Terminal axónico: Diferenzas entre revisións

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Miguelferig (conversa | contribucións)
Miguelferig (conversa | contribucións)
Liña 11:
As moléculas do neurotransmisor están contidas dentro de vesículas que se forman dentro das neuronas, que viaxan ata o extremo do axón, onde se fusionan coa membrana. Os ións de calcio activan despois unha fervenza bioquímica que dá lugar á fusión de vesículas coa membrana presináptica e liberan o seu continuo na fenda sináptica uns 180&nbsp;[[microsegundo|µs]] despois da entrada de calcio.<ref name="Llinás81">{{cite journal |doi=10.1016/S0006-3495(81)84899-0 |title=Relationship between presynaptic calcium current and postsynaptic potential in squid giant synapse |year=1981 |last1=Llinás |first1=R |last2=Steinberg |first2=IZ |last3=Walton |first3=K |journal=Biophysical Journal |volume=33 |issue=3 |pages=323–51 |pmid=6261850 |pmc=1327434 |author-name-separator= |author-separator=,}}</ref> Activadas pola unión de ións de calcio, as proteínas da vesícula sináptica empezan a separarse, o que dá lugar á creación dun [[poro de fusión]]. A presenza do poro permite a liberación dos neurotransmisores na fenda sináptica.<ref>{{cite web |last=Chudler |first=Eric H. |title=Neuroscience for kids Neurotransmitters and Neuroactive Peptides |date=November 24, 2011 |url=http://faculty.washington.edu/chudler/chnt1.html |accessdate=February 6, 2013 |archiveurl=http://web.archive.org/web/20081218122223/http://faculty.washington.edu/chudler/chnt1.html |archivedate=December 18, 2008 |deadurl=no}}</ref> O proceso polo que se libera o contido das vesículas denomínase [[exocitose]].
 
Desenvolvéronse métodos para visualizar a actividade sináptica no cerebro por medio dunha tinguidura fluorescente que detecta os niveis do calcio e o fluxo de calcio na neurona presináptica.<ref name="Sauber">
==Mapado da actividade==
{{Neuron map|[[Neuron]]}}
 
Dr. [[Wade Regehr]], professor of [[Neurobiology]] developed a method to physiologically see the synaptic activity that occurs in the brain. A dye alters the fluorenscence properties when attached to calcium. Using [[Fluorescence microscope|fluorescence-microscopy]] techniques calcium levels are detected, and therefore the influx of calcium in the [[Chemical synapse|presynaptic neuron]].<ref name="Sauber">
{{cite web
| last = Sauber
Liña 23 ⟶ 20:
| archivedate=2006-09-01
|deadurl=yes |accessdate=July 3, 2013}}
</ref><ref name="Wade">
</ref> Regehr's laboratory specializes in pre-synaptic calcium dynamics which occurs at the axon terminals. Regehr studies the implication of [[calcium]] Ca<sup>2+</sup> as it affects synaptic strength.<ref name="Wade">
{{cite web
| last = Regehr
Liña 37 ⟶ 34:
| url = http://neuro.med.harvard.edu/faculty/regehr.html
|archiveurl=http://web.archive.org/web/20081220175022/http://neuro.med.harvard.edu/faculty/regehr.html |archivedate=20 December 2008 |deadurl=no |accessdate=July 3, 2013}}
</ref> By studying the physiological process and mechanisms, a further understanding is made of neurological disorders such as [[epilepsy]], [[schizophrenia]] and [[major depressive disorder]], as well as [[memory]] and [[learning]].<ref>{{cite press release |title=NINDS Announces New Javits Neuroscience Investigator Awardees |publisher=[[National Institute of Neurological Disorders and Stroke]] |date=May 4, 2005 |url=http://www.ninds.nih.gov/news_and_events/news_articles/news_article_javits_200505.htm |accessdate=February 6, 2013 |archiveurl=http://web.archive.org/web/20090117120348/http://www.ninds.nih.gov/news_and_events/news_articles/news_article_javits_200505.htm |archivedate=January 17, 2009 |deadurl=no}}</ref><ref>{{cite web
| title = Scholar Awards
| publisher = The McKnight Endowment Fund for Neuroscience