Name: quantitative autoradiographic method for determination of regional rates of cerebral protein synthesis in vivo
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Description: Watch this Scientific Journal Video about Quantitative Autoradiographic Method for Determination of Regional Rates of Cerebral Protein Synthesis In Vivo at JoVE.com

The authors would like to acknowledge Zengyan Xia for the genotyping of the mice, Tom Burlin for the processing of amino acids and films, and Mei Qin for performing some of the rCPS experiments. This research was supported by the Intramural Research Program of the NIMH, ZIA MH00889. RMS was also supported by an Autism Speaks Postdoctoral Fellowship 8679 and a FRAXA Postdoctoral Fellowship.

Note: All animal procedures were approved by the National Institute of Mental Health Animal Care and Use Committee and were performed according with the National Institutes of Health Guidelines on the Care and Use of Animals.
An overview of the protocol is presented in Figure 1.
1. Surgically implant catheters in a femoral vein and artery for administration of the tracer and collection of timed arterial blood samples, respectively. Comple...

<ol>
	<li>West, A. E., 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=Calcium+regulation+of+neuronal+gene+expression.">Calcium regulation of neuronal gene expression.</a> Proceedings of the National Academy of Sciences of the United States of America. 98, 11024-11031 (2001).</li><li>Siegel, G., Agranoff, B., Albers, R. W., Fisher, S., Uhler, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Basic Neurochemistry. , (1999).</li><li>Nguyen, P. V., Abel, T., Kandel, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Requirement+of+a+critical+period+of+transcription+for+induction+of+a+late+phase+of+LTP.">Requirement of a critical period of transcription for induction of a late phase of LTP.</a> Science. 265, 1104-1107 (1994).</li><li>Mao, Z., Bonni, A., Xia, F., Nadal-Vicens, M., Greenberg, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuronal+activity-dependent+cell+survival+mediated+by+transcription+factor+MEF2.">Neuronal activity-dependent cell survival mediated by transcription factor MEF2.</a> Science. 286, 785-790 (1999).</li><li>Pfeiffer, B. E., Huber, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+advances+in+local+protein+synthesis+and+synaptic+plasticity.">Current advances in local protein synthesis and synaptic plasticity.</a> The Journal of Neuroscience: the Official Journal of the Society for Neuroscience. 26, 7147-7150 (2006).</li><li>Smith, C. B., Deibler, G. E., Eng, N., Schmidt, K., Sokoloff, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+local+cerebral+protein+synthesis+in+vivo:+influence+of+recycling+of+amino+acids+derived+from+protein+degradation.">Measurement of local cerebral protein synthesis in vivo: influence of recycling of amino acids derived from protein degradation.</a> Proceedings of the National Academy of Sciences of the United States of America. 85, 9341-9345 (1988).</li><li>Schmidt, K. C., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resolution,+sensitivity+and+precision+with+autoradiography+and+small+animal+positron+emission+tomography:+implications+for+functional+brain+imaging+in+animal+research.">Resolution, sensitivity and precision with autoradiography and small animal positron emission tomography: implications for functional brain imaging in animal research.</a> Nuclear Medicine and Biology. 32, 719-725 (2005).</li><li>Banker, G., Cotman, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characteristics+of+different+amino+acids+as+protein+precursors+in+mouse+brain:+advantages+of+certain+carboxyl-labeled+amino+acids.">Characteristics of different amino acids as protein precursors in mouse brain: advantages of certain carboxyl-labeled amino acids.</a> Archives of Biochemistry and Biophysics. 142, 565-573 (1971).</li><li>Frerichs, K. U., 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=Suppression+of+protein+synthesis+in+brain+during+hibernation+involves+inhibition+of+protein+initiation+and+elongation.">Suppression of protein synthesis in brain during hibernation involves inhibition of protein initiation and elongation.</a> Proceedings of the National Academy of Sciences of the United States of America. 95, 14511-14516 (1998).</li><li>Abrams, R. M., Burchfield, D. J., Sun, Y., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rates+of+local+cerebral+protein+synthesis+in+fetal+and+neonatal+sheep.">Rates of local cerebral protein synthesis in fetal and neonatal sheep.</a> The American Journal of Physiology. 272, R1235-R1244 (1997).</li><li>Nakanishi, 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=Positive+correlations+between+cerebral+protein+synthesis+rates+and+deep+sleep+in+Macaca+mulatta.">Positive correlations between cerebral protein synthesis rates and deep sleep in Macaca mulatta.</a> The European Journal of Neuroscience. 9, 271-279 (1997).</li><li>Sun, Y., Deibler, G. E., Sokoloff, L., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+regional+rates+of+cerebral+protein+synthesis+adjusted+for+regional+differences+in+recycling+of+leucine+derived+from+protein+degradation+into+the+precursor+pool+in+conscious+adult+rats.">Determination of regional rates of cerebral protein synthesis adjusted for regional differences in recycling of leucine derived from protein degradation into the precursor pool in conscious adult rats.</a> Journal of Neurochemistry. 59, 863-873 (1992).</li><li>Scammell, T. E., Schwartz, W. J., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=No+evidence+for+a+circadian+rhythm+of+protein+synthesis+in+the+rat+suprachiasmatic+nuclei.">No evidence for a circadian rhythm of protein synthesis in the rat suprachiasmatic nuclei.</a> Brain Research. 494, 155-158 (1989).</li><li>Smith, C. B., Eintrei, C., Kang, J., Sun, Y. <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+thiopental+anesthesia+on+local+rates+of+cerebral+protein+synthesis+in+rats.">Effects of thiopental anesthesia on local rates of cerebral protein synthesis in rats.