Reseptor warna: Perbedaan antara revisi

[[Berkas:Cone cell en.png|thumbjmpl|Struktur sel kerucut.]]

Osterberg pada tahun 1935 mengatakan, ada sekitar enam juta sel kerucut pada mata manusia.<ref name="Osterberg">G. Osterberg (1935). “Topography of the layer of rods and cones in the human retina,” Acta Ophthalmol., Suppl. 13:6, pp. 1–102.</ref> Sementara Curcio pada tahun 1990 mengatakan ada sekitar 4,5 juta sel kerucut dan 90 juta sel batang pada retina manusia.<ref>{{cite book |title=The human eye: structure and function |url=https://archive.org/details/humaneyestructur0000oyst|last=Oyster |first=C. W. |year=1999 |publisher=Sinauer Associates |location= |page= }}</ref><ref>{{Cite journal | last1 = Curcio | first1 = CA. | last2 = Sloan | first2 = KR. | last3 = Kalina | first3 = RE. | last4 = Hendrickson | first4 = AE. | title = Human photoreceptor topography. | journal = J Comp Neurol | volume = 292 | issue = 4 | pages = 497–523 | month = Feb | year = 1990 | doi = 10.1002/cne.902920402 | pmid = 2324310 }}</ref>

Sel kerucut kurang sensitif terhadap cahaya dibandingkan sel batang, tapitetapi sel kerucut mampu membedakan warna. Sel kerucut juga dapat melihat detail yang lebih halus dan karena memiliki respon yang cepat terhadap perubahan.<ref name="Kandel">{{cite book

| first = E.R.

| last = Kandel

| authorlink =

| coauthors = Schwartz, J.H, and Jessell, T. M.

| year = 2000

| title = Principles of Neural Science

| edition = 4th

| publisher = McGraw-Hill

| location = New York

}}</ref>

Karena manusia biasanya memiliki tiga jenis sel kerucut dengan iodopsin berbeda, yang memiliki kurva respon yang berbeda, dengan demikian manusia menanggapi variasi warna dengan cara yang berbeda. Hal ini yang mebuat manusia memiliki penglihatan [[trikromatik]]. Pada kasus but warna, satu atau lebih sel kerucut tidak berfungsi sebagai mana mestinya, sehingga penderita buta warna tidak bisa melihat warna tertentu.

Pernah juga di laporkan bahwa ada manusimanusia yang memiliki empat atau lebih sel kerucut yang membuat mereka memiliki penglihatan [[tetrakromatik]].<ref name="Jameson 2001" >{{cite journal

|volume=8
|issue=2
|pages=244–261

|url=http://www.klab.caltech.edu/cns186/papers/Jameson01.pdf
|format=PDF

Kerusakan pada sel kerucut akan menyebapkan kebutaan.

One of the diseases related to cone cells present in retina is Retinoblastoma. Retinoblastoma is a rare, cancerous tumor of a part of the eye called the retina. Cancer of the retina common in children which is caused by the mutation of both copies of retinoblastoma genes (RB1). , the protein encoded by RB1 regulates a signal transduction pathway while controlling the cell cycle progression as normally. The scientists have come to a conclusion that retinoblastoma seems to originate in cone precursor cells present in the retina that consist of natural signalling networks which restrict cell death and promote cell survival after losing the RB1. It has been found that TRβ2 which is a transcription factor specifically affiliated with cones is essential for rapid reproduction and existence of the retinoblastoma cell.<ref name="Tumorigenesis: Cone cells set the stage">{{cite journal|last=Skinner|first=Mhairi|title=Tumorigenesis: Cone cells set the stage|journal=Nature Reviews Cancer|date=August|year=2009|volume=9|pages=534|doi=10.1038/nrc2710|accessdate=12 April 2012}}</ref> The drug that will be useful in the treatment of this disease is MDM2 (murine double minute 2) gene. Some of the symptoms include:

== Pranala Luarluar ==

* {{en}} [http://www.neuinfo.org/nif/nifgwt.html?query=%22Cone%20Cell%22 NIF Search&nbsp;– Cone Cell] {{Webarchive|url=https://web.archive.org/web/20120220045736/http://www.neuinfo.org/nif/nifgwt.html?query=%22Cone%20Cell%22 |date=2012-02-20 }} via the [[Neuroscience Information Framework]]

* {{en}} [http://www.nanobotmodels.com/node/33 Model and image of cone cell] {{Webarchive|url=https://archive.today/20130104021248/http://www.nanobotmodels.com/node/33 |date=2013-01-04 }}

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