High prevalence of low prognosis by the POSEIDON criteria in women undergoing planned oocyte cryopreservation.

OBJECTIVE: Planned oocyte cryopreservation (OC) is being increasingly utilized worldwide. However, some women cannot accumulate sufficient oocytes because of poor response to stimulation. The POSEIDON classification is a novel system to classify patients with 'expected' or 'unexpected' inappropriate ovarian response to exogenous gonadotropins. Our study aimed to examine the prevalence of POSEIDON patients among women undergoing planned OC. STUDY DESIGN: We retrospectively reviewed the first cycles of 160 consecutive patients undergoing planned OC. Patients were classified into the four POSEIDON groups or as 'non-POSEIDON' based on age, AMH level and the number of oocytes retrieved. The primary outcome measure was the prevalence of POSEIDON patients. RESULTS: Overall, 63 patients (39.4 %) were classified as POSEIDON patients, 12 in group 1, 12 in group 2, 8 in group 3, and 31 in group 4. Compared to non-POSEIDON patients, POSEIDON patients had increased basal FSH levels and reduced serum AMH levels and antral follicle counts, required higher FSH starting doses and increased gonadotropin requirements and reached lower peak serum estradiol levels. Additionally, POSEIDON patients had a lower number of oocytes retrieved (7.6 ± 3.1 vs.20.2 ± 9.9, p < 0.001) and vitrified (5.8 ± 2.9 vs.14.7 ± 6.8, p < 0.001) than non-POSEIDON counterparts, respectively. CONCLUSION: We found a high prevalence of patients being classified as low prognosis according to the POSEIDON criteria among patients seeking planned OC. POSEIDON patients had increased gonadotropin requirements and a significantly lower number of oocytes retrieved and vitrified. This novel, unexpected finding adds clinically relevant information for counselling and management of patients undergoing planned OC.

Publisher Correction: Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Splice-specific deficiency of the PTSD-associated gene PAC1 leads to a paradoxical age-dependent stress behavior.

The pituitary adenylate cyclase-activating polypeptide receptor (PAC1, also known as ADCYAP1R1) is associated with post-traumatic stress disorder and modulation of stress response in general. Alternative splicing of PAC1 results in multiple gene products, which differ in their mode of signalling and tissue distribution. However, the roles of distinct splice variants in the regulation of stress behavior is poorly understood. Alternative splicing of a short exon, which is known as the "hop cassette", occurs during brain development and in response to stressful challenges. To examine the function of this variant, we generated a splice-specific zebrafish mutant lacking the hop cassette, which we designated 'hopless'. We show that hopless mutant larvae display increased anxiety-like behavior, including reduced dark exploration and impaired habituation to dark exposure. Conversely, adult hopless mutants displayed superior ability to rebound from an acute stressor, as they exhibited reduced anxiety-like responses to an ensuing novelty stress. We propose that the developmental loss of a specific PAC1 splice variant mimics prolonged mild stress exposure, which in the long term, predisposes the organism's stress response towards a resilient phenotype. Our study presents a unique genetic model demonstrating how early-life state of anxiety paradoxically correlates with reduced stress susceptibility in adulthood.

Neurotensin Enhances Locomotor Activity and Arousal and Inhibits Melanin-Concentrating Hormone Signaling.

BACKGROUND: Hypothalamic neurotensin (Nts)-secreting neurons regulate fundamental physiological processes including metabolism and feeding. However, the role of Nts in modulation of locomotor activity, sleep, and arousal is unclear. We previously identified and characterized Nts neurons in the zebrafish hypothalamus. MATERIALS AND METHODS: In order to study the role of Nts, nts mutant (nts-/-), and overexpressing zebrafish were generated. RESULTS: The expression of both nts mRNA and Nts protein was reduced during the night in wild-type zebrafish. Behavioral assays revealed that locomotor activity was decreased during both day and night, while sleep was increased exclusively during the nighttime in nts-/- larvae. Likewise, inducible overexpression of Nts increased arousal in hsp70:Gal4/uas:Nts larvae. Furthermore, the behavioral response to light-to-dark transitions was reduced in nts-/- larvae. In order to elucidate potential contenders that may mediate Nts action on these behaviors, we profiled the transcriptome of 6 dpf nts-/- larvae. Among other genes, the expression levels of melanin-concentrating hormone receptor 1b were increased in nts-/- larvae. Furthermore, a portion of promelanin-concentrating hormone 1 (pmch1) and pmch2 neurons expressed the nts receptor. In addition, expression of the the two zebrafish melanin-concentrating hormone (Mch) orthologs, Mch1 and Mch2, was increased in nts-/- larvae. CONCLUSION: These results show that the Nts and Mch systems interact and modulate locomotor activity and arousal.

