Neuropeptide W, an endogenous NPBW1 and NPBW2 ligand, produced an analgesic effect via activation of the descending pain modulatory system during a rat formalin test.

Neuropeptide W (NPW) messenger ribonucleic acid (mRNA) and NPBW1 and/or NPBW2 mRNA are expressed in the descending pain inhibitory system. In the present study, we examined whether NPW microinjected into the descending pain inhibitory system, such as the periaqueductal gray (PAG), locus coeruleus (LC), and rostral ventromedial medulla (RVM), produces an analgesic effect using a rat formalin test. Microinjections of NPW into the PAG ipsilateral and contralateral to the formalin-injected side, LC ipsilateral and contralateral to the formalin-injected side, and RVM produced an analgesic effect. In the RVM study, the analgesic effect was antagonized by WAY100135, a 5-HT1A antagonist, and enhanced by prazosin, an α1 antagonist, and SB269970, a 5-HT7 antagonist. Naloxone, an opioid antagonist, also antagonized the effect of NPW in the RVM study. In the ipsilateral LC study, the analgesic effect was antagonized by WAY100135, idazoxan, an α2 antagonist, and naloxone and was enhanced by prazosin and SB269970. In the contralateral LC study, the analgesic effect was antagonized by prazosin, idazoxan, SB269970, and naloxone. The analgesic effect was antagonized by WAY100135, SB269970, idazoxan, and naloxone in the ipsilateral and contralateral PAG studies. These findings strongly suggest that NPBW1/W2 activation by NPW microinjection into the RVM, LC, and PAG affect the descending pain modulatory system and produce anti-nociceptive and pro-nociceptive effects in the rat formalin test.

Comparison of physiological functions between neuromedin U-related peptide and neuromedin S-related peptide in the rat central nervous system.

Two novel peptides, neuromedin U precursor-related peptide (NURP) and neuromedin S precursor-related peptide (NSRP), are produced from neuromedin U (NMU) and neuromedin S (NMS) precursors, respectively, as these precursors have multiple consensus sequences for proteolytic processing. Our group has shown previously that one of these two novel peptides, NURP, stimulates body temperature and locomotor activity, but not food intake. However, the physiological function of the other peptide, NSRP, has remained unclear. Therefore, the aim of this study was to characterize differences in the regions of the rat brain targeted by the NMU/NMS peptide family, including NURP and NSRP, and their physiological functions. First, we explored the regions of c-Fos expression after intracerebroventricular (i.c.v.) injection of NURP and NSRP and found that these were fewer than after i.c.v. injection of NMU and NMS in the hypothalamus, possibly because NURP and NSRP cannot activate NMU/NMS receptors. In the ventral subiculum, which is one region of the hippocampus, c-Fos expression was evident only after i.c.v. injection of NURP. We also examined the effects of NSRP on food intake, body temperature and locomotor activity. Like NURP, NSRP increased both body temperature and locomotor activity, but not food intake, indicating that NSRP is also a functional peptide. However, these effects of NSRP were distinctly weaker than those of NURP. These findings suggest differences in the affinity of NURP and/or NSRP for specific receptors, or in their respective biological activities.

The effect of chronic neuropeptide-S treatment on non-motor parameters in experimental model of Parkinson's disease.

AIM: Besides motor impairment, non-motor symptoms including cognitive decline, anxiety, and depression are observed in Parkinson's Disease (PD). The aim of this study was to investigate whether chronic administration of central neuropeptide-S (NPS) improves non-motor symptoms in 6-hydroxydopamine (6-OHDA)-induced parkinsonian rats. MATERIAL AND METHODS: Experimental PD was utilized by unilateral stereotaxic injection of the 6-OHDA into the medial forebrain bundle (MFB), while the sham-operated animals underwent the same surgical procedures. NPS (1 nmol) or vehicle was daily administered through an intracerebroventricular (icv) cannula for 7 days. Radial arm maze (RAM) test was used to evaluate the working memory; whereas, elevated plus maze (EPM) test and sucrose preference test were used to monitor the anxiety and depression status, respectively. The levels of dopamine, glutamic acid, and glutamine was determined in harvested striatal and hippocampal tissue samples. The immunoreactivities for tyrosine hydroxylase (TH) was determined using immunohistochemistry. RESULTS: In the RAM test, the 6-OHDA-induced increases in the reference and working memory errors were reduced by the central NPS administration. The decreased sucrose preference in the parkinsonian rats was increased by centrally administered NPS. The levels of dopamine levels in striatum and hippocampus were decreased in the parkinsonian rats, however, they were not altered by the centrally administered NPS. Additionally, NPS treatment significantly attenuated the 6-OHDA-induced loss of TH neuronal number. CONCLUSION: Consequently, NPS appears to be a therapeutic candidate for the treatment of non-motor complications of PD.

Neuropeptide S Displays as a Key Neuromodulator in Olfactory Spatial Memory.

