1
|
Ganeyan A, Ganesh CB. Organization of enkephalinergic neuronal system in the central nervous system of the gecko Hemidactylus frenatus. Brain Struct Funct 2024:10.1007/s00429-024-02805-4. [PMID: 38713249 DOI: 10.1007/s00429-024-02805-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/23/2024] [Indexed: 05/08/2024]
Abstract
Enkephalins are endogenous opioid pentapeptides that play a role in neurotransmission and pain modulation in vertebrates. However, the distribution pattern of enkephalinergic neurons in the brains of reptiles has been understudied. This study reports the organization of the methionine-enkephalin (M-ENK) and leucine-enkephalin (L-ENK) neuronal systems in the central nervous system of the gecko Hemidactylus frenatus using an immunofluorescence labeling method. Although M-ENK and L-ENK-immunoreactive (ir) fibers extended throughout the pallial and subpallial subdivisions, including the olfactory bulbs, M-ENK and L-ENK-ir cells were found only in the dorsal septal nucleus. Enkephalinergic perikarya and fibers were highly concentrated in the periventricular and lateral preoptic areas, as well as in the anterior and lateral subdivisions of the hypothalamus, while enkephalinergic innervation was observed in the hypothalamic periventricular nucleus, infundibular recess nucleus and median eminence. The dense accumulation of enkephalinergic content was noticed in the pars distalis of the hypophysis. In the thalamus, the nucleus rotundus and the dorsolateral, medial, and medial posterior thalamic nuclei contained M-ENK and L-ENK-ir fibers, whereas clusters of M-ENK and L-ENK-ir neurons were observed in the pretectum, mesencephalon, and rhombencephalon. The enkephalinergic fibers were also seen in the area X around the central canal, as well as the dorsal and ventral horns. The widespread distribution of enkephalin-containing neurons within the central nervous system implies that enkephalins regulate a variety of functions in the gecko, including sensory, behavioral, hypophysiotropic, and neuroendocrine functions.
Collapse
Affiliation(s)
- Ananya Ganeyan
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad, 580 003, India
| | - C B Ganesh
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad, 580 003, India.
| |
Collapse
|
2
|
Wang Y, Xue Y, Yan C, Yu X, Zhang L, Wang Y, Lan Y, Zhang X. Ovary metabolome and cecal microbiota changes in aged laying hens supplemented with vitamin E. Poult Sci 2024; 103:103760. [PMID: 38678750 PMCID: PMC11067459 DOI: 10.1016/j.psj.2024.103760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/05/2024] [Accepted: 04/08/2024] [Indexed: 05/01/2024] Open
Abstract
This study was aimed to evaluate the effect of vitamin E (VE) on laying performance, VE deposition, antioxidant capacity, immunity, follicle development, estrogen secretion, ovary metabolome, and cecal microbiota of laying hens. One hundred and twenty XinYang Black-Feathered laying hens (70 wk old) were randomly assigned to 2 groups (6 replicates of 20 birds), and fed a basal diet (containing 20 mg/kg VE, control (CON) group) and a basal diet supplemented with 20 mg/kg VE (VE group). The experiment lasted for 10 wk. Results showed that VE supplementation increased laying performance, antioxidant capacity, and immunity, as evidenced by increased (P < 0.05) performance (laying rate), antioxidant (glutathione peroxidase, total superoxide dismutase, total antioxidant capacity, and catalase) and immune (immunoglobulins) parameters, and decreased (P < 0.05) feed/egg ratio and malondialdehyde. Meanwhile, VE group had higher (P < 0.05) pregrade follicles, ovary index and serum estrogen levels than CON group. 16S rRNA sequencing showed that VE supplementation altered the cecal microbiota composition by increasing Bacteroides, Rikenellaceae_RC9_gut_group, Prevotellaceae_UCG-001 and Megamonas abundances and reducing Christensenellaceae_R-7_group abundance (at genus level), which are mainly associated with the production of short-chain fatty acids. Metabolomic profiling of the ovary revealed that the major metabolites altered by VE supplementation were mainly related to follicle development, estrogen secretion, anti-inflammatory, antioxidant, phototransduction, bile acid synthesis, and nutrient transport. Furthermore, changes in cecal microbiota (at genus level) and ovary metabolites were highly correlated with laying performance, antioxidant, and immune parameters. In summary, VE contributed to the laying performance of aged laying hens by enhancing antioxidant, immune, and ovarian functions, promoting follicle development and estrogen secretion, and regulating gut microbiota and ovary metabolites. These findings will provide a new perspective on the mechanisms of egg production in aged poultry ovaries.
