The effects of neuropeptide W on food consumption and feeding behavior in neonatal meat-type chicks: Role of CRF1/CRF2 and NPY1 receptors.

In several studies, the regulatory role of the neuropeptide W (NPW) system in food intake has been demonstrated. Considering the lack of avian studies in this field, the current research was conducted to evaluate the effects of intracerebroventricular (ICV) infusion of NPW and its interferences with corticotropin, melanocortin, and neuropeptide Y (NPY) receptors on meal consumption and feeding behaviors of broilers. In the first experiment, birds were injected with NPW (0.75, 1.5, and 3 nmol) in addition to saline. In the second experiment, saline, CRF1 receptor antagonist (NBI35965, 30 µg), NPW (3 nmol), and simultaneous injections of NBI35965 and NPW were performed. Experiments 3-8 were identical to experiment 2, except that CRF2 receptor antagonist (K41498, 30 µg), MC3/MC4 receptor antagonist (SHU9119, 0.5 nmol), MC4 receptor antagonist (HS024, 0.5 nmol), NPY1 receptor antagonist (BMS193885, 1.25 nmol), NPY2 receptor antagonist (CYM9484, 1.25 nmol), and NPY5 receptor (antagonist L-152,804, 1.25 nmol) were administrated instead of NBI35965. After that, cumulative feed intake and feeding behavior were monitored for 2 h and 30 min after injections, respectively. Following the infusion of NPW (1.5 and 3 nmol), there was a significant stimulation of meal consumption in chickens (P < 0.05). Concomitant injection of NBI35965 and K41498 with NPW enhanced the appetite-increasing effect of NPW (P < 0.05); while BMS193885 suppressed this effect of NPW (P < 0.05). Injection of SHU9119, HS024, CYM9484, and L-152804 with NPW at the same time, had no significant effect on NPW-induced hyperphagia (P > 0.05). NPW also significantly decreased the standing period and the number of jumps, steps, and exploratory pecks, and led to an increase in sitting period and feeding pecks (P < 0.05). Based on the observations, it seems that NPW-induced hyperphagia could be mediated through CRF1, CRF2, and NPY1 receptors in neonatal broilers.

Central effects of opioidergic system on food intake in birds and mammals: a review.

Undoubtedly, the food intake process is one of the most necessary physiological functions for the survival of animals and humans. Although; this operation seems simple on the surface, the regulation of the mechanisms involved in it requires the cooperation of many neurotransmitters, peptides, and hormonal factors in the nervous and endocrine systems. Understanding the signals that regulate energy levels and appetite, may open new approaches to therapeutics and drugs used in obesity-related complications. Improving the quality of animal products and health is also possible due to this research. The present review is aimed to sum up the current findings on central effects of opioids on the food consumption of birds and mammals. Based on the reviewed articles, the opioidergic system appears to be one of the key elements in the birds' and mammals' food intake and is closely related to other systems involved in appetite regulation. According to the findings, it seems that the effects of this system on nutritional mechanisms are often applied via kappa- and mu-opioid receptors. Controversial observations have been made regarding opioid receptors, highlighting the need for further studies, especially at the molecular level. The role of opiates in taste or diet craving also showed the efficacy of this system, especially the mu-opioid receptor, on preferences such as diets containing high sugar and fat. Finally, putting the results of this study together with the findings of human experiments and other primates can lead to a correct comprehension of the appetite regulation processes, especially the role of the opioidergic system.

Molecular mechanisms highlighting the potential role of COVID-19 in the development of neurodegenerative diseases.

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to the pulmonary manifestations, COVID-19 patients may present a wide range of neurological disorders as extrapulmonary presentations. In this view, several studies have recently documented the worsening of neurological symptoms within COVID-19 morbidity in patients previously diagnosed with neurodegenerative diseases (NDs). Moreover, several cases have also been reported in which the patients presented parkinsonian features after initial COVID-19 symptoms. These data raise a major concern about the possibility of communication between SARS-CoV-2 infection and the initiation and/or worsening of NDs. In this review, we have collected compelling evidence suggesting SARS-CoV-2, as an environmental factor, may be capable of developing NDs. In this respect, the possible links between SARS-CoV-2 infection and molecular pathways related to most NDs and the pathophysiological mechanisms of the NDs such as Alzheimer's disease, vascular dementia, frontotemporal dementia, Parkinson's disease, and amyotrophic lateral sclerosis will be explained.

Thermal manipulation during Pre and Post-Hatch on thermotolerance of male broiler chickens exposed to chronic heat stress.