Neuropeptide S (NPS) is an endogenous peptide recently recognized to be presented in the brainstem and believed to play an important role in maintaining memory. The deletion of NPS or NPS receptor (NPSR) in mice shows a deficit in memory formation. Our recent studies have demonstrated that central administration of NPS facilitates olfactory function and ameliorates olfactory spatial memory impairment induced by muscarinic cholinergic receptor antagonist and N-methyl-D-aspartate receptor antagonist. However, it remains to be determined if endogenous NPS is an indispensable neuromodulator in the control of the olfactory spatial memory. In this study, we examined the effects of NPSR peptidergic antagonist [D-Val5]NPS (10 and 20 nmol, intracerebroventricular) and nonpeptidergic antagonist SHA 68 (10 and 50 mg/kg, intraperitoneal) on the olfactory spatial memory using computer-assisted 4-hole-board olfactory spatial memory test in mice. Furthermore, immunofluorescence was employed to identify the distributions of c-Fos and NPSR immunoreactive (-ir) neurons in olfactory system and hippocampal formation known to closely relate to the olfactory spatial memory. [D-Val5]NPS dosing at 20 nmol and SHA 68 dosing at 50 mg/kg significantly decreased the number of visits to the 2 odorants interchanged spatially, switched odorants, in recall trial, and simultaneously reduced the percentage of Fos-ir in NPSR-ir neurons, which were densely distributed in the anterior olfactory nucleus, piriform cortex, subiculum, presubiculum, and parasubiculum. These findings suggest that endogenous NPS is a key neuromodulator in olfactory spatial memory.

Interventions for preventing mastitis after childbirth.

BACKGROUND: Despite the health benefits of breastfeeding, initiation and duration rates continue to fall short of international guidelines. Many factors influence a woman's decision to wean; the main reason cited for weaning is associated with lactation complications, such as mastitis. Mastitis is an inflammation of the breast, with or without infection. It can be viewed as a continuum of disease, from non-infective inflammation of the breast to infection that may lead to abscess formation. OBJECTIVES: To assess the effectiveness of preventive strategies (for example, breastfeeding education, pharmacological treatments and alternative therapies) on the occurrence or recurrence of non-infective or infective mastitis in breastfeeding women post-childbirth. SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (3 October 2019), and reference lists of retrieved studies. SELECTION CRITERIA: We included randomised controlled trials of interventions for preventing mastitis in postpartum breastfeeding women. Quasi-randomised controlled trials and trials reported only in abstract form were eligible. We attempted to contact the authors to obtain any unpublished results, wherever possible.  Interventions for preventing mastitis may include: probiotics, specialist breastfeeding advice and holistic approaches.   DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted data and assessed the certainty of the evidence using GRADE. MAIN RESULTS: We included 10 trials (3034 women). Nine trials (2395 women) contributed data. Generally, the trials were at low risk of bias in most domains but some were high risk for blinding, attrition bias, and selective reporting. Selection bias (allocation concealment) was generally unclear. The certainty of evidence was downgraded due to risk of bias and to imprecision (low numbers of women participating in the trials). Conflicts of interest on the part of trial authors, and the involvement of industry funders may also have had an impact on the certainty of the evidence. Most trials reported our primary outcome of incidence of mastitis but there were almost no data relating to adverse effects, breast pain, duration of breastfeeding, nipple damage, breast abscess or recurrence of mastitis. Probiotics versus placebo Probiotics may reduce the risk of mastitis more than placebo (risk ratio (RR) 0.51, 95% confidence interval (CI) 0.35 to 0.75; 2 trials; 399 women; low-certainty evidence). It is uncertain if probiotics reduce the risk of breast pain or nipple damage because the certainty of evidence is very low. Results for the biggest of these trials (639 women) are currently unavailable due to a contractual agreement between the probiotics supplier and the trialists. Adverse effects were reported in one trial, where no woman in either group experienced any adverse effects. Antibiotics versus placebo or usual care The risk of mastitis may be similar between antibiotics and usual care or placebo (RR 0.37, 95% CI 0.10 to 1.34; 3 trials; 429 women; low-certainty evidence). The risk of mastitis may be similar between antibiotics and fusidic acid ointment (RR 0.22, 95% CI 0.03 to 1.81; 1 trial; 36 women; low-certainty evidence) or mupirocin ointment (RR 0.44, 95% CI 0.05 to 3.89; 1 trial; 44 women; low-certainty evidence) but we are uncertain due to the wide CIs. None of the trials reported adverse effects. Topical treatments versus breastfeeding advice The risk of mastitis may be similar between fusidic acid ointment and breastfeeding advice (RR 0.77, 95% CI 0.27 to 2.22; 1 trial; 40 women; low-certainty evidence) and mupirocin ointment and breastfeeding advice (RR 0.39, 95% CI 0.12 to 1.35; 1 trial; 48 women; low-certainty evidence) but we are uncertain due to the wide CIs. One trial (42 women) compared topical treatments to each other. The risk of mastitis may be similar between fusidic acid and mupirocin (RR 0.51, 95% CI 0.13 to 2.00; low-certainty evidence) but we are uncertain due to the wide CIs. Adverse events were not reported. Specialist breastfeeding education versus usual care The risk of mastitis (RR 0.93, 95% CI 0.17 to 4.95; 1 trial; 203 women; low-certainty evidence) and breast pain (RR 0.93, 95% CI 0.36 to 2.37; 1 trial; 203 women; low-certainty evidence) may be similar but we are uncertain due to the wide CIs. Adverse events were not reported. Anti-secretory factor-inducing cereal versus standard cereal The risk of mastitis (RR 0.24, 95% CI 0.03 to 1.72; 1 trial; 29 women; low-certainty evidence) and recurrence of mastitis (RR 0.39, 95% CI 0.03 to 4.57; 1 trial; 7 women; low-certainty evidence) may be similar but we are uncertain due to the wide CIs. Adverse events were not reported. Acupoint massage versus routine care Acupoint massage probably reduces the risk of mastitis compared to routine care (RR 0.38, 95% CI 0.19 to 0.78;1 trial; 400 women; moderate-certainty evidence) and breast pain (RR 0.13, 95% CI 0.07 to 0.23; 1 trial; 400 women; moderate-certainty evidence). Adverse events were not reported. Breast massage and low frequency pulse treatment versus routine care Breast massage and low frequency pulse treatment may reduce risk of mastitis (RR 0.03, 95% CI 0.00 to 0.21; 1 trial; 300 women; low-certainty evidence). Adverse events were not reported. AUTHORS' CONCLUSIONS: There is some evidence that acupoint massage is probably better than routine care, probiotics may be better than placebo, and breast massage and low frequency pulse treatment may be better than routine care for preventing mastitis. However, it is important to note that we are aware of at least one large trial investigating probiotics whose results have not been made public, therefore, the evidence presented here is incomplete. The available evidence regarding other interventions, including breastfeeding education, pharmacological treatments and alternative therapies, suggests these may be little better than routine care for preventing mastitis but our conclusions are uncertain due to the low certainty of the evidence. Future trials should recruit sufficiently large numbers of women in order to detect clinically important differences between interventions and results of future trials should be made publicly available.