Collapse
Affiliation(s)
- Yongxia Wang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an 311300, China
| | - Yajie Xue
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an 311300, China
| | - CongCong Yan
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an 311300, China
| | - Xu Yu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an 311300, China
| | - Ling Zhang
- Anhui Province Key Laboratory of Local Livestock and Poultry Genetic Resource Conservation and Bio-breeding, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230000, China
| | - Yufang Wang
- Qujiang District Animal Husbandry and Veterinary Station, Quzhou 324000, China
| | - Yahua Lan
- Qujiang District Animal Husbandry and Veterinary Station, Quzhou 324000, China
| | - Xiaodong Zhang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, College of Animal Science and Technology, College of Veterinary Medicine, Zhejiang A&F University, Lin'an 311300, China.
| |
Collapse
|
3
|
Shinde D, Bhat SK, Ganesh CB. The opioid peptide leucine enkephalin modulates hypothalamic-hypophysial axis in the cichlid fish Oreochromis mossambicus. Anim Reprod Sci 2024; 263:107451. [PMID: 38490066 DOI: 10.1016/j.anireprosci.2024.107451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/25/2024] [Accepted: 03/06/2024] [Indexed: 03/17/2024]
Abstract
In vertebrates, opioid peptides are thought to be involved in the regulation of reproduction; however, the significance of enkephalins in testicular function remains unclear. We examined the influence of δ-opioid receptor agonist leucine enkephalin (L-ENK) on the hypophysial-testicular axis of the cichlid fish Oreochromis mossambicus. Treatment with a low dose of L-ENK (60 µg) caused a significant increase in the numbers of primary and secondary spermatocytes and early and late spermatids, concomitant with intense immunolabelling of testicular androgen receptors, but did not significantly alter serum luteinizing hormone (LH) and 11-ketotestosterone (11-KT) levels compared to those of controls. Nevertheless, treatment with a high dose of L-ENK (200 µg) caused a significant reduction in the numbers of secondary spermatocytes as well as late spermatids associated with marginal immunolabelling of androgen receptors and significantly lower concentrations of serum 11-KT and LH compared to controls. In addition, the serum cortisol level was not affected in low-dose L-ENK-treated fish, but its level was significantly increased in the high-dose L-ENK-treated group. Together, these findings indicate that a low dose of L-ENK stimulates the germ cells at the meiosis stage and promotes further stages of spermatogenesis, whereas a high concentration of L-ENK inhibits spermatogenesis at the advanced stages. This effect appears to be mediated through the suppression of testicular steroidogenesis and the reduction of LH release in the pituitary gland of tilapia. The findings also suggest that elevated L-ENK levels in teleosts may exert their inhibitory influence on the hypophysial-testicular axis via glucocorticoids.
Collapse
Affiliation(s)
- Deepak Shinde
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India
| | - Shilpa K Bhat
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India
| | - C B Ganesh
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India.
| |
Collapse
|
4
|
Ganeyan A, Ganesh CB. The opioid peptide leucine-enkephalin disrupts seasonal and gonadotropin-induced ovarian recrudescence in the gecko Hemidactylus frenatus. Comp Biochem Physiol A Mol Integr Physiol 2023; 283:111454. [PMID: 37263377 DOI: 10.1016/j.cbpa.2023.111454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 06/03/2023]
Abstract
The enkephalins are known to regulate many physiological functions, including reproduction in vertebrates. However, the role of leucine-enkephalin (L-ENK) in the ovarian recrudescence activity of reptiles is not known. In the present study, we studied the influence of L-ENK on seasonal and FSH-induced ovarian recrudescence during the breeding and non-breeding phases of the cycle in the tropical and subtropical gecko Hemidactylus frenatus. In the first experiment, treatment with 5 and 25 μg L-ENK resulted in a dose-dependent inhibitory effect on the hypothalamic gonadotropin-releasing hormone (GnRH) neurons and ovary, as indicated by a significantly decreased percent area of GnRH-immunoreactive (GnRH-ir) fibres in the median eminence and pars distalis of the pituitary gland, concomitant with complete absence of stage V (late vitellogenic) follicles in the ovary compared to those of experimental controls. In the second experiment, administration of FSH to lizards in the regression phase stimulated the recruitment of stage IV and V (vitellogenic) follicles in contrast to their absence in initial controls or treatment controls. However, similar treatment of FSH in combination with 25 μg L-ENK did not result in the development of stage IV or V follicles. Together, these results suggest for the first time that treatment with 5 and 25 μg L-ENK exerts a dose-dependent inhibitory effect on the hypothalamic GnRH release into the median eminence and pituitary gland, leading to the blockade of ovarian recrudescence. These results also suggest a possible direct inhibitory effect of L-ENK at the level of the ovary in the gecko.
