Camillo Golgi

Italian physician

• Born: July 7, 1843; Corteno, Italy
• Died: January 21, 1926; Pavia, Italy

Nineteenth-century physician and histologist Camillo Golgi was the first Italian scientist to be awarded the Nobel Prize. He is best known for his work on the human nervous system, including the discovery of a tendon sensory organ called the Golgi receptor. He is also known for formulating a method of staining nerve cells and tissues in order to observe their behavior.

Primary field: Physiology

Specialties: Microbiology; histology

Early Life

Camillo Golgi was born in Corteno, Lombardy, Italy on July 7, 1843. He studied medicine at the University of Pavia, intending to become a physician like his father. Golgi received his medical degree in 1865 but never practiced medicine, choosing instead to focus on medical research. His early interest was in psychiatry, and he became a student intern at the Institute of Psychiatry at Pavia under criminologist Cesare Lombroso. As an assistant to Lombroso, Golgi studied mental illness, working to incorporate the family history of patients with available clinical data. This work inspired Golgi to search for connections between mental illness and abnormalities in the nervous system.

Golgi’s introduction to histology, the study of cells and tissue with a microscope, began under the tutelage of pathologist Giulio Bizzozero. (Golgi’s wife, Lina Aletti, was Bizzozero’s niece.) In the late nineteenth century, doctors did not understand that the brain is comprised of of individual neurons. Although scientists made use of the cell theory developed by German botanist Matthias Schleidon and German physiologist Theodor Schwann in 1839, the theory had not yet been applied to the nervous system. At the time, differentiating individual brain cells under a microscope was impossible.

Many types of human cells are roughly spherical in shape, but nerve cells, or neurons, are long and narrow. When scientists of Golgi’s era attempted to section these tissues in preparation for viewing under a microscope, they destroyed these fragile structures. Scientists theorized that nervous tissue might actually be continuous cytoplasm (the gel-like substance inside cells), and not be composed of cells at all.

Life’s Work

Golgi developed a staining technique that proved nervous system tissue is made up primarily of cells. This breakthrough occurred after he exposed nervous system tissue hardened by potassium bichromate to silver nitrate. Hardening the tissue protected the long, delicate neurons. Silver particles adhered to the neurilemma (the membrane around the neuron), staining it black. Under the microscope, the finest details stood out against a contrasting yellow background. Scientists were able to observe the structure of the neuron for the first time.

Golgi’s black reaction was a crucial development in the field of neuroscience. His work helped scientists discover that each neuron has a soma, or cell body, with long, narrow extensions called axons and dendrites. These extensions, or processes, reach out to interact with other neurons. Electrical signals are transmitted cell-to-cell along networks of neurons, sending the messages necessary for thought and movement.

Densely populated neurons are difficult to see clearly, but when only a few of them are stained, pathways between interconnected neurons become clear. Golgi’s selective staining technique was the key to understanding the organization of this complex tissue. For the first time, scientists realized that signals were being communicated between neurons in the brain and spinal cord. Golgi’s black reaction stains certain neurons in brain tissue, but not others. Histologists still do not understand this phenomenon.

Golgi applied the black reaction to the study of brain structures including the olfactory lobes (the control center in the brain for the sense of smell), gray matter (nervous tissue of the brain and spinal cord), and the cerebellum (a portion of the brain that coordinates movement and balance). His published results of these studies, along with his anatomical drawings, earned him the Nobel Prize in Physiology or Medicine in 1906. The black reaction is still in use today.

By 1872, financial problems had forced Golgi from the University of Pavia. He became chief medical officer at a hospital in Abbiategrosso, Italy. In 1876, Golgi returned to the University of Pavia, this time as a professor of histology. There he directed his own laboratory, taking on students and assistants to continue his research.

