Editing Camillo Golgi (section)

==Contributions==

===Black reaction or Golgi's staining===
[[File:Golgi's drawing of nervous system.gif|thumb|The first illustration by Golgi of the nervous system. Vertical section of the olfactory bulb of a dog (in 1875).]]
The [[Central nervous system]] was difficult to study during Golgi's time because the cells were hard to identify. The available [[Staining (biology)|tissue staining techniques]] were useless for studying [[nervous tissue]]. While working as chief medical officer at the Hospital of the Chronically Ill, he experimented with metal impregnation of nervous tissue, using mainly [[silver]] ([[silver staining]]). In early 1873, he discovered a method of staining nervous tissue that would stain a limited number of cells at random in their entirety. He first treated the tissue with potassium dichromate to harden it, and then with silver nitrate. Under the microscope, the outline of the neuron became distinct from the surrounding tissue and cells. The silver chromate precipitate, as a reaction product, selectively stains only some cellular components randomly, sparing other cell parts. The silver chromate particles create a stark black deposit on the [[Soma (biology)|soma]] (nerve cell body) as well as on the [[axon]] and all [[dendrites]], providing an exceedingly clear and well-contrasted picture of [[neuron]] against a yellow background. This makes it easier to trace the structure of the nerve cells in the brain for the first time.<ref name="benti"/> Since cells are selective stained in black, he called the process ''la reazione nera'' ("the black reaction"), but today it is called [[Golgi's method]] or the Golgi stain.<ref>{{cite journal|last1=Chu|first1=NS|title=[Centennial of the nobel prize for Golgi and Cajal—founding of modern neuroscience and irony of discovery]|journal=Acta Neurologica Taiwanica|date=2006|volume=15|issue=3|pages=217–222|pmid=16995603}}</ref> On 16 February 1873, he wrote to his friend Niccolò Manfredi:
{{Blockquote|I am delighted that I have found a new reaction to demonstrate, even to the blind, the structure of the interstitial stroma of the cerebral cortex.}}
His discovery was published in the ''Gazzeta Medica Italiani'' on 2 August 1873.<ref>{{cite journal|last1=DeFelipe|first1=Javier|title=The dendritic spine story: an intriguing process of discovery|journal=Frontiers in Neuroanatomy|date=2015|volume=9|page=14|doi=10.3389/fnana.2015.00014|pmid=25798090|pmc=4350409|doi-access=free }}</ref>

===Nervous system===
[[Image:Golgi Hippocampus.jpg|thumb|Drawing by Camillo Golgi of a [[hippocampus]] stained with the silver nitrate method]]
In 1871, a German anatomist [[Joseph von Gerlach]] postulated that the brain is a complex "protoplasmic network", in the form of a continuous network called the reticulum. Using his black reaction, Golgi could trace various regions of the cerebro-spinal axis, clearly distinguishing the different nervous projections, namely [[axon]] from the [[dendrite]]s. He drew up a new classification of cells on the basis of the structure of their nervous prolongation. He described an extremely dense and intricate network, composed of a web of intertwined branches of axons coming from different cell layers ("diffuse nervous network"). This network structure, which emerges from the axons, is essentially different from that hypothesized by Gerlach. It was the main organ of the central nervous system according to Golgi. Thus, Golgi presented the [[reticular theory]] which states that the brain is a single network of nerve fibres, and not of discrete cells.<ref name="Marina Bentivoglio">{{cite web |author=Marina Bentivoglio |title=Life and Discoveries of Camillo Golgi |url=https://www.nobelprize.org/nobel_prizes/medicine/laureates/1906/golgi-article.html |work=Nobelprize.org |publisher= Nobel Media |date=20 April 1998 |access-date=23 August 2013 }}</ref><ref name=cimi>{{cite journal |author= Cimino G |title= Reticular theory versus neuron theory in the work of Camillo Golgi |journal= Physis Riv Int Stor Sci |volume= 36|issue= 2 | pages= 431–472 |year= 1999 |pmid= 11640243}}</ref> Although Golgi's earlier works between 1873 and 1885 clearly depicted the axonal connections of [[cerebellar cortex]] and [[olfactory bulb]] as independent of one another, his later works including the Nobel Lecture showed the entire granular layer of the cerebellar cortex occupied by a network of branching and anastomosing nerve processes. This was due to his strong conviction in the reticular theory.<ref>{{cite journal |author= Raviola E, Mazzarello P|title=The diffuse nervous network of Camillo Golgi: facts and fiction |journal=Brain Res Rev |volume=66 |issue=1–2 | pages=75–82 |year=2011 |pmid=20840856 |doi= 10.1016/j.brainresrev.2010.09.005|s2cid=11871228 }}</ref><ref name="Marina Bentivoglio"/> Golgi's theory was challenged by Ramón y Cajal, who used the same technique developed by Golgi. According to Ramón y Cajal's [[Neuron doctrine|neurone theory]], the nervous system is but a collection of individual cells, the neurones, which are interconnected to form a network.<ref>{{cite journal|last1=Bock|first1=Ortwin|title=Cajal, Golgi, Nansen, Schäfer and the Neuron Doctrine|journal=Endeavour|date=2013|volume=37|issue=4|pages=228–234|doi=10.1016/j.endeavour.2013.06.006|pmid=23870749}}</ref>

