Name: spectral confocal imaging of fluorescently tagged nicotinic receptors in knock-in mice with chronic nicotine administration
Uploaded: 2012-02-10T12:00:00
Description: Watch this Scientific Journal Video about Spectral Confocal Imaging of Fluorescently tagged Nicotinic Receptors in Knock-in Mice with Chronic Nicotine Administration at JoVE.com

Anthony Renda was supported by a University of Victoria Graduate Fellowship Award. This research was supported by a Natural Sciences and Engineering Research Council of Canada Discovery Grant, a NARSAD Young investigator Award (to R.N.), a Victoria Foundation - Myre and Winifred Sim Fund, a Canadian Foundation for Innovation grant, a British Columbia Knowledge Development Fund and a Natural Sciences and Engineering Research Council of Canada Research Tools and Instrumentation Grant. We thank Jillian McKay, Christina Barnes, Ariel Sullivan, Jennifer MacDonald and Daniel Morgado for excellent mouse husbandry.

1. Pump implantation
<ol>
	<li>Before pump implantation, fill and prepare the Alzet mini-osmotic pumps (Alzet, Model 2002, Cupertino, USA) being careful not to introduce air bubbles. This model of mini-osmotic pump delivers solution at a rate of 0.5 &mu;l/hr for 14 days. Ensure sterile conditions. Weigh empty and filled pumps. At the conclusion of experiment (10 days after implantation), the remaining liquid in the pump can be removed with a syringe and needle and weighed to calculate the volume pumped.</li>
	<li>Pumps...