Ecdysis triggering hormone modulates molt behaviour in the redclaw crayfish Cherax quadricarinatus, providing a mechanistic evidence for conserved function in molt regulation across Pancrustacea.

Molting enables growth and development across ecdysozoa. The molting process is strictly controlled by hormones - ecdysteroids. Ecdysteroidogenesis occurs in theprothoracic glands and stimulated by prothoracicotropic hormone in insects, while it ensues in the Y-organ and regulated by the molt inhibiting hormone in crustaceans. A peak in ecdysteroids in the hemolymph induces a cascade of multiple neuropeptides including Ecdysis Triggering Hormone (ETH) and Corazonin. The role of ETH is well defined in controlling the molt process in insects, but it is yet to be defined in crustaceans. In this study, we investigated the behavioral response of intermolt crayfish to ETH and Corazonin injections as well as the impact of ETH on the molt period using in vivo assays. Injection of Corazonin and ETH resulted in a clear and immediate eye twitching response to these two neuropeptides. The Corazonin injection induced eye twitching in slow and asynchronous manner, while ETH injection caused eye twitching in a relatively fast and synchronous way. A single injection of ETH to crayfish resulted in a remarkable prolong molt period, at twice the normal molting cycle, suggesting that ETH plays a key role in controlling the molt cycle in decapod crustaceans. Given the key significance of ETH in molt regulation and its plausible application in pest control, we characterized ETH across the pancrustacean orders. Bioinformatic analysis shows the mature ETH sequence is identical in all studied decapod species. ETH can be classified into specific groups based on the associated motif in each insect order and shows an insect motif -KxxPRx to be conserved in crustaceans.

Elevated intracranial pressure after head trauma can be suppressed by antisecretory factor-a pilot study.