In addition to this, Golgi was the first to give clear descriptions of the structure of the [[cerebellum]], [[hippocampus]], [[spinal cord]], [[Olfactory bulb|olfactory lobe]], as well as [[Striatum|striatal]] and cortical lesions in a case of [[chorea]]. In 1878, he also discovered a receptor organ that senses changes in muscle tension, and is now known as [[Golgi tendon organ]] or Golgi receptor; and Golgi-Mazzoni corpuscles (pressure transductors).<ref name="mazz98">{{cite journal|last1=Mazzarello|first1=P.|title=Camillo Golgi (1843–1926)|journal=Journal of Neurology, Neurosurgery & Psychiatry|date=1998|volume=64|issue=2|pages=212|doi=10.1136/jnnp.64.2.212|pmid=9489532|pmc=2169935}}</ref> He further developed a stain specific for [[myelin]] (a specialised membrane which wraps around the axon) using [[potassium dichromate]] and [[mercuric chloride]]. Using this he discovered the myelin annular apparatus, often called the horny funnel of Golgi-Rezzonico.<ref name="mazz99"/>

===Kidney===
Golgi studied kidney function during 1882 to 1889. In 1882, he published his observations on the mechanism of [[renal hypertrophy]], which he understood to be due to renal cell proliferation. In 1884, he described tubular cell mitoses in the kidney of a person suffering from [[tubulointerstitial nephritis]], and he noted that the process was an essential part of repairing the kidney tissue. He was the first to dissect out intact [[nephrons]], and show that the distal tubulus ([[loop of Henle]]) of the nephron returns to its originating [[Glomerulus (kidney)|glomerulus]], a finding that he published in 1889 ("Annotazioni intorno all'Istologia dei reni dell'uomo e di altri mammifieri e sull'istogenesi dei canalicoli oriniferi". ''Rendiconti R. Acad. Lincei'' 5: 545–557, 1889).<ref>{{cite journal|last1=Dal Canton|first1=Ilaria|last2=Calligaro|first2=Alessandro L.|last3=Dal Canton|first3=Francesca|last4=Frosio-Roncalli|first4=Moris|last5=Calligaro|first5=Alberto|title=Contributions of Camillo Golgi to Renal Histology and Embryology|journal=American Journal of Nephrology|date=1999|volume=19|issue=2|pages=304–307|doi=10.1159/000013465|pmid=10213832|s2cid=29666037}}</ref>