<ol>
	<li>Perry, D. C., Davila-Garcia, M. I., Stockmeier, C. A., Kellar, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+nicotinic+receptors+in+brains+from+smokers:+membrane+binding+and+autoradiography+studies.">Increased nicotinic receptors in brains from smokers: membrane binding and autoradiography studies.</a> J. Pharmacol. Exp. Ther. 289, 1545-1552 (1999).</li><li>Schwartz, R. D., Kellar, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nicotinic+cholinergic+receptor+binding+sites+in+the+brain:+regulation+in+vivo.">Nicotinic cholinergic receptor binding sites in the brain: regulation in vivo.</a> Science. 220, 214-216 (1983).</li><li>Marks, M. J., Burch, J. B., Collins, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+chronic+nicotine+infusion+on+tolerance+development+and+nicotinic+receptors.">Effects of chronic nicotine infusion on tolerance development and nicotinic receptors.</a> J. Pharmacol. Exp. Ther. 226, 817-8125 (1983).</li><li>Carlezon, W. A. J., Nestler, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elevated+levels+of+GluR1+in+the+midbrain:+a+trigger+for+sensitization+to+drugs+of+abuse.">Elevated levels of GluR1 in the midbrain: a trigger for sensitization to drugs of abuse.</a> Trends Neurosci. 25, 610-615 (2002).</li><li>Fitzgerald, L. W., Ortiz, J., Hamedani, A. G., Nestler, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drugs+of+abuse+and+stress+increase+the+expression+of+GluR1+and+NMDAR1+glutamate+receptor+subunits+in+the+rat+ventral+tegmental+area:+common+adaptations+among+cross-sensitizing+agents.">Drugs of abuse and stress increase the expression of GluR1 and NMDAR1 glutamate receptor subunits in the rat ventral tegmental area: common adaptations among cross-sensitizing agents.</a> J. Neurosci. 16, 274-2782 (1996).</li><li>Saal, D., Dong, Y., Bonci, A., Malenka, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drugs+of+abuse+and+stress+trigger+a+common+synaptic+adaptation+in+dopamine+neurons.">Drugs of abuse and stress trigger a common synaptic adaptation in dopamine neurons.</a> Neuron. 37, 577-5782 (2003).</li><li>Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+green+fluorescent+protein.">The green fluorescent protein.</a> Annu. Rev. Biochem. 67, 509-544 (1998).</li><li>Chalfie, M., Tu, Y., Euskirchen, G., Ward, W. W., Prasher, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Green+fluorescent+protein+as+a+marker+for+gene+expression.">Green fluorescent protein as a marker for gene expression.</a> Science. 263, 802-805 (1994).</li><li>Feng, G., Mellor, R. H., Bernstein, M., Keller-Peck, C., Nguyen, Q. T., Wallace, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+neuronal+subsets+in+transgenic+mice+expressing+multiple+spectral+variants+of+GFP.">Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP.</a> Neuron. 28, 41-51 (2000).</li><li>Livet, J., Weissman, T. A., Kang, H., Draft, R. W., Lu, J., Bennis, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+strategies+for+combinatorial+expression+of+fluorescent+proteins+in+the+nervous+system.">Transgenic strategies for combinatorial expression of fluorescent proteins in the nervous system.</a> Nature. 450, 56-62 (2007).</li><li>Nashmi, R., Dickinson, M. E., McKinney, S., Jareb, M., Labarca, C., Fraser, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+of+&#945;4&#946;2+nicotinic+acetylcholine+receptors+assessed+with+functional+fluorescently+labeled+subunits:+effects+of+localization,+trafficking,+and+nicotine-induced+upregulation+in+clonal+mammalian+cells+and+in+cultured+midbrain+neurons.">Assembly of &#945;4&#946;2 nicotinic acetylcholine receptors assessed with functional fluorescently labeled subunits: effects of localization, trafficking, and nicotine-induced upregulation in clonal mammalian cells and in cultured midbrain neurons.</a> J. Neurosci. 23, 11554-11567 (2003).</li><li>Nashmi, R., Xiao, C., Deshpande, P., McKinney, S., Grady, S. R., Whiteaker, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+nicotine+cell+specifically+upregulates+functional+Î±4*+nicotinic+receptors:+basis+for+both+tolerance+in+midbrain+and+enhanced+long-term+potentiation+in+perforant+path.">Chronic nicotine cell specifically upregulates functional Î±4* nicotinic receptors: basis for both tolerance in midbrain and enhanced long-term potentiation in perforant path.</a> J. Neurosci. 27, 8202-8218 (2007).</li><li>Dickinson, M. E., Bearman, G., Tilie, S., Lansford, R., Fraser, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-spectral+imaging+and+linear+unmixing+add+a+whole+new+dimension+to+laser+scanning+fluorescence+microscopy.">Multi-spectral imaging and linear unmixing add a whole new dimension to laser scanning fluorescence microscopy.</a> BioTechniques. 31, 1272-1278 (2001).</li><li>Nashmi, R., Fraser, S. E., Lester, H., Dickinson, M. E., Periasamy, A., Day, R. N. <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 imaging: fret microscopy and spectroscopy. , 180-192 (2005).</li><li>Zimmermann, T., Rietdorf, J., Girod, A., Georget, V., Pepperkok, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+imaging+and+linear+un-mixing+enables+improved+FRET+efficiency+with+a+novel+GFP2-YFP+FRET+pair.">Spectral imaging and linear un-mixing enables improved FRET efficiency with a novel GFP2-YFP FRET pair.</a> FEBS Lett. 531, 245-249 (2002).</li><li>Larson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Nikon+C1si+combines+high+spectral+resolution,+high+sensitivity,+and+high+acquisition+speed.">The Nikon C1si combines high spectral resolution, high sensitivity, and high acquisition speed.</a> Cytometry A. 69, 825-8234 (2006).