Help
Translate
Jump to:
navigation
,
search
Settings
Group
Recent translations
Recent additions
Sandbox messages
Amacrine Cell
Artificial Intelligence
Autapse
Axon
Bipolar Cell
Cell Body
Chrome
Citizen Science and Citizen Neuroscience
Competitions
Dendrite
E2198
Encountered in cubes
F-Scores and Accuracy
FAQ
Firefox
Ganglion Cell
Glial Cell
GrimReaper
How to Play
Internet Explorer
J-RGC
Main Page
Meet the Lab
Mergers
On-Off Direction-Selective Ganglion Cell
Orientation Selective Ganglion Cell
Overcoming Obstacles
Player Roles
Retinal Neuron Classification
Serial block-face scanning electron microscopy (SBFSEM)
Synapse
Template:Get Involved
Template:How to Play
Template:Links
Template:The Neuroscience
Template:The Technology
The Consensus
The Eye and Retina
The Eyewire Lexicon
Language
aa - Afar
ab - Abkhazian
ace - Achinese
aeb - Tunisian Arabic
af - Afrikaans
ak - Akan
aln - Gheg Albanian
am - Amharic
an - Aragonese
ang - Old English
anp - Angika
ar - Arabic
arc - Aramaic
arn - Mapuche
arq - Algerian Arabic
ary - Moroccan Arabic
arz - Egyptian Arabic
as - Assamese
ast - Asturian
av - Avaric
avk - Kotava
awa - Awadhi
ay - Aymara
az - Azerbaijani
azb - تورکجه
ba - Bashkir
bar - Bavarian
bbc - Batak Toba
bbc-latn - Batak Toba
bcc - Southern Balochi
bcl - Bikol Central
be - Belarusian
be-tarask - Belarusian (Taraškievica orthography)
bg - Bulgarian
bgn - Western Balochi
bho - Bhojpuri
bi - Bislama
bjn - Banjar
bm - Bambara
bn - Bengali
bo - Tibetan
bpy - Bishnupriya
bqi - Bakhtiari
br - Breton
brh - Brahui
bs - Bosnian
bto - Iriga Bicolano
bug - Buginese
bxr - буряад
ca - Catalan
cbk-zam - Chavacano de Zamboanga
cdo - Min Dong Chinese
ce - Chechen
ceb - Cebuano
ch - Chamorro
cho - Choctaw
chr - Cherokee
chy - Cheyenne
ckb - Central Kurdish
co - Corsican
cps - Capiznon
cr - Cree
crh - Crimean Turkish
crh-cyrl - Crimean Turkish (Cyrillic script)
crh-latn - Crimean Turkish (Latin script)
cs - Czech
csb - Kashubian
cu - Church Slavic
cv - Chuvash
cy - Welsh
da - Danish
de - German
de-at - Austrian German
de-ch - Swiss High German
de-formal - German (formal address)
diq - Zazaki
dsb - Lower Sorbian
dtp - Central Dusun
dv - Divehi
dz - Dzongkha
ee - Ewe
egl - Emilian
el - Greek
eml - Emiliano-Romagnolo
en - English
en-ca - Canadian English
en-gb - British English
eo - Esperanto
es - Spanish
et - Estonian
eu - Basque
ext - Extremaduran
fa - Persian
ff - Fulah
fi - Finnish
fit - Tornedalen Finnish
fj - Fijian
fo - Faroese
fr - French
frc - Cajun French
frp - Arpitan
frr - Northern Frisian
fur - Friulian
fy - Western Frisian
ga - Irish
gag - Gagauz
gan - Gan Chinese
gan-hans - Simplified Gan script
gan-hant - Traditional Gan script
gd - Scottish Gaelic
gl - Galician
glk - Gilaki
gn - Guarani
gom-latn - Goan Konkani (Latin script)
got - Gothic
grc - Ancient Greek
gsw - Swiss German
gu - Gujarati
gv - Manx
ha - Hausa
hak - Hakka Chinese
haw - Hawaiian
he - Hebrew
hi - Hindi
hif - Fiji Hindi
hif-latn - Fiji Hindi (Latin script)
hil - Hiligaynon
ho - Hiri Motu
hr - Croatian
hrx - Hunsrik
hsb - Upper Sorbian
ht - Haitian Creole
hu - Hungarian
hy - Armenian
hz - Herero
ia - Interlingua
id - Indonesian
ie - Interlingue
ig - Igbo
ii - Sichuan Yi
ik - Inupiaq
ike-cans - Eastern Canadian (Aboriginal syllabics)
ike-latn - Eastern Canadian (Latin script)
ilo - Iloko
inh - Ingush
io - Ido
is - Icelandic
it - Italian
iu - Inuktitut
ja - Japanese
jam - Jamaican Creole English
jbo - Lojban
jut - Jutish
jv - Javanese
ka - Georgian
kaa - Kara-Kalpak
kab - Kabyle
kbd - Kabardian
kbd-cyrl - Адыгэбзэ
kg - Kongo
khw - Khowar
ki - Kikuyu
kiu - Kirmanjki
kj - Kuanyama
kk - Kazakh