Collapse
Affiliation(s)
- Ananya Ganeyan
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India
| | - C B Ganesh
- Neuroendocrinology Research Laboratory, Department of Studies in Zoology, Karnatak University, Dharwad 580 003, India.
| |
Collapse
|
5
|
Effect of Leucine-enkephalin on Lipid Deposition and GSK-3β/mTOR Signaling in the Liver of Zebrafish. Int J Pept Res Ther 2023. [DOI: 10.1007/s10989-023-10506-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
|
6
|
Dvořáček J, Kodrík D. Drosophila reward system - A summary of current knowledge. Neurosci Biobehav Rev 2021; 123:301-319. [PMID: 33421541 DOI: 10.1016/j.neubiorev.2020.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 12/16/2020] [Accepted: 12/27/2020] [Indexed: 01/19/2023]
Abstract
The fruit fly Drosophila melanogaster brain is the most extensively investigated model of a reward system in insects. Drosophila can discriminate between rewarding and punishing environmental stimuli and consequently undergo associative learning. Functional models, especially those modelling mushroom bodies, are constantly being developed using newly discovered information, adding to the complexity of creating a simple model of the reward system. This review aims to clarify whether its reward system also includes a hedonic component. Neurochemical systems that mediate the 'wanting' component of reward in the Drosophila brain are well documented, however, the systems that mediate the pleasure component of reward in mammals, including those involving the endogenous opioid and endocannabinoid systems, are unlikely to be present in insects. The mushroom body components exhibit differential developmental age and different functional processes. We propose a hypothetical hierarchy of the levels of reinforcement processing in response to particular stimuli, and the parallel processes that take place concurrently. The possible presence of activity-silencing and meta-satiety inducing levels in Drosophila should be further investigated.
Collapse
Affiliation(s)
- Jiří Dvořáček
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
| | - Dalibor Kodrík
- Institute of Entomology, Biology Centre, CAS, and Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic
| |
Collapse
|
7
|
Ganesh CB. Influence of leucine-enkephalin on pituitary-ovary axis of the cichlid fish Oreochromis mossambicus. FISH PHYSIOLOGY AND BIOCHEMISTRY 2017; 43:1253-1264. [PMID: 28382489 DOI: 10.1007/s10695-017-0369-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/27/2017] [Indexed: 06/07/2023]
Abstract
The present investigation was conducted to elucidate the influence of an opioid peptide, leucine-enkephalin (L-ENK), on the reproductive axis of the tilapia Oreochromis mossambicus. In the first experiment, administration (i.p.) of 25, 100, and 300 μg L-ENK to the stripped female tilapia, for a period of 22 days, resulted in a significantly higher number of stage I follicles compared to those of initial controls and experimental controls, whereas the mean number of stage II and III follicles and serum levels of E2 did not significantly differ among different experimental groups. A significant increase in the number of stage V (fully ripened) follicles was concomitant with significant reduction in the follicular diameter in 25 or 100 μg L-ENK-treated fish compared to those of experimental controls. However, significant reduction in the mean number and diameter of these follicles was observed in 300 μg L-ENK-treated fish compared to those of experimental controls and 25 or 100 μg L-ENK-treated fish. In the second experiment, the stimulatory effect of 25 μg L-ENK on the ovary was abolished in combination with gonadotropin-releasing hormone antagonist (GnRH-A). In conclusion, these results suggest that L-ENK exerts stimulatory as well as inhibitory effects on the ovary in a dose-dependent manner, and that these effects are possibly mediated through the GnRH, for the first time in fish.
Collapse
Affiliation(s)
- C B Ganesh
- Department of Studies in Zoology, Karnatak University, Dharwad, 580 003, India.