</li><li>Melvin, N. R., Sutherland, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+caveats+of+standard+immunohistochemical+procedures:+implications+for+optical+disector-based+designs.">Quantitative caveats of standard immunohistochemical procedures: implications for optical disector-based designs.</a> J. Histochem. Cytochem. 58, 577-5784 (2010).</li><li>Jones, I. W., Wonnacott, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+doesn't+nicotinic+ACh+receptor+immunoreactivity+knock+out.">Why doesn't nicotinic ACh receptor immunoreactivity knock out.</a> Trends Neurosci. 28, 343-345 (2005).</li><li>Moser, N., Mechawar, N., Jones, I., Gochberg-Sarver, A., Orr-Urtreger, A., Plomann, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+the+suitability+of+nicotinic+acetylcholine+receptor+antibodies+for+standard+immunodetection+procedures.">Evaluating the suitability of nicotinic acetylcholine receptor antibodies for standard immunodetection procedures.</a> J. Neurochem. , (2007).</li><li>Whiteaker, P., Cooper, J. F., Salminen, O., Marks, M. J., McClure-Begley, T. D., Brown, R. W., Collins, A. C., Lindstrom, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunolabeling+demonstrates+the+interdependence+of+mouse+brain+a4+and+b2+nicotinic+acetylcholine+receptor+subunit+expression.">Immunolabeling demonstrates the interdependence of mouse brain a4 and b2 nicotinic acetylcholine receptor subunit expression.</a> The Journal of Comparative Neurology. 499, 1016-1038 (2006).</li><li>Marks, M. J., McClure-Begley, T. D., Whiteaker, P., Salminen, O., Brown, R. W. B., Cooper, J., Collins, A. C., Lindstrom, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+nicotinic+acetylcholine+receptor+protein+underlies+chronic+nicotine-induced+up-regulation+of+nicotinic+agonist+binding+sites+in+mouse+brain.">Increased nicotinic acetylcholine receptor protein underlies chronic nicotine-induced up-regulation of nicotinic agonist binding sites in mouse brain.</a> The Journal of Pharmacology and Experimental Therapeutics. , 337-3187 (2011).</li><li>Marks, M. J., Rowell, P. P., Cao, J. Z., Grady, S. R., McCallum, S. E., Collins, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subsets+of+acetylcholine-stimulated+86[Rb]++efflux+and+125[I]-epibatidine+binding+sites+in+C57BL/6+mouse+brain+are+differentially+affected+by+chronic+nicotine+treatment.">Subsets of acetylcholine-stimulated 86[Rb]+ efflux and 125[I]-epibatidine binding sites in C57BL/6 mouse brain are differentially affected by chronic nicotine treatment.</a> Neuropharmacology. 46, 1141-1157 (2004).</li><li>King, S. L., Caldarone, B. J., Picciotto, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta2-subunit-containing+nicotinic+acetylcholine+receptors+are+critical+for+dopamine-dependent+locomotor+activation+following+repeated+nicotine+administration.">Beta2-subunit-containing nicotinic acetylcholine receptors are critical for dopamine-dependent locomotor activation following repeated nicotine administration.</a> Neuropharmacology. 47, 132-139 (2004).</li><li>Robinson, S. F., Marks, M. J., Collins, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inbred+mouse+strains+vary+in+oral+self-selection+of+nicotine.">Inbred mouse strains vary in oral self-selection of nicotine.</a> Psychopharmacology (Berl). 124, 332-339 (1996).</li><li>Sparks, J. A., Pauly, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+continuous+oral+nicotine+administration+on+brain+nicotinic+receptors+and+responsiveness+to+nicotine+in+C57Bl/6+mice.">Effects of continuous oral nicotine administration on brain nicotinic receptors and responsiveness to nicotine in C57Bl/6 mice.</a> Psychopharmacology (Berl). , 141-145 (1999).</li><li>Rahman, S., Zhang, J., Engleman, E. A., Corrigall, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroadaptive+changes+in+the+mesoaccumbens+dopamine+system+after+chronic+nicotine+self-administration:+a+microdialysis+study.">Neuroadaptive changes in the mesoaccumbens dopamine system after chronic nicotine self-administration: a microdialysis study.</a> Neuroscience. 129, 415-4124 (2004).</li><li>Picciotto, M. R., Zoli, M., Rimondini, R., Lena, C., Marubio, L. M., Pich, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acetylcholine+receptors+containing+the+Î²2+subunit+are+involved+in+the+reinforcing+properties+of+nicotine.">Acetylcholine receptors containing the Î²2 subunit are involved in the reinforcing properties of nicotine.</a> Nature. 391, 173-177 (1998).</li><li>Fowler, C. D., Lu, Q., Johnson, P. M., Marks, M. J., Kenny, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Habenular+&#945;5+nicotinic+receptor+subunit+signalling+controls+nicotine+intake.">Habenular &#945;5 nicotinic receptor subunit signalling controls nicotine intake.</a> Nature. 471, 597-601 (2011).</li><li>Maskos, U., Molles, B. E., Pons, S., Besson, M., Guiard, B. P., Guilloux, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nicotine+reinforcement+and+cognition+restored+by+targeted+expression+of+nicotinic+receptors.">Nicotine reinforcement and cognition restored by targeted expression of nicotinic receptors.</a> Nature. 436, 103-107 (2005).</li><li>Matta, S. G., Balfour, D. J., Benowitz, N. L., Boyd, R. T., Buccafusco, J. J., Caggiula, A. R., Craig, C. R., Collins, A. C., Damaj, M. I., Donny, E. C., Gardiner, P. S., Grady, S. R., Heberlein, U., Leonard, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Guidelines+on+nicotine+dose+selection+for+in+vivo+research.">Guidelines on nicotine dose selection for in vivo research.</a> Psychopharmacology. 190, 269-319 (2007).</li><li>Lang, T., Rizzoli, S. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane+protein+clusters+at+nanoscale+resolution:+more+than+pretty+pictures.">Membrane protein clusters at nanoscale resolution: more than pretty pictures.</a> Physiology (Bethesda). 25, 116-1124 (2010).</li></ol>

