المؤلفين أشكر Teele Palumaa للحصول على المساعدة مع الأرقام. بتمويل من منح المشروع 1008046 من مجلس البحوث الطبية، أستراليا الوطنية للصحة و.

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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+analysis+of+gene+expression+patterns+in+developing+mouse+neocortex+using+serial+analysis+of+gene+expression.">Global analysis of gene expression patterns in developing mouse neocortex using serial analysis of gene expression.</a> Mol. Cell. Neurosci. 19, 560-573 (2002).</li><li>Gunnersen, J. M., Kim, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sez-6+proteins+affect+dendritic+arborization+patterns+and+excitability+of+cortical+pyramidal+neurons.">Sez-6 proteins affect dendritic arborization patterns and excitability of cortical pyramidal neurons.</a> Neuron. 56, 621-639 (2007).</li><li>Kennedy, M. J., Davison, I. G., Robinson, C. G., Ehlers, M. 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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synaptogenesis+of+hippocampal+neurons+in+primary+cell+culture.">Synaptogenesis of hippocampal neurons in primary cell culture.</a> Cell Tissue Res. , 338-341 (2009).</li><li>Vaillant, A. R., Zanassi, P., Walsh, G. S., Aumont, A., Alonso, A., Miller, F. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signaling+mechanisms+underlying+reversible,+activity-dependent+dendrite+formation.">Signaling mechanisms underlying reversible, activity-dependent dendrite formation.</a> Neuron. 34, 985-998 (2002).</li><li>Park, M., Penick, E. C., Edwards, J. G., Kauer, J. A., Ehlers, M. 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يعلن الكتاب أنه ليس لديهم مصالح مالية المتنافسة.

تقنية الموضحة هنا هي مكملة لتلك التي biotinylation سطح الخلية (التي استعرضها Arancibia-Càrcamo وآخرون) 12 وهذا هو الأسلوب المفضل للحفاظ على المعلومات حول توطين التحت خلوية من البروتين المنضوية، قدم الأجسام المضادة الأولية المناسبة ل حاتمة خارج الخلية هو متاح. بالإضافة إ...

في إنشاء وظيفة من البروتينات التي تم تشخيصها حديثا، ويمكن التحقيق في توطين التحت خلوية والاتجار من البروتين في مسألة توفر أدلة مهمة حول دور المحتمل / ثانية من 1،2 البروتين. قدم تحليل المعلوماتية الحيوية من Transcriptome على من القشرة المخية الحديثة النامية 3 لنا مع قائمة من الجينات واظهار التعبير تغيير خلال الماوس corticogenesis الدماغ. نحن ثم اعتمدت نهجا خروج المغلوب الجينات للتأكد من أن البروتين المشفرة بواسطة واحد من هذه الجينات، sez6، دورا رئيسيا في تطوير الخلايا العصبية. لاحظنا أن الجينات المتعلقة الاستيلاء 6، أو Sez6 والبروتين الموجود في التشعبات النامية وهذا هو ايضا في العمود الفقري شجيري، هياكل متخصصة في التشعبات التي تتلقى إشارات ودمج مثير. وعلاوة على ذلك، عندما يفتقر هذا البروتين، تفشل التشعبات ونقاط الاشتباك العصبي مثير لتشكيل بشكل صحيح 4. شكل الإسوي المهيمنة المحتمل من البروتين لديه ملامح transmembranه على الرغم من مستقبلات، وعندما تم فحص توزيع التحت خلوية من البروتين immunolabeled بواسطة المجهر متحد البؤر المجهري أو عن طريق immunoelectron معظم، إن لم يكن كلها، للإشارة ظهرت المرتبطة حويصلات صغيرة في حجرة somatodendritic في القليل، أو لا، البروتين المسمى على غشاء البلازما على سطح الخلية. من أجل إظهار قاطع أن هذا المستقبل المفترضة مع مجال واسع خارج الخلية توقع والاتجار بهم لغشاء البلازما، واعتمدنا نهجا الخلية الحية باستخدام مصل كنا قد ولدت خارج الخلية إلى جزء من البروتين لتسمية البروتين على سطح الخلية. من خلال الجمع بين هذا النهج &quot;تغذية الأجسام المضادة&quot; مع اثنين من تطبيقات المسمى تفاضلي الضد الثانوية مفصولة خطوة الحجب واسعة وخطوة permeabilization، تمكنا من تحديد اثنين من تجمعات مختلفة من البروتين تتميز ملزمة لالأجسام المضادة الثانوية fluorescently المسمى الحاملة fluoresc مختلفةبه والأنف والحنجرة. وهكذا، كنا قادرين على التمييز بين البروتين الذي قد المنضوية بواسطة الإلتقام خلال خطوة الضد الحضانة من البروتين الذي إما بقيت على سطح الخلية أو تم الاتجار بهم إلى السطح خلال هذه الفترة. باستخدام هذا الأسلوب، أنشأنا أن البروتين من الفائدة والاتجار بهم من وإلى سطح الخلية في الخلايا العصبية. لذلك، أثبتت هذه التقنية بسرعة نسبيا وبسيطة أكثر إفصاحا من الطرق التقليدية أو مناعية قبل التضمين immunogold المجهر الإلكتروني، على الرغم من حقيقة أننا تستخدم نفس الأرنب بولكلونل مصل لجميع هذه التقنيات. هذه التقنية تنطبق بصورة عامة على أي بروتين الغشاء قدم جيدة الأضداد الاعتراف الحواتم المجال خارج الخلية هو متاح. وقد استخدمت هذه التقنية سابقا لدراسة الاتجار مستقبلات لمستقبلات الغلوتامات GluR1 الوحيدات 5.