</a> The American Journal of Physiology. 274, E852-E859 (1998).</li><li>Sun, Y., Deibler, G. E., Smith, C. B. <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+axotomy+on+protein+synthesis+in+the+rat+hypoglossal+nucleus:+examination+of+the+influence+of+local+recycling+of+leucine+derived+from+protein+degradation+into+the+precursor+pool.">Effects of axotomy on protein synthesis in the rat hypoglossal nucleus: examination of the influence of local recycling of leucine derived from protein degradation into the precursor pool.</a> Journal of Cerebral Blood Flow and Metabolism: Official Journal of the International Society of Cerebral Blood Flow and Metabolism. 13, 1006-1012 (1993).</li><li>Smith, C. B., Yu, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rates+of+protein+synthesis+in+the+regenerating+hypoglossal+nucleus:+effects+of+testosterone+treatment.">Rates of protein synthesis in the regenerating hypoglossal nucleus: effects of testosterone treatment.</a> Neurochemical Research. 19, 623-629 (1994).</li><li>Orzi, F., Sun, Y., Pettigrew, K., Sokoloff, L., Smith, C. B. <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+acute+and+delayed+effects+of+prior+chronic+cocaine+administration+on+regional+rates+of+cerebral+protein+synthesis+in+rats.">Effects of acute and delayed effects of prior chronic cocaine administration on regional rates of cerebral protein synthesis in rats.</a> The Journal of Pharmacology and Experimental Therapeutics. 272, 892-900 (1995).</li><li>Nadel, J., 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=Voluntary+exercise+regionally+augments+rates+of+cerebral+protein+synthesis.">Voluntary exercise regionally augments rates of cerebral protein synthesis.</a> Brain Research. 1537, 125-131 (2013).</li><li>Sun, Y., 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=Rates+of+local+cerebral+protein+synthesis+in+the+rat+during+normal+postnatal+development.">Rates of local cerebral protein synthesis in the rat during normal postnatal development.</a> The American Journal of Physiology. 268, R549-R561 (1995).</li><li>Smith, C. B., Sun, Y., Sokoloff, L. <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+aging+on+regional+rates+of+cerebral+protein+synthesis+in+the+Sprague-Dawley+rat:+examination+of+the+influence+of+recycling+of+amino+acids+derived+from+protein+degradation+into+the+precursor+pool.">Effects of aging on regional rates of cerebral protein synthesis in the Sprague-Dawley rat: examination of the influence of recycling of amino acids derived from protein degradation into the precursor pool.</a> Neurochemistry International. 27, 407-416 (1995).</li><li>Ingvar, M. C., Maeder, P., Sokoloff, L., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+aging+on+local+rates+of+cerebral+protein+synthesis+in+rats.">The effects of aging on local rates of cerebral protein synthesis in rats.</a> Monographs in Neural Sciences. 11, 47-50 (1984).</li><li>Sare, R. M., Huang, T., Burlin, T., Loutaev, I., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decreased+rates+of+cerebral+protein+synthesis+measured+in+vivo+in+a+mouse+model+of+Tuberous+Sclerosis+Complex:+unexpected+consequences+of+reduced+tuberin.">Decreased rates of cerebral protein synthesis measured in vivo in a mouse model of Tuberous Sclerosis Complex: unexpected consequences of reduced tuberin.</a> Journal of Neurochemistry. 145, 417-425 (2018).</li><li>Liu, Z. H., Huang, T., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lithium+reverses+increased+rates+of+cerebral+protein+synthesis+in+a+mouse+model+of+fragile+X+syndrome.">Lithium reverses increased rates of cerebral protein synthesis in a mouse model of fragile X syndrome.</a> Neurobiology of Disease. 45, 1145-1152 (2012).</li><li>Qin, M., 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=Altered+cerebral+protein+synthesis+in+fragile+X+syndrome:+studies+in+human+subjects+and+knockout+mice.">Altered cerebral protein synthesis in fragile X syndrome: studies in human subjects and knockout mice.</a> Journal of Cerebral Blood Flow and Metabolism: Official Journal of the International Society of Cerebral Blood Flow and Metabolism. 33, 499-507 (2013).</li><li>Qin, M., Kang, J., Burlin, T. V., Jiang, C., Smith, C. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postadolescent+changes+in+regional+cerebral+protein+synthesis:+an+in+vivo+study+in+the+FMR1+null+mouse.">Postadolescent changes in regional cerebral protein synthesis: an in vivo study in the FMR1 null mouse.</a> The Journal of Neuroscience: the Official Journal of the Society for Neuroscience. 25, 5087-5095 (2005).</li><li>Qin, M., 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=R-Baclofen+Reverses+a+Social+Behavior+Deficit+and+Elevated+Protein+Synthesis+in+a+Mouse+Model+of+Fragile+X+Syndrome.">R-Baclofen Reverses a Social Behavior Deficit and Elevated Protein Synthesis in a Mouse Model of Fragile X Syndrome.</a> The International Journal of Neuropsychopharmacology. 18, pyv034 (2015).</li><li>Qin, M., 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=Cerebral+protein+synthesis+in+a+knockin+mouse+model+of+the+fragile+X+premutation.">Cerebral protein synthesis in a knockin mouse model of the fragile X premutation.</a> ASN Neuro. 6, (2014).</li><li>Smith, C. B., Kang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+protein+synthesis+in+a+genetic+mouse+model+of+phenylketonuria.">Cerebral protein synthesis in a genetic mouse model of phenylketonuria.</a> Proceedings of the National Academy of Sciences of the United States of America. 97, 11014-11019 (2000).</li><li>Reivich, M., Jehle, J., Sokoloff, L., Kety, 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=Measurement+of+regional+cerebral+blood+flow+with+antipyrine-14C+in+awake+cats.">Measurement of regional cerebral blood flow with antipyrine-14C in awake cats.</a> Journal of Applied Physiology. 27, 296-300 (1969).</li></ol>