kk-arab - Kazakh (Arabic script)
kk-cn - Kazakh (China)
kk-cyrl - Kazakh (Cyrillic script)
kk-kz - Kazakh (Kazakhstan)
kk-latn - Kazakh (Latin script)
kk-tr - Kazakh (Turkey)
kl - Kalaallisut
km - Khmer
kn - Kannada
ko - Korean
ko-kp - 한국어 (조선)
koi - Komi-Permyak
kr - Kanuri
krc - Karachay-Balkar
kri - Krio
krj - Kinaray-a
ks - Kashmiri
ks-arab - Kashmiri (Arabic script)
ks-deva - Kashmiri (Devanagari script)
ksh - Colognian
ku - Kurdish
ku-arab - كوردي (عەرەبی)
ku-latn - Kurdish (Latin script)
kv - Komi
kw - Cornish
ky - Kyrgyz
la - Latin
lad - Ladino
lb - Luxembourgish
lbe - лакку
lez - Lezghian
lfn - Lingua Franca Nova
lg - Ganda
li - Limburgish
lij - Ligurian
liv - Livonian
lmo - Lombard
ln - Lingala
lo - Lao
loz - Lozi
lrc - Northern Luri
lt - Lithuanian
ltg - Latgalian
lus - Mizo
lv - Latvian
lzh - Literary Chinese
lzz - Laz
mai - Maithili
map-bms - Basa Banyumasan
mdf - Moksha
mg - Malagasy
mh - Marshallese
mhr - Eastern Mari
mi - Maori
min - Minangkabau
mk - Macedonian
ml - Malayalam
mn - Mongolian
mo - молдовеняскэ
mr - Marathi
mrj - Western Mari
ms - Malay
mt - Maltese
mus - Creek
mwl - Mirandese
my - Burmese
myv - Erzya
mzn - Mazanderani
na - Nauru
nah - Nāhuatl
nan - Min Nan Chinese
nap - Neapolitan
nb - Norwegian Bokmål
nds - Low German
nds-nl - Low Saxon
ne - Nepali
new - Newari
ng - Ndonga
niu - Niuean
nl - Dutch
nl-informal - Nederlands (informeel)
nn - Norwegian Nynorsk
nov - Novial
nrm - Nouormand
nso - Northern Sotho
nv - Navajo
ny - Nyanja
oc - Occitan
om - Oromo
or - Oriya
os - Ossetic
pa - Punjabi
pag - Pangasinan
pam - Pampanga
pap - Papiamento
pcd - Picard
pdc - Pennsylvania German
pdt - Plautdietsch
pfl - Palatine German
pi - Pali
pih - Norfuk / Pitkern
pl - Polish
pms - Piedmontese
pnb - Western Punjabi
pnt - Pontic
prg - Prussian
ps - Pashto
pt - Portuguese
pt-br - Brazilian Portuguese
qqq - Message documentation
qu - Quechua
qug - Chimborazo Highland Quichua
rgn - Romagnol
rif - Riffian
rm - Romansh
rmy - Romani
rn - Rundi
ro - Romanian
roa-tara - tarandíne
ru - Russian
rue - Rusyn
rup - Aromanian
ruq - Megleno-Romanian
ruq-cyrl - Megleno-Romanian (Cyrillic script)
ruq-latn - Megleno-Romanian (Latin script)
rw - Kinyarwanda
sa - Sanskrit
sah - Sakha
sat - Santali
sc - Sardinian
scn - Sicilian
sco - Scots
sd - Sindhi
sdc - Sassarese Sardinian
se - Northern Sami
sei - Seri
ses - Koyraboro Senni
sg - Sango
sgs - Samogitian
sh - Serbo-Croatian
shi - Tachelhit
shi-latn - Tašlḥiyt
shi-tfng - ⵜⴰⵛⵍⵃⵉⵜ
si - Sinhala
sk - Slovak
sl - Slovenian
sli - Lower Silesian
sm - Samoan
sma - Southern Sami
sn - Shona
so - Somali
sq - Albanian
sr - Serbian
sr-ec - Serbian (Cyrillic script)
sr-el - Serbian (Latin script)
srn - Sranan Tongo
ss - Swati
st - Southern Sotho
stq - Saterland Frisian
su - Sundanese
sv - Swedish
sw - Swahili
szl - Silesian
ta - Tamil
tcy - Tulu
te - Telugu
tet - Tetum
tg - Tajik
tg-cyrl - Tajik (Cyrillic script)
tg-latn - Tajik (Latin script)
th - Thai
ti - Tigrinya
tk - Turkmen
tl - Tagalog
tly - Talysh
tn - Tswana
to - Tongan
tokipona - Toki Pona
tpi - Tok Pisin
tr - Turkish
tru - Turoyo
ts - Tsonga
tt - Tatar
tt-cyrl - Tatar (Cyrillic script)
tt-latn - Tatar (Latin script)
tum - Tumbuka
tw - Twi
ty - Tahitian
tyv - Tuvinian
tzm - Central Atlas Tamazight
udm - Udmurt
ug - Uyghur
ug-arab - Uyghur (Arabic script)
ug-latn - Uyghur (Latin script)
uk - Ukrainian
ur - Urdu
uz - Uzbek
uz-cyrl - ўзбекча
uz-latn - oʻzbekcha
ve - Venda
vec - Venetian
vep - Veps
vi - Vietnamese
vls - West Flemish
vmf - Main-Franconian
vo - Volapük
vot - Votic
vro - Võro
wa - Walloon
war - Waray
wo - Wolof
wuu - Wu Chinese
xal - Kalmyk
xh - Xhosa
xmf - Mingrelian