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			<td height="21" style="height:21px;width:383px;">PBS with Ca and Mg</td>
			<td style="width:269px;">Invitrogen</td>
			<td style="width:119px;">14040182</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Neurobasal medium</td>
			<td style="width:269px;">Invitrogen</td>
			<td style="width:119px;">21103-049</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">B27 supplement</td>
			<td style="width:269px;">Invitrogen</td>
			<td style="width:119px;">17504-044</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">L-glutamine</td>
			<td style="width:269px;">Invitrogen</td>
			<td style="width:119px;">25030-081</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Papain Dissociation System</td>
			<td style="width:269px;">Worthington Biochemical Corporation</td>
			<td style="width:119px;">PDS</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Bovine Serum Albumin&#160;</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">A9418</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:383px;">Hank&#39;s balanced salt solution without calcium, magnesium, phenol red</td>
			<td style="width:269px;">Invitrogen (Gibco)</td>
			<td style="width:119px;">14175-079</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Poly-D-Lysine</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">P0899</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Natural mouse laminin</td>
			<td style="width:269px;">Invitrogen</td>
			<td style="width:119px;">23017-015</td>
			<td>Thaw on ice prior to making aliquots</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Fetal bovine serum HyClone</td>
			<td style="width:269px;">Thermo Fisher</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">fluorodeoxyuridine</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">F0503</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">uridine</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">U3003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">18 mm round glass coverslips</td>
			<td style="width:269px;">Menzel Gl&#228;ser</td>
			<td>CB00180RA1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">VECTASHIELD aqueous mounting medium</td>
			<td style="width:269px;">Vector Laboratories</td>
			<td style="width:119px;">H1400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Donkey anti-rabbit Dylight 649&#160;</td>
			<td>Jackson ImmunoResearch Laboratories</td>
			<td style="width:119px;">711-495-152</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">AffiniPure Fab fragment Goat anti-Rabbit 1gG (H+L)&#160;</td>
			<td>Jackson ImmunoResearch Laboratories</td>
			<td>111-007-003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Paraformaldehyde</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">P6148</td>
			<td>TOXIC - handle in fume hood</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:383px;">Triton-X-100</td>
			<td style="width:269px;">Sigma Aldrich Australia</td>
			<td style="width:119px;">T8787</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Alexafluor 488-conjugated donkey anti-rabbit 2&#176; antibody</td>
			<td style="width:269px;">Invitrogen - Molecular Probes</td>
			<td style="width:119px;">A21206</td>
			<td></td>
		</tr>
	</tbody>
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differential labeling of cell-surface and internalized proteins after antibody feeding of live cultured neurons