We present a quantitative method for determination of regional rates of cerebral protein synthesis (rCPS) in vivo in experimental animals. This method has considerable advantages over existing methods: 1. Measurements are made in the awake behaving animal, so they reflect ongoing processes in the functioning brain. 2. Measurements are made by means of quantitative autoradiography affording the ability to determine rCPS in all regions and subregions of the brain simultaneously. 3. The kinetic model of the method takes int...

Protein synthesis is&#160;an important biological process required for long-term adaptive change in the nervous system1. Inhibiting protein synthesis blocks long-term memory storage in both invertebrates and vertebrates2. Protein synthesis is essential for maintenance of the late phases of some forms of long-term potentiation (LTP) and long-term depression (LTD)3, neuronal survival during development4, and for general maintenance of the neuron and its synaptic connections5. Measurement of rates of brain protein synthesis may be an important tool with which to study adaptive changes as well as neurodevelopmental disorders and disorders related to learning and memory.
We have developed a method to quantify rates of cerebral protein synthesis in vivo in an awake animal that offers inherent advantages over other techniques that estimate rates in ex vivo or in vitro preparations of brain tissue6. Foremost is the applicability to measurements in the intact brain in an awake animal. This is a key consideration because it allows measurements with synaptic structure and function in place and without concerns about post mortem effects. Moreover, the quantitative autoradiographic approach that we employ achieves a high degree of spatial localization. Whereas the energy of 14C is such that we cannot localize the tracer at the subcellular or cellular level, we can measure rates in cell layers and small brain regions such as hypothalamic nuclei, with approximately a 25 &#181;m resolution7.
One challenge of in vivo measurements with radiotracers is to ensure that radiolabel measured is in the product of the reaction of interest rather than unreacted labeled precursor or other extraneous labeled metabolic products6. We chose L-[1-14C]-leucine as the tracer amino acid because it is either incorporated into protein or rapidly metabolized to 14CO2, which is diluted in the large pool of unlabeled CO2 in brain resulting from the high rate of energy metabolism8. Moreover, any 14C not incorporated into protein exists primarily as free [14C]-leucine, which over the 60 min experimental period, is almost entirely cleared from the tissue6. Proteins are then fixed to tissue with formalin and subsequently rinsed with waterto remove any free [14C]-leucine before autoradiography.
Another important consideration is the issue of the dilution of the specific activity of the precursor amino acid pool by unlabeled amino acids derived from tissue proteolysis. We have shown that in adult rat and mouse, about 40% of the precursor leucine pool for protein synthesis in the brain comes from amino acids derived from protein breakdown6. This must be included in the computation of regional rates of cerebral protein synthesis (rCPS) and must be confirmed in studies in which this relationship may change. The theoretical basis and the assumptions of the method have been presented in detail elsewhere6. In this paper, we focus on the procedural issues of the application of this methodology.
This method has been employed for the determination of rCPS in ground squirrels9, sheep10, rhesus monkeys11, rats12,13,14,15,16,17,18,19,20,21, a mouse model of Tuberous Sclerosis complex22, a mouse model of fragile X syndrome23,24,25,26, fragile X premutation mice27, and a mouse model of phenylketonuria28. In this manuscript, we present the procedures for measurement of rCPS with the in vivo autoradiographic L-[1-14C]-leucine method. We present rCPS in brain regions of an awake control mouse. We also demonstrate that in vivo administration of anisomycin, an inhibitor of translation, abolishes protein synthesis in the brain.

