Name: presynaptic dopamine dynamics in striatal brain slices with fast-scan cyclic voltammetry
Uploaded: 2012-01-12T13:00:00
Description: Watch this Scientific Journal Video about Presynaptic Dopamine Dynamics in Striatal Brain Slices with Fast-scan Cyclic Voltammetry at JoVE.com

Financiamento fornecido pelo Instituto Nacional de Abuso do Álcool e Alcoolismo (NIAAA; AA-016967 e AA016967-01S1; TAM), Wayne State University arranque fundos, e Wayne State University Program Research Grant. O conteúdo é da exclusiva responsabilidade dos autores e não representam a posição oficial da NIAAA ou o National Institutes of Health.

1. Fundamentos experimentais Fabricação de eletrodos <ul type="circle"><li> Existem inúmeros microeletrodos de fibra de carbono métodos de fabricação mais uma vez são feitas in-house. Normalmente o que determina os detalhes de fabricação de eletrodos é a técnica eletroquímica que é aplicada ao eletrodo (por exemplo, amperometria vs FSCV). Para FSCV, microeletrodos podem ser feitas em casa usando o procedimento de três etapas seguintes. Para uma descrição mais completa de carbo...

<ol>
	<li>Pike, C. M., Grabner, C. P., Harkins, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Amperometric+Electrodes.">Fabrication of Amperometric Electrodes.</a> J. Vis. Exp. (27), e1040-e1040 (2009).</li><li>Lack, A. K., Diaz, M. R., Chappell, A., DuBois, D. W., McCool, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+ethanol+and+withdrawal+differentially+modulate+pre-+and+postsynaptic+function+at+glutamatergic+synapses+in+rat+basolateral+amygdala.">Chronic ethanol and withdrawal differentially modulate pre- and postsynaptic function at glutamatergic synapses in rat basolateral amygdala.</a> J. Neuropyhysiol. 98, 3185-3196 (2007).</li><li>John, C. E., Jones, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltammetric+characterization+of+the+effect+of+monoamine+uptake+inhibitors+and+release+on+dopamine+and+serotonin+uptake+in+mouse+caudate-putamen+and+substantia+nigra+slices.">Voltammetric characterization of the effect of monoamine uptake inhibitors and release on dopamine and serotonin uptake in mouse caudate-putamen and substantia nigra slices.</a> Neuropharmacology. 52, 1596-1605 (2007).</li><li>Wightman, R. M., Amatore, C., Engstrom, R. C., Hale, P. D., Kistensen, E. W., Kuhr, W. G., May, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+characterization+of+dopamine+overflow+and+uptake+in+the+rat+striatum.">Real-time characterization of dopamine overflow and uptake in the rat striatum.</a> Neuroscience. 25, 513-523 (1988).</li><li>Wightman, R. M., Zimmerman, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+dopamine+extracellular+concentration+in+rat+striatum+by+impulse+flow+and+uptake.">Control of dopamine extracellular concentration in rat striatum by impulse flow and uptake.</a> Brain. Res. Brain. Res. Rev. 15, 135-144 (1990).</li><li>Jones, S. R., Garris, P. A., Kilts, C. D., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+dopamine+uptake+in+the+basolateral+amygdaloid+nucleus,+caudate-putamen,+and+nucleus+accumbens+of+the+rat.">Comparison of dopamine uptake in the basolateral amygdaloid nucleus, caudate-putamen, and nucleus accumbens of the rat.</a> J. Neurochem. 64, 2581-2589 (1995).</li><li>Michael, D. J., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+monitoring+of+biogenic+amine+neurotransmission+in+real+time.">Electrochemical monitoring of biogenic amine neurotransmission in real time.</a> J. Pharm. Biomed. Anal. 19, 33-46 (1999).</li><li>Pajski, M. L., Venton, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adenosine+release+evoked+by+short+electrical+stimulations+in+striatal+brain+slices+is+primarily+activity+dependent.">Adenosine release evoked by short electrical stimulations in striatal brain slices is primarily activity dependent.</a> A.C.S. Chem. Neurosci. 1, 775-787 (2010).</li><li>Sanford, A. L., Morton, S. W., Whitehouse, K. L., Oara, H. M., Lugo-Morales, L. Z., Roberts, J. G., Sombers, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltammetric+detection+of+hydrogen+peroxide+at+carbon+fiber+microelectrodes.">Voltammetric detection of hydrogen peroxide at carbon fiber microelectrodes.</a> Anal. Chem. 82, 5205-5210 (2010).</li><li>Park, J., Kile, B. M., Wightman, R. M. <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+voltammetric+monitoring+of+norepinephrine+release+in+the+rat+ventral+bed+nucleus+of+the+stria+terminalis+and+anteroventral+thalamic+nucleus.">In vivo voltammetric monitoring of norepinephrine release in the rat ventral bed nucleus of the stria terminalis and anteroventral thalamic nucleus.</a> Eur. J. Neurosci. 30, 2121-2133 (2009).