Around 1886, Golgi became interested in malaria. Malaria is an infection caused by protozoan (single-celled eukaryotic) parasites that results in repeated cycles of fever and chills. The disease is transmitted by the bite of infected Anopheles mosquitoes and is common in tropical climates where mosquitoes are plentiful. Mosquitoes become infected with malaria by biting a person or bird with malaria. They transmit the disease by going on to bite an uninfected person. When a person is infected, the parasites reproduce in the liver and then penetrate the red blood cells. They continue to reproduce inside the red blood cells, breaking out at predictable intervals to cause bouts of fever.

Golgi investigated the periodic nature of fevers in malaria patients, concluding that there were actually two forms of malaria: one that causes fever every other day, and one that causes fever every third day. Golgi discovered differences in the reproductive rates between the two forms of the disease. Whenever new parasites broke out of red blood cells and into the bloodstream, the patient suffered another bout of fever. Golgi was the first scientist to notice that the timing of fevers corresponded to the reproductive cycle of the parasite.

Golgi discovered the intracellular organelle known as the Golgi apparatus by accident while observing partially stained Perkinje cells (neurons from the cerebellar cortex). The Golgi apparatus is described as resembling a stack of pita bread, because it is comprised of stacked, flattened sacs of membrane.

Golgi named the organelle the “apparato reticolare interno” (“internal reticular apparatus”). This later became known as the Golgi apparatus, or, more simply, the Golgi. He published the discovery in 1898, but some scientists dismissed it as an artifact of the staining process. Artifacts of staining include thickened spots of stain or other microscopic irregularities that could be confused with real cellular structures. It was not until the invention of the electron microscope in the 1930s that the discovery was confirmed. Electron microscopes produce images with much better magnification and resolution than the light microscopes available to Golgi.

We now know that the Golgi apparatus functions in the cell like a post office does in a city, sorting and shipping proteins to their destinations. Newly synthesized proteins enter the apparatus, where polysaccharide (carbohydrate) chains bound to their surfaces are added to, or trimmed. These polysaccharide chains act as the address labels, showing the destination of each kind of protein. Just as a business letter has the name and address both on the envelope and the letter itself, matching polysaccharide chains are attached both to the protein and to the membranous vesicle that contains it.

When the proteins are ready, vesicles, or bubbles of membrane, pinch off the Golgi apparatus in much the same way as a bubble is blown from bubble gum. These vesicles travel to their destinations inside the cell, or to the plasma membrane of the cell to be used elsewhere in the body.

Golgi and his wife were never able to have children of their own. They adopted Golgi’s niece, Carolina, and raised her as their own daughter. In recognition of their contributions to the study of the nervous system, Golgi and the Spanish histologist Santiago Ramón y Cajal shared the 1906 Nobel Prize in Physiology or Medicine. Golgi was sixty-three at the time. In his later years, he became an influential dean and faculty member at the University of Pavia. In 1900, he became a politician, where his focus remained on public health. Italy joined World War I in 1915. Despite his advanced age, Golgi headed up a military hospital in Pavia that treated wounded soldiers. Golgi retired in 1918 and died in Pavia, Italy, on January 21, 1926.

Impact

Golgi helped to improve our understanding of the human brain and nervous system. Researchers worldwide still use his method of nervous tissue staining. The neuron doctrine, which holds that individual cells make up the nervous system, was established as a direct result of his work. The Golgi Hall at the Museum of History at the University of Pavia houses an exhibit on Golgi’s life and accomplishments. His Nobel diploma is on display there.

Bibliography

Alberts, Bruce, et al. Essential Cell Biology. New York: Garland Science, 2009. Print. Offers an introduction to the basic concepts of cell biology. Illustrated.

Mazzarello, Paolo. Golgi: A Biography of the Founder of Modern Neuroscience. Oxford: Oxford UP, 2009. Print. Presents a detailed review of Golgi’s life and work, including his achievements in neuroscience, cell biology, and microbiology.

Mironov, Alexander A. The Golgi Apparatus: State of the Art 110 Years after Camillo Golgi’s Discovery. New York: Springer, 2010. Print. Details the function of the Golgi apparatus and reviews scientific developments related to the fields of molecular biology and microscopy.