===Malaria===
A French Army physician [[Charles Louis Alphonse Laveran]] discovered that [[malaria]] was caused by microscopic parasite (now called ''[[Plasmodium falciparum]]'') in 1880. But scientists were sceptical until Golgi intervened. It was Golgi who helped him prove that malarial parasite was a microscopic [[protozoan]]. From 1885, Golgi studied the malarial parasite and its transmission. He established two types of malaria, tertian and quartan [[fever]]s caused by ''[[Plasmodium vivax]]'' and ''[[Plasmodium malariae]]'' respectively.<ref>{{cite journal|author=Golgi C. |title=Sul ciclo evolutivo dei parassiti malarici nella febbre terzana : diagnosi differenziale tra i parassiti endoglobulari malarici della terzana e quelli della quartana|trans-title=On the cycle of development of malarial parasites in tertian fever: differential diagnosis between the intracellular parasites of tertian and quartant fever|journal=Archivio per le Scienza Mediche|volume= 13|pages=173–196|year= 1889}}</ref> In 1886, he discovered that malarial fever ([[Paroxysmal attack|paroxysm]]) was produced by the asexual stage in the human blood (called erythrocytic cycle, or Golgi cycle).<ref>{{cite journal|last1=Antinori|first1=Spinello|last2=Galimberti|first2=Laura|last3=Milazzo|first3=Laura|last4=Corbellino|first4=Mario|title=Biology of human malaria plasmodia including ''Plasmodium knowlesi''|journal=Mediterranean Journal of Hematology and Infectious Diseases|date=2012|volume=4|issue=1|pages=2012013|doi=10.4084/MJHID.2012.013|pmid=22550559|pmc=3340990}}</ref> In 1889–1890, Golgi and [[Ettore Marchiafava]] described the differences between benign tertian malaria and malignant tertian malaria (the latter caused by ''P. falciparum''). By 1898, along with [[Giovanni Battista Grassi]], [[Amico Bignami]], [[Giuseppe Bastianelli]], [[Angelo Celli]] and Marchiafava, he confirmed that malaria was transmitted by [[Anopheles|anopheline]] mosquitoes.<ref>{{cite journal|last1=Cox|first1=Francis EG|title=History of the discovery of the malaria parasites and their vectors|journal=Parasites & Vectors|date=2010|volume=3|issue=1|pages=5|doi=10.1186/1756-3305-3-5|pmid=20205846|pmc=2825508 |doi-access=free }}</ref>

===Cell organelle===

An organelle in eukaryotic cells now known as [[Golgi apparatus]] or Golgi complex, or sometimes simply as Golgi, was discovered by Camillo Golgi.<ref>{{cite journal|last1=Bentivoglio|first1=Marina|title=The Discovery of the Golgi Apparatus|journal=Journal of the History of the Neurosciences|date=1999|volume=8|issue=2|pages=202–208|doi=10.1076/jhin.8.2.202.1833|pmid=11624302}}</ref> Golgi modified his black reaction using osmium dichromate solution with which he stained the nerve cells ([[Purkinje cell]]s) of the cerebellum of a barn owl.<ref name=drosch>{{cite journal|last1=Dröscher|first1=Ariane|title=The history of the golgi apparatus in neurones from its discovery in 1898 to electron microscopy|journal=Brain Research Bulletin|date=1998|volume=47|issue=3|pages=199–203|doi=10.1016/S0361-9230(98)00080-X|pmid=9865850|s2cid=36117803}}</ref> He noticed thread-like networks inside the cells and named them ''apparato reticolare interno'' (internal reticular apparatus). Recognising them to be unique cellular components, he presented his discovery before the Medical-Surgical Society of Pavia in April 1898.<ref>{{cite journal|last1=Mazzarello|first1=Paolo|last2=Garbarino|first2=Carla|last3=Calligaro|first3=Alberto|title=How Camillo Golgi became "the Golgi"|journal=FEBS Letters|date=2009|volume=583|issue=23|pages=3732–3737|doi=10.1016/j.febslet.2009.10.018|pmid=19833130|s2cid=23309035|doi-access=free|bibcode=2009FEBSL.583.3732M }}</ref> After the same was confirmed by his assistant Emilio Veratti, he published it in the ''Bollettino della Società medico-chirurgica di Pavia''.<ref>{{cite journal|last1=Dröscher|first1=A|title=Camillo Golgi and the discovery of the Golgi apparatus|journal=Histochemistry and Cell Biology|date=1998|volume=109|issue=5–6|pages=425–30|pmid=9681625|doi=10.1007/s004180050245|s2cid=9679562}}</ref> However, most scientists disputed his discovery as nothing but a staining artefact. Their microscopes were not powerful enough to identify the organelles. By the 1930s, Golgi's description was largely rejected.<ref name=drosch/> It was only firmly established 50 years after its discovery, when electron microscopes were developed.<ref>{{cite journal|last1=Bentivoglio|first1=M|last2=Mazzarello|first2=P|title=One hundred years of the Golgi apparatus: history of a disputed cell organelle|journal=Italian Journal of Neurological Sciences|date=1998|volume=19|issue=4|pages=241–247|pmid=10933465|doi=10.1007/bf02427612|s2cid=31879493}}</ref>