The use of a fluorescent receptor in a knock-in mouse model to determine quantity and localization of a specific ion channel provides a number of advantages. In contrast to proteins such as actin, which is ubiquitously expressed in all cells, ion channels are present in far fewer numbers and their expression varies between neuronal subtypes making accurate analysis via traditional immunohistochemical techniques challenging. The &alpha;4YFP gene product is expressed at WT levels, being under control of the same promoter...

<table border="1">
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>mini-osmotic pumps</td>
 <td>Alzet</td>
 <td>model 2002</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>saline</td>
 <td>Teknova</td>
 <td>S5819</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>(-)-nicotine hydrogen tartrate salt</td>
 <td>Sigma </td>
 <td>N5260</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>eye drops</td>
 <td>Novartis</td>
 <td>Tear-Gel</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Vetbond glue</td>
 <td>3M</td>
 <td>1469SB</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>heparin sodium salt</td>
 <td>Sigma </td>
 <td>H4784</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>10x PBS</td>
 <td>Invitrogen</td>
 <td>70011</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>ketamine</td>
 <td>Wyeth Animal Health</td>
 <td>0856-4403-01</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>medatomidine hydrochloride</td>
 <td>Pfizer</td>
 <td>1950673</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>23G butterfly needle</td>
 <td>Becton Dickinson</td>
 <td>367253</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>paraformaldehyde</td>
 <td>Electron Microscopy Sciences</td>
 <td>15710</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>plastic embedding mold</td>
 <td>VWR</td>
 <td>18986-1</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>O.C.T. Mounting Compound</td>
 <td>Tissue-Tek</td>
 <td>4583</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Mowiol 4-88</td>
 <td>EMD-Calbiochem</td>
 <td>475904</td>
 <td>pH 8.5</td>
 </tr>
</table>

spectral confocal imaging of fluorescently tagged nicotinic receptors in knock-in mice with chronic nicotine administration

Ligand-gated ion channels in the central nervous system (CNS) are implicated in numerous conditions with serious medical and social consequences. For instance, addiction to nicotine via tobacco smoking is a leading cause of premature death worldwide (World Health Organization) and is likely caused by an alteration of ion channel distribution in the brain1. Chronic nicotine exposure in both rodents and humans results in increased numbers of nicotinic acetylcholine receptors (nAChRs) in brain tissue1-3. Similarly, alterations in the glutamatergic GluN1 or GluA1 channels have been implicated in triggering sensitization to other addictive drugs such as cocaine, amphetamines and opiates4-6.

Consequently, the ability to map and quantify distribution and expression patterns of specific ion channels is critically important to understanding the mechanisms of addiction. The study of brain region-specific effects of individual drugs was advanced by the advent of techniques such as radioactive ligands. However, the low spatial resolution of radioactive ligand binding prevents the ability to quantify ligand-gated ion channels in specific subtypes of neurons. 

Genetically encoded fluorescent reporters, such as green fluorescent protein (GFP) and its many color variants, have revolutionized the field of biology7.By genetically tagging a fluorescent reporter to an endogenous protein one can visualize proteins in vivo7-10. One advantage of fluorescently tagging proteins with a probe is the elimination of antibody use, which have issues of nonspecificity and accessibility to the target protein. We have used this strategy to fluorescently label nAChRs, which enabled the study of receptor assembly using F&ouml;rster Resonance Energy Transfer (FRET) in transfected cultured cells11.More recently, we have used the knock-in approach to engineer mice with yellow fluorescent protein tagged &alpha;4 nAChR subunits (&alpha;4YFP), enabling precise quantification of the receptor ex vivo at submicrometer resolution in CNS neurons via spectral confocal microscopy12. The targeted fluorescent knock-in mutation is incorporated in the endogenous locus and under control of its native promoter, producing normal levels of expression and regulation of the receptor when compared to untagged receptors in wildtype mice. This knock-in approach can be extended to fluorescently tag other ion channels and offers a powerful approach of visualizing and quantifying receptors in the CNS.