Modeling sleep and neuropsychiatric disorders in zebrafish.

What are the molecular and cellular mechanisms that link neurological disorders and sleep disturbances? The transparent zebrafish model could bridge this gap in knowledge due to its unique genetic and imaging toolbox, and amenability to high-throughput screening. Sleep is well-characterized in zebrafish and key regulators of the sleep/wake cycle are conserved, including melatonin and hypocretin/orexin (Hcrt), whereas novel sleep regulating proteins are continually being identified, such as Kcnh4a, Neuromedin U, and QRFP. Sleep deficiencies have been observed in various zebrafish models for genetic neuropsychiatric disorders, ranging from psychomotor retardation and autism to anxiety disorders. Understanding the link between neuropsychiatric disorders and sleep phenotypes in zebrafish may ultimately provide a platform for identifying therapeutic targets for clinical trials in humans.

The Hypocretin/Orexin Neuronal Networks in Zebrafish.

The hypothalamic Hypocretin/Orexin (Hcrt) neurons secrete two Hcrt neuropeptides. These neurons and peptides play a major role in the regulation of feeding, sleep wake cycle, reward-seeking, addiction, and stress. Loss of Hcrt neurons causes the sleep disorder narcolepsy. The zebrafish has become an attractive model to study the Hcrt neuronal network because it is a transparent vertebrate that enables simple genetic manipulation, imaging of the structure and function of neuronal circuits in live animals, and high-throughput monitoring of behavioral performance during both day and night. The zebrafish Hcrt network comprises ~16-60 neurons, which similar to mammals, are located in the hypothalamus and widely innervate the brain and spinal cord, and regulate various fundamental behaviors such as feeding, sleep, and wakefulness. Here we review how the zebrafish contributes to the study of the Hcrt neuronal system molecularly, anatomically, physiologically, and pathologically.

Hypothalamic leptin-neurotensin-hypocretin neuronal networks in zebrafish.

Neurotensin (NTS) is a 13 amino acid neuropeptide that is expressed in the hypothalamus. In mammals, NTS-producing neurons that express leptin receptor (LepRb) regulate the function of hypocretin/orexin (HCRT) and dopamine neurons. Thus, the hypothalamic leptin-NTS-HCRT neuronal network orchestrates key homeostatic output, including sleep, feeding, and reward. However, the intricate mechanisms of the circuitry and the unique role of NTS-expressing neurons remain unclear. We studied the NTS neuronal networks in zebrafish and cloned the genes encoding the NTS neuropeptide and receptor (NTSR). Similar to mammals, the ligand is expressed primarily in the hypothalamus, while the receptor is expressed widely throughout the brain in zebrafish. A portion of hypothalamic nts-expressing neurons are inhibitory and some coexpress leptin receptor (lepR1). As in mammals, NTS and HCRT neurons are localized adjacently in the hypothalamus. To track the development and axonal projection of NTS neurons, the NTS promoter was isolated. Transgenesis and double labeling of NTS and HCRT neurons showed that NTS axons project toward HCRT neurons, some of which express ntsr. Moreover, another target of NTS neurons is ntsr-expressing dopaminergeric neurons. These findings suggest structural circuitry between leptin, NTS, and hypocretinergic or dopaminergic neurons and establish the zebrafish as a model to study the role of these neuronal circuits in the regulation of feeding, sleep, and reward.