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Rostami F, Jaafari Suha A, Janahmadi M, Hosseinmardi N. Aquaporin-4 inhibition attenuates Pentylenetetrazole-induced behavioral seizures and cognitive impairments in kindled rats. Physiol Behav 2024; 278:114521. [PMID: 38492911 DOI: 10.1016/j.physbeh.2024.114521] [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: 10/10/2023] [Revised: 03/08/2024] [Accepted: 03/13/2024] [Indexed: 03/18/2024]
Abstract
Epilepsy is a neurological condition distinguished by recurrent and unexpected seizures. Astrocytic channels and transporters are essential for maintaining normal neuronal functionality. The astrocytic water channel, aquaporin-4 (AQP4), which plays a pivotal role in regulating water homeostasis, is a potential target for epileptogenesis. In present study, we examined the effect of different doses (10, 50, 100 μM and 5 mM) of AQP4 inhibitor, 2-nicotinamide-1, 3, 4-thiadiazole (TGN-020), during kindling acquisition, on seizure parameters and seizure-induced cognitive impairments. Animals were kindled by injection of pentylenetetrazole (PTZ: 37.5 mg/kg, i.p.). TGN-020 was administered into the right lateral cerebral ventricle 30 min before PTZ every alternate day. Seizure parameters were assessed 20 min after PTZ administration. One day following the last PTZ injection, memory performance was investigated using spontaneous alternation in Y-maze and novel object recognition (NOR) tests. The inhibition of AQP4 during the kindling process significantly decreased the maximal seizure stage and seizure duration (two-way ANOVA, P = 0.0001) and increased the latency of seizure onset and the number of PTZ injections required to induce different seizure stages (one-way ANOVA, P = 0.0001). Compared to kindled rats, the results of the NOR tests showed that AQP4 inhibition during PTZ-kindling prevented recognition memory impairment. Based on these results, AQP4 could be involved in seizure development and seizure-induced cognitive impairment. More investigation is required to fully understand the complex interactions between seizure activity, water homeostasis, and cognitive dysfunction, which may help identify potential therapeutic targets for these conditions.
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Affiliation(s)
- Fatemeh Rostami
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Jaafari Suha
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narges Hosseinmardi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Ali SO, Ghaiad HR, Elmasry GF, Mehana NA. Sinapic Acid Mitigates Pentylenetetrazol-induced Acute Seizures By Modulating the NLRP3 Inflammasome and Regulating Calcium/calcineurin Signaling: In Vivo and In Silico Approaches. Inflammation 2024:10.1007/s10753-024-02019-0. [PMID: 38662166 DOI: 10.1007/s10753-024-02019-0] [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: 01/31/2024] [Revised: 03/25/2024] [Accepted: 04/02/2024] [Indexed: 04/26/2024]
Abstract
Sinapic acid (SA) is a naturally occurring carboxylic acid found in citrus fruits and cereals. Recent studies have shown that SA has potential anti-seizure properties due to its anti-inflammatory, antioxidant, and anti-apoptotic effects. The present study investigated the neuroprotective role of SA at two different dosages in a pentylenetetrazol (PTZ)-induced acute seizure model. Mice were divided into six groups: normal control, PTZ, SA (20 mg/kg), SA (20 mg/kg) + PTZ, SA (40 mg/kg), and SA (40 mg/kg) + PTZ. SA was orally administered for 21 days, followed by a convulsive dose of intraperitoneal PTZ (50 mg/kg). Seizures were estimated via the Racine scale, and animals were behaviorally tested using the Y-maze. Brain tissues were used to assess the levels of GABA, glutamate, oxidative stress markers, calcium, calcineurin, (Nod)-like receptor protein-3 (NLRP3), interleukin (IL)-1β, apoptosis-associated speck-like protein (ASC), Bcl-2-associated death protein (Bad) and Bcl-2. Molecular docking of SA using a multistep in silico protocol was also performed. The results showed that SA alleviated oxidative stress, restored the GABA/glutamate balance and calcium/calcineurin signaling, downregulated NLRP3 and apoptosis, and improved recognition and ambulatory activity in PTZ-treated mice. In silico results also revealed that SA strongly interacts with the target proteins NLRP3 and ASC. Overall, the results suggest that SA is a promising antiseizure agent and that both doses of SA are comparable, with 40 mg/kg SA being superior in normalizing glutathione, calcium and IL-1β, in addition to calcineurin, NLRP3, ASC and Bad.
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Affiliation(s)
- Shimaa O Ali
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, 11562, Egypt
| | - Heba R Ghaiad
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, 11562, Egypt.
| | - Ghada F Elmasry
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, 11562, Egypt
| | - Noha A Mehana
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El-Aini Street, Cairo, 11562, Egypt.
