Negri bodies are
eosinophilic
Eosinophilic (Greek suffix -phil-, meaning ''loves eosin'') is the staining of tissues, cells, or organelles after they have been washed with eosin, a dye.
Eosin is an acidic dye for staining cell cytoplasm, collagen, and muscle fibers. ''E ...
, sharply outlined,
pathognomonic inclusion bodies
Inclusion bodies are aggregates of specific types of protein found in neurons, a number of tissue cells including red blood cells, bacteria, viruses, and plants. Inclusion bodies of aggregations of multiple proteins are also found in muscle cells ...
(2–10
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer ( American spelling), also commonly known as a micron, is a unit of length in the International System of Uni ...
in diameter) found in the
cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. ...
of certain
nerve cells containing the
virus of rabies, especially in
pyramidal cell
Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal neurons are the primary excitation units of the mammalian prefrontal co ...
s
within
Ammon's horn of the
hippocampus
The hippocampus (via Latin from Greek , 'seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic syste ...
. They are also often found in the
Purkinje cells
of the
cerebellar cortex
The cerebellum (Latin for "little brain") is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as or even larger. In humans, the cerebe ...
from postmortem brain samples of
rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...
victims. They consist of ribonuclear proteins produced by the virus.
They are named for
Adelchi Negri.
History and use as a Rabies Diagnosis
Adelchi Negri, an assistant pathologist working in the laboratory of
Camillo Golgi
Camillo Golgi (; 7 July 184321 January 1926) was an Italian biologist and pathologist known for his works on the central nervous system. He studied medicine at the University of Pavia (where he later spent most of his professional career) betwe ...
, observed these inclusions in rabbits and dogs with
rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, ...
. These findings were presented in 1903 at a meeting of the Società Medico-Chirurgica of Pavia. The American pathologist
Anna Wessels Williams made the same discovery, but because Negri published his results first, the bodies bear his name.
Negri was convinced the inclusions were a parasitic
protozoon and the
etiologic agent of rabies. Later that same year, however,
Paul Remlinger and
Rifat-Bey Frasheri in
Constantinople
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth (Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis (" ...
and, separately,
Alfonso di Vestea in
Naples
Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adm ...
showed that the etiologic agent of rabies is a filterable
virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsk ...
. Negri continued until 1909 to try to prove that the intraneuronal inclusions named after him corresponded to steps in the developmental cycle of a protozoan.
In spite of his incorrect etiologic hypothesis, Negri's discovery represented a breakthrough in the rapid diagnosis of rabies, and the detection of Negri bodies, using a method developed by
Anna Wessels Williams, remained the primary way to detect rabies for the next thirty years.
References
External links
Slide at pathmicro.med.sc.edu – see bottomSee pathology video of Negri bodies
{{DEFAULTSORT:Negri Bodies
Histopathology
Rabies
Hippocampus (brain)
Neuropathology