In this paper we describe a methodology to quantify changes in nAChR expression in specific CNS neurons after exposure to chronic nicotine. Our methods include mini-osmotic pump implantation, intracardiac perfusion fixation, imaging and analysis of fluorescently tagged nicotinic receptor subunits from &alpha;4YFP knock-in mice (Fig. 1). We have optimized the fixation technique to minimize autofluorescence from fixed brain tissue.We describe in detail our imaging methodology using a spectral confocal microscope in conjunction with a linear spectral unmixing algorithm to subtract autofluoresent signal in order to accurately obtain &alpha;4YFP fluorescence signal. Finally, we show results of chronic nicotine-induced upregulation of &alpha;4YFP receptors in the medial perforant path of the hippocampus.

Watch this Scientific Journal Video about Spectral Confocal Imaging of Fluorescently tagged Nicotinic Receptors in Knock-in Mice with Chronic Nicotine Administration at JoVE.com

Spectral Confocal Imaging of Fluorescently tagged Nicotinic Receptors in Knock-in Mice with Chronic Nicotine Administration

We have developed a novel technique of quantifying nicotinic acetylcholine receptor changes within subcellular regions of specific subtypes of CNS neurons to better understand the mechanisms of nicotine addiction by using a combination of approaches including fluorescent protein tagging of the receptor using the knock-in approach and spectral confocal imaging.

Ligand-gated ion channels in the central nervous system (CNS) are implicated in numerous conditions with serious medical and social consequences.  For ...

Research

JoVE Journal

Neuroscience

Subcutaneous Administration of Muscarinic Antagonists and Triple-Immunostaining of the Levator Auris Longus Muscle in Mice

Hind limb muscles of rodents, such as gastrocnemius and tibialis anterior, are frequently used for in vivo  pharmacological studies of the signals ...

Imaging Calcium Responses in GFP-tagged Neurons of Hypothalamic Mouse Brain Slices

Despite an enormous increase in our knowledge about the mechanisms underlying the encoding of information in the brain, a central question concerning the ...

Live Imaging of Nicotine Induced Calcium Signaling and Neurotransmitter Release Along Ventral Hippocampal Axons

Sustained enhancement of axonal signaling and increased neurotransmitter release by the activation of pre-synaptic nicotinic acetylcholine receptors ...

Quantifying Infra-slow Dynamics of Spectral Power and Heart Rate in Sleeping Mice

Three vigilance states dominate mammalian life: wakefulness, non-rapid eye movement (non-REM) sleep, and REM sleep. As more neural correlates of behavior ...

Automated Gait Analysis in Mice with Chronic Constriction Injury

The von Frey test is a classical method that has been widely used to examine the sensory function of neuropathic pain animals. However, it has some ...

An In Vivo Blood-brain Barrier Permeability Assay in Mice Using Fluorescently Labeled Tracers

An In Vivo Blood-brain Barrier Permeability Assay in Mice Using Fluorescently Labeled Tracers

Blood-brain barrier (BBB) is a specialized barrier that protects the brain microenvironment from toxins and pathogens in the circulation and maintains ...

Spectral Reflectometric Microscopy on Myelinated Axons In Situ

Spectral Reflectometric Microscopy on Myelinated Axons In Situ

In a mammalian nervous system, myelin provides an electrical insulation by enwrapping the axon fibers in a multilayered spiral. Inspired by its ...

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

Quantitative Cell Biology of Neurodegeneration in Drosophila Through Unbiased Analysis of Fluorescently Tagged Proteins Using ImageJ

With the rising prevalence of neurodegenerative diseases, it is increasingly important to understand the underlying pathophysiology that leads to neuronal ...

Probing Nicotinic Acetylcholine Receptor Function in Mouse Brain Slices via Laser Flash Photolysis of Photoactivatable Nicotine

Acetylcholine (ACh) acts through receptors to modulate a variety of neuronal processes, but it has been challenging to link ACh receptor function with ...

Diffusion Tensor Magnetic Resonance Imaging in Chronic Spinal Cord Compression

Chronic spinal cord compression is the most common cause of spinal cord impairment in patients with nontraumatic spinal cord damage. Conventional magnetic ...