|
Cerebellar abiotrophy (CA), also referred to as the cerebellar cortical abiotrophy (CCA), is a genetic neurological disease in animals best known to affect certain breeds of horses, dogs and cats. It develops when the neurons known as Purkinje cells, located in the cerebellum of the brain, begin to die off. These cells affect balance and coordination. They have a critical role to play in the brain. The Purkinje layer allows communication between the granular and molecular cortical layers in the cerebellum. Put simply, without Purkinje cells, an animal loses its sense of space and distance, making balance and coordination difficult. ''Abiotrophy'' means the loss of a vital nutritive factor. The exact cause of cerebellar abiotrophy is not known, but it is thought to be due to an intrinsic metabolic defect. In most cases, the Purkinje neurons begin to die off shortly after the animal is born and the condition is noticeable when the animal is less than six months old, though sometimes the onset of symptoms is gradual and the animal is much older before the owner or caretaker notices a problem. CA cannot be prevented, other than by selective breeding to avoid the gene, and it cannot be cured. Genetic testing can detect carriers. In addition to dogs and horses, there also have been cases of cerebellar abiotrophy in Siamese and Domestic shorthair cats; in Angus, Polled Hereford, Charolais and Holstein Friesian cattle; Merino and Wiltshire sheep; and Yorkshire pigs. ==Other terms used== The condition in Kerry Blue Terriers is sometimes called ''progressive neuronal abiotrophy'' (PNA).〔(Breed Information: Kerry Health ), ''United States Kerry Blue Terrier Club'', accessed November 6, 2011〕 Other terms used to describe the condition in dogs include cerebellar cortical atrophy and postnatal cerebellar cortical degeneration. Cerebellar abiotrophy in horses was originally thought to be a form of cerebellar hypoplasia and was described as such in older research literature. However, it was discovered that in horses, the die-off of purkinje cells began after the animal was born, rather than occurring ''in utero.'' Cerebellar hypoplasia is particularly common in cats and has similar symptoms. There are other diseases that lead to cerebellar degeneration, but the loss of Purkinje cells is a clear way to diagnose CA, and the combination of symptoms is sufficiently unique that CA can easily be distinguished from other conditions, even in a living animal. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cerebellar abiotrophy」の詳細全文を読む スポンサード リンク
|