View source for Template:Psychostimulant addiction

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<center>This annotated image insertion template is intended for transcluding to a variety of psychostimulant and addiction articles, as well as those on related protein topics.<br />The image file is located at '''[[COMMONS:File:ΔFosB.svg]]''' and a reusable version of this image is located at '''[[COMMONS:File:Annotated ΔFosB.svg screenshot.png]]'''.</center>
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| caption = {{{caption|This diagram depicts the signaling events in the [[Mesolimbic pathway|brain's reward center]] that are induced by chronic high-dose exposure to psychostimulants that increase the concentration of synaptic dopamine, like {{if pagename | Amphetamine = amphetamine| other = [[amphetamine]]}}, {{if pagename| Methamphetamine = methamphetamine| other = [[methamphetamine]]}}, and {{if pagename | Phenethylamine = phenethylamine| other = [[phenethylamine]]}}. Following presynaptic {{if pagename| Dopamine = dopamine| other = [[dopamine]]}} and [[glutamate]] [[cotransmission|co-release]] by such psychostimulants,<ref name="Nestler-Renthal Figure 2" /><ref name="Glutamate-dopamine cotransmission review">{{cite journal | vauthors = Broussard JI | title = Co-transmission of dopamine and glutamate | journal = J. Gen. Physiol. | volume = 139 | issue = 1 | pages = 93–96 | date = January 2012 | pmid = 22200950 | pmc = 3250102 | doi = 10.1085/jgp.201110659 | quote =  Coincident and convergent input often induces plasticity on a postsynaptic neuron. The NAc integrates processed information about the environment from basolateral amygdala, hippocampus, and prefrontal cortex (PFC), as well as projections from midbrain dopamine neurons. Previous studies have demonstrated how dopamine modulates this integrative process. For example, high frequency stimulation potentiates hippocampal inputs to the NAc while simultaneously depressing PFC synapses (Goto and Grace, 2005). The converse was also shown to be true; stimulation at PFC potentiates PFC–NAc synapses but depresses hippocampal–NAc synapses. In light of the new functional evidence of midbrain dopamine/glutamate co-transmission (references above), new experiments of NAc function will have to test whether midbrain glutamatergic inputs bias or filter either limbic or cortical inputs to guide goal-directed behavior. }}</ref> [[Neurotransmitter receptor|postsynaptic receptors]] for these [[neurotransmitter]]s trigger internal signaling events through a [[cAMP-dependent pathway]] and a [[Calcium signaling|calcium-dependent pathway]] that ultimately result in increased {{abbr|CREB|cAMP response element-binding protein}} phosphorylation.<ref name="Nestler-Renthal Figure 2" /><ref name="Amphetamine KEGG ΔFosB">{{cite web | title=Amphetamine – Homo sapiens (human) | url=http://www.genome.jp/kegg-bin/show_pathway?hsa05031+2354 | work=KEGG Pathway | accessdate=31 October 2014 | author=Kanehisa Laboratories | date=10 October 2014 | quote = Most addictive drugs increase extracellular concentrations of dopamine (DA) in nucleus accumbens (NAc) and medial prefrontal cortex (mPFC), projection areas of mesocorticolimbic DA neurons and key components of the "brain reward circuit". Amphetamine achieves this elevation in extracellular levels of DA by promoting efflux from synaptic terminals.&nbsp;... Chronic exposure to amphetamine induces a unique transcription factor delta FosB, which plays an essential role in long-term adaptive changes in the brain.}}</ref>{{if pagename|Amphetamine=|other=<ref name="Meth cAMP/calcium-dependent cascade">{{cite journal | vauthors = Cadet JL, Brannock C, Jayanthi S, Krasnova IN | title = Transcriptional and epigenetic substrates of methamphetamine addiction and withdrawal: evidence from a long-access self-administration model in the rat | journal = Mol. Neurobiol. | volume = 51 | issue = 2 | pages = 696–717 | year = 2015 | pmid = 24939695 | pmc = 4359351 | doi = 10.1007/s12035-014-8776-8 | quote = [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4359351/figure/Fig1/ Figure 1]}}</ref>}}  Phosphorylated CREB increases levels of ΔFosB, which in turn represses the {{nowrap|c-Fos}} gene with the help of [[corepressor]]s;<ref name="Nestler-Renthal Figure 2">{{cite journal | author = Renthal W, Nestler EJ | title = Chromatin regulation in drug addiction and depression | journal = Dialogues Clin. Neurosci. | volume = 11 | issue = 3 | pages = 257–268 | date = September 2009 | pmid = 19877494 | pmc = 2834246 | doi = | url =  | quote= [Psychostimulants] increase cAMP levels in striatum, which activates protein kinase A (PKA) and leads to phosphorylation of its targets. This includes the cAMP response element binding protein (CREB), the phosphorylation of which induces its association with the histone acetyltransferase, CREB binding protein (CBP) to acetylate histones and facilitate gene activation. This is known to occur on many genes including fosB and {{nowrap|c-fos}} in response to psychostimulant exposure. ΔFosB is also upregulated by chronic psychostimulant treatments, and is known to activate certain genes (eg, cdk5) and repress others (eg, {{nowrap|c-fos}}) where it recruits HDAC1 as a corepressor.