BACKGROUND: Control of intracranial pressure (ICP) is a key element in neurointensive care for directing treatment decisions in patients with severe traumatic brain injury (TBI). The anti-inflammatory protein antisecretory factor (AF) has been demonstrated to reduce experimentally induced high ICP in animal models. This report describes the first steps to investigate the uptake, safety, and influence of AF for reduction of elevated ICP in patients with TBI in a clinical setting. METHOD: Four patients with severe TBI (Glasgow Coma Scale < 9) that required neurointensive care with ICP monitoring due to signs of refractory intracranial hypertension were investigated. One hundred milliliters of Salovum®, a commercially available egg yolk powder with high contents of AF peptides, was administrated either via nasogastric (patients 1 and 2) or rectal tube (patients 2, 3, and 4) every 8 h for 2 to 3 days as a supplement to the conventional neurointensive care. ICP was registered continuously. Plasma levels of AF were measured by enzyme-linked immunosorbent assay (ELISA) to confirm that Salovum® was absorbed appropriately into the bloodstream. RESULTS: In the first two patients, we observed that when delivered by the nasogastric route, there was an accumulation of the Salovum® solution in the stomach with difficulties to control ICP due to impaired gastric emptying. Therefore, we tested to administer Salovum® rectally. In the third and fourth patients, who both showed radiological signs of extensive brain edema, ICP could be controlled during the course of rectal administration of Salovum®. The ICP reduction was statistically significant and was accompanied by an increase in blood levels of AF. No adverse events that could be attributed to AF treatment or the rectal approach for Salovum® administration were observed. CONCLUSIONS: The outcomes suggest that AF can act as a suppressor of high ICP induced by traumatic brain edema. Use of AF may offer a new therapeutic option for targeting cerebral edema in clinical practice.

Distinct Co-Modulation Rules of Synapses and Voltage-Gated Currents Coordinate Interactions of Multiple Neuromodulators.

Multiple neuromodulators act in concert to shape the properties of neural circuits. Different neuromodulators usually activate distinct receptors but can have overlapping targets. Therefore, circuit output depends on neuromodulator interactions at shared targets, a poorly understood process. We explored quantitative rules of co-modulation of two principal targets of neuromodulation: synapses and voltage-gated ionic currents. In the stomatogastric ganglion of the male crab Cancer borealis, the neuropeptides proctolin (Proc) and the crustacean cardioactive peptide (CCAP) modulate synapses of the pyloric circuit and activate a voltage-gated current (IMI) in multiple neurons. We examined the validity of a simple dose-dependent quantitative rule, that co-modulation by Proc and CCAP is predicted by the linear sum of the individual effects of each modulator up to saturation. We found that this rule is valid for co-modulation of synapses, but not for the activation of IMI, in which co-modulation was sublinear. The predictions for the co-modulation of IMI activation were greatly improved if we assumed that the intracellular pathways activated by two peptide receptors inhibit one another. These findings suggest that the pathways activated by two neuromodulators could have distinct interactions, leading to distinct co-modulation rules for different targets even in the same neuron. Given the evolutionary conservation of neuromodulator receptors and signaling pathways, such distinct rules for co-modulation of different targets are likely to be common across neuronal circuits.SIGNIFICANCE STATEMENT We examine the quantitative rules of co-modulation at multiple shared targets, the first such characterization to our knowledge. Our results show that dose-dependent co-modulation of distinct targets in the same cells by the same two neuromodulators follows different rules: co-modulation of synaptic currents is linearly additive up to saturation, whereas co-modulation of the voltage-gated ionic current targeted in a single neuron is nonlinear, a mechanism that is likely generalizable. Given that all neural systems are multiply modulated and neuromodulators often act on shared targets, these findings and the methodology could guide studies to examine dynamic actions of neuromodulators at the biophysical and systems level in sensory and motor functions, sleep/wake regulation, and cognition.

Graded Transmission without Action Potentials Sustains Rhythmic Activity in Some But Not All Modulators That Activate the Same Current.

Neurons in the central pattern-generating circuits in the crustacean stomatogastric ganglion (STG) release neurotransmitter both as a graded function of presynaptic membrane potential that persists in TTX and in response to action potentials. In the STG of the male crab Cancer borealis, the modulators oxotremorine, C. borealis tachykinin-related peptide Ia (CabTRP1a), red pigment concentrating hormone (RPCH), proctolin, TNRNFLRFamide, and crustacean cardioactive peptide (CCAP) produce and sustain robust pyloric rhythms by activating the same modulatory current (IMI), albeit on different subsets of pyloric network targets. The muscarinic agonist oxotremorine, and the peptides CabTRP1a and RPCH elicited rhythmic triphasic intracellular alternating fluctuations of activity in the presence of TTX. Intracellular waveforms of pyloric neurons in oxotremorine and CabTRP1a in TTX were similar to those in the intact rhythm, and phase relationships among neurons were conserved. Although cycle frequency was conserved in oxotremorine and TTX, it was altered in CabTRP1a in the presence of TTX. Both rhythms were primarily driven by the pacemaker kernel consisting of the Anterior Burster and Pyloric Dilator neurons. In contrast, in TTX the circuit remained silent in proctolin, TNRNFLRFamide, and CCAP. These experiments show that graded synaptic transmission in the absence of voltage-gated Na+ current is sufficient to sustain rhythmic motor activity in some, but not other, modulatory conditions, even when each modulator activates the same ionic current. This further demonstrates that similar rhythmic motor patterns can be produced by qualitatively different mechanisms, one that depends on the activity of voltage-gated Na+ channels, and one that can persist in their absence.SIGNIFICANCE STATEMENT The pyloric rhythm of the crab stomatogastric ganglion depends both on spike-mediated and graded synaptic transmission. We activate the pyloric rhythm with a wide variety of different neuromodulators, all of which converge on the same voltage-dependent inward current. Interestingly, when action potentials and spike-mediated transmission are blocked using TTX, we find that the muscarinic agonist oxotremorine and the neuropeptide CabTRP1a sustain rhythmic alternations and appropriate phases of activity in the absence of action potentials. In contrast, TTX blocks rhythmic activity in the presence of other modulators. This demonstrates fundamental differences in the burst-generation mechanisms in different modulators that would not be suspected on the basis of their cellular actions at the level of the targeted current.