yi - Yiddish
yo - Yoruba
yue - Cantonese
za - Zhuang
zea - Zeelandic
zh - Chinese
zh-cn - Chinese (China)
zh-hans - Simplified Chinese
zh-hant - Traditional Chinese
zh-hk - Chinese (Hong Kong)
zh-mo - 中文(澳門)
zh-my - 中文(马来西亚)
zh-sg - Chinese (Singapore)
zh-tw - Chinese (Taiwan)
zu - Zulu
Export for off-line translation
Export in native format
{{DISPLAYTITLE:La célula amacrina}}Las «células amacrinas» son interneuronas retinales que funcionan en la capa plexiforme interna (IPL), la segunda capa sináptica de la retina, donde las [[Bipolar Cell|neuronas bipolares]] y las [[Ganglion Cell|células ganglionares]] hacen [[Synapse|sinapsis]]. Hay casi 40 tipos de células amacrinas, clasificadas por el alcance de su campo de conexión, la/s capa/s de la IPL en la que se encuentran y su neurotransmisor. There is no clear distinction between [[Dendrite|dendrites]] and [[Axon|axons]] in the processes of most of the amacrine cells, though they are often referred to as dendrites in general. Like horizontal cells, amacrine cells work laterally affecting the output from [[Bipolar Cell|bipolar cells]], however, their tasks are often more specialized. Each type of amacrine cell connects with a particular type of [[Bipolar Cell|bipolar cell]], and generally has a particular type of neurotransmitter. For example, one such population, AII, 'piggybacks' rod bipolar cells onto the cone bipolar circuitry. It connects rod bipolar cell output with cone bipolar cell input, and from there the signal can travel to the respective [[Ganglion Cell|ganglion cells]]. [[File:StarburstMarathonCell.png|thumb|right|500px|[[Starburst Amacrine Cell|Starburst amacrine cell]] reconstructed in Eyewire]] Most are inhibitory using either GABA or glycine as neurotransmitters. ==Physiology== [[File:Receptive field.png|200px|thumb|right|Receptive fields illustrated]] ===Visual Response Properties=== Amacrine cells are responsible for mediating "antagonistic inputs from bipolar cells in [a] ganglion cell's surround."<ref name="Tessier">Tessier-Lavigne, M. "Visual Processing by the Retina." ''Principles of Neural Science''. New York: McGraw-Hill Medical, 2000. 507-522.</ref> Thus, amacrine cells take excitatory signals coming from bipolar cells and consequently mediate inhibitory signals to a postsynaptic ganglion cell in the 'center' of its respective receptive field. In terms of visual response properties, this means that an amacrine cell in this sort of lateral pathway located within the surround of an ON-center ganglion cell's receptive field will ''depolarize'' in the presence of light on the surround of the ganglion cell's receptive field, while one located in the surround of an OFF-center ganglion cell's receptive field will ''hyperpolarize'' under the same circumstances (and ''depolarize'' in the absence of light on the surround). ON-center ganglion cells are therefore inhibited by amacrine cells in their surrounds when light shines on the surround of their receptive fields, while OFF-center ganglion cells do not receive this inhibitory input under the same circumstances, but instead receive it in the absence of light on the ganglion cell receptive field surround. As detailed below, [[Starburst Amacrine Cell|starburst amacrine cells (SAC)]] exhibit very selective visual response properties that have to do with a stimulus' direction with respect to the SAC's dendrites. ===Cellular Biophysics=== Amacrine cells are interesting biophysically in that they operate using both sodium-mediated action potentials and sodium-independent graded potential changes. This has been shown in inhibitory (i.e., GABAergic/glycinergic) amacrine cells<ref name="Bieda 1999">M. C. Bieda & D. R. Copenhagen (1999) [http://jn.physiology.org/content/81/6/3092.long Sodium Action Potentials Are Not Required for Light-Evoked Release of GABA or Glycine From Retinal Amacrine Cells] J. Neurophysiol. <strong>81</strong> (6): 3092-3095</ref>, which make up the majority of amacrine cells, though it is unclear if this holds for all amacrine cells. Starburst amacrine cells exhibit very strange biophysics. Distinct SAC dendrites are selectively activated by visual stimuli moving centrifugally with respect to those distinct dendrites. SAC dendrite-specific direction selectivity is thought to underlie the direction selectivity of [[On-Off Direction-Selective Ganglion Cell|on/off direction-selective ganglion cells]]<ref name="Denk 2002"></ref>, but the mechanism by which this direction selectivity is generated in SAC dendrites remains unknown. ==Anatomy== ===Location=== [[File:Narrow field amacrine.jpg|200px|thumb|right|Narrow-field amacrine cells<ref name="Masland 1998"></ref>]] Amacrine cells have their [[Cell Body|cell bodies]] located in the inner nuclear layer of the retina and have projections in the inner plexiform layer. Different subtypes of amacrine cells project differently in the inner plexiform layer<ref name="Masland 1998">M. A. MacNeil & R. H. Masland (1998) [http://download.cell.com/neuron/pdf/PIIS089662730080478X.pdf Extreme Diversity among Amacrine Cells: Implications for Function] Neuron <strong>20</strong>: 971-982</ref>, as shown in the figure to the right depicting different types of narrow-field amacrine cells. ===Shape=== [[File:Two amacrine cells.jpg|thumb|right|300px|Two amacrine cells with distinctive shapes. They can be easily mapped to their respective class in the catalog.<ref name="Masland 1998"></ref>]] Amacrine cells send projections from their cell bodies into the inner plexiform layer. These projections arborize differently for different subtypes of amacrine cells. Amacrine cells have these projections distributed roughly circularly in the inner plexiform layer, though some subtypes arborize asymmetrically. Most amacrine cells can be classified according to the diameter of their projection arborization: "narrow-field" cells have arbors less than 125 µm in diameter, "medium-field" cell arbors range from 125 to 400 µm in diameter, and "wide-field" cell arbors are larger than 400 µm.<ref name="Masland 1998"></ref> Their overall shapes alone are enough to serve as criterion for the classification. ===Connections=== Amacrine cells are postsynaptic targets of [[Bipolar Cell|bipolar cells]]; these bipolar-to-amacrine cell synapses occur in the inner plexiform layer and are thought to be excitatory. Amacrine cells have their postsynaptic targets in the inner plexiform layer as well. Amacrine cell dendrites are known to synapse onto [[Ganglion Cell |ganglion cell]] neurites in the IPL, mediating "antagonistic inputs from bipolar cells in the ganglion cell's surround." <ref name="Tessier"></ref> These synapses are thought to be inhibitory.; this suggests that amacrine cells serve to regulate the output of [[Bipolar Cell|bipolar cells]] in a negative-feedback loop fashion, and in fact it is thought that these amacrine-to-bipolar cell synapses are inhibitory. Further, "amacrine processes are also seen to contact other amacrine processes" in the IPL. These amacrine-to-amacrine cell synapses, interestingly enough, are thought to be excitatory. Amacrine cells are also known to form "reciprocal synapses" onto the [[Bipolar Cell |bipolar cells]] that synapse onto