Intracerebroventricularly Administered Oxytocin Attenuated Cortisol Secretion, but not Behavioral Responses, during Isolation in Holstein Steers

Journal of Veterinary Medical Science

Madoka SUTOH²  Hiroaki OKAMURA³  Ken-ichi YAYOU³  Shuichi ITO⁴  Satoshi OHKURA¹  Etsuko KASUYA³ 

[1] Laboratory of Animal Production Science, Nagoya University;Endocrinology and Metabolism Research Team, National Institute of Livestock and Grassland Science;Laboratory of Neurobiology, National Institute of Agrobiological Sciences;Department of Animal Science, Tokai University

关键词: behavior;    cortisol;    isolation;    oxytocin;    steer;   

DOI  :  10.1292/jvms.70.665

学科分类：兽医学

来源: Japanese Society of Veterinary Science

【 摘 要 】

References(23)Cited-By(8)In rodents, intracerebroventricular oxytocin administration attenuated hypothalamo-pituitary-adrenal (HPA) responses and anxiety behavior during stress. We examined the effects of intracerebroventricular injection of oxytocin on isolation-induced stress responses in cattle. In a methodological test, we determined the dosage of oxytocin applied in a main test which did not induce an increase in plasma cortisol concentration or stereotyped behaviors. In a main test, 5 steers aged from 199 to 250 days were assigned to the following three treatments randomly: T1, no isolation after injection of 200 μl of artificial cerebrospinal fluid (aCSF); T2, isolation after aCSF injection; and T3, isolation after 0.5 μg of oxytocin in 200 μl aCSF injection. The isolation was conducted by leaving the experimental steer alone in its stall for one hour while its peers were taken outside. In T2, the isolation induced a rapid increase in plasma cortisol concentration. The maximum %-changes from the pre-isolation value were significantly attenuated by oxytocin injection (T2 vs. T3, p<0.05). The isolation also induced an increase in the frequency (number of occurrences/1 hr isolation) of vocalizations and body orientation changes, and a decrease in the percentage of time spent lying and ruminating. The effect of oxytocin on these behavioral responses to isolation was not apparent. These results indicate that intracerebroventricularly injected oxytocin at low dose attenuated the cortisol response to isolation in steers while the effect on behavior was very small in this experimental condition.

【 授权许可】

Unknown