Prokineticin-2 promotes chemotaxis and alternative A2 reactivity of astrocytes.

Astrocyte reactivity is disease- and stimulus-dependent, adopting either a proinflammatory A1 phenotype or a protective, anti-inflammatory A2 phenotype. Recently, we demonstrated, using cell culture, animal models and human brain samples, that dopaminergic neurons produce and secrete higher levels of the chemokine-like signaling protein Prokineticin-2 (PK2) as a compensatory protective response against neurotoxic stress. As astrocytes express a high level of PK2 receptors, herein, we systematically characterize the role of PK2 in astrocyte structural and functional properties. PK2 treatment greatly induced astrocyte migration, which was accompanied by a shift in mitochondrial energy metabolism, a reduction in proinflammatory factors, and an increase in the antioxidant genes Arginase-1 and Nrf2. Overexpression of PK2 in primary astrocytes or in the in vivo mouse brain induced the A2 astrocytic phenotype with upregulation of key protective genes and A2 reactivity markers including Arginase-1 and Nrf2, PTX3, SPHK1, and TM4SF1. A small-molecule PK2 agonist, IS20, not only mimicked the protective effect of PK2 in primary cultures, but also increased glutamate uptake by upregulating GLAST. Notably, IS20 blocked not only MPTP-induced reductions in the A2 phenotypic markers SPHK1 and SCL10a6 but also elevation of the of A1 marker GBP2. Collectively, our results reveal that PK2 regulates a novel neuron-astrocyte signaling mechanism by promoting an alternative A2 protective phenotype in astrocytes, which could be exploited for development of novel therapeutic strategies for PD and other related chronic neurodegenerative diseases. PK2 signals through its receptors on astrocytes and promotes directed chemotaxis. PK2-induced astrocyte reactivity leads to an increase in antioxidant and anti-inflammatory proteins while increasing glutamate uptake, along with decreased inflammatory factors. © 2018 Wiley Periodicals, Inc.

Sex- and context-dependent effects of oxytocin on social sharing.

We interact socially and form bonds with others because such experiences are rewarding. However, an insecure attachment style or social anxiety can reduce these rewarding effects. The neuropeptide oxytocin (OXT) may facilitate social interactions either by increasing their rewarding experience or by attenuating anxiety, although effects can be sex- and attachment-style dependent. In this study, 128 pairs of same-sex friends completed a social sharing paradigm in a double-blind, placebo-controlled, between-subject design with one friend inside an MRI scanner and the other in a remote behavioral testing room. In this way we could examine whether intranasal-OXT differentially modulated the emotional impact of social sharing and associated neural processing. Additionally, we investigated if OXT effects were modulated by sex and attachment style. Results showed that in women, but not men, OXT increased ratings for sharing stimuli with their friend but not with a stranger, particularly in the friend in the scanner. Corresponding neuroimaging results showed that OXT decreased both amygdala and insula activity as well as their functional connectivity in women when they shared with friends but had the opposite effect in men. On the other hand, OXT did not enhance responses in brain reward circuitry. In the PLC treated group amygdala responses in women when they shared pictures with their friend were positively associated with attachment anxiety and OXT uncoupled this. Our findings demonstrate that OXT facilitates the impact of sharing positive experiences with others in women, but not men, and that this is associated with differential effects on the amygdala and insula and their functional connections. Furthermore, OXT particularly reduced increased amygdala responses during sharing in individuals with higher attachment anxiety. Thus, OXT effects in this context may be due more to reduced anxiety when sharing with a friend than to enhanced social reward.

Cortistatin attenuates angiotensin II-induced abdominal aortic aneurysm through inactivation of the ERK1/2 signaling pathways.

Abdominal aortic aneurysm (AAA) is a fatal disease that is associated with chronic inflammation in the vessel wall. Cortistatin is implicated in inflammation, vascular smooth muscle cell migration and other cardiovascular pathologies. But, the hypothetical effect of cortistatin on AAA remains uncertain. We investigated the effect of cortistatin administration to angiotensin (Ang) II-induced AAA formation in apolipoprotein E deficient (Apoe-/-) mice. We showed that cortistatin administration significantly suppresses incidence and severity of AAA in Apoe-/- mice. A significant increase in macrophage infiltration, excretion of inflammatory cytokines, activities and expression levels of MMP2 and MMP9, reactive oxygen species levels and cell apoptosis in aneurysmal aortic wall of Apoe-/- mice infused with Ang-II, and these events were significantly alleviated by co-treatment with cortistatin. Mechanistic studies showed that the protective effects of cortistatin were related to the blocking of ERK1/2 signaling pathways, while does not was not actually affect JNK, P38 phosphorylation. In conclusion, cortistatin appears to play an essential role in the formation of AAA and indicate cortistatin may as novel therapeutic option for AAA.