&nbsp;... Chronic exposure to psychostimulants increases glutamatergic [signaling] from the prefrontal cortex to the NAc. Glutamatergic signaling elevates Ca2+ levels in NAc postsynaptic elements where it activates CaMK (calcium/calmodulin protein kinases) signaling, which, in addition to phosphorylating CREB, also phosphorylates HDAC5.}}<br />[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2834246/figure/DialoguesClinNeurosci-11-257-g002/ Figure 2: Psychostimulant-induced signaling events]</ref><ref name="Nestler1" /><ref name="Nestler2" /> {{nowrap|c-Fos}} [[gene repression|repression]] acts as a molecular switch that enables the accumulation of ΔFosB in the neuron.<ref name="{{nowrap|c-Fos}} repression">{{cite journal |author=Nestler EJ | title=Review. Transcriptional mechanisms of addiction: role of DeltaFosB | journal = Philos. Trans. R. Soc. Lond., B, Biol. Sci. | volume=363 | issue=1507 | pages=3245–3255 | date=October 2008 | pmid=18640924 | doi=10.1098/rstb.2008.0067 | pmc=2607320 | quote = Recent evidence has shown that ΔFosB also represses the {{nowrap|c-fos}} gene that helps create the molecular switch—from the induction of several short-lived Fos family proteins after acute drug exposure to the predominant accumulation of ΔFosB after chronic drug exposure}}</ref> A highly stable (phosphorylated) form of ΔFosB, one that persists in neurons for {{nowrap|1–2}}&nbsp;months, slowly accumulates following repeated high-dose exposure to stimulants through this process.<ref name="Nestler1" /><ref name="Nestler2" /> ΔFosB functions as "one of the master control proteins" that produces addiction-related [[neuroplasticity|structural changes in the brain]], and upon sufficient accumulation, with the help of its downstream targets (e.g., [[nuclear factor kappa B]]), it induces an addictive state.<ref name="Nestler1">{{cite journal | author = Robison AJ, Nestler EJ | title = Transcriptional and epigenetic mechanisms of addiction | journal = Nat. Rev. Neurosci. | volume = 12 | issue = 11 | pages = 623–637 | date = November 2011 | pmid = 21989194 | pmc = 3272277 | doi = 10.1038/nrn3111 | quote = ΔFosB serves as one of the master control proteins governing this structural plasticity.&nbsp;... ΔFosB also represses G9a expression, leading to reduced repressive histone methylation at the cdk5 gene. The net result is gene activation and increased CDK5 expression.&nbsp;... In contrast, ΔFosB binds to the {{nowrap|c-fos}} gene and recruits several co-repressors, including HDAC1 (histone deacetylase 1) and SIRT 1 (sirtuin 1).&nbsp;... The net result is {{nowrap|c-fos}} gene repression.}}<br />[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272277/figure/F4/ Figure 4: Epigenetic basis of drug regulation of gene expression]</ref><ref name="Nestler2">{{cite journal | author = Nestler EJ | title = Transcriptional mechanisms of drug addiction | journal = Clin. Psychopharmacol. Neurosci. | volume = 10 | issue = 3 | pages = 136–143 | date = December 2012 | pmid = 23430970 | pmc = 3569166 | doi = 10.9758/cpn.2012.10.3.136 | quote = The 35-37 kD ΔFosB isoforms accumulate with chronic drug exposure due to their extraordinarily long half-lives.&nbsp;... As a result of its stability, the ΔFosB protein persists in neurons for at least several weeks after cessation of drug exposure.&nbsp;... ΔFosB overexpression in nucleus accumbens induces NFκB&nbsp;...  In contrast, the ability of ΔFosB to repress the {{nowrap|c-Fos}} gene occurs in concert with the recruitment of a histone deacetylase and presumably several other repressive proteins such as a repressive histone methyltransferase}}</ref>}}}
|header = {{{header|[[Signaling cascade]] in the [[nucleus accumbens]] that results in psychostimulant addiction}}}<br />{{navbar|Psychostimulant addiction|mini = yes}}
|header_align = center
|header_background = {{{headerbg|#F0F8FF}}}
|alt = The signaling cascade involved in psychostimulant addiction
|image = ΔFosB.svg
|align = {{{align|center}}}
|image-width = 600
|image-left = 0
|image-top = 0
|width = 600
|height = 620
|annot-font-size = 14
|annot-text-align = center
|annotations = 
<!--Note located at the top right-->
{{Annotation|475|5|'''Note: colored text contains article links.'''|font-size=12}}