</li><li>Hashemi, P., Dankoski, E. C., Petrovic, J., Keithley, R. B., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voltammetric+detection+of+5-hydroxytryptamine+release+in+the+rat+brain.">Voltammetric detection of 5-hydroxytryptamine release in the rat brain.</a> Anal. Chem. 81, 9462-9471 (2009).</li><li>Borue, X., Cooper, S., Hirsh, J., Condron, B., Venton, B. 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+evaluation+of+serotonin+release+and+clearnece+in+drosophila.">Quantitative evaluation of serotonin release and clearnece in drosophila.</a> J. Neuroscience. Methods. 179, 300-308 (2009).</li><li>Vickrey, T. L., Condron, B., Venton, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+endogenous+dopamine+changes+in+drosophila+melanogaster+using+fast-scan+cyclic+voltammetry.">Detection of endogenous dopamine changes in drosophila melanogaster using fast-scan cyclic voltammetry.</a> Anal. Chem. 81, 9306-9313 (2009).</li><li>Makos, M. A., Han, K. A., Heien, M. L., Ewing, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+in+vivo+electrochemistry+to+study+the+physiological+effects+of+cocaine+and+other+stimulants+on+the+drosophila+melanogaster+dopamine+transporter.">Using in vivo electrochemistry to study the physiological effects of cocaine and other stimulants on the drosophila melanogaster dopamine transporter.</a> A.C.S. Chem Neurosci. 1, 74-83 (2009).</li><li>Budygin, E. A., John, C. E., Mateo, Y., Daunais, J. B., Friedman, D. P., Grant, K. A., Jones, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+ethanol+exposure+alters+presynaptic+dopamine+function+in+striatum+of+monkeys:+a+preliminary+study.">Chronic ethanol exposure alters presynaptic dopamine function in striatum of monkeys: a preliminary study.</a> Synapse. 50, 266-268 (2003).</li><li>Jones, S. R., Gainetdinov, R. R., Jaber, M., Giros, B., Wightman, R. M., Caron, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Profound+neuronal+plasticity+in+response+to+inactivation+of+the+dopamine+transporter.">Profound neuronal plasticity in response to inactivation of the dopamine transporter.</a> PNAS. 95, 4029-4034 (1998).</li><li>Kennedy, R. T., Jones, S. R., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+observation+of+dopamine+autoreceptor+effects+in+rat+striatal+slices.">Dynamic observation of dopamine autoreceptor effects in rat striatal slices.</a> J. Neurochem. 59, 449-445 (1992).</li><li>Rice, M. E., Cragg, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nicotine+amplifies+reward-related+dopamine+signals+in+striatum.">Nicotine amplifies reward-related dopamine signals in striatum.</a> Nat. Neurosci. 7, 583-584 (2004).</li><li>Zhang, L., Doyon, W. M., Clark, J. J., Phillips, P. E., Dani, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controls+of+tonic+and+phasic+dopamine+transmission+in+the+dorsal+and+ventral.">Controls of tonic and phasic dopamine transmission in the dorsal and ventral.</a> 76, 396-404 (2009).</li><li>Paredes, D., Grnaholm, A. C., Bickford, P. 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+NGF+and+BDNF+on+baseline+glutamate+and+dopamine+release+in+the+hippocampal+formation+of+the+adult+rat.">Effects of NGF and BDNF on baseline glutamate and dopamine release in the hippocampal formation of the adult rat.</a> Brain. Res. 11141, 56-64 (2007).</li><li>Goggi, J., Puller, I. A., Carney, S. L., Bradford, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Signalling+pathways+involved+in+the+short-term+potentiation+of+dopamine+release+by+BDNF.">Signalling pathways involved in the short-term potentiation of dopamine release by BDNF.</a> Brain. Res. 968, 156-161 (2003).</li><li>Cheer, J. F., Wassum, K. M., Heien, M. L., Phillips, P. E., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cannabinoids+enhance+subsecond+doapmine+relese+in+the+nucleus+accumbens+of+awake+rats.">Cannabinoids enhance subsecond doapmine relese in the nucleus accumbens of awake rats.</a> J. Neurosci. 24, 4393-4400 (2004).</li><li>Phillips, P. E., Stuber, G. D., Heien, M. L., Wightman, R. M., Carelli, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subsecond+dopamine+release+promotes+cocaine+seeking.">Subsecond dopamine release promotes cocaine seeking.</a> Nature. 422, 614-618 (2003).</li><li>Robinson, D. L., Heien, M. L., Wightman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency+of+dopamine+concentration+transients+increases+in+dorsal+and+ventral+striatum+of+male+rats+duing+introduction+of+conspecifics.">Frequency of dopamine concentration transients increases in dorsal and ventral striatum of male rats duing introduction of conspecifics.</a> J. Neurosci. 22, 10477-10486 (2002).</li></ol>