| |
Collapse
|
8
|
Albrizio M, Guaricci AC, Milano S, Macrì F, Aiudi G. Mu opioid receptor in spermatozoa, eggs and larvae of gilthead sea bream (Sparus Aurata) and its involvement in stress related to aquaculture. FISH PHYSIOLOGY AND BIOCHEMISTRY 2014; 40:997-1009. [PMID: 24338156 DOI: 10.1007/s10695-013-9900-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
In aquaculture, unfavourable conditions experienced during early development may have strong downstream effects on the adult phenotype and fitness. Sensitivity to stress, leading to disease, reduced growth and mortality, is higher in larvae than in adult fish. In this study, conducted on sea bream (Sparus aurata), we evidenced the presence of the mu opioid receptor in gametes and larvae at different developmental stages. Moreover, we evaluated the possibility of reducing the effects of artificially produced stress, altering temperature, salinity and pH, by naloxone (an opioid antagonist) and calcium. Results evidenced that mu opioid receptor is present in larvae and in gametes of both sexes and that, during larval growth, its expression level changes accordingly; furthermore, naloxone/calcium association is efficacious in increasing the survival period of treated larvae compared to controls. We conclude that in sea bream rearing, the use of naloxone/calcium against stress can improve fish farming techniques by reducing larval mortality and consequently increasing productivity.
Collapse
Affiliation(s)
- Maria Albrizio
- Department of Emergencies and Organ Transplantation, Section of Veterinary Clinics and Animal Productions, University of Bari Aldo Moro, Strada Prov. per Casamassima Km3, 70010, Valenzano, BA, Italy,
| | | | | | | | | |
Collapse
|
9
|
Kumar S, Nagaraju GP, Song H, von Kalm L, Borst DW. Exposure to exogenous enkephalins disrupts reproductive development in the Eastern lubber grasshopper, Romalea microptera (Insecta: Orthoptera). PLoS One 2012; 7:e51126. [PMID: 23226477 PMCID: PMC3511379 DOI: 10.1371/journal.pone.0051126] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Accepted: 10/31/2012] [Indexed: 11/18/2022] Open
Abstract
Enkephalins play a major role in reproductive physiology in crustaceans; however their role in reproductive development in insects is largely unknown. We investigated the effect of exposure to exogenous leucine-enkephalin (Leu-Enk), methionine-enkephalin (Met-Enk), and the opioid antagonist naloxone on gonad development in the Eastern lubber grasshopper, Romalea microptera. Injection of either Leu-Enk or naloxone alone significantly increased the testicular index and testicular follicular diameter in males, and the ovarian index, oocyte length, and oocyte diameter in females. In contrast, injection of Met-Enk inhibited all measures of reproductive development in both sexes. Surprisingly, co-injection of naloxone with either enkephalin enhanced the effect associated with administration of the enkephalin alone. This study clearly demonstrates the ability of enkephalins to disrupt insect sexual development and also suggests the existence of conserved enkephaline-dependent regulatory mechanisms in insects and crustaceans.
Collapse
Affiliation(s)
- Sandeep Kumar
- Department of Biology, University of Central Florida, Orlando, FL, USA.
| | | | | | | | | |
Collapse
|
10
|
Abstract
Control of reproductive development in crustaceans requires neuropeptides, ecdysone and methyl farnesoate (MF). A major source of neuropeptides is the X-organ-sinus gland (XO-SG) complex located in the eyestalk ganglia of crustaceans. The other regulatory factors (either peptides or neuromodulators) are produced in the brain and thoracic ganglia (TG). Two other regulatory non-peptide compounds, the steroid ecdysone and the sesquiterpene MF, are produced by the Y-organs and the mandibular organs, respectively. In the current review, I have tried to recapitulate recent studies on the role of gonadal regulatory factors in regulating crustacean reproduction.
Collapse
|
11
|
Christie AE, Stemmler EA, Dickinson PS. Crustacean neuropeptides. Cell Mol Life Sci 2010; 67:4135-69. [PMID: 20725764 PMCID: PMC11115526 DOI: 10.1007/s00018-010-0482-8] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 07/09/2010] [Accepted: 07/28/2010] [Indexed: 10/19/2022]
Abstract
Crustaceans have long been used for peptide research. For example, the process of neurosecretion was first formally demonstrated in the crustacean X-organ-sinus gland system, and the first fully characterized invertebrate neuropeptide was from a shrimp. Moreover, the crustacean stomatogastric and cardiac nervous systems have long served as models for understanding the general principles governing neural circuit functioning, including modulation by peptides. Here, we review the basic biology of crustacean neuropeptides, discuss methodologies currently driving their discovery, provide an overview of the known families, and summarize recent data on their control of physiology and behavior.
Collapse
Affiliation(s)
- Andrew E Christie
- Program in Neuroscience, John W. and Jean C. Boylan Center for Cellular and Molecular Physiology, Mount Desert Island Biological Laboratory, Old Bar Harbor Road, P.O. Box 35, Salisbury Cove, ME 04672, USA.
| | | | | |
Collapse
|