The aim of this study was to evaluate the effects of thermal manipulation (TM) during pre and post-hatch periods on thermotolerance of male broiler chickens exposed to chronic heat stress (CHS) during the finisher phase (34 ± 2°C, 6 h/day). Seven hundred fertile eggs of Ross 308 were assigned to the following groups: 1) control group incubated and housed in standard conditions, 2) pre-hatch treatment (PRE), the eggs were exposed to 39.5°C and 65% RH for 12 h, d from embryonic d 7 to 16 and after hatching the chicks where housed in standard conditions; 3 and 4) post-hatch TM at d 3 (PO3) and post-hatch TM at d 5 (PO5), which had the same incubation conditions as control and exposed to 36 to 38°C for 24 h at 3 and 5 days of age, respectively. TM in PRE group resulted in delay in the hatch time (6 h) along with reduction in body weight compared to control (P = 0.02). TM caused a significant reduction of facial surface temperature (FST) until d 28 (P < 0.02), but not significant during CHS. Body weight gain was suppressed in PO3 and PO5 groups at d 14 (P = 0.007) and compensated at d 28. However, TM led to higher BWG (P = 0.000) but lower FCR (P = 0.03) and mortality at the first week of CHS compared to control. European production efficiency index was higher in TM-treated chickens compared to control (P = 0.01). TM reduced the blood concentration of uric acid, total protein, T3, and T4 in which thyroid hormones in PO3 and PO5 treatments showed more reduction rather than other groups. In PRE group, chickens had lower abdominal fat pad than control (P = 0.0001). The relative weight of heart was decreased in TM groups (P = 0.001). It was concluded that TM may induce thermotolerance in growing broilers, possibly through the modification of physiological parameters of broilers especially during the first week of CHS.

Cannabinoid-glutamate interactions in the regulation of food intake in neonatal layer- type chicks: role of glutamate NMDA and AMPA receptors.

The involvement of the endocannabinoid system in the brain functions is likely the conclusion of its capability to interact with specific neurotransmitters in several brain regions. The present study was designed to examine the role of the glutamatergic system on cannabinoid-induced hyperphagia in chicken. In this survey 10 experiments designed to investigate interaction of cannabinoidergic and glutamatergic systems on feeding behavior in neonatal chickens. In experiment 1, chicken were intracerebroventricular (ICV) injected with saline, 2-AG (2-Arachidonoylglycerol, 5.28 nmol, CB1 receptors agonist), MK-801(NMDA receptor antagonist, 15 nmol) and co-administration of 2-AG + MK-801. In experiment 2, injection of saline, 2-AG (5.28 nmol), CNQX) AMPA/kainate receptor antagonist, 390 nmol) and their combination (2-AG + CNQX) was done. In Experiment 3, injections were saline, 2-AG (5.28 nmol), AIDA)mGluR1 antagonist, 2 nmol) and 2-AG + AIDA. Experiments 4 and 5 were similar to experiment 3, except birds injected with LY341495 (mGLUR2 glutamate antagonist, 150 nmol) and UBP1112 (mGLUR3 glutamate antagonist, 2 nmol) instead of AIDA. Experiments 6-10 followed the procedure similar to experiments 1-5, except chickens received ICV injection of CB65 (CB2 receptor agonist, 3 nmol), instead of 2-AG. Then the cumulative food intake measured until 120 min post injection. According to the results, ICV injection of 2-AG and CB65 significantly increased food intake (P < 0.001). Co-injection of 2-AG and MK-801 significantly amplified hyperphagic effect of CB1 receptors agonist(P < 0.001). Moreover, co-administration of CB65 plus CNQX significantly increased CB65- induced hyperphagia in FD3 neonatal layer-type chickens (P < 0.001). These results suggest there is an interaction between endocannabinoids and glutamatergic systems via NMDA and AMPA receptors in feeding behavior of neonatal layer-type chickens.

Paracrine Neuroprotective Effects of Neural Stem Cells on Glutamate-Induced Cortical Neuronal Cell Excitotoxicity.

PURPOSE: Glutamate is a major excitatory neurotransmitter in mammalian central nervous system. Excessive glutamate releasing overactivates its receptors and changes calcium homeostasis that in turn leads to a cascade of intracellular events causing neuronal degeneration. In current study, we used neural stem cells conditioned medium (NSCs-CM) to investigate its neuroprotective effects on glutamate-treated primary cortical neurons. METHODS: Embryonic rat primary cortical cultures were exposed to different concentrations of glutamate for 1 hour and then they incubated with NSCs-CM. Subsequently, the amount of cell survival in different glutamate excitotoxic groups were measured after 24 h of incubation by trypan blue exclusion assay and MTT assay. Hoechst and propidium iodide were used for determining apoptotic and necrotic cell death pathways proportion and then the effect of NSCs-CM was investigated on this proportion. RESULTS: NSCs conditioned medium increased viability rate of the primary cortical neurons after glutamate-induced excitotoxicity. Also we found that NSCs-CM provides its neuroprotective effects mainly by decreasing apoptotic cell death rate rather than necrotic cell death rate. CONCLUSION: The current study shows that adult neural stem cells could exert paracrine neuroprotective effects on cortical neurons following a glutamate neurotoxic insult.