O protocolo apresentado aqui demonstra como preparar e usar fatias do mouse coronal do cérebro para experimentos FSCV. Embora este método é específico para obtenção e medição dinâmica da dopamina, outros neurotransmissores, como a adenosina, peróxido de hidrogênio, noradrenalina e serotonina têm sido monitoradas in vivo ou in vitro com FSCV 3, 8-11. FSCV pode ser usado para monitorar algumas dessas substâncias neuroquímicas outros por simples modificações da forma de onda apl...

<table border="1"><tbody><tr><td> Nome </td><td> Companhia </td><td> Número CAS </td></tr><tr><td width="274"> Reagente </td><td></td><td></td></tr><tr><td width="274"> Cloreto de Potássio </td><td> Pescador </td><td width="142" valign="top"> 7447407 </td></tr><tr><td width="274"> Cloreto de sódio </td><td> Merck Química </td><td width="142" valign="top"> 7647145 </td></tr><tr><td width="274"> Cloreto de magnésio </td><td width="194" valign="top"> Pescador </td><td width="142" valign="top"> 7791186 </td></tr><tr><td width="274"> Cloreto de cálcio </td><td width="194" valign="top"> Pescador </td><td width="142" valign="top"> 10035048 </td></tr><tr><td width="274"> Bicarbonato de sódio </td><td width="194" valign="top"> Merck Química </td><td width="142" valign="top"> 144558 </td></tr><tr><td width="274"> Fosfato de sódio, dibásico </td><td width="194" valign="top"> EMD Chemicals </td><td width="142" valign="top"> 7558794 </td></tr><tr><td width="274"> D-glucose </td><td width="194" valign="top"> Pescador </td><td width="142" valign="top"> 50997 </td></tr><tr><td width="274"> Ácido ascórbico </td><td width="194" valign="top"> Pescador </td><td width="142" valign="top"> 50817 </td></tr><tr><td width="274"> Sacarose </td><td width="194" valign="top"> Pescador </td><td> 57501 </td></tr><tr><td width="274">&nbsp;</td><td width="194" valign="top">&nbsp;</td><td>&nbsp;</td></tr><tr><td width="274"> Materiais </td><td width="194" valign="top"> Vendedor </td><td> Número de catálogo </td></tr><tr><td width="274"> Fibra de carbono </td><td> Goodfellow Oakdale, PA </td><td></td></tr><tr><td width="274"> Capilar de vidro </td><td> AM Sistemas Carlsborg WA. </td><td> 602000 </td></tr><tr><td width="274"> Fio de prata </td><td> A-M Sistemas Carlsborg WA. </td><td> 787000 </td></tr><tr><td width="274"> Eletrodo de tungstênio estimulando </td><td> Um plásticos, Roanoke, VA </td><td></td></tr><tr><td width="274"> Fio de platina </td><td></td><td></td></tr><tr><td width="274"> Do cabo </td><td> Squires Electronics, Cornelius, OR </td><td></td></tr><tr><td width="274"> Loctite adesivo instantâneo 404 </td><td> Hankal Corp Rocky Hill CT. </td><td></td></tr><tr><td width="274"> Gilete </td><td> Mundial de precisão Instruments Inc. FL. </td><td></td></tr><tr><td width="274"> BD Spinal agulha </td><td> Sistemas de BD Medical, Franlin Lake, NJ </td><td> REF 405234 </td></tr><tr><td width="274"> Lâmina