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Ghrelin/GHS-R1A antagonism in memory test and its effects on central molecular signaling involved in addiction in rats. Pharmacol Biochem Behav 2023; 224:173528. [PMID: 36870422 DOI: 10.1016/j.pbb.2023.173528] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 12/23/2022] [Accepted: 02/12/2023] [Indexed: 03/06/2023]
Abstract
Central ghrelin signaling seems to play important role in addiction as well as memory processing. Antagonism of the growth hormone secretagogue receptor (GHS-R1A) has been recently proposed as a promising tool for the unsatisfactory drug addiction therapy. However, molecular aspects of GHS-R1A involvement in specific brain regions remain unclear. The present study demonstrated for the first time that acute as well as subchronic (4 days) administration of the experimental GHS-R1A antagonist JMV2959 in usual intraperitoneal doses including 3 mg/kg, had no influence on memory functions tested in the Morris Water Maze in rats as well as no significant effects on the molecular markers linked with memory processing in selected brain areas in rats, specifically on the β-actin, c-Fos, two forms of the calcium/calmodulin-dependent protein kinase II (CaMKII, p-CaMKII) and the cAMP-response element binding protein (CREB, p-CREB), within the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), dorsal striatum, and hippocampus (HIPP). Furthermore, following the methamphetamine intravenous self-administration in rats, the 3 mg/kg JMV2959 pretreatment significantly reduced or prevented the methamphetamine-induced significant decrease of hippocampal β-actin and c-Fos as well as it prevented the significant decrease of CREB in the NAC and mPFC. These results imply, that the GHS-R1A antagonist/JMV2959 might reduce/prevent some of the memory-linked molecular changes elicited by methamphetamine addiction within brain structures associated with memory (HIPP), reward (NAc), and motivation (mPFC), which may contribute to the previously observed significant JMV2959-induced reduction of the methamphetamine self-administration and drug-seeking behavior in the same animals. Further research is necessary to corroborate these results.
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Reich N, Hölscher C. Beyond Appetite: Acylated Ghrelin As A Learning, Memory and Fear Behavior-modulating Hormone. Neurosci Biobehav Rev 2022; 143:104952. [DOI: 10.1016/j.neubiorev.2022.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 04/27/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022]
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The Effect of Ghrelin on Apoptosis, Necroptosis and Autophagy Programmed Cell Death Pathways in the Hippocampal Neurons of Amyloid-β 1–42-Induced Rat Model of Alzheimer’s Disease. Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10457-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Masule MV, Rathod S, Agrawal Y, Patil CR, Nakhate KT, Ojha S, Goyal SN, Mahajan UB. Ghrelin mediated regulation of neurosynaptic transmitters in depressive disorders. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2022; 3:100113. [PMID: 35782191 PMCID: PMC9240712 DOI: 10.1016/j.crphar.2022.100113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 06/07/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Ghrelin is a peptide released by the endocrine cells of the stomach and the neurons in the arcuate nucleus of the hypothalamus. It modulates both peripheral and central functions. Although ghrelin has emerged as a potent stimulator of growth hormone release and as an orexigenic neuropeptide, the wealth of literature suggests its involvement in the pathophysiology of affective disorders including depression. Ghrelin exhibits a dual role through the advancement and reduction of depressive behavior with nervousness in the experimental animals. It modulates depression-related signals by forming neuronal networks with various neuropeptides and classical neurotransmitter systems. The present review emphasizes the integration and signaling of ghrelin with other neuromodulatory systems concerning depressive disorders. The role of ghrelin in the regulation of neurosynaptic transmission and depressive illnesses implies that the ghrelin system modulation can yield promising antidepressive therapies. Ghrelin is the orexigenic type of neuropeptide. It binds with the growth hormone secretagogue receptor (GHSR). GHSR is ubiquitously present in the various brain regions. Ghrelin is involved in the regulation of depression-related behavior. The review focuses on the neurotransmission and signaling of ghrelin in neuropsychiatric and depressive disorders.
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Affiliation(s)
- Milind V. Masule
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
| | - Sumit Rathod
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Yogeeta Agrawal
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Chandragouda R. Patil
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
| | - Kartik T. Nakhate
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Sameer N. Goyal
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
- Corresponding author.
| | - Umesh B. Mahajan
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
- Corresponding author.
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Targeting the Ghrelin Receptor as a Novel Therapeutic Option for Epilepsy. Biomedicines 2021; 10:biomedicines10010053. [PMID: 35052733 PMCID: PMC8773216 DOI: 10.3390/biomedicines10010053] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 12/12/2022] Open
Abstract
Epilepsy is a neurological disease affecting more than 50 million individuals worldwide. Notwithstanding the availability of a broad array of antiseizure drugs (ASDs), 30% of patients suffer from pharmacoresistant epilepsy. This highlights the urgent need for novel therapeutic options, preferably with an emphasis on new targets, since “me too” drugs have been shown to be of no avail. One of the appealing novel targets for ASDs is the ghrelin receptor (ghrelin-R). In epilepsy patients, alterations in the plasma levels of its endogenous ligand, ghrelin, have been described, and various ghrelin-R ligands are anticonvulsant in preclinical seizure and epilepsy models. Up until now, the exact mechanism-of-action of ghrelin-R-mediated anticonvulsant effects has remained poorly understood and is further complicated by multiple downstream signaling pathways and the heteromerization properties of the receptor. This review compiles current knowledge, and discusses the potential mechanisms-of-action of the anticonvulsant effects mediated by the ghrelin-R.
