Transportation-induced nausea-like behavior in goats and the effects of anti-motion sickness medication.

This study investigated the nausea-like behavior induced by road transportation in goats, and the effects of an anti-motion sickness (MS) medication on this behavior. In the first experiment, 11 adult Shiba goats were road transported twice with either a saline (control) or a commercial anti-MS medication (Travelmin) injection at the first or second transportation. Almost all goats showed nausea-like behavior, which was defined as pointing their heads downward, closing their eyes, and staying relatively still. These goats did not respond when they were touched during blood collection. The anti-MS medication significantly reduced the total time spent in nausea-like behavior (P < 0.05) and tended to increase the frequency of escape attempts during blood collection (P < 0.1). In a second experiment, the effects of the anti-MS medication were examined in goats held under normal housing. The anti-MS medication increased the time spent feeding (P < 0.01) and reduced the time spent in rumination (P < 0.05) but did not change the frequency of lying down nor plasma cortisol concentrations. Our results indicate that the nausea-like behavior in transported goats might be induced, at least in part, by regulatory mechanisms similar to the MS.

Radial polarity in the first cranial neuromast of selected teleost fishes.

The neuromast is a sensory structure of the lateral line system in aquatic vertebrates, which consists of hair cells and supporting cells. Hair cells are mechanosensory cells, generally arranged with bidirectional polarity. Here, we describe a neuromast with hair cells arranged radially instead of bidirectionally in the first cranial neuromast of four teleost species: red seabream (Pagrus major), spotted halibut (Verasper variegatus), brown sole (Pseudopleuronectes herzensteini), and marbled sole (Pseudopleuronectes yokohamae). In these four species, this polarity was identified only in the first cranial neuromast, where it appeared at the rostral edge of the otic vesicle before hatching. We investigated the initial appearance and fate of this unique neuromast using scanning electron microscopy. We also assessed characteristics of radial neuromast pertaining to morphogenesis, development, and innervation using a vital fluorescent marker and immunohistochemistry in V. variegatus. The kinocilium initially appears at the center of each hair cell, then moves to its outer perimeter to form radial polarity by around 7 days postfertilization. However, hair cells arranged radially disappear about 15 days after hatching. This is followed by the appearance of bidirectionally arranged hair cells, indicating that polarity replacement from radial to bidirectional has occurred. In P. herzensteini, both afferent and efferent synapses between the nerve fibers and hair cells were observed by transmission electron microscopy, suggesting that radial neuromast is functional. Our discovery suggests that neuromasts with radial polarity could enable larval fish to assimilate multiaxial stimuli during this life stage, potentially assisting them in detecting small water vibrations or water pressure changes.

The effects of cisplatin, an emetic agent, on behavior and plasma cortisol levels in goats.

Ruminants are not considered to experience nausea because they do not possess the emetic reflex. This study examined the effects of administration of cisplatin (cis-diamminedichloro platinum (II): CDDP), a common emetic agent, on the behavior of goats. In Experiment 1, adult Shiba goats received intravenous (IV) administration of CDDP. CDDP-administered goats spent a shorter time feeding (P < 0.01), lied down earlier (P < 0.01), and spent a longer period lying down (P < 0.01) than the saline-administered control goats, and sometimes, they directed their face downward and close their eyes. These behavioral responses were followed by a significant (P < 0.01) increase in plasma cortisol (Cor) levels, which indicated that goats experienced stress. The dose dependency was found in the extent of the CDDP effects. In Experiment 2, the effects of pretreatment of ondansetron (Ond), an antiemetic agent, were examined. Pretreatment of Ond extended the latency of lying (P < 0.01), shortened the time spent lying (P < 0.05), and reduced the extent of the increase in plasma Cor levels (P < 0.01). These results suggested that CDDP administration generated some state of stress in goats via the similar physiological mechanisms as emesis-caused stress in emetic species.

Innervation of wing membrane in Japanese little horseshoe bats, Rhinolophus cornutus.

The spinal nerves supplying the wing membranes of Japanese little horseshoe bats, Rhinolophus cornutus were studied. The wing membrane was innervated by nerve branches of the radial, ulnar, and median nerves, showing that the membrane was formed from the skin of the forelimb rather than that of the thoracolumbar skin. The radial nerve was mainly composed of the ventral rami of C7-T1, the ulnar nerve by C8-T2, and the median nerve by C8-T1. These components of R. cornutus tended to be from a narrower range of spinal nerves and to position more caudally than those of humans. In addition, the ulnar nerve showed a distribution pattern different from that of other mammals.