cirúrgica </td><td> Feather Safety razor Co. LTD. Japão </td><td></td></tr><tr><td width="274"></td><td></td><td></td></tr><tr><td width="274"> Software </td><td width="194" valign = &quot;top&quot;&gt; Vendedor </td><td> Número de catálogo </td></tr><tr><td width="274"> Software TH </td><td> ESA Inc., Chelmsford, MA </td><td></td></tr><tr><td width="274"> Instrumento </td><td width="194" valign="top"> Vendedor </td><td> Número de catálogo </td></tr><tr><td width="274"> Câmara de gravação de submersão </td><td> Personalizado Científico, Denver, CO </td><td></td></tr><tr><td width="274"> Neorolog isolador de estímulo </td><td> Digitmeter, Hertfordshire, Inglaterra </td><td></td></tr><tr><td width="274"> Controlador de temperatura automático </td><td> Warner Instrument Corporation </td><td></td></tr><tr><td width="274"> Microscópio (SZX7) </td><td> Olimpo </td><td></td></tr><tr><td width="274"> Microscópio </td><td> Pescador </td><td></td></tr><tr><td width="274"> Vibratome sistema de seccionamento 3000 </td><td> St. Loué, MO. </td><td></td></tr><tr><td width="274"> Bomba de perfusão </td><td> Watson Marlow Limited, Falmouth Cornualha - Inglaterra </td><td> H110708 </td></tr><tr><td width="274"> Micropipeta extrator </td><td> Narishige, Tóquio, Japão </td><td></td></tr><tr><td width="274"> ChemClamp potenciostato </td><td> Corporações Dagan, Minneapolis, MN. </td><td></td></tr></tbody></table>

presynaptic dopamine dynamics in striatal brain slices with fast-scan cyclic voltammetry

Extensa pesquisa centrou-se no neurotransmissor dopamina devido à sua importância no mecanismo de ação das drogas de abuso (por exemplo, cocaína e anfetaminas), o papel que ela desempenha nas doenças psiquiátricas (por exemplo, esquizofrenia e Déficit de Atenção e Hiperatividade), e seu envolvimento na degenerativas doenças como mal de Parkinson e doença de Huntington. Em condições fisiológicas normais, a dopamina é conhecida por regular a atividade locomotora, cognição, aprendizagem, afetam emocional e secreção de hormônios neuroendócrinos. Uma das maiores densidades de neurônios de dopamina está dentro do corpo estriado, que pode ser dividido em duas distintas regiões neuroanatômicas conhecida como nucleus accumbens eo núcleo caudado-putamen. O objetivo é ilustrar um protocolo geral para a fatia de voltametria cíclica fast-scan (FSCV) dentro do striatum mouse. FSCV é um bem definidas técnica eletroquímica proporcionando a oportunidade de medir a liberação de dopamina e absorção em tempo real em dregiões do cérebro iscrete. Microeletrodos de fibra de carbono (diâmetro de ~ 7 mm) são usados ​​em FSCV para detectar oxidação da dopamina. A vantagem analítica de utilizar FSCV para detectar a dopamina é a sua resolução melhorada temporal de 100 milissegundos e resolução espacial de menos de dez microns, fornecendo informações complementares no microdiálise in vivo.