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Beheshti S, Dehestani H. Differential expression levels of the hippocampal ghrelin and its receptor mRNA during memory consolidation. Behav Brain Res 2021; 408:113270. [PMID: 33811951 DOI: 10.1016/j.bbr.2021.113270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 03/23/2021] [Accepted: 03/28/2021] [Indexed: 12/30/2022]
Abstract
Ghrelin is a peptide, secreted mainly from the stomach. But, it is also produced in the brain. Studies have confirmed the positive impact of ghrelin on memory formation. However, the expression levels of ghrelin or its receptors were not measured in the brain during the process of memory formation. The probable alteration in the expression levels of ghrelin or its receptors in the brain during memory formation can be a reason for the contribution of its signaling in this process. We quantified the gene expression levels of ghrelin and its receptors in the hippocampus during fear and spatial memory consolidation. Thirty- nine adult male Wistar rats weighing 180-220 g were utilized. Memory consolidation was evaluated using the inhibitory avoidance task and Morris water maze. Rats were euthanized at different times (1, 3, and 24 h) post-training and their hippocampi were removed and freezed directly in liquid nitrogen. Quantitative real-time polymerize chain reaction (PCR) was used to quantify the messenger ribonucleic acid (mRNA) expression levels of the hippocampal ghrelin and its receptors. The mRNA levels of ghrelin exhibited a significant increase, 24 h post-training in the inhibitory avoidance task, while its receptor levels were down-regulated. Also, the mRNA expression levels of the hippocampal ghrelin were not changed significantly during memory consolidation in the Morris water maze, while its receptor showed a significant increase, 24 h post-training. The results show a differential profile of the expression levels of the hippocampal ghrelin or its receptor mRNA during fear or spatial memory consolidation. This proposes that a local increase in the hippocampal ghrelin or its receptor levels might be crucial for fear, and spatial memory consolidation. However, due to the small sample sizes, it is worth noting the preliminary nature of the conclusions in the present study.
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Affiliation(s)
- Siamak Beheshti
- Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran.
| | - Hadi Dehestani
- Department of Plant and Animal Biology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
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Zahiri H, Rostampour M, Khakpour B, Rohampour K. The effect of ghrelin injection in the CA1 region of hippocampus on the MK801- induced memory impairment in wistar rats. Behav Brain Res 2021; 405:113209. [PMID: 33639267 DOI: 10.1016/j.bbr.2021.113209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 02/20/2021] [Accepted: 02/21/2021] [Indexed: 01/28/2023]
Abstract
N-Methyl-D-Aspartate (NMDA) receptors are critically involved in the learning and memory formation and dizocilpine (MK-801) is an antagonist of NMDA receptor. Ghrelin plays a crucial role in learning and memory processes. The present study was conducted to the evaluation of ghrelin effect on passive avoidance memory impairment induced by MK801. In this experimental study, 24 male wistar rats were randomly distributed into 3 groups of 8 each. Passive avoidance tests of animals were evaluated using Shuttle Box apparatus. One week after the surgery, ghrelin (3 nmol) was injected intra-hippocampally, 5 min before the MK-801administration. MK-801 (0.15 mg/kg) was injected intraperitoneally (i.p.), 10 min before the test session. Pre-test injection of MK-801 significantly decreased STL (step through latency) at 24 h and 48 h (P < 0.001) and 10 days (P < 0.01) and increased TDC (time spent in dark compartment) at 24 h, 48 h and 10 days (P < 0.001) after training in comparison with control group. Pre-test injection of ghrelin + MK-801 significantly increased STL at 24 h (P < 0.01), 48 h and 10 days (P < 0.001) and decreased TDC at 24 h, 48 h and 10 days (P < 0.001) after training in comparison with MK-801 received group. It is concluded that pre-test injection of MK-801 impaired passive avoidance memory. Administration of ghrelin before MK-801 ameliorated memory impairment induced by MK-801. It is assumed that this compensative effect of ghrelin was mediated by NMDA receptor.