Female Japanese quail visually differentiate testosterone-dependent male attractiveness for mating preferences.

Biased mating due to female preferences towards certain traits in males is a major mechanism driving sexual selection, and may constitute an important evolutionary force in organisms with sexual reproduction. In birds, although the role of male ornamentation, plumage coloration, genetic dissimilarity, and body size have on mate selection by females have been examined extensively, few studies have clarified exactly how these characteristics affect female mate preferences. Here, we show that testosterone (T)-dependent male attractiveness enhances female preference for males of a polygamous species, the Japanese quail. A significant positive correlation between female mating preference and circulating T in the male was observed. The cheek feathers of attractive males contained higher levels of melanin and were more brightly colored. The ability of females to distinguish attractive males from other males was negated when the light source was covered with a sharp cut filter (cutoff; < 640 nm). When females were maintained under short-day conditions, the expression of retinal red-sensitive opsin decreased dramatically and they became insensitive to male attractiveness. Our results showed that female preference in quail is strongly stimulated by male feather coloration in a T-dependent manner and that female birds develop a keen sense for this coloration due to upregulation of retinal red-sensitive opsin under breeding conditions.

Histochemical properties of bovine and ovine mammary glands during fetal development.

In order to obtain more information on the development of bovine and ovine fetal mammary glands, a series of mammary glands from fetuses of different ages were analyzed. A total of 16 bovine fetuses with curved crown rump lengths ranging from 12 cm (80 days) to 75 cm (240 days) and 15 ovine fetuses ranging from 55 days to 131 days were examined. We used hematoxylin and eosin stain and Oil-Red-O stain to analyze the developmental and morphogenetic processes of mammary glands. In addition, we used immunohistochemical staining to determine the pattern of expression of cytokeratin 18 (CK18) during luminal epithelial differentiation, α-smooth-muscle actin (α-SMA) for myoepithelial differentiation, Ki-67 for cell proliferation, and estrogen receptor α (ERα). Our analyzes showed: (a) The primary mammary duct begin to proliferate in a lengthwise within the teat at 90 days in bovine fetuses and 63 days in ovine fetus; (b) luminal epithelial cells and myoepithelial cells appeared from 90 days in bovine fetuses and 63 days in ovine fetus; (c) proliferation of epithelial cells appeared to coincide with the development of the primary and secondary ducts; and (d) ERα was not found in the fetal mammary gland, but adipocytes showed the presence of ERα. Overall, these results indicate that the sequence of events in the prenatal development of the mammary gland of sheep is similar to that of cattle.

Avian blood induced intranuclear translocation of STAT3 via the chicken leptin receptor.

Leptin is a multi-functional adipokine in vertebrates. The leptin gene and protein are found in many vertebrates; however, the existence of leptin in birds remains controversial. Here we detected leptin-like activity in avian blood using chicken leptin receptor (chLEPR) and green fluorescent protein (GFP)-fused chicken signal transducer and activator of transcription (chSTAT3) co-expressed in CHO-K1 cells (CHO-chLEPR/STAT3). We validated that rat serum specifically induces intranuclear migration of GFP-fused chSTAT3 (GFP-chSTAT3) in CHO-chLEPR/STAT3 cells, but not in CHO-K1 cells expressing GFP-STAT3 (CHO-chSTAT3) before testing the avian blood samples. Blood of chickens (Gallus gallus), wild jungle crows (Corvus macrorhynchos), and carrion crows (Corvus corone) accumulated the GFP signal into nuclei, and frequency varied in each blood sample. Western blotting showed that chicken and crow blood samples specifically phosphorylated GFP-chSTAT3 in the chLEPR-transfected cells. These results indicate that avian blood contains a leptin-like molecule that specifically binds to LEPR, suggesting that the leptin system is conserved across all vertebrate classes.

Species identification key of Korean mammal hair.