<table>
	<tbody>
		<tr>
			<td>Mice</td>
			<td>The Jackson Laboratory</td>
			<td>003024</td>
			<td>Fmr1 knockout breeding pairs</td>
		</tr>
		<tr>
			<td>Anisomycin</td>
			<td>Tocris Bioscience</td>
			<td>1290</td>
			<td></td>
		</tr>
		<tr>
			<td>Microhematocrit Tubes</td>
			<td>Drummond Scientific</td>
			<td>1-000-3200-H</td>
			<td>capillary tubes</td>
		</tr>
		<tr>
			<td>Critoseal Capillary Tube Sealant</td>
			<td>Leica Microsystems</td>
			<td>39215003</td>
			<td>sealant putty</td>
		</tr>
		<tr>
			<td>Glass vial inserts</td>
			<td>Agilent</td>
			<td>5183-2089</td>
			<td>used to collect blood samples</td>
		</tr>
		<tr>
			<td>Digi-Med Blood Pressure Analyzer</td>
			<td>Micro-Med Inc.</td>
			<td>BPA-400</td>
			<td>blood pressure analyzer</td>
		</tr>
		<tr>
			<td>Bayer Breeze 2 Blood Glucose Monitoring System</td>
			<td>Bayer Breeze</td>
			<td>9570A</td>
			<td>glucose meter</td>
		</tr>
		<tr>
			<td>Gastight syringe</td>
			<td>Hamilton Co.</td>
			<td>1710</td>
			<td>tuberculin glass syringe</td>
		</tr>
		<tr>
			<td>HeatMax HotHands-2 Hand Warmers</td>
			<td>HeatMax</td>
			<td>Model HH2</td>
			<td>warming pads</td>
		</tr>
		<tr>
			<td>Heparin Lock Flush Solution</td>
			<td>Fresenius Kabi USA, LLC</td>
			<td>504505</td>
			<td>heparin saline</td>
		</tr>
		<tr>
			<td>Clear animal container</td>
			<td>Instech</td>
			<td>MTANK/W</td>
			<td>animal enclosure</td>
		</tr>
		<tr>
			<td>Spring tether</td>
			<td>Instech</td>
			<td>PS62</td>
			<td>catheter tube/rodent attachment</td>
		</tr>
		<tr>
			<td>Swivel</td>
			<td>Instech</td>
			<td>375/25</td>
			<td>hooks to spring tether</td>
		</tr>
		<tr>
			<td>Swivel arm and mount</td>
			<td>Instech</td>
			<td>SMCLA</td>
			<td>hooks to swivel and animal enclosure</td>
		</tr>
		<tr>
			<td>Tether button</td>
			<td>Instech</td>
			<td>VAB62BS/22</td>
			<td>attaches to bottom of spring tether</td>
		</tr>
		<tr>
			<td>Stainless steel tube</td>
			<td>Made in-house</td>
			<td>N/A</td>
			<td>used to snake catheters through mouse</td>
		</tr>
		<tr>
			<td>Matrx VIP 3000</td>
			<td>Matrx</td>
			<td>91305430</td>
			<td>isoflurane vaporizer</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Stoelting Co.</td>
			<td>50207</td>
			<td>isoflurane/halothane adsorber</td>
		</tr>
		<tr>
			<td>Clippers</td>
			<td>Oster Finisher</td>
			<td>Model 59</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical skin hooks</td>
			<td>Made in-house (??)</td>
			<td>N/A (??)</td>
			<td></td>
		</tr>
		<tr>
			<td>0.9% Sodium Chloride Saline</td>
			<td>APP Pharmaceuticals LLC</td>
			<td>918610</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>Fine Science Tools</td>
			<td>11274-20</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical scissors</td>
			<td>Fine Science Tools</td>
			<td>14058-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscissors</td>
			<td>Fine Science Tools</td>
			<td>15000-00</td>
			<td></td>
		</tr>
		<tr>
			<td>UNIFY silk surgical sutures</td>
			<td>AD Surgical</td>
			<td>#S-S618R13</td>
			<td>6-0 USP, non-absorbable</td>
		</tr>