من أجل إظهار توطين سطح الخلية من مستقبلات عبر الغشاء المفترضة في الخلايا العصبية مثقف، ونحن المسمى البروتين على سطح الخلايا العصبية الحية مع الأجسام المضادة الأولية المحددة التي أثيرت ضد جزء من البروتين خارج الخلية. بالنظر إلى أن المستقبلات يتم الاتجار من وإلى السطح، إذا تم permeabilized الخلايا بعد التثبيت ثم سوف يتم الكشف عن كل من سطح الخلية والبروتينات الداخلية من قبل نفس الأجسام المضادة الثانوية المسمى. هنا، ونحن تكييفها طريقة تستخدم لدراسة الاتجار البروتين (&quot;تغذية الأجسام المضادة&quot;) لتفاضلي البروتين التسمية التي كان قد كتبها المنضوية الإلتقام خلال خطوة الضد الحضانة والبروتين الذي إما بقيت على سطح الخلية أو تم الاتجار بهم إلى السطح خلال هذه الفترة . وقدم القدرة على التمييز بين هذه حمامات اثنين من البروتين ممكن من خلال إدماج خطوة الحجب بين عشية وضحاها مع تتركز درجة عالية من الأجسام المضادة الثانوية أونلبلد بعد incubatio الأوليةن من الخلايا العصبية unpermeabilized مع الأجسام المضادة الثانوية fluorescently المسمى. بعد عرقلة الخطوة، permeabilization من الخلايا العصبية يسمح الكشف عن تجمع المنضوية مع الأجسام المضادة الثانوية فلوري المسمى مع fluorophore مختلفة. باستخدام هذه التقنية تمكنا من الحصول على معلومات مهمة عن مكان التحت خلوية من هذا المستقبل المفترضة، وكشف عن أنه كان، في الواقع، يتم الاتجار بهم إلى سطح الخلية في الخلايا العصبية. هذه التقنية قابلة للتطبيق على نطاق واسع لمجموعة من أنواع الخلايا والبروتينات على سطح الخلية، وتوفير الأجسام المضادة مناسبة لحاتمة خارج الخلية هو متاح.

المزدوجة لون تقنية المناعية فلوري المقدمة هنا هو مفيد لوصفها المجالات خارج الخلية البروتينات عبر الغشاء في الخلايا الحية (كما هو موضح تخطيطي في الشكل 1). خلال فترة الحضانة، وربط الحواتم المناعية الوصول إليها ونسبة من السكان من جزيئات البروتين، جنبا إلى جنب ?...

Watch this Scientific Journal Video about Differential Labeling of Cell-surface and Internalized Proteins after Antibody Feeding of Live Cultured Neurons at JoVE.com

Differential Labeling of Cell-surface and Internalized Proteins after Antibody Feeding of Live Cultured Neurons

نحن تصف طريقة لتسمية البروتين على سطح الخلايا العصبية الحية باستخدام الأجسام المضادة بولكلونل محددة لالحواتم خارج الخلية. البروتين ملزمة الأجسام المضادة على سطح الخلية وبالتالي المنضوية عبر الإلتقام يمكن تمييزها عن البروتين المتبقية على، أو الاتجار بهن ل، والسطح أثناء الحضانة.

وصفها الفرق من سطح الخلية والمنضوية البروتينات الأجسام المضادة بعد تغذية الخلايا العصبية مثقف لايف

In order to demonstrate the cell-surface localization of a putative transmembrane receptor in cultured neurons, we labeled the protein on the surface of ...

differential-labeling-cell-surface-internalized-proteins-after

Research

JoVE Journal

Neuroscience

15.3K Views.  The University of Melbourne.  نحن تصف طريقة لتسمية البروتين على سطح الخلايا العصبية الحية باستخدام الأجسام المضادة بولكلونل محددة لالحواتم خارج الخلية. البروتين ملزمة الأجسام المضادة على سطح الخلية وبالتالي المنضوية عبر الإلتقام يمكن تمييزها عن البروتين المتبقية عل...

Video: Differential Labeling of Cell-surface and Internalized Proteins after Antibody Feeding of Live Cultured Neurons

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.

مضان الانتعاش بعد Photobleaching (FRAP) من البروتينات المرتبطة دلاليا الإسفار في العمود الفقري شجيري الخلايا العصبية الحصين مثقف

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.