<!--Membranes/Pore-->
{{Annotation|320|325|[[Nuclear pore]]}}
{{Annotation|350|362|[[Nuclear membrane]]}}
{{Annotation|475|425|[[Plasma membrane]]}}

<!--Left: channels and receptors-->
{{Annotation|65|48|[[Calcium channel, voltage-dependent, L type, alpha 1C subunit|Ca<sub>v</sub>1.2]]}}
{{Annotation|43|98|[[NMDA receptor|NMDAR]]}}
{{Annotation|33|185|[[AMPA receptor|AMPAR]]}}
{{Annotation|41|238|[[Dopamine receptor D1|DRD1]]}}
{{Annotation|42|285|[[Dopamine receptor D5|DRD5]]}}
{{Annotation|47|331|[[Dopamine receptor D2|DRD2]]}}
{{Annotation|56|366|[[Dopamine receptor D3|DRD3]]}}
{{Annotation|84|385|[[Dopamine receptor D4|DRD4]]}}

<!--Bottom: G proteins and cAMP-->
{{Annotation|172|256|[[Gs alpha subunit|G<sub>s</sub>]]}}
{{Annotation|173|325|[[Gi alpha subunit|G<sub>i/o</sub>]]}}
{{Annotation|234|288|[[Adenylyl cyclase|AC]]}}
{{Annotation|18|595|[[cyclic adenosine monophosphate|'''cAMP''']]|font-size=9.5}}
{{Annotation|269|340|[[cyclic adenosine monophosphate|'''cAMP''']]|font-size=10}}
{{Annotation|312|288|[[Protein kinase A|PKA]]}}

<!--Middle: Inside neuron, outside nucleus-->
{{Annotation|228|110.5|[[Calmodulin|CaM]]}}
{{Annotation|329|99|[[Ca2+/calmodulin-dependent protein kinase II|CaMKII]]}}
{{Annotation|301|215|[[Dopamine- and cAMP-regulated neuronal phosphoprotein|DARPP-32]]}}
{{Annotation|328|161.5|[[Protein phosphatase 1|PP1]]}}
{{Annotation|247.5|159|[[Protein phosphatase 2B|PP2B]]}}

<!--Right: Inside nucleus-->
{{Annotation|458|163|[[Cyclic AMP response element-binding protein|<span style="color:MediumVioletRed">CREB</span>]]}}
{{Annotation|440|222|'''[[ΔFosB|<span style="color:MediumVioletRed">ΔFosB</span>]]'''}}
{{Annotation|447|241|'''[[JunD|<span style="color:MediumVioletRed">JunD</span>]]'''}}
{{Annotation|542|233.5|[[c-Fos|<span style="color:MediumVioletRed">{{nowrap|c-Fos}}</span>]]}}
{{Annotation|442|274.5|[[Sirtuin 1|SIRT1]]}}
{{Annotation|468.5|299|[[Histone deacetylase 1|HDAC1]]}}

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{{#ifeq:{{{Colorcode}}}|no||{{Annotation|495|35|{{#tag:ref|<!-- 
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