The hair microstructures of Korean terrestrial mammals from 23 species (22 wild and one domestic) were analyzed using light and scanning electron microscopy (SEM) to construct a hair identification key. The hairs were examined using the medulla structures and cuticular scales of guard hairs from the dorsal regions of mature adult animals. All cuticular scale structures in the hair of Rodentia, Lagomorpha, Carnivora and Insectivora showed the petal pattern, and those of Artiodactyla and Chiroptera showed the wave pattern and coronal pattern, respectively. Rodentia, Lagomorpha and Carnivora showed multicellular, and Insectivora and Artiodactyla showed unicellular regular, mesh or columnar in the medulla structures, respectively. Chiroptera did not show the medulla structures in their hair. We found that it is possible to distinguish between species and order based on general appearance, medulla structures and cuticular scales. Thus, we constructed a hair identification key with morphological characteristics from each species. This study suggests that hair identification keys could be useful in fields, such as forensic science, food safety and foraging ecology.

Light transmission of the ocular media in birds and mammals.

Differences in the ultraviolet (UV) cutoff of ocular media between birds and mammals have been revealed by spectrophotometric measurements of the transmission of light wavelengths by the cornea, lens and vitreous body in chickens, crows, quails, rats, rabbits and pigs. The light transmission values of the cornea were shown to be above 50% for wavelengths of 330-800 nm in birds, 300-800 nm in rat and 310-800 nm in mammals except for rat. For the lens, the light transmission values were shown to be above 50% for wavelengths of 320-800 nm in birds and rat and 390-800 nm in mammals except for rat. Thus, among the ocular media, the cornea in birds and the lens in mammals except for rat may play a role as a major UV cutoff filter.

Shape discrimination and concept formation in the jungle crow (Corvus macrorhynchos).

We investigated whether jungle crows can learn concepts by using printouts of shapes in a simultaneous two-alternative task. Jungle crows were first trained with a red triangle and red square until they reached the discrimination criterion (80% of correct choices in two blocks of 10 trials each). Then, we tested crows with successive transfer tests to investigate both the discrimination cues being used and concept formation ability, by using novel triangular and non-triangular stimuli. All of the jungle crows learnt to discriminate between the triangle and square during training. The discrimination performance was generally not affected either by changes in the colour of the stimuli or when both shape and colour cues conflicted, with the previously non-rewarded shape but matching colour (red square) versus rewarded shape but non-matching colour (green triangle). The use of only outlines of the familiar stimuli also did not affect discrimination behaviour of crows. In addition, crows significantly discriminated novel triangular shapes during the limited trials given, suggesting their ability to form the concept of triangularity. However, failure to discriminate when the novel stimuli size deviated from the original suggests that there is a limit to shape concept formation in a familiar-novel context in the jungle crow.

Population abundance of potentially pathogenic organisms in intestinal microbiome of jungle crow (Corvus macrorhynchos) shown with 16S rRNA gene-based microbial community analysis.

Jungle Crows (Corvus macrorhynchos) prefer human habitats because of their versatility in feeding accompanied with human food consumption. Therefore, it is important from a public health viewpoint to characterize their intestinal microbiota. However, no studies have been involved in molecular characterization of the microbiota based on huge and reliable number of data acquisition. In this study, 16S rRNA gene-based microbial community analysis coupled with the next-generation DNA sequencing techniques was applied to the taxonomic classification of intestinal microbiome for three jungle crows. Clustering of the reads into 130 operational taxonomic units showed that at least 70% of analyzed sequences for each crow were highly homologous to Eimeria sp., which belongs to the protozoan phylum Apicomplexa. The microbiotas of three crows also contained potentially pathogenic bacteria with significant percentages, such as the genera Campylobacter and Brachyspira. Thus, the profiling of a large number of 16S rRNA gene sequences in crow intestinal microbiomes revealed the high-frequency existence or vestige of potentially pathogenic microorganisms.

Long-term memory of color stimuli in the jungle crow (Corvus macrorhynchos).

Wild-caught jungle crows (n = 20) were trained to discriminate between color stimuli in a two-alternative discrimination task. Next, crows were tested for long-term memory after 1-, 2-, 3-, 6-, and 10-month retention intervals. This preliminary study showed that jungle crows learn the task and reach a discrimination criterion (80% or more correct choices in two consecutive sessions of ten trials) in a few trials, and some even in a single session. Most, if not all, crows successfully remembered the constantly reinforced visual stimulus during training after all retention intervals. These results suggest that jungle crows have a high retention capacity for learned information, at least after a 10-month retention interval and make no or very few errors. This study is the first to show long-term memory capacity of color stimuli in corvids following a brief training that memory rather than rehearsal was apparent. Memory of visual color information is vital for exploitation of biological resources in crows. We suspect that jungle crows could remember the learned color discrimination task even after a much longer retention interval.