them<ref name="Dowling 1966">J. E. Dowling & B. B. Boycott (1996) [http://links.jstor.org/sici?sici=0080-4649%2819661115%29166%3A1002%3C80%3AOOTPRE%3E2.0.CO%3B2-N title=Organization of the Primate Retina: Electron Microscopy] Proc. R. Soc. A <strong>166</strong> (1002): 80–111</ref> Thus, amacrine cells form synapses onto [[Bipolar Cell|bipolar cells]], [[Ganglion Cell|ganglion cells]], and other amacrine cells, all in the inner plexiform layer. A few types of amacrine cells are associated with their respective functions and with corresponding [[Ganglion Cell|ganglion cells]]. For example, [[Starburst Amacrine Cell|starburst amacrine cells]] are known to make synapses onto [[On-Off Direction-Selective Ganglion Cell|on/off direction-selective ganglion cells]] (On/Off DSGCs) <ref name="Briggman2011">K. L. Briggman, M. Helmstaedter & W. Denk (2011)[http://www.itr.unisa.edu.au:2080/people/CompNeuroLab/papers/Briggman11.pdf Wiring specificity in the direction-selectivity circuit of the retina] Nature <strong>471</strong>: 183-188. doi:[http://dx.doi.org/10.1038/nature09818 10.1038/nature09818]</ref>, and wide-field (WF) amacrine cells, also known as polyaxonal amacrine cells, are considered to be associated with object motion sensitive ganglion cells either directly or indirectly via [[Bipolar Cell|bipolar cells]] <ref name="Baccus2008">S. A. Baccus et al. (2008) [http://www.neuro.cjb.net/content/28/27/6807.full.pdf A Retinal Circuit That Computes Object Motion] J. Neurosci. <strong>28</strong> (27): 6807-6817 doi:[http://dx.doi.org/10.1523/JNEUROSCI.4206-07.2008 10.1523/JNEUROSCI.4206-07.2008]</ref>. ==Molecules== ===Molecular markers=== There exist several molecular markers for amacrine cells, including ''Pax6'', ''Tcfap2b'', ''Gad1'', and ''GlyT1''. However, no markers exclusively expressed in amacrine cells are known to exist, and there exist "far fewer molecular markers [for amacrine cells] than known morphological types" of amacrine cells.<ref name="Cherry 2009">T. J. Cherry, J. M. Trimarchi, M. B. Stadler & C. L. Cepko (2009)[http://www.pnas.org/content/106/23/9495.full Development and diversification of retinal amacrine interneurons at single cell resolution] Proc. Natl. Acad. Sci. USA <strong>106</strong> (23): 9495–9500</ref> Antibodies against choline acetyltransferase (ChAT), the acetylcholine biosynthetic enzyme, are useful in staining amacrine cells in the retina, as it has been thought for some time that amacrine cells are the only cholinergic retinal neurons. However, at least one study has shown that there may exist cholinergic ganglion cells through staining against an alternative splice variant of ChAT mRNA in rat retina.<ref name="Yasuhara 2003">O. Yasuhara et al. (2003) [http://www.jneurosci.org/content/23/7/2872.full.pdf Demonstration of Cholinergic Ganglion Cells in Rat Retina: Expression of an Alternative Splice Variant of Choline Acetyltransferase] J. Neurosci. <strong>23</strong> (7): 2872–2881</ref> Staining the retina against tyrosine hydroxylase (TH), a key enzyme in the dopamine biosynthetic pathway, reveals the dopaminergic amacrine cells.<ref name="Marc">Marc, Robert E. "Retinal Neurotransmitters." ''The Visual Neurosciences''. Vol. 1. Cambridge: The MIT Press, 2003. 304-319.</ref> It should be noted, though, that (nor)adrenergic cells also contain TH, and thus in order to isolate only dopaminergic cells, staining should also be carried out against dopamine β-hydroxylase and phenylethanolamine N-methyltransferase, enzymes found in the (nor)adrenaline biosynthetic pathways, but not in the dopamine pathway.