تحليل الصرف العمود الفقري شجيري الخلايا العصبية في الجهاز العصبي المركزي لؤلؤ

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

Live Imaging of Dorsal Root Axons after Rhizotomy

The primary sensory axons injured by spinal root injuries fail to regenerate into the spinal cord, leading to chronic pain and permanent sensory loss. Regeneration of dorsal root (DR) axons into spinal cord is prevented at the dorsal root entry zone (DREZ), the interface between the CNS and PNS. Our understanding of the molecular and cellular events that prevent regeneration at DREZ is incomplete, in part because complex changes associated with nerve injury have been deduced from postmortem analyses. Dynamic cellular processes, such as axon regeneration, are best studied with techniques that capture real-time events with multiple observations of each living animal. Our ability to monitor neurons serially in vivo has increased dramatically owing to revolutionary innovations in optics and mouse transgenics. Several lines of thy1-GFP transgenic mice, in which subsets of neurons are genetically labeled in distinct fluorescent colors, permit individual neurons to be imaged in vivo1. These mice have been used extensively for in vivo imaging of muscle2-4 and brain5-7, and have provided novel insights into physiological mechanisms that static analyses could not have resolved. Imaging studies of neurons in living spinal cord have only recently begun. Lichtman and his colleagues first demonstrated their feasibility by tracking injured dorsal column (DC) axons with wide-field microscopy8,9. Multi-photon in vivo imaging of deeply positioned DC axons, microglia and blood vessels has also been accomplished10. Over the last few years, we have pioneered in applying in vivo imaging to monitor regeneration of DR axons using wide-field microscopy and H line of thy1-YFP mice. These studies have led us to a novel hypothesis about why DR axons are prevented from regenerating within the spinal cord11.
In H line of thy1-YFP mice, distinct YFP+ axons are superficially positioned, which allows several axons to be monitored simultaneously. We have learned that DR axons arriving at DREZ are better imaged in lumbar than in cervical spinal cord. In the present report we describe several strategies that we have found useful to assure successful long-term and repeated imaging of regenerating DR axons. These include methods that eliminate repeated intubation and respiratory interruption, minimize surgery-associated stress and scar formation, and acquire stable images at high resolution without phototoxicity.

An in vivo imaging protocol to monitor primary sensory axons following dorsal root crush is described. The procedures utilize wide-field fluorescence microscopy and thy1-YFP transgenic mice, and permit repeated imaging of axon regeneration over 4 cm in the PNS and axon interactions with the interface of the CNS.

يعيش بين محاور التصوير الجذر الظهرية بعد بضع الجذور

The primary sensory axons injured by spinal root injuries fail to regenerate into the spinal cord, leading to chronic pain and permanent sensory loss. ...

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.

حفز النمو في الخلايا العصبية شجيري متعاطف مثقف

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 ...

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated. Thus, simultaneous recordings of neuronal activity and behavior are essential to correlate brain activity to behavior. For such behavioral analyses, the fruit fly, Drosophila melanogaster, allows us to incorporate genetically encoded calcium indicators such as GCaMP1, to monitor neuronal activity, and to use sophisticated genetic manipulations for optogenetic or thermogenetic techniques to specifically activate identified neurons2-5. Use of a thermogenetic technique has led us to find critical neurons for feeding behavior (Flood et al., under revision). As a main part of feeding behavior, a Drosophila adult extends its proboscis for feeding6 (proboscis extension response; PER), responding to a sweet stimulus from sensory cells on its proboscis or tarsi. Combining the protocol for PER7 with a calcium imaging technique8 using GCaMP3.01, 9, I have established an experimental system, where we can monitor activity of neurons in the feeding center &#x2013; the suboesophageal ganglion (SOG), simultaneously with behavioral observation of the proboscis. I have designed an apparatus ("Fly brain Live Imaging and Electrophysiology Stage": "FLIES") to accommodate a Drosophila adult, allowing its proboscis to freely move while its brain is exposed to the bath for Ca2+ imaging through a water immersion lens. The FLIES is also appropriate for many types of live experiments on fly brains such as electrophysiological recording or time lapse imaging of synaptic morphology. Because the results from live imaging can be directly correlated with the simultaneous PER behavior, this methodology can provide an excellent experimental system to study information processing of neuronal networks, and how this cellular activity is coupled to plastic processes and memory.

Simultaneous Recording of Calcium Signals from Identified Neurons and Feeding Behavior of Drosophila melanogaster

The fruit fly, Drosophila melanogaster, extends its proboscis for feeding, responding to a sugar stimulus from its proboscis or tarsus. I have combined observations of the proboscis extension response (PER) with a calcium imaging technique, allowing us to monitor the activity of neurons in the brain, simultaneously with behavioral observation.

