying neuronal protein palmitoylation using the IP-ABE assay. The IP-ABE assay mainly requires standard IP and western blotting reagents, and is only limited by the availability of antibodies against the target substrate. This assay can easily be adapted for the purification and detection of transfected palmitoylated proteins in heterologous cell cultures, primary neuronal cultures derived from various brain tissues of both mouse and rat, and even primary brain tissue itself.

Detection of Protein Palmitoylation in Cultured Hippocampal Neurons by Immunoprecipitation and Acyl-Biotin Exchange ABE

The reversible addition of palmitate to proteins is an important regulator of intracellular protein trafficking. This is of particular interest in neurons where many synaptic proteins are palmitoylated. We utilize a simple biochemical method to detect palmitoylated proteins in cultured neurons, which can be adapted for multiple cell types and tissues.

Immunoprecipitation 및 아실-비오틴 거래소 (아베)에 의한 양식 Hippocampal 뉴런의 단백질 Palmitoylation의 감지

Palmitoylation is a post-translational lipid  modification involving the attachment of a 16-carbon saturated fatty acid,  palmitate, to cysteine residues ...

Visualization of Endosome Dynamics in Living Nerve Terminals with Four-dimensional Fluorescence Imaging

Four-dimensional (4D) light imaging has been used to study behavior of small structures within motor nerve terminals of the thin transversus abdominis muscle of the garter snake. Raw data comprises time-lapse sequences of 3D z-stacks. Each stack contains 4-20 images acquired with epifluorescence optics at focal planes separated by 400-1,500 nm. Steps in the acquisition of image stacks, such as adjustment of focus, switching of excitation wavelengths, and operation of the digital camera, are automated as much as possible to maximize image rate and minimize tissue damage from light exposure. After acquisition, a set of image stacks is deconvolved to improve spatial resolution, converted to the desired 3D format, and used to create a 4D "movie" that is suitable for variety of computer-based analyses, depending upon the experimental data sought. One application is study of the dynamic behavior of two classes of endosomes found in nerve terminals-macroendosomes (MEs) and acidic endosomes (AEs)-whose sizes (200-800 nm for both types) are at or near the diffraction limit. Access to 3D information at each time point provides several advantages over conventional time-lapse imaging. In particular, size and velocity of movement of structures can be quantified over time without loss of sharp focus. Examples of data from 4D imaging reveal that MEs approach the plasma membrane and disappear, suggesting that they are exocytosed rather than simply moving vertically away from a single plane of focus. Also revealed is putative fusion of MEs and AEs, by visualization of overlap between the two dye-containing structures as viewed in each three orthogonal projections.

Four-dimensional (4D) imaging is utilized to study the behavior and interactions among two types of endosomes in living vertebrate nerve terminals. Movement of these small structures is characterized in three dimensions, permitting confirmation of events such as endosome fusion and exocytosis.

네 차원 형광 이미징과 신경 말단 생활에 엔도 좀 역학의 시각화

Four-dimensional (4D) light imaging has been used to study behavior of small structures within motor nerve terminals of the thin transversus abdominis ...