Knockout of the Gnrh genes in zebrafish: effects on reproduction and potential compensation by reproductive and feeding-related neuropeptides.

Gonadotropin-releasing hormone (GNRH) is known as a pivotal upstream regulator of reproduction in vertebrates. However, reproduction is not compromised in the hypophysiotropic Gnrh3 knockout line in zebrafish (gnrh3-/-). In order to determine if Gnrh2, the only other Gnrh isoform in zebrafish brains, is compensating for the loss of Gnrh3, we generated a double Gnrh knockout zebrafish line. Surprisingly, the loss of both Gnrh isoforms resulted in no major impact on reproduction, indicating that a compensatory response, outside of the Gnrh system, was evoked. A plethora of factors acting along the reproductive hypothalamus-pituitary axis were evaluated as possible compensators based on neuroanatomical and differential gene expression studies. In addition, we also examined the involvement of feeding factors in the brain as potential compensators for Gnrh2, which has known anorexigenic effects. We found that the double knockout fish exhibited upregulation of several genes in the brain, specifically gonadotropin-inhibitory hormone (gnih), secretogranin 2 (scg2), tachykinin 3a (tac3a), and pituitary adenylate cyclase-activating peptide 1 (pacap1), and downregulation of agouti-related peptide 1 (agrp1), indicating the compensation occurs outside of Gnrh cells and therefore is a noncell autonomous response to the loss of Gnrh. While the differential expression of gnih and agrp1 in the double knockout line was confined to the periventricular nucleus and hypothalamus, respectively, the upregulation of scg2 corresponded with a broader neuronal redistribution in the lateral hypothalamus and hindbrain. In conclusion, our results demonstrate the existence of a redundant reproductive regulatory system that comes into play when Gnrh2 and Gnrh3 are lost.

Anti-diuretic activity of a CAPA neuropeptide can compromise Drosophila chill tolerance.

For insects, chilling injuries that occur in the absence of freezing are often related to a systemic loss of ion and water balance that leads to extracellular hyperkalemia, cell depolarization and the triggering of apoptotic signalling cascades. The ability of insect ionoregulatory organs (e.g. the Malpighian tubules) to maintain ion balance in the cold has been linked to improved chill tolerance, and many neuroendocrine factors are known to influence ion transport rates of these organs. Injection of micromolar doses of CAPA (an insect neuropeptide) have been previously demonstrated to improve Drosophila cold tolerance, but the mechanisms through which it impacts chill tolerance are unclear, and low doses of CAPA have been previously demonstrated to cause anti-diuresis in insects, including dipterans. Here, we provide evidence that low (femtomolar) and high (micromolar) doses of CAPA impair and improve chill tolerance, respectively, via two different effects on Malpighian tubule ion and water transport. While low doses of CAPA are anti-diuretic, reduce tubule K+ clearance rates and reduce chill tolerance, high doses facilitate K+ clearance from the haemolymph and increase chill tolerance. By quantifying CAPA peptide levels in the central nervous system, we estimated the maximum achievable hormonal titres of CAPA and found further evidence that CAPA may function as an anti-diuretic hormone in Drosophila melanogaster We provide the first evidence of a neuropeptide that can negatively affect cold tolerance in an insect and further evidence of CAPA functioning as an anti-diuretic peptide in this ubiquitous insect model.

Expression profile and reproductive regulation of APGWamide in Pacific abalone (Haliotis discus hannai).

Neuropeptides in the central nervous system regulate reproductive activities in vertebrates. Ala-Pro-Gly-Trp-NH2 (APGWamide), a neuromediator expressed in the neural ganglia of mollusks, controls sexual maturation and reproduction. To clarify the role of APGWamide in sexual behavior regulation and gamete cell maturation in mollusks, we cloned the cDNA of APGWamide precursor (Hdh-APGWamide) and examined the spatiotemporal expression of the transcript in the Pacific abalone Haliotis discus hannai. The 222-amino acid sequence of the precursor deduced from the cDNA sequence showed typical features of gastropod APGWamide precursors. Phylogenetic analysis revealed that Hdh-APGWamide is classified with other gastropod APGWamide precursors, which form a separate branch from those of the bivalves. Hdh-APGWamide mRNA was highly expressed in the neural ganglia in both sexes. In females, the three ganglia (pleuro-pedal ganglion, PPG; branchial ganglion, and cerebral ganglion) showed similar expression in immature and mature animals, whereas in males, the level in the PPG only was higher at maturity (P < 0.05). In vivo injection of APGWamide or 5-hydroxytryptamine (10-3 M) increased the frequency of spawning and the number of released sperm cells by mature males (P < 0.05), while concentrations above 10-7 M enhanced germinal vesicle breakdown in fully developed cultured oocytes (P < 0.05). Thus, the phylogenetic branch of the APGWamide precursor gene in Haliotidae was separate from the other branches under the phylum Mollusca, and this gene exhibited ganglion-specific expression, indicating that it may induce final maturation and spawning in both sexes of Haliotis spp.