Watch this Scientific Journal Video about Presynaptic Dopamine Dynamics in Striatal Brain Slices with Fast-scan Cyclic Voltammetry at JoVE.com

Presynaptic Dopamine Dynamics in Striatal Brain Slices with Fast-scan Cyclic Voltammetry

Usando fast-scan voltametria cíclica para medir eletricamente evocado dinâmica pré-sinápticos em fatias de cérebro estriado.

Pré-sináptica de dopamina Dynamics em fatias de cérebro estriado com Fast-scan voltametria cíclica

Extensive research has focused on the neurotransmitter dopamine because of its importance in the mechanism of action of drugs of abuse (e.g. cocaine and ...

Research

JoVE Journal

Neuroscience

Vibrodissociation of Neurons from Rodent Brain Slices to Study Synaptic Transmission and Image Presynaptic Terminals

Vibrodissociation de neurônios de fatias do cérebro de roedores para estudar a transmissão sináptica e Imagem Terminais pré-sináptica

Mechanical dissociation of neurons from the central nervous system has the advantage that presynaptic boutons remain attached to the isolated neuron of ...

Neurociência

Multi-electrode Array Recordings of Neuronal Avalanches in Organotypic Cultures

Multieletrodos Recordings Array of Avalanches Neuronal em culturas organotípicas

The cortex is spontaneously active, even in the absence of any particular input or motor output.  During development, this activity is important for the ...

Voltage Biasing, Cyclic Voltammetry, &amp; Electrical Impedance Spectroscopy for Neural Interfaces

Voltage Biasing, Cyclic Voltammetry, & Electrical Impedance Spectroscopy for Neural Interfaces

Tensão de polarização, voltametria cíclica, espectroscopia de impedância elétrica e para Interfaces Neurais

Electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measure properties of the electrode-tissue interface without additional invasive ...

Paired Whole Cell Recordings in Organotypic Hippocampal Slices

Emparelhados Recordings células inteiras em organotï¿½icas fatias do hipocampo

Pair recordings involve simultaneous whole cell patch clamp recordings from two synaptically connected neurons, enabling not only direct ...

Whole-cell Patch-clamp Recordings in Brain Slices

Gravações de células inteiras de patch-clamp em Brain Slices

Whole-cell patch-clamp recording is an electrophysiological technique that allows the study of the&#160;electrical properties of a substantial part of the ...

Modeling Fast-scan Cyclic Voltammetry Data from Electrically Stimulated Dopamine Neurotransmission Data Using QNsim1.0

Modelagem de Dados de Voltammetria Cíclica de Dados Rápidos de Dados de Neurotransmissão de Dopamina Estimulados Eletricamente Usando QNsim1.0

Central dopaminergic (DAergic) pathways have an important role in a wide range of functions, such as attention, motivation, and movement. Dopamine (DA) is ...

Evaluation of Synapse Density in Hippocampal Rodent Brain Slices

Avaliação da densidade de sinapse em fatias Hippocampal cérebro de roedor

In the brain, synapses are specialized junctions between neurons, determining the strength and spread of neuronal signaling. The number of synapses is ...

Two-photon Calcium Imaging in Neuronal Dendrites in Brain Slices

Imagem de dois fotões cálcio em dendritos neuronais no cérebro fatias

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ ...

In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal

In Vivo Single-Molecule Tracking at the Drosophila Presynaptic Motor Nerve Terminal

Na Vivo Único-molécula de rastreamento no Terminal do nervo Motor pré-sináptica da drosófila

An increasing number of super-resolution microscopy techniques are helping to uncover the mechanisms that govern the nanoscale cellular world. ...

Stereotaxic Surgery for Genetic Manipulation in Striatal Cells of Neonatal Mouse Brains

Cirurgia estereotáxica para manipulação genética em células estriadas de cérebro de rato Neonatal

Many genes are expressed in embryonic brains, and some of them are continuously expressed in the brain after birth. For such persistently expressed genes, ...