<ref name="Marc"></ref> ===Neurotransmitters=== Most amacrine cells are inhibitory and secrete only GABA or glycine, though in total, amacrine cells as a class use eight different neurotransmitters<ref name="Tessier"></ref>, including acetylcholine, dopamine, and several neuropeptides, such as vasoactive intestinal peptide (VIP), substance P, and somatostatin.<ref name="Masland 2012">Masland, R. H. Personal communication. April 6, 2012.</ref> A particular class of amacrine cells—the [[Starburst Amacrine Cell|starburst amacrine cell]]—has been found to be both cholinergic ''and'' GABAergic.<ref name="Masland 1992">D. M. O'Malley, J. H. Sandell & R. H. Masland (1992) [http://www.jneurosci.org/content/12/4/1394.full.pdf Co-release of Acetylcholine and GABA by the Starburst Amacrine Cells] J. Neurosci. <strong>12</strong> (4): 1394–1408</ref> According to retinal neuron expert Richard Masland, it appears that every amacrine cell is GABA- or glycinergic, with those amacrine cells that secrete other neurotransmitters secreting them concurrently with GABA or glycine.<ref name="Masland 2012"></ref> ==History== The first characterization of amacrine cells is often attributed to Santiago Ramón y Cajal. Using the Golgi method of staining neurons, he first saw these cells in the avian retina in the late 1880s, naming them "amacrine" cells ("amacrine" meaning "without axon" in Greek). Though he was the first to call them amacrine cells, he built on the earlier work of J. Müller, who had previously described "spongioblasts" in the retina that were likely the very same cells Ramón y Cajal later named "amacrine."<ref name="Uchiyama 2005">H. Uchiyama & W. K. Stell (2005) [http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=398652 Association amacrine cells of Ramón y Cajal: Rediscovery and reinterpretation] Visual Neuroscience <strong>22</strong>: 881—891</ref> ==Open questions/status/relevance to Eyewire== ===Open questions=== Though it is more or less well-established how inhibitory amacrine cells function, it is less clear what functions non-GABAergic/glycinergic amacrine cells have in the retina. In particular, it is not well understood for which functions [[Starburst Amacrine Cell|starburst amacrine cells]] require acetylcholine secretion or how [[Starburst Amacrine Cell|starburst amacrine cells]] might use both GABA and acetylcholine in concert to accomplish certain fucntions. [[Starburst Amacrine Cell|Starburst amacrine cells]] also exhibit very curious biophysics in that any given individual SAC dendrite is selectively activated by visual stimuli centrifugal with respect to that particular dendrite.<ref name="Denk 2002">Thomas Euler, Peter B. Detwiler & Winfried Denk (2002). [http://retina.anatomy.upenn.edu/pdfiles/5908.pdf Directionally selective calcium signals in dendrites of starburst amacrine cells] Nature <strong>418</strong>: 845-852</ref> The mechanism for this selectivity remains unknown. Also, as stated above, no amacrine cell-exclusive molecular markers are known to exist<ref name="Cherry 2009"></ref>; the discovery of such a marker would be incredibly beneficial to further amacrine cell research. ===Status/relevance to Eyewire=== Thus far, dozens of [[Starburst Amacrine Cell|starburst amacrine cells]] have been reconstructed through Eyewire, as well as at least one AII amacrine cell. == References == <references />
Navigation menu
Personal tools
English
Create account
Log in
Namespaces
Translate
Variants
Views
Language statistics
Message group statistics
Export
More
Search
Navigation
Main page
Recent changes
Random page
Help
Tools
Special pages
Printable version