Effect of intracerebroventricular injections of prolactin-releasing peptide on prolactin release and stress-related responses in steers.

Some evidence suggests that there might be a species difference in the effect of intracerebroventricularly administered (ICV) prolactin-releasing peptide (PrRP) between rodents and sheep. We compared the levels of cortisol (CORT) and prolactin (PRL), rectal temperature (RT) and behavioral responses to ICV bovine PrRP (bPrRP) in steers. ICV bPrRP (0.2, 2 and 20 nmol/200 µL) tended to evoke a dose-related increase in CORT concentrations and 0.2 nmol of bPrRP induced transient increase in PRL concentrations. A significant time-treatment interaction was observed for the percent change of CORT (P<0.05) and PRL (P<0.05) from pre-injection value. The time-treatment interaction for changes in RT was not significant (P=0.50). There tended to be a difference among the four treatments in terms of maximum change in RT from the pre-injection value between 0 and 90 min (P<0.1). Stress-related behavioral signs were not observed in the present experiment. These findings indicate that ICV bPrRP increased CORT and PRL levels, suggesting that central PrRP might participate in controlling the hypothalamo-pituitary-adrenal axis and PRL release in cattle, unlike sheep. In contrast, central PrRP is unlikely to be involved in controlling the behavior of this species because ICV bPrRP did not induce marked changes in their behavior.

High levels of apolipoproteins found in the soluble fraction of avian cornea.

Water-soluble proteins in avian corneas were profiled by two-dimensional electrophoresis and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Comparative protein profiling of avian and mammalian corneas revealed five major protein spots specifically detected in avian species. These proteins were identified as apolipoproteins A1 and D by tandem mass spectrometry sequencing. This is the first report of the presence of apolipoproteins in avian cornea. These results could provide insight into the role of lipid metabolism in the avian-specific function of cornea.

Categorical learning between 'male' and 'female' photographic human faces in jungle crows (Corvus macrorhynchos).

We trained jungle crows to discriminate among photographs of human face according to their sex in a simultaneous two-alternative task to study their categorical learning ability. Once the crows reached a discrimination criterion (greater than or equal to 80% correct choices in two consecutive sessions; binomial probability test, p<.05), they next received generalization and transfer tests (i.e., greyscale, contour, and 'full' occlusion) in Experiment 1 followed by a 'partial' occlusion test in Experiment 2 and random stimuli pair test in Experiment 3. Jungle crows learned the discrimination task in a few trials and successfully generalized to novel stimuli sets. However, all crows failed the greyscale test and half of them the contour test. Neither occlusion of internal features of the face, nor randomly pairing of exemplars affected discrimination performance of most, if not all crows. We suggest that jungle crows categorize human face photographs based on perceptual similarities as other non-human animals do, and colour appears to be the most salient feature controlling discriminative behaviour. However, the variability in the use of facial contours among individuals suggests an exploitation of multiple features and individual differences in visual information processing among jungle crows.

Light and electron microscopy study of the pecten oculi of the jungle crow (Corvus macrorhynchos).

In this study, the pecten oculi of a diurnally active bird, the Japanese jungle crow (Corvus macrorhynchos), was examined using light and electron microscopy. In this species, the pecten consisted of 24-25 highly vascularized pleats held together apically by a heavily pigmented 'bridge' and projected freely into the vitreous body in the ventral part of the eye cup. Ascending and descending blood vessels of varying caliber, together with a profuse network of capillaries, essentially constituted the vascular framework of the pecten. A distinct distribution of melanosomes was discernible on the pecten, the concentration being highest at its apical end, moderate at the crest of the pleats and lowest at the basal and lateral margins. Overlying and within the vascular network, a close association between blood vessels and melanocytes was evident. It is conjectured that such an association may have evolved to augment the structural reinforcement of this nutritive organ in order to keep it firmly erectile within the gel-like vitreous. Such erectility may be an essential prerequisite for its optimal functioning as well as in its overt use as a protective shield against the effects of ultraviolet light, which otherwise might lead to damage of the pectineal vessels.

Distribution of retinal cone photoreceptor oil droplets, and identification of associated carotenoids in crow (Corvus macrorhynchos).