Regulation of motivation for food by neuromedin U in the paraventricular nucleus and the dorsal raphe nucleus.

BACKGROUND: Motivation for high-fat food is thought to contribute to excess caloric intake in obese individuals. A novel regulator of motivation for food may be neuromedin U (NMU), a highly-conserved neuropeptide that influences food intake. Although these effects of NMU have primarily been attributed to signaling in the paraventricular nucleus of the hypothalamus (PVN), NMU has also been found in other brain regions involved in both feeding behavior and motivation. We investigate the effects of NMU on motivation for food and food intake, and identify the brain regions mediating these effects. METHODS: The motivational state for a particular reinforcer (e.g., high-fat food) can be assessed using a progressive-ratio schedule of reinforcement under which an increasing number of lever presses are required to obtain subsequent reinforcers. Here, we have used a progressive-ratio operant responding paradigm in combination with an assessment of cumulative food intake to evaluate the effects of NMU administration in rats, and identify the brain regions mediating these effects. RESULTS: We found that peripheral administration of NMU decreases operant responding for high-fat food in rats. Evaluation of Fos-like immunoreactivity in response to peripheral NMU indicated the PVN and dorsal raphe nucleus (DRN) as sites of action for NMU. NMU infusion into either region mimics the effects of peripheral NMU on food intake and operant responding for food. NMU-containing projections from the lateral hypothalamus (LH) to the PVN and DRN were identified as an endogenous source of NMU. CONCLUSIONS: These results identify the DRN as a site of action for NMU, demonstrate that the LH provides endogenous NMU to the PVN and DRN and implicate NMU signaling in the PVN and DRN as a novel regulator of motivation for high-fat foods.

Immunization with neural derived peptides plus scar removal induces a permissive microenvironment, and improves locomotor recovery after chronic spinal cord injury.

BACKGROUND: Immunization with neural derived peptides (INDP) as well as scar removal-separately-have shown to induce morphological and functional improvement after spinal cord injury (SCI). In the present study, we compared the effect of INDP alone versus INDP with scar removal on motor recovery, regeneration-associated and cytokine gene expression, and axonal regeneration after chronic SCI. Scar removal was conducted through a single incision with a double-bladed scalpel along the stump, and scar renewal was halted by adding α,α'-dipyridyl. RESULTS: During the chronic injury stage, two experiments were undertaken. The first experiment was aimed at testing the therapeutic effect of INDP combined with scar removal. Sixty days after therapeutic intervention, the expression of genes encoding for TNFα, IFNγ, IL4, TGFß, BDNF, IGF1, and GAP43 was evaluated at the site of injury. Tyrosine hydroxylase and 5-hydroxytryptamine positive fibers were also studied. Locomotor evaluations showed a significant recovery in the group treated with scar removal + INDP. Moreover; this group presented a significant increase in IL4, TGFß, BDNF, IGF1, and GAP43 expression, but a decrease of TNFα and IFNγ. Also, the spinal cord of animals receiving both treatments presented a significant increase of serotonergic and catecholaminergic fibers as compared to other the groups. The second experiment compared the results of the combined approach versus INDP alone. Rats receiving INDP likewise showed improved motor recovery, although on a lesser scale than those who received the combined treatment. An increase in inflammation and regeneration-associated gene expression, as well as in the percentage of serotonergic and catecholaminergic fibers was observed in INDP-treated rats to a lesser degree than those in the combined therapy group. CONCLUSIONS: These findings suggest that INDP, both alone and in combination with scar removal, could modify the non-permissive microenvironment prevailing at the chronic phase of SCI, providing the opportunity of improving motor recovery.

Effect of gonadotropin-inhibitory hormone on luteinizing hormone secretion in humans.