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Affiliation(s)
- Hamideh Zahiri
- Student Research Committee, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Mohammad Rostampour
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran; Cellular and Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran; Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
| | - Behrooz Khakpour
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran; Cellular and Molecular Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran; Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Kambiz Rohampour
- Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran; Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
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Alachkar A, Ojha SK, Sadeq A, Adem A, Frank A, Stark H, Sadek B. Experimental Models for the Discovery of Novel Anticonvulsant Drugs: Focus on Pentylenetetrazole-Induced Seizures and Associated Memory Deficits. Curr Pharm Des 2020; 26:1693-1711. [PMID: 32003682 DOI: 10.2174/1381612826666200131105324] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Epilepsy is a chronic neurological disorder characterized by irregular, excessive neuronal excitability, and recurrent seizures that affect millions of patients worldwide. Currently, accessible antiepileptic drugs (AEDs) do not adequately support all epilepsy patients, with around 30% patients not responding to the existing therapies. As lifelong epilepsy treatment is essential, the search for new and more effective AEDs with an enhanced safety profile is a significant therapeutic goal. Seizures are a combination of electrical and behavioral events that can induce biochemical, molecular, and anatomic changes. Therefore, appropriate animal models are required to evaluate novel potential AEDs. Among the large number of available animal models of seizures, the acute pentylenetetrazole (PTZ)-induced myoclonic seizure model is the most widely used model assessing the anticonvulsant effect of prospective AEDs, whereas chronic PTZ-kindled seizure models represent chronic models in which the repeated administration of PTZ at subconvulsive doses leads to the intensification of seizure activity or enhanced seizure susceptibility similar to that in human epilepsy. In this review, we summarized the memory deficits accompanying acute or chronic PTZ seizure models and how these deficits were evaluated applying several behavioral animal models. Furthermore, major advantages and limitations of the PTZ seizure models in the discovery of new AEDs were highlighted. With a focus on PTZ seizures, the major biochemicals, as well as morphological alterations and the modulated brain neurotransmitter levels associated with memory deficits have been illustrated. Moreover, numerous medicinal compounds with concurrent anticonvulsant, procognitive, antioxidant effects, modulating effects on several brain neurotransmitters in rodents, and several newly developed classes of compounds applying computer-aided drug design (CADD) have been under development as potential AEDs. The article details the in-silico approach following CADD, which can be utilized for generating libraries of novel compounds for AED discovery. Additionally, in vivo studies could be useful in demonstrating efficacy, safety, and novel mode of action of AEDs for further clinical development.
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Affiliation(s)
- Alaa Alachkar
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, United States.,Zayed Centre for Health Sciences, United Arab Emirates University, Al Ain, United States
| | - Shreesh K Ojha
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, United States.,Zayed Centre for Health Sciences, United Arab Emirates University, Al Ain, United States
| | - Adel Sadeq
- College of Pharmacy, Al Ain University, Al Ain, United Arab Emirates
| | - Abdu Adem
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, United States.,Zayed Centre for Health Sciences, United Arab Emirates University, Al Ain, United States
| | - Annika Frank
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Universitaetsstr. 1, 40225 Düsseldorf, Germany
| | - Holger Stark
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Universitaetsstr. 1, 40225 Düsseldorf, Germany
| | - Bassem Sadek
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, P.O. Box 17666 Al Ain, United States.,Zayed Centre for Health Sciences, United Arab Emirates University, Al Ain, United States
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Yadegary A, Nazari-Serenjeh F, Darbandi N. Synergistic improvement effect of nicotine-ghrelin co-injection into the anterior ventral tegmental area on morphine-induced amnesia. Neuropeptides 2020; 80:102025. [PMID: 32029269 DOI: 10.1016/j.npep.2020.102025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 01/15/2020] [Accepted: 01/29/2020] [Indexed: 11/15/2022]
Abstract
In the present study the effect of ghrelin or ghrelin/nicotine injection into the anterior ventral tegmental area (aVTA) on morphine-induced amnesia in passive avoidance learning have been evaluated. Also, the role of the aVTA nicotinic receptors in possible ghrelin-induced effects has been investigated. All animals were bilaterally implanted with chronic cannulas in the aVTA. A step-through type passive avoidance task was used for measurement of memory. We found that post-training subcutaneous (s.c.) injection of morphine (0.5-7.5 mg/kg) dose-dependently reduced the step-through latency, indicating morphine-induced amnesia. Post-training bilateral infusion of ghrelin (0.3, 1.5 and 3 nmol/μl) in a dose-dependent manner reversed amnesia induced by morphine (7.5 mg/kg, s.c.). Furthermore, reversal effect of ghrelin (3 nmol/μl) was blocked by pre-treatment of intra-aVTA administration of mecamylamine (1-3 μg/rat), a nicotinic acetylcholine receptor antagonist. Intra-aVTA administration of the higher dose of mecamylamine (3 μg/rat) into the aVTA by itself decreased the step-through latency and induced amnesia. In addition, post-training intra-aVTA administration of nicotine (0.25, 0.5, 1 μg/rat) which alone cannot affect memory consolidation, decreased significantly the amnesia induced by morphine (7.5 mg/kg, s.c.). Co-treatment of an ineffective dose of ghrelin (0.3 nmol/μl) with an ineffective dose of nicotine (0.25 μg/rat) significantly increased step-through latency of morphine (7.5 mg/kg, s.c.) treated animals, indicating the synergistic effect of the drugs. Taken together, our results suggest that intra-aVTA administration of ghrelin reversed morphine-induced amnesia and that ghrelin interacts synergistically with nicotine to mitigate morphine-induced amnesia.
