Perturbation of heart rate variability in cattle fed BSE-infected material

The brainstem is the region of the brain of cattle with the highest concentration of the abnormal prion protein associated with bovine spongiform encephalopathy (BSE), and specific nuclei in the medulla oblongata of the brainstem, which exhibit changes as a result of the disease, are involved in the modulation of heart rate variability (HRV). The low- and high-frequency components of the HRV of 48 control cattle, 43 cattle fed 1 g of brain homogenate from BSE field cases and 42 cattle fed 100 g of brain homogenate from BSE field cases were analysed repeatedly for a year. There was a significant difference (P<0.001) between the level of high-frequency HRV observed in the control cattle and in both groups of cattle exposed to BSE. There was also a significant difference (P<0.01) between the low-frequency HRV of the cattle given the high dose and the other two groups.