BACKGROUND: Gonadotropin-inhibitory hormone (GnIH, human homologue of RFRP-3) suppresses gonadotropin secretion in animal models, but its effects have not been studied in the human. OBJECTIVE: We tested the hypotheses that exogenous GnIH inhibits LH secretion (i) in postmenopausal women and (ii) in men concurrently administered exogenous kisspeptin. DESIGN: Following in vitro and in vivo preclinical studies to functionally characterize the GnIH peptide, a dose-finding study (human GnIH: 1·5-150 µg/kg/h, iv for 3 h) was undertaken, and 50 µg/kg/h selected for further evaluation. Five postmenopausal women were administered 50 µg/kg/h iv infusion for 3 h or vehicle on two separate days. Four men were administered kisspeptin-10 (0·3 µg/kg iv bolus) with simultaneous infusion of GnIH (50 µg/kg/h, iv for 3 h) or vehicle. PARTICIPANTS: Healthy postmenopausal women (mean age 58 ± 2 years, LH: 30·8 ± 2·9 IU/l, FSH: 78·7 ± 6·4 IU/l, oestradiol: <50 pmol/l) and men (39·8 ± 2·1 years, mean total testosterone 12·1 ± 1·8 nmol/l, LH 2·2 ± 0·2 IU/l). PRIMARY OUTCOME: Change in area under curve (AUC) of LH during GnIHvs vehicle. RESULTS: During GnIH administration in postmenopausal women, LH secretion decreased (ΔAUC: -9·9 ± 1·8 IU/3 h) vs vehicle (ΔAUC: -0·5 ± 1·7 IU/3 h; P = 0·02). Kisspeptin-10-stimulated LH responses in men were not affected by GnIH co-administration (60-min AUC of LH 6·2 ± 0·8 IU/h with kisspeptin-10 alone, 6·3 ± 1·0 IU/h, kisspeptin-10 with GnIH, P = 0·72). Exogenous GnIH was well tolerated, with no adverse events reported. CONCLUSIONS: Gonadotropin-inhibitory hormone decreased LH secretion in postmenopausal women in this first-in-human study. Kisspeptin-stimulated LH secretion in men was not inhibited during concomitant administration of GnIH.

Intracerebroventricular injection of RFRP-3 delays puberty onset and stimulates growth hormone secretion in female rats.

BACKGROUND: Puberty onset is a complex, organized biological process with multilevel regulation, and its physiopathological mechanisms are yet to be elucidated. RFRP-3, the mammalian ortholog to gonadotropin-inhibitory hormone, is implicated in inhibiting the synthesis and release of gonadotropin in mammals. However, it is unclear whether RFRP-3 participates in regulating pubertal development. METHODS: This study investigated the functional significance and regulatory mechanism of hypothalamic RFRP-3 neuropeptide in the onset of puberty in young female rats. On postnatal day 22, we implanted cannulas into the lateral ventricles of female rat pups. From postnatal day 28 to postnatal day 36, the intracerebroventricular injection of RFRP-3, or vehicle, was conducted twice a day. To investigate whether puberty onset was affected, we examined the body weight, age of vaginal opening, serum hormone levels, uterus and ovary development, and hypothalamic Kiss-1 mRNA expression. RESULTS: Intracerebroventricular injection of RFRP-3 significantly decreased the serum concentrations of luteinizing hormone and estradiol, delayed uterine maturation, and postponed the time of vaginal opening. This study suggests that RFRP-3 can delay the onset of puberty in young female rats; the expression of Kiss-1 mRNA is potently inhibited in the RFRP-3 group. Moreover, our data show that RFRP-3 elevates serum growth hormone levels. CONCLUSIONS: These data suggest that intracerebroventricular injection of RFRP-3 significantly delays the onset of puberty in female rats. Additionally, RFRP-3 may be associated with prepubertal rise in the secretion of growth hormone.

Intranasal oxytocin increases facial expressivity, but not ratings of trustworthiness, in patients with schizophrenia and healthy controls.

BACKGROUND: Blunted facial affect is a common negative symptom of schizophrenia. Additionally, assessing the trustworthiness of faces is a social cognitive ability that is impaired in schizophrenia. Currently available pharmacological agents are ineffective at improving either of these symptoms, despite their clinical significance. The hypothalamic neuropeptide oxytocin has multiple prosocial effects when administered intranasally to healthy individuals and shows promise in decreasing negative symptoms and enhancing social cognition in schizophrenia. Although two small studies have investigated oxytocin's effects on ratings of facial trustworthiness in schizophrenia, its effects on facial expressivity have not been investigated in any population. METHOD: We investigated the effects of oxytocin on facial emotional expressivity while participants performed a facial trustworthiness rating task in 33 individuals with schizophrenia and 35 age-matched healthy controls using a double-blind, placebo-controlled, cross-over design. Participants rated the trustworthiness of presented faces interspersed with emotionally evocative photographs while being video-recorded. Participants' facial expressivity in these videos was quantified by blind raters using a well-validated manualized approach (i.e. the Facial Expression Coding System; FACES). RESULTS: While oxytocin administration did not affect ratings of facial trustworthiness, it significantly increased facial expressivity in individuals with schizophrenia (Z = -2.33, p = 0.02) and at trend level in healthy controls (Z = -1.87, p = 0.06). CONCLUSIONS: These results demonstrate that oxytocin administration can increase facial expressivity in response to emotional stimuli and suggest that oxytocin may have the potential to serve as a treatment for blunted facial affect in schizophrenia.