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Affiliation(s)
- Atena Yadegary
- Department of Biology, Faculty of Science, Arak University, Arak, Iran
| | | | - Niloufar Darbandi
- Department of Biology, Faculty of Science, Arak University, Arak, Iran
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Nazari-Serenjeh F, Darbandi N, Majidpour S, Moradi P. Ghrelin modulates morphine-nicotine interaction in avoidance memory: Involvement of CA1 nicotinic receptors. Brain Res 2019; 1720:146315. [DOI: 10.1016/j.brainres.2019.146315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/26/2019] [Accepted: 06/27/2019] [Indexed: 11/29/2022]
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Neuroprotective effect of ghrelin in methamphetamine-treated male rats. Neurosci Lett 2019; 707:134304. [DOI: 10.1016/j.neulet.2019.134304] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 05/26/2019] [Accepted: 05/28/2019] [Indexed: 11/23/2022]
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14
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Buckinx A, Van Den Herrewegen Y, Pierre A, Cottone E, Ben Haj Salah K, Fehrentz JA, Kooijman R, De Bundel D, Smolders I. Differential Effects of a Full and Biased Ghrelin Receptor Agonist in a Mouse Kindling Model. Int J Mol Sci 2019; 20:ijms20102480. [PMID: 31137460 PMCID: PMC6567032 DOI: 10.3390/ijms20102480] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 12/23/2022] Open
Abstract
The ghrelin system has received substantial recognition as a potential target for novel anti-seizure drugs. Ghrelin receptor (ghrelin-R) signaling is complex, involving Gαq/11, Gαi/o, Gα12/13, and β-arrestin pathways. In this study, we aimed to deepen our understanding regarding signaling pathways downstream the ghrelin-R responsible for mediating anticonvulsive effects in a kindling model. Mice were administered the proconvulsive dopamine 1 receptor-agonist, SKF81297, to gradually induce a kindled state. Prior to every SKF81297 injection, mice were treated with a ghrelin-R full agonist (JMV-1843), a Gαq and Gα12 biased ligand unable to recruit β-arrestin (YIL781), a ghrelin-R antagonist (JMV-2959), or saline. Mice treated with JMV-1843 had fewer and less severe seizures compared to saline-treated controls, while mice treated with YIL781 experienced longer and more severe seizures. JMV-2959 treatment did not lead to differences in seizure severity and number. Altogether, these results indicate that the Gαq or Gα12 signaling pathways are not responsible for mediating JMV-1843′s anticonvulsive effects and suggest a possible involvement of β-arrestin signaling in the anticonvulsive effects mediated by ghrelin-R modulation.
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Affiliation(s)
- An Buckinx
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
| | - Yana Van Den Herrewegen
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
| | - Anouk Pierre
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
| | - Eleonora Cottone
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
| | - Khoubaib Ben Haj Salah
- Max Mousseron Institute of Biomolecules UMR524, CNRS, University of Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, 34090 Montpellier, France.
| | - Jean-Alain Fehrentz
- Max Mousseron Institute of Biomolecules UMR524, CNRS, University of Montpellier, Ecole Nationale Supérieure de Chimie de Montpellier, 34090 Montpellier, France.
| | - Ron Kooijman
- Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium.
| | - Dimitri De Bundel
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
| | - Ilse Smolders
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium.
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15
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Zahiri H, Rostampour M, Khakpour B, Rohampour K. The effect of ghrelin and adenosine mono phosphate kinase (AMPK) on the passive avoidance memory in male wistar rats. Neuropeptides 2019; 73:66-70. [PMID: 30553544 DOI: 10.1016/j.npep.2018.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/25/2018] [Accepted: 11/25/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Hamideh Zahiri
- Student Research Committee, Guilan University of Medical Sciences, Rasht, Iran
| | - Mohammad Rostampour
- Department of Physiology, Guilan University of Medical Sciences, Rasht, Iran; Cellular and Molecular Research Center, Guilan University of Medical Sciences, Rasht, Iran.