في وقت واحد من تسجيل إشارات الكالسيوم من الخلايا العصبية التي تم تحديدها وسلوك التغذية من ذبابة الفاكهة السوداء البطن</em

To study neuronal networks in terms of their function in behavior, we must analyze how neurons operate when each behavioral pattern is generated.  Thus, ...

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.

المقررة الإنتشار الأفقي والإيماس من غشاء بروتينات في الخلايا العصبية مثقف باستخدام الاسترداد الإسفار وPhotobleaching الإسفار الخسارة

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

Post-embedding Immunogold Labeling of Synaptic Proteins in Hippocampal Slice Cultures

Immunoelectron microscopy is a powerful tool to study biological molecules at the subcellular level. Antibodies coupled to electron-dense markers such as colloidal gold can reveal the localization and distribution of specific antigens in various tissues1. The two most widely used techniques are pre-embedding and post-embedding techniques. In pre-embedding immunogold-electron microscopy (EM) techniques, the tissue must be permeabilized to allow antibody penetration before it is embedded. These techniques are ideal for preserving structures but poor penetration of the antibody (often only the first few micrometers) is a considerable drawback2. The post-embedding labeling methods can avoid this problem because labeling takes place on sections of fixed tissues where antigens are more easily accessible. Over the years, a number of modifications have improved the post-embedding methods to enhance immunoreactivity and to preserve ultrastructure3-5.
Tissue fixation is a crucial part of EM studies. Fixatives chemically crosslink the macromolecules to lock the tissue structures in place. The choice of fixative affects not only structural preservation but also antigenicity and contrast. Osmium tetroxide (OsO4), formaldehyde, and glutaraldehyde have been the standard fixatives for decades, including for central nervous system (CNS) tissues that are especially prone to structural damage during chemical and physical processing. Unfortunately, OsO4 is highly reactive and has been shown to mask antigens6, resulting in poor and insufficient labeling. Alternative approaches to avoid chemical fixation include freezing the tissues. But these techniques are difficult to perform and require expensive instrumentation. To address some of these problems and to improve CNS tissue labeling, Phend et al. replaced OsO4 with uranyl acetate (UA) and tannic acid (TA), and successfully introduced additional modifications to improve the sensitivity of antigen detection and structural preservation in brain and spinal cord tissues7. We have adopted this osmium-free post-embedding method to rat brain tissue and optimized the immunogold labeling technique to detect and study synaptic proteins.
We present here a method to determine the ultrastructural localization of synaptic proteins in rat hippocampal CA1 pyramidal neurons. We use organotypic hippocampal cultured slices. These slices maintain the trisynaptic circuitry of the hippocampus, and thus are especially useful for studying synaptic plasticity, a mechanism widely thought to underlie learning and memory. Organotypic hippocampal slices from postnatal day 5 and 6 mouse/rat pups can be prepared as described previously8, and are especially useful to acutely knockdown or overexpress exogenous proteins. We have previously used this protocol to characterize neurogranin (Ng), a neuron-specific protein with a critical role in regulating synaptic function8,9 . We have also used it to characterize the ultrastructural localization of calmodulin (CaM) and Ca2+/CaM-dependent protein kinase II (CaMKII)10. As illustrated in the results, this protocol allows good ultrastructural preservation of dendritic spines and efficient labeling of Ng to help characterize its distribution in the spine8. Furthermore, the procedure described here can have wide applicability in studying many other proteins involved in neuronal functions.

The localization and distribution of proteins provide important information for understanding their cellular functions. The superior spatial resolution of electron microscopy (EM) can be used to determine the subcellular localization of a given antigen following immunohistochemistry. For tissues of the central nervous system (CNS), preserving structural integrity while maintaining antigenicity has been especially difficult in EM studies. Here, we adopt a procedure that has been used to preserve structures and antigens in the CNS to study and characterize synaptic proteins in rat hippocampal CA1 pyramidal neurons.

بعد تضمين التعريف Immunogold من البروتينات متشابك في الثقافات شريحة الحصين

Immunoelectron microscopy is a powerful tool to study biological molecules at the subcellular level. Antibodies coupled to electron-dense markers such as ...

