Mammals’ urine contains chemosignals known to affect the sexual behaviour and reproductive physiology of both male and female recipient. Here we demonstrated that male urine can also elicit physiological changes on sexual maturation rates in the Brandt’s voles. In the first experiment we showed that urine from breeding adult male anticipated the puberty on female voles and at opposite delayed puberty on males. The results from the second and third experiments showed a strong agonistic behaviour between male Brandt’s voles compared to that of females. The introduction into social groups of an adult male, but not an adult female, increased the agonistic responses of the resident male. The results suggest a high rate of competition for mating in the male. Therefore, we conclude that a breeding adult male uses chemosignals to differently affect the sexual maturation of pre-pubertal conspecifics as a tactic for reducing competitive mating pressure. Little or no competitive pressure for copulation was seen in the oestrous female, and its urine had no effect on the maturation rate of young Brandt’s voles.
Unilateral deafferentation induced by transection of the C4-C8 dorsal roots of spinal cord, followed by a complex of abnormal self-mutilating behavior, is interpreted as an animal model of chronic nociception. The objective of our study was to test the differences in tail-flick latency between intact control and unilaterally deafferented animals and to assess the changes in their acute nociceptive sensation. The initial hypothesis was that deafferentation-induced painful sensation might cause stress-induced analgesia that should be manifested as prolonged tail-flick latency. The experiment was carried out on 11 male and 10 female adult Wistar rats. The tail-flick latency was repeatedly measured over a period of 10 consecutive weeks both in the preoperative baseline period and following multiple cervical dorsal rhizotomy. Contrary to our hypothesis, unilateral deafferentation was followed by a significant shortening of the tail-flick latency both in males and females. In deafferented animals, compared to the controls, variations of tail-flick latency were reduced. In individual animals after deafferentation, concurrent dynamic changes were observed in self-mutilating behavior, in a loss and regaining of body weight, and in tail-flick latency. Our data suggest that changes in tail-flick latency may be interpreted in terms of central sensitization and that tail-flick latency might be considered as a useful marker of chronic nociception.
Čeleď kabarovitých představuje pro většinu lidí nejméně zajímavou čeleď kopytníků. Zahrnuje 7 málo známých druhů žijících ve východní Asii (od východního Afghánistánu přes Himálaj, Tibet a Čínu po střední a východní Sibiř). Tento článek obsahuje hlavní charakteristiky jednotlivých druhů včetně jejich fylogeneze a shrnuje dosavadní znalostí o životě kabarů. Vzhledem k tomu, že kabaři představují významný zdroj pro tradiční čínskou medicínu, stávají se v poslední době i jednou z nejvíce ohrožených čeledí kopytníků., The family Moschidae involves 7 species of musk deer, inhabiting forests and mountains of East Asia (from Afghanistan to the Himalayas, from Tibet and China to Siberia). This article summarizes current knowledge of individual species characteristics, including their phylogeny and natural history. Since these animals are a valuable source for the traditional Chinese medicine, they are the most endangered ungulate species in the world., and Jan Pluháček.