Behavioural and physiological responses to stressors in sheep with temperament classified by genotype or phenotype.

The single nucleotide polymorphism (SNP) rs107856856, located in the tryptophan hydroxylase-2 gene, is associated with the behavioural phenotype for sheep temperament measured at weaning. Here, we tested the association between that SNP and physiological and behavioural responses to stressors in adult sheep. Two groups of adult sheep, one with genotype A/A (calm genotype) and the other with G/G (nervous genotype) in rs107856856, were selected from 160 sheep and were exposed, twice, to an open-field arena and an isolation box test (IBT). During each repeat, the behaviour and physiological responses (cortisol, prolactin, dehydroepiandrosterone [DHEA], brain derived neurotrophic factor [BDNF], characteristics of the response of body temperature, and oxidative stress) were measured. The behavioural and physiological responses of the sheep were compared between genotypes and also between groups classified on their phenotype as assessed by their initial isolation box score ("low responders" and "high responders"). The SNP rs107856856 had some effects on the behavioural phenotype (IBT score) but no effects on the physiological response to stress (cortisol, prolactin, DHEA, BDNF, oxidative stress or changes in body temperature) in the adult sheep, probably because the sheep were exposed, and therefore had adapted, to human contact during their life.

Proton beam therapy for cervical lymph node metastasis in an octogenarian with melanoma of unknown primary: a case report.

An 80-year-old man with an approximately 3-cm mass in the right submandibular region presented to our institution. Magnetic resonance imaging revealed enlarged lymph nodes (LNs) in the right neck, and fluorine-18-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) indicated positive FDG accumulation in the right neck LNs only. Excisional biopsy was performed for suspected malignant lymphoma, and the biopsy revealed melanoma. Close examination of the skin, nasal cavity, oral pharyngeal and laryngeal cavities, and gastrointestinal tract were performed. No primary tumor was detected by these examinations, and the patient was diagnosed with cervical LN metastasis from melanoma of unknown primary of clinical stage T0N3bM0 stage IIIC. The patient refused cervical neck dissection because of his age and comorbidity of Alzheimer's disease and instead opted for proton beam therapy (PBT) at a total dose of 69 Gy (relative biological effectiveness) in 23 fractions. He did not receive any systemic therapy. The enlarged LNs shrunk slowly, and FDG PET/CT at 1 year after PBT showed that the right submandibular LN had shrunk from 27 to 7 mm in length, and there was no significant FDG accumulation. At 6 years and 4 months after PBT, the patient is alive without any recurrence.

Facilitatory and inhibitory role of central amylin administration in the regulation of the gonadotropin-releasing hormone pulse generator activity in goats.

Pulsatile gonadotropin-releasing hormone (GnRH) secretion is essential for regulating reproductive functions in mammals. GnRH pulses are governed by a neural mechanism that is termed the GnRH pulse generator. In the present study, we investigated the role of central calcitonin receptor (CTR) signaling in the regulation of the GnRH pulse generator activity in ovariectomized goats by administering amylin, an endogenous ligand for CTR, into the lateral ventricle. GnRH pulse generator activity was measured using multiple unit activity (MUA) recordings in the mediobasal hypothalamus. We analyzed changes in the interval of characteristic increases in MUA (MUA volleys). The MUA volley interval shortened immediately after amylin administration, followed by prolonged intervals. Double in situ hybridization for KISS1 (kisspeptin gene) and CALCR (CTR gene) revealed that low expression levels of CALCR were found in the arcuate kisspeptin neurons, which is suggested as the main population of neurons, involved in GnRH pulse generator activity. These results suggest that central amylin-CTR signaling has a biphasic role in the regulation of GnRH pulse generator activity by acting on cells other than the arcuate kisspeptin neurons in goats.

Peripheral administration of SB223412, a selective neurokinin-3 receptor antagonist, suppresses pulsatile luteinizing hormone secretion by acting on the gonadotropin-releasing hormone pulse generator in estrogen-treated ovariectomized female goats.

Accumulating evidence suggests that KNDy neurons located in the hypothalamic arcuate nucleus (ARC), which are reported to express kisspeptin, neurokinin B, and dynorphin A, are indispensable for the gonadotropin-releasing hormone (GnRH) pulse generation that results in rhythmic GnRH secretion. The aims of the present study were to investigate the effects of peripheral administration of the neurokinin 3 receptor (NK3R/TACR3, a receptor for neurokinin B) antagonist, SB223412, on GnRH pulse-generating activity and pulsatile luteinizing hormone (LH) secretion in ovariectomized Shiba goats treated with luteal phase levels of estrogen. The NK3R antagonist was infused intravenously for 4 h {0.16 or 1.6 mg/(kg body weight [BW]·4 h)} during which multiple unit activity (MUA) in the ARC was recorded, an electrophysiological technique commonly employed to monitor GnRH pulse generator activity. In a separate experiment, the NK3R antagonist (40 or 200 mg/[kg BW·day]) was administered orally for 7 days to determine whether the NK3R antagonist could modulate pulsatile LH secretion when administered via the oral route. Intravenous infusion of the NK3R antagonist significantly increased the interval of episodic bursts of MUA compared with that of the controls. Oral administration of the antagonist for 7 days also significantly prolonged the interpulse interval of LH pulses. The results of this study demonstrate that peripheral administration of an NK3R antagonist suppresses pulsatile LH secretion by acting on the GnRH pulse generator, suggesting that NK3R antagonist administration could be used to modulate reproductive functions in ruminants.

Establishment of long-term chronic recording technique of in vivo ovarian parenchymal temperature in Japanese Black cows.

The reproductive performance of cattle can be suppressed by heat stress. Reproductive organ temperature, especially ovarian temperature, may affect follicle development and ovulation. The establishment of a technique for long-term measurement of ovarian temperature could prove useful in understanding the mechanisms underlying the temperature-dependent changes in follicular development and subsequent ovulation in cows. Here we report a novel method facilitating long-term and continuous recording of ovarian parenchymal temperature in cows. The method revealed that the ovarian temperature in the luteal phase was constantly maintained lower than the vaginal temperature, and that the diurnal temperature variation in the ovary was significantly greater than that in the vagina, suggesting that the ovaries may require a lower temperature than other organs to maintain their functions. This novel method could be used for the further understanding of ovarian functions during estrous cycles in cows.