		<tr>
			<td>PE-8 polyethylene tubing</td>
			<td>SAI Infusion Technologies</td>
			<td>PE-8-25</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Becton Dickinson and Co.</td>
			<td>309659</td>
			<td>1cc/mL</td>
		</tr>
		<tr>
			<td>PE-10 polyethylene tubing</td>
			<td>Clay Adams</td>
			<td>427400</td>
			<td></td>
		</tr>
		<tr>
			<td>MCID Analysis</td>
			<td>Imaging Research Inc.</td>
			<td>Version 7.0</td>
			<td>optical density analysis</td>
		</tr>
		<tr>
			<td>Gelatin-coated slides (75x25mm)</td>
			<td>FD Neurotechnologies</td>
			<td>PO101</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryostat</td>
			<td>Leica</td>
			<td>CM1850</td>
			<td></td>
		</tr>
		<tr>
			<td>Super RX-N medical x-ray film</td>
			<td>Fuji</td>
			<td>47410-19291</td>
			<td></td>
		</tr>
		<tr>
			<td>Hypercassettes (8x10 in)</td>
			<td>Amersham Pharmacia Biotech</td>
			<td>11649</td>
			<td></td>
		</tr>
		<tr>
			<td>[1-14C]leucine</td>
			<td>Moravek</td>
			<td>MC404E</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge tube</td>
			<td>Sarstedt Aktiengesellschaft &#38; Co.</td>
			<td>72.692.005</td>
			<td>used to deproteinize blood samples</td>
		</tr>
		<tr>
			<td>Glass pasteur pipette</td>
			<td>Wheaton</td>
			<td>357335</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass wool</td>
			<td>Sigma-Aldrich</td>
			<td>18421</td>
			<td></td>
		</tr>
		<tr>
			<td>Nitrogen</td>
			<td>NIH Supply Center</td>
			<td>6830009737285</td>
			<td></td>
		</tr>
		<tr>
			<td>Scintillation fluid</td>
			<td>CytoScint</td>
			<td>882453</td>
			<td></td>
		</tr>
		<tr>
			<td>Liquid scintilllation counter</td>
			<td>Packard Tri-Carb</td>
			<td>2250CA</td>
			<td></td>
		</tr>
		<tr>
			<td>Amino acid analyzer</td>
			<td>Pickering Laboratories</td>
			<td>Pinnacle PCX</td>
			<td></td>
		</tr>
		<tr>
			<td>HPLC unit</td>
			<td>Agilent Technologies</td>
			<td>1260 Infinity</td>
			<td>include 1260 Bio-Inert Pump</td>
		</tr>
		<tr>
			<td>Surgical microscope</td>
			<td>Wild Heerbrugg</td>
			<td>M650</td>
			<td></td>
		</tr>
		<tr>
			<td>Sulfosalicylic acid</td>
			<td>Sigma-Aldrich</td>
			<td>MKBS1634V</td>
			<td>5-sulfosalicylic acid dihydrate</td>
		</tr>
		<tr>
			<td>Norleucine</td>
			<td>Sigma</td>
			<td>N8513</td>
			<td></td>
		</tr>
		<tr>
			<td>1.0 N HCl</td>
			<td>Sigma-Aldrich</td>
			<td>H9892</td>
			<td></td>
		</tr>
		<tr>
			<td>[H3]leucine</td>
			<td>Moraevk</td>
			<td>MC672</td>
			<td></td>
		</tr>
		<tr>
			<td>Falcon tube</td>
			<td>Thermo Scientific</td>
			<td>339652</td>
			<td>50 mL conical centrifuge tubes</td>
		</tr>
		<tr>
			<td>Stopwatch</td>
			<td>Heuer Microsplit</td>
			<td>Model 1000</td>
			<td>1/100 min</td>
		</tr>
		<tr>
			<td>Euthanasia Solution</td>
			<td>Vet One</td>
			<td>H6438</td>
			<td></td>
		</tr>
		<tr>
			<td>Northern Light Precision Illuminator</td>
			<td>Imaging Research Inc.</td>
			<td>Model B95</td>
			<td>fluorescent light box</td>
		</tr>
		<tr>
			<td>Micro-NIKKOR 55mm f/2.8</td>
			<td>Nikon</td>
			<td>1442</td>
			<td>CDD camera</td>
		</tr>
	</tbody>
</table>