Membrane Potential Dye Imaging of Ventromedial Hypothalamus Neurons From Adult Mice to Study Glucose Sensing

Studies of neuronal activity are often performed using neurons from rodents less than 2 months of age due to the technical difficulties associated with increasing connective tissue and decreased neuronal viability that occur with age. Here, we describe a methodology for the dissociation of healthy hypothalamic neurons from adult-aged mice. The ability to study neurons from adult-aged mice allows the use of disease models that manifest at a later age and might be more developmentally accurate for certain studies. Fluorescence imaging of dissociated neurons can be used to study the activity of a population of neurons, as opposed to using electrophysiology to study a single neuron. This is particularly useful when studying a heterogeneous neuronal population in which the desired neuronal type is rare such as for hypothalamic glucose sensing neurons. We utilized membrane potential dye imaging of adult ventromedial hypothalamic neurons to study their responses to changes in extracellular glucose. Glucose sensing neurons are believed to play a role in central regulation of energy balance. The ability to study glucose sensing in adult rodents is particularly useful since the predominance of diseases related to dysfunctional energy balance (e.g.&#160;obesity) increase with age.

The activity of single neurons from adult-aged mice can be studied by dissociating neurons from specific brain regions and using fluorescent membrane potential dye imaging. By testing responses to changes in glucose, this technique can be used to study the glucose sensitivity of adult ventromedial hypothalamic neurons.

غشاء المحتملة صبغ التصوير من بطني إنسي المهاد الخلايا العصبية من الفئران الكبار لدراسة الجلوكوز الاستشعار

Studies of neuronal activity are often performed using neurons from rodents less than 2 months of age due to the technical difficulties associated with ...

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

In the brain, membrane trafficking systems play important roles in regulating neuronal functions, such as neuronal morphology, synaptic plasticity, survival, and glial communications. To date, numerous studies have reported that defects in these systems cause various neuronal diseases. Thus, understanding the mechanisms underlying vesicle dynamics may provide influential clues that could aid in the treatment of several neuronal disorders. Here, we describe a method for quantifying vesicle motilities, such as motility distance and rate of movement, using a software plug-in for the ImageJ platform. To obtain images for quantification, we labeled neuronal endosome-lysosome structures with EGFP-tagged vesicle marker proteins and observed the movement of vesicles using a time-lapse microscopy. This method is highly useful and simplify measuring vesicle motility in neurites, such as axons and dendrites, as well as in the soma of both neurons and glial cells. Furthermore, this method can be applied to other cell lines, such as fibroblasts and endothelial cells. This approach could provide a valuable advancement of our understanding of membrane trafficking.

The investigation of membrane trafficking is crucial for understanding neuronal functions. Here, we introduce a method for quantifying vesicle motility in neurons. This is a convenient method that can be adapted to the quantification of membrane trafficking in the nervous system.

كمي من إندوسوم و ليسوسوم التحركات في الخلايا العصبية المستزرعة باستخدام تحقيقات الفلورسنت

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

Measuring Synaptic Vesicle Endocytosis in Cultured Hippocampal Neurons

During endocytosis, fused synaptic vesicles are retrieved at nerve terminals, allowing for vesicle recycling and thus the maintenance of synaptic transmission during repetitive nerve firing. Impaired endocytosis in pathological conditions leads to decreases in synaptic strength and brain functions. Here, we describe methods used to measure synaptic vesicle endocytosis at the mammalian hippocampal synapse in neuronal culture. We monitored synaptic vesicle protein endocytosis by fusing a synaptic vesicular membrane protein, including synaptophysin and VAMP2/synaptobrevin, at the vesicular lumenal side, with pHluorin, a pH-sensitive green fluorescent protein that increases its fluorescence intensity as the pH increases. During exocytosis, vesicular lumen pH increases, whereas during endocytosis vesicular lumen pH is re-acidified. Thus, an increase of pHluorin fluorescence intensity indicates fusion, whereas a decrease indicates endocytosis of the labelled synaptic vesicle protein. In addition to using the pHluorin imaging method to record endocytosis, we monitored vesicular membrane endocytosis by electron microscopy (EM) measurements of Horseradish peroxidase (HRP) uptake by vesicles. Finally, we monitored the formation of nerve terminal membrane pits at various times after high potassium-induced depolarization. The time course of HRP uptake and membrane pit formation indicates the time course of endocytosis.

Synaptic vesicle endocytosis is detected by light microscopy of pHluorin fused with synaptic vesicle protein and by electron microscopy of vesicle uptake.