| | - Behrouz Khakpour
- Department of Physiology, Guilan University of Medical Sciences, Rasht, Iran; Cellular and Molecular Research Center, Guilan University of Medical Sciences, Rasht, Iran
| | - Kambiz Rohampour
- Neuroscience Research Center, Guilan University of Medical Sciences, Rasht, Iran
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16
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Sang YM, Wang LJ, Mao HX, Lou XY, Zhu YJ. The association of short-term memory and cognitive impairment with ghrelin, leptin, and cortisol levels in non-diabetic and diabetic elderly individuals. Acta Diabetol 2018; 55:531-539. [PMID: 29492658 DOI: 10.1007/s00592-018-1111-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 01/29/2018] [Indexed: 01/02/2023]
Abstract
AIMS This study assessed short-term memory and biochemical indicators with the levels of ghrelin, leptin, and cortisol between cognitive impairment and normal older adults with or without diabetes. METHODS We enrolled 286 older adults (aged 65-85 years) with or without diabetes from the local community. Short-term memory was assessed using pictures of common objects; cognitive functioning was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). The physiological indexes assessed were plasma levels of fasting ghrelin and leptin, ghrelin level at 2_h after breakfast, 24-h urinary cortisol value, body mass index, and plasma cortisol levels at 8:00 a.m., 4:00 p.m., and 12:00 p.m. RESULTS In both non-diabetic and diabetic subjects, short-term memory was significantly lower in the impaired cognition group (5.99 ± 2.90 in non-diabetic subjects and 4.71 ± 2.14 in diabetic subjects) than in the normal cognition group (8.14 ± 2.23 in non-diabetic subjects and 7.82 ± 3.37 in diabetic subjects). Baseline ghrelin level was significantly lower in the impaired cognition group (9.07 ± 1.13 ng/mL in non-diabetic subjects and 7.76 ± 1.34 ng/mL in diabetic subjects) than in the normal cognition group (10.94 ± 1.53 ng/mL in non-diabetic subjects and 9.93 ± 1.76 ng/mL in diabetic subjects); plasma cortisol levels at 8:00 a.m., 4:00 p.m., and 12:00 p.m. were significantly higher in the impaired cognition group than in the normal cognition group, while no significant difference was observed in plasma levels of fasting leptin between different groups. CONCLUSIONS Fasting plasma ghrelin and cortisol levels may be markers of cognitive decline and memory loss. It is possible that adjusting their levels may have a therapeutic effect, and this should be investigated in future studies.
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Affiliation(s)
- Yu Ming Sang
- Department of Endocrinology, Jinhua Central Hospital, Jinhua, Zhejiang province, China.
| | - Li Jun Wang
- Department of Psychology, Zhejiang Normal University, Jinhua, China
| | - Hong Xian Mao
- Department of Endocrinology, Jinhua Central Hospital, Jinhua, Zhejiang province, China
| | - Xue Yong Lou
- Department of Endocrinology, Jinhua Central Hospital, Jinhua, Zhejiang province, China
| | - Yi Jun Zhu
- The Central Laboratory, Jinhua Central Hospital, Jinhua, Zhejiang province, China
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17
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Beheshti S, Aslani N. Local injection of d-lys-3-GHRP-6 in the rat amygdala, dentate gyrus or ventral tegmental area impairs memory consolidation. Neuropeptides 2018; 67:20-26. [PMID: 29137815 DOI: 10.1016/j.npep.2017.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/26/2017] [Accepted: 11/03/2017] [Indexed: 12/16/2022]
Abstract
It is well known that the hormone ghrelin affects learning and memory in different experimental models of learning. Though, the effect of antagonism of ghrelin receptor type 1a (GHS-R1a) in various regions of the brain and on different stages of learning has not been examined. In this study the effect of injection of a GHS-R1a selective antagonist (d-Lys-3-GHRP-6) into the basolateral amygdala, dentate gyrus or ventral tegmental area was examined on memory consolidation in the passive avoidance task. Adult male Wistar rats weighing 230-280g were used. Animals underwent stereotaxic surgery and cannulated in their amygdala, dentate gyrus or ventral tegmental area. One week after surgery, the rats received different doses of d-Lys-3-GHRP-6 (0.08, 0.8, and 8nM), immediately after training. The control groups received solvent of the drug. Twenty four hours later in the test day, memory retrieval was assessed. In all groups, post-training injection of d-Lys-3-GHRP-6 decreased step-through latency and increased entries into the dark compartment and time spent in the dark compartment, significantly and in a dose-dependent manner. The results indicate that antagonism of the GHS-R1a in the rat amygdala, dentate gyrus or ventral tegmental area impairs memory consolidation and show that the ghrelin signaling has a widespread influence on cognitive performance.
