Analysis of the electroencephalogram in growing calves by use of power spectrum and cross correlation
Takeuchi, T.; Sitizyo, K.; Harada, E.
American Journal of Veterinary Research 59(6): 777-781
1998
ISSN/ISBN: 0002-9645 PMID: 9622751 Document Number: 490665
Ten healthy, 1- to 10-week-old, Japanese Black calves were examined using electroencephalography (EEG). After the second week of age, rhythmic waves with frequencies of 6 to 9 Hz (alpha rhythm-like pattern) appeared in the EEG, and were recorded in the occipital and vertex areas; the duration of these waves was <30 s. Power distribution of the 7.5- to 10-Hz frequency band in the occipital area significantly increased after the sixth week. The highest frequency (18 to 30 Hz) band increased in the frontal and occipital areas after the seventh week. Normalized cross-correlation coefficients at 0 time shift were >0.6 throughout the experimental period. The normalized cross-correlation coefficients obtained from caudal interhemispheric sites increased after the second week, and were significantly greater than those in rostral sites. It is concluded that developmental changes in the EEG of calves during the first 10 weeks are characterized by appearance of the alpha rhythm-like pattern and increase of the power distributions of the 7.5- to 10-Hz and 18- to 30-Hz frequency bands, which may be a useful indicator for estimating brain activity in young calves.