The topography of cone oil droplets and their carotenoids were investigated in the retina of jungle crow (Corvus macrorhynchos). Fresh retina was sampled for the study of retinal cone oil droplets, and extracted retinal carotenoids were saponified using methods adapted from a recent study, then identified with reverse-phase high-performance liquid chromatography (HPLC). To assess the effects of saponification conditions on carotenoid recovery from crow retina, we varied base concentration and total time of saponification across a wide range of conditions, and again used HPLC to compare carotenoid concentrations. Based on colors, at least four types of oil droplets were recognized, i.e., red, orange, green, and translucent, across the retina. With an average of 91,202 /mm(2), density gradually declines in an eccentric manner from optic disc. In retina, the density and size of droplets are inversely related. In the peripheral zone, oil droplets were significantly larger than those of the central area. The proportion of orange oil droplets (33%) was higher in the central area, whereas green was predominant in other areas. Three types of carotenoid (astaxanthin, galloxanthin and lutein), together with one unknown carotenoid, were recovered from the crow retina; astaxanthin was the dominant carotenoid among them. The recovery of carotenoids was affected by saponification conditions. Astaxanthin was well recovered in weak alkali (0.06 M KOH), in contrast, xanthophyllic carotenoids were best recovered in strong alkali (0.6 M KOH) after 12 h of saponification at freeze temperature.

Seasonal morphological changes in the ovary of the Jungle crow (Corvus macrorhynchos).

Morphometric and histological studies were conducted to examine the seasonal ovarian changes in the Jungle crow of the Kanto area, Japan, from December to June. The ovary weights, largest diameters and atresias of the ovarian follicles and steroid-producing cells were examined. Hematoxylin and eosin-stained ovary sections and ImageJ software were used. The most developed ovary weight increased 373-fold in April, compared to those in December, followed by a 29-fold decrease in June. The average largest follicle diameter of the December and the January ovaries were 1.03 ± 0.35 and 1.05 ± 0.3 mm, respectively. The average largest follicle diameter increased by 2-fold in February, 4-fold in March and 8-fold in April, compared to those of December and January. Thereafter, the average largest follicle diameter declined by 6-fold in June. The average ovary weight and the largest follicle diameter in April increased significantly (P < 0.05) compared to those of December and January, followed by a significant decrease (P < 0.05) in June. The ovary weight correlated well with the expansion of the largest follicular diameter. Non-bursting and bursting atresias of smaller follicles were more common in the December, January, February and June ovaries, and bursting atresias of larger follicles were more common in the March, April and May ovaries. Ovarian steroidogenic cells became heavily charged with lipids in December, January, February and June, and they depleted their lipids in March and April, which might be due to steroid synthesis. Our results indicate that there are significant seasonal histomorphologic variations in the Jungle crow ovary.

Microstructure characteristics of the cornea in birds and mammals.

In this study, the microstructure of the cornea was compared among chickens (Gallus gallus), jungle crows (Corvus macrorhynchos), rats (Rattus norvegicus) and rabbits (Oryctolagus cuniculus). The density of keratocytes in the mammals was over 3 times that in the birds. The size of the keratocytes in the birds and rat were significantly lower than those in the rabbit. Using scanning and transmission electron microscopy, the bundles of collagen fibers in the birds were found to be well arranged, while those in the mammals were arranged randomly. The collagen lamellae of the birds were significantly thicker than those of the mammals, and the numbers of collagen lamellae in the birds were significantly smaller than in the mammals. The center-to-center distances between the collagen fibrils of the chicken and rabbit were significantly larger than those of the crow and rat. The densities of collagen fibrils in the chicken and rabbit were significantly less than those of the crow and rat.

Feather microstructure of the black-billed magpie (Pica pica sericea) and jungle crow (Corvus macrorhynchos).

The jungle crow (Corvus macrorhynchos) distribution stretches from eastern Eurasia continent to southeastern Asia. The distribution of the black-billed magpie (Pica pica sericea) stretches from Korea and China to the Kyushu area in Japan. They are both in the Family, Corvidae, and have iridescent feather colors, but the iridescent feather color of the black-billed magpie is more remarkable than that of the jungle crow. We observed the feather microstructure of these birds using electron microscope. On the barbules surface, the barbules twist and prong between the jungle crow and black-billed magpie were not similar. In the barbules cross section, the black-billed magpie showed a complex structure of melanin granules, the jungle crow showed a simple structure of melanin granules.