Pathology

The task of the unit is to conduct research and teaching in the field of pathology in animals.

Research

Prion diseases
The unit has contributed to research on prion diseases since the late 1990s. Scrapie in sheep, chronic wasting disease in reindeer, mad cow disease in cattle and Creutzfeldt-Jakob disease in humans are examples of prion diseases. The various forms of the disease are mostly linked to certain species, but there has also been evidence of infection between different species, such as mad cow disease that was transmitted via food to humans. The diseases are caused by the transformation of the normal prion protein in the brain into an abnormal form (called a "prion") which is difficult to break down and which therefore accumulates in the brain tissue and causes damage. This change can occur spontaneously in individual animals or prions can be transmitted (natural infection or via food) from a sick to a healthy animal and cause the disease to spread.

We have worked with how scrapie develops and how the diseases can be detected in live animals. A line of Norwegian goats, with a mutation in the prion protein that prevents the protein from being made, has also been extensively studied. These goats are interesting because they can reveal the normal function of the prion protein, which in turn can reveal what happens to the cells in prion disease. Some of the findings are that the goats are damaged in peripheral nerves and react abnormally strongly to infections. They are also resistant to scrapie. Today we are part of an NFR project that studies possible transmission of scrapie from reindeer to sheep, which is relevant because a large number of sheep grazed in the same area where scrapie was detected. We are also part of a group at NMBU that has a contribution to a larger EU project and where the goats without prion protein will be studied further.

Peripheral neuropathy

An ongoing project by the unit is studies of peripheral neuropathy and the protein NDRG1, a protein associated with demyelinating disease in peripheral nerves in humans and animals. An inherited mutation in the NDRG1 gene in the dog breed Alaskan malamute causes clinical nerve disease early in life, where the dogs gradually lose their function in the hind legs, among other things. The gene is important for the cells that protect peripheral nerve fibers, known as Schwann cells. Normally, these cells form a fat-rich, insulating material around the axons of the nerves. In sick individuals, this so-called myelin layer will be weakened. Using primary cell cultures, studies are performed on Schwann cells, isolated from sick and healthy dogs, where we look for the reason why myelin homeostasis in peripheral nerves ceases. The cell cultures are analyzed using methods such as immunocytochemistry, western blot and qPCR, where we compare subcellular expression of NDRG1, vesicle transport and the cytoskeleton between healthy and diseased genotype. The disease in Alaskan malamute has similarities with the human disease Charcot-Marie-Tooths disease type 4D. To develop better treatment for hereditary neuropathies, it is important to increase understanding of how NDRG1 is needed to maintain myelin in peripheral nerves.

The unit also has a collaboration with The Equine Clinic at the faculty of Veterinary Medicine where myelination of peripheral nerves is also central. The disease AEP (aquired equine polyneuropathy) has been a major problem, especially in Northern Europe, in recent years. The horses develop a peripheral nerve disease i.a. due to an apparent failure of the Schwann cell's ability to form and / or maintain the myelin chains. The result is an occasional severe ataxia, which can lead to the horses being killed. The cause is unclear, but the disease is probably related to elements in the feed. We have grown Schwann cells from sick and healthy horses in the laboratory, and are planning, among other things. to incubate cells from healthy horses with serum from sick horses.

Congenital tremors in pigs (shaking piglets)

The unit participates in an interdisciplinary project on congenital tremors in piglets. (Click here for a video showin a piglet with the disease.) This is a neurological phenomenon that causes congenital muscle tremors of varying degrees. The shaiking can make it difficult for the piglets to get enough colostrum and therefore increase mortality and reduce growth. The symptoms are caused by changes in the insulating myelin chains along the nerve-transmitting axons of the nerves in the brain and spinal cord. The condition occurs all over the world, including in Norway. In 2016, the form of shaking disease that we have in Norway was associated with a new virus, called atypical porcine pestivirus (APPV).

Since the virus has been newly discovered, there are large knowledge gaps about how it causes disease, what disease changes it causes, how it is transmitted and about the immune development of infected animals. Today, there are also no known preventive measures to avoid the introduction of the virus or to treat sick individuals. Through the project, we want to establish increased knowledge about morphological changes and disease mechanisms in the central nervous system, especially in the myelin chains and in the myelin-producing oligodendrocytes, as well as in the brain's defense cells, microglia. We also want to increase knowledge about the virus' distribution in different tissues, and its significance for infection and convalescence. Increased knowledge about the disease can contribute to better animal health and animal welfare in pigs.


Teaching

In the 4th semester, we  teach the subject “General pathology” in coordination with immunology, genetics and pathophysiology. The teaching consists of lectures, colloquia and a comprehensive course in basic histopathology. The aim of this teaching is for students to learn basic disease mechanisms, as well as to see these in connection with changes in the tissues.

The students come back to us in the 7th and 8th semester as there are group rotations with teaching in the autopsy room between 09-12 (in parallel with organ-based lectures in the 7th semester). The aim here is to learn the systematic implementation of an autopsy with sampling from different animal species, to be able to assess what is normal and what are pathoanatomical changes in the organs and learn to describe the changes using correct concepts. Based on these descriptions, students will make pathoanatomical diagnoses and discuss possible etiology (cause of disease). Being able to discuss and understand the development of the disease (pathogenesis) is also important. The students summarize the findings and conclusions made in student records that must be submitted to the responsible pathologist.

Published 24. March 2022 - 16:54 - Updated 24. March 2022 - 17:05