quantitative autoradiographic method for determination of regional rates of cerebral protein synthesis in vivo

Protein synthesis is required for development and maintenance of neuronal function and is involved in adaptive changes in the nervous system. Moreover, it is thought that dysregulation of protein synthesis in the nervous system may be a core phenotype in some developmental disorders. Accurate measurement of rates of cerebral protein synthesis in animal models is important for understanding these disorders. The method that we have developed was designed to be applied to the study of awake, behaving animals. It is a quantitative autoradiographic method, so it can yield rates in all regions of the brain simultaneously. The method is based on the use of a tracer amino acid, L-[1-14C]-leucine, and a kinetic model of the behavior of L-leucine in the brain. We chose L-[1-14C]-leucine as the tracer because it does not lead to extraneous labeled metabolic products. It is either incorporated into protein or rapidly metabolized to yield 14CO2 which is diluted in a large pool of unlabeled CO2 in the brain. The method and the model also allow for the contribution of unlabeled leucine derived from tissue proteolysis to the tissue precursor pool for protein synthesis. The method has the spatial resolution to determine protein synthesis rates in cell and neuropil layers, as well as hypothalamic and cranial nerve nuclei. To obtain reliable and reproducible quantitative data, it is important to adhere to procedural details. Here we present the detailed procedures of the quantitative autoradiographic L-[1-14C]-leucine method for the determination of regional rates of protein synthesis in vivo.

Here we show a representative experiment demonstrating the effects of prior administration of a protein synthesis inhibitor on rCPS. Anisomycin in normal saline was administered to an adult C57/BL6 male wild-type mouse subcutaneously (100 mg/kg) 30 min prior to initiation of rCPS determination. Effects of anisomycin treatment compared to a vehicle-treated control animal show that rCPS is almost undetectable in the anisomycin-treated mouse (Figure 4). These da...

Watch this Scientific Journal Video about Quantitative Autoradiographic Method for Determination of Regional Rates of Cerebral Protein Synthesis In Vivo at JoVE.com

Quantitative Autoradiographic Method for Determination of Regional Rates of Cerebral Protein Synthesis In Vivo

Protein synthesis is&#160;a critical biological process for cells. In brain, it is required for adaptive changes. Measurement of rates of protein synthesis in the intact brain requires careful methodological considerations. Here we present the L-[1-14C]-leucine quantitative autoradiographic method for determination of regional rates of cerebral protein synthesis in vivo.

Protein synthesis is required for development and maintenance of neuronal function and is involved in adaptive changes in the nervous system. Moreover, it ...

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