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Affiliation(s)
- Siamak Beheshti
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
| | - Neda Aslani
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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18
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Ge T, Yang W, Fan J, Li B. Preclinical evidence of ghrelin as a therapeutic target in epilepsy. Oncotarget 2017; 8:59929-59939. [PMID: 28938694 PMCID: PMC5601790 DOI: 10.18632/oncotarget.18349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/22/2017] [Indexed: 12/17/2022] Open
Abstract
Ghrelin, an orexigenic peptide synthesized by endocrine cells of the gastric mucosa, plays a major role in inhibiting seizures. However, the underlying mechanism of ghrelin's anticonvulsant action is still unclear. Nowadays, there are considerable evidences showing that ghrelin is implicated in various neurophysiological processes, including learning and memory, neuroprotection, neurogenesis, and inflammatory effects. In this review, we will summarize the effects of ghrelin on epilepsy. It may provide a comprehensive picture of the role of ghrelin in epilepsy.
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Affiliation(s)
- Tongtong Ge
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Wei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Jie Fan
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Bingjin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
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19
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Koyuncuoğlu T, Vızdıklar C, Üren D, Yılmaz H, Yıldırım Ç, Atal SS, Akakın D, Kervancıoğlu Demirci E, Yüksel M, Yeğen BÇ. Obestatin improves oxidative brain damage and memory dysfunction in rats induced with an epileptic seizure. Peptides 2017; 90:37-47. [PMID: 28223092 DOI: 10.1016/j.peptides.2017.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/08/2017] [Accepted: 02/16/2017] [Indexed: 11/16/2022]
Abstract
Obestatin was shown to alleviate renal, gastrointestinal and haemorrhage-induced brain injury in rats. In order to investigate the neuroprotective effects of obestatin on seizure-induced oxidative brain injury, an epileptic seizure was induced with a single intraperitoneal (i.p.) dose of pentylenetetrazole (PTZ, 45mg/kg) in male Wistar rats. Thirty minutes before the PTZ injection, rats were treated with either saline or obestatin (1μg/kg, i.p.). Seizure was video-taped and then evaluated by using Racine's scoring (0-5). For the assessment of memory function, passive-avoidance test was performed before seizure induction, which was repeated on the 3rd day of seizure. The rats were decapitated at the 24th or 72nd hour of seizures and brain tissues were obtained for histopathological examination and for measuring levels of malondialdehyde (MDA), glutathione (GSH), reactive oxygen radicals and myeloperoxidase (MPO) activity. Obestatin treatment reduced the average seizure score, decreased the occurrence and duration of generalized tonic-clonic seizures, presenting with a shorter latency to their onset. Increased lipid peroxidation and enhanced generation of oxygen-derived radicals detected at the post-seizure 72nd h were suppressed by the consecutive treatments of obestatin, but no changes were observed by the single obestatin treatment in the 24-h seizure group. Neuronal damage and increased GFAP immunoreactivity, observed in the hippocampal areas and cortex of PTZ-induced rats were alleviated in 3-day obestatin-treated PTZ group. PTZ-induced memory dysfunction was significantly improved in obestatin-treated PTZ group as compared to saline-treated rats. The present data indicate that obestatin ameliorated the severity of PTZ-induced seizures, improved memory dysfunction and reduced neuronal damage by limiting oxidative damage.
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Affiliation(s)
| | - Caner Vızdıklar
- Marmara University School of Medicine, Department of Physiology, Turkey
| | - Doğan Üren
- Marmara University School of Medicine, Department of Physiology, Turkey
| | - Hakan Yılmaz
- Marmara University School of Medicine, Department of Physiology, Turkey
| | - Çağan Yıldırım
- Marmara University School of Medicine, Department of Physiology, Turkey
| | - Sefa Semih Atal
- Marmara University School of Medicine, Department of Physiology, Turkey
| | - Dilek Akakın
- Marmara University School of Medicine, Department of Histology and Embryology, Turkey
| | | | - Meral Yüksel
- Marmara University Vocational School of Health Related Professions, Istanbul, Turkey
| | - Berrak Ç Yeğen
- Marmara University School of Medicine, Department of Physiology, Turkey.
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20
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Tabari SSS, Babri S, Mirzaie F, Farajdokht F, Mohaddes G. Enduring amnesia induced by ICV scopolamine is reversed by sesame oil in male rats. Acta Cir Bras 2016; 31:520-6. [DOI: 10.1590/s0102-865020160080000004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/12/2016] [Indexed: 11/21/2022] Open
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21
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Beheshti S, Shahrokhi S. Blocking the ghrelin receptor type 1a in the rat brain impairs memory encoding. Neuropeptides 2015; 52:97-102. [PMID: 26072187 DOI: 10.1016/j.npep.2015.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/18/2015] [Accepted: 05/21/2015] [Indexed: 12/17/2022]
Abstract
Studies have shown that intracerebral administration of ghrelin hormone affects learning and memory in different experimental models of learning. However, the effect of antagonism of ghrelin receptor type 1a (GHS-R1a) on different stages of learning has not been investigated. In this study the effect of intracerebroventricular (i.c.v) injection of a GHS-R1a selective antagonist (d-Lys-3-GHRP-6) was examined on acquisition and consolidation of learning in the passive avoidance task. In total, 72 male Wistar rats weighing 230-280g were randomly distributed into 9 groups of 8 each. Animals underwent stereotaxic surgery and cannulated in their right ventricle. One week after surgery, the rats received different doses of d-Lys-3-GHRP-6 (0.2, 2, 20 and 80nM/5μl; i.c.v) 10min before, or (2, 20 and 80nM/5μl; i.c.v) immediately after training. The control groups received solvent of the drug. Twenty four hours later in the test day, memory retrieval was assessed. Pre-training injection of d-Lys-3-GHRP-6 decreased step-through latency (STL) and increased number of step-throughs into the dark compartment (NST) in a dose-dependent manner, but failed to be statistically significant. It also increased time spent in the dark compartment (TDC), significantly and in a dose-dependent manner. Post-training injection of d-Lys-3-GHRP-6 decreased step-through latency and increased time spent in the dark compartment and number of step-throughs into the dark compartment, significantly and in a dose-dependent manner. The results indicate that antagonism of the GHS-R1a in the rat brain impairs memory encoding on both acquisition and consolidation stages. Further studies are required to elucidate the main brain regions affected by the antagonist.
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Affiliation(s)
- Siamak Beheshti
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran.
| | - Shahrzad Shahrokhi
- Division of Animal Sciences, Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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22
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Arslan G, Ayyildiz M, Agar E. The interaction between ghrelin and cannabinoid systems in penicillin-induced epileptiform activity in rats. Neuropeptides 2014; 48:345-52. [PMID: 25256087 DOI: 10.1016/j.npep.2014.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 02/03/2023]
Abstract
The majority of experimental and clinical studies show that ghrelin and cannabinoids are potent inhibitors of epileptic activity in various models of epilepsy. A number of studies have attempted to understand the connection between ghrelin and cannabinoid signalling in the regulation of food intake. Since no data show a functional interaction between ghrelin and cannabinoids in epilepsy, we examined the relationship between these systems via penicillin-induced epileptiform activity in rats. Doses of the CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA) (2.5 and 7.5 µg), the CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3 carboxamide (AM-251) (0.25 and 0.5 µg) and ghrelin (0.5 and 1 µg) were administered intracerebroventricularly (i.c.v.) 30 minutes after the intracortical (i.c.) application of penicillin. In the interaction groups, the animals received either an effective dose of ACEA (7.5 µg, i.c.v.) or a non-effective dose of ACEA (2.5 µg, i.c.v.) or effective doses of AM-251 (0.25, 0.5 µg, i.c.v.) 10 minutes after ghrelin application. A 1 µg dose of ghrelin suppressed penicillin-induced epileptiform activity. The administration of a 0.25 µg dose of AM-251 increased the frequency of penicillin-induced epileptiform activity by producing status epilepticus-like activity. A 7.5 µg dose of ACEA decreased the frequency of epileptiform activity, whereas a non-effective dose of ACEA (2.5 µg) did not change it. Effective doses of AM-251 (0.25, 0.5 µg) reversed the ghrelin's anticonvulsant activity. The application of non-effective doses of ACEA (2.5 µg) together with ghrelin (0.5 µg) within 10 minutes caused anticonvulsant activity, which was reversed by the administration of AM-251 (0.25 µg). The electrophysiological evidence from this study suggests a possible interaction between ghrelin and cannabinoid CB1 receptors in the experimental model of epilepsy.
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Affiliation(s)
- Gokhan Arslan
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Mustafa Ayyildiz
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Erdal Agar
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey.
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23
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Babri S, Mohaddes G, Feizi I, Mohammadnia A, Niapour A, Alihemmati A, Amani M. Effect of troxerutin on synaptic plasticity of hippocampal dentate gyrus neurons in a β-amyloid model of Alzheimer׳s disease: An electrophysiological study. Eur J Pharmacol 2014; 732:19-25. [DOI: 10.1016/j.ejphar.2014.03.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 03/11/2014] [Accepted: 03/17/2014] [Indexed: 01/08/2023]
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24
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Parent MB, Darling JN, Henderson YO. Remembering to eat: hippocampal regulation of meal onset. Am J Physiol Regul Integr Comp Physiol 2014; 306:R701-13. [PMID: 24573183 DOI: 10.1152/ajpregu.00496.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A wide variety of species, including vertebrate and invertebrates, consume food in bouts (i.e., meals). Decades of research suggest that different mechanisms regulate meal initiation (when to start eating) versus meal termination (how much to eat in a meal, also known as satiety). There is a very limited understanding of the mechanisms that regulate meal onset and the duration of the postprandial intermeal interval (ppIMI). In the present review, we examine issues involved in measuring meal onset and some of the limited available evidence regarding how it is regulated. Then, we describe our recent work indicating that dorsal hippocampal neurons inhibit meal onset during the ppIMI and describe the processes that may be involved in this