The effect of serotonergic system on nociceptin/orphanin FQ induced food intake in chicken.

The present study was designed to examine the effects of intracerebroventricular injection of para-chlorophenylalanine (PCPA) (cerebral serotonin depletive), fluoxetine (selective serotonin reuptake inhibitor), 8-OH-DPAT (5-HT1A autoreceptor agonist) and SB 242084 (5-HT2c receptor antagonist) on nociceptin/orphanin FQ (N/OFQ) induced feeding response in chickens. A guide cannula was surgically implanted into the lateral ventricle of chickens. Before the experiments, 3-h fasting periods had been given to all experimental birds. In experiment 1, chickens were injected with PCPA (1.5 µg) followed by an N/OFQ injection (16 nmol) intracerebroventricularly. In experiment 2, birds received fluoxetine (10 µg) prior to the injection of N/OFQ. In experiment 3, chickens were administered with N/OFQ after the 8-OH-DPAT administration (15.25 nmol). In experiment 4, birds were injected with SB 242084 (1.5 µg) followed by an N/OFQ injection. Cumulative food intake was measured at 3 h post injection. The results of this study show that N/OFQ increases food intake in broiler cockerels (P < 0.05) and that this effect is amplified by pretreatment with PCPA and SB 242084 in an additive manner (P < 0.05). The effect of N/OFQ is not changed by pretreatment with 8-OH-DPAT (P > 0.05). Furthermore, the stimulatory effect of N/OFQ on food intake was significantly attenuated by pretreatment with fluoxetine. These results suggest that N/OFQ induced hyperphagia is mediated by serotonergic mechanisms, and possibly imply an interaction between N/OFQ and the serotonergic system (via 5-HT2C receptors) on food intake in chickens.

Leptin mRNA in bovine spermatozoa.

Leptin is a hormonal product of the ob gene, which is involved in energy metabolism and reproduction. Expression of leptin and its receptor in reproductive organs suggests that in addition to its endocrine effects, it may have paracrine/autocrine effects on reproduction. Also, the expression of leptin in human and pig spermatozoa and its secretion by these cells suggest a direct role for leptin in sperm physiology. The present study was the first to investigate the presence of the leptin mRNA transcript in Holstein cattle spermatozoa by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Total RNA was extracted from different concentrations of ejaculated or epididymal sperm cells and after synthesis of complementary DNA was subjected to PCR amplification. In both ejaculated and epididymal spermatozoa, leptin transcript was amplified with first set of primers. The first amplicon was used for a nested PCR with second set of primers. Intron-spanning primers were located in exons 2 and 3 to rule out the possibility of a DNA contamination. Amplificons of leptin were only detectable when more than 100 million epididymal or ejaculated spermatozoa was used. Presence of leptin mRNA in the bull spermatozoa suggests that leptin might be involved in the physiological processes of bovine spermatozoa, which remain to be further clarified.

Intralateral hypothalamic area injection of isoproterenol and propranolol affects food and water intake in broilers.

The role played by adrenergic system in water intake, especially food intake, has long been known in mammals. In avian species, there have been many experiments exploring the effects of the adrenergic system in different sites in the central nervous system in meat- and egg-type poultry. This study was designed to examine the possible effects of intralateral hypothalamic area (ILHy) microinjections of a beta-adrenergic agonist, isoproterenol, and a beta-adrenoceptor blocker, propranolol, on food and water intake in 3-h food-deprived and 3-h water-deprived broiler cockerels. Our findings suggest that the beta-adrenergic system directly affects food especially water intake in broilers. Although isoproterenol significantly (P < or = 0.05) decreased food intake for the first 15 min, it reduced food intake during the experiment. Isoproterenol reduced water intake significantly (P < or = 0.05), which was abolished by pretreatment with propranolol. It is proposed that beta-adrenoceptors in LHy play a direct and indirect role in the regulation of food especially water intake in broiler cockerels.

The effects of bicuculline and muscimol on glutamate-induced feeding behavior in broiler cockerels.

This study was designed to examine the effects of intracerebroventricular (ICV) injection of bicuculline (GABA(A) receptor antagonist) and muscimol (GABA(A) receptor agonist) on glutamate-induced eating response in 24-h food-deprived (FD24) broiler cockerels. At first, guide cannula was surgically implanted in the right lateral ventricle of chickens. In experiment 1, birds were ICV injected with different doses of glutamate. In experiment 2, birds were administered with effective dose of glutamate after bicuculline. In experiment 3, chickens received muscimol prior to the injection of glutamate, and cumulative food intake was determined at 3-h postinjection. The results of this study showed that glutamate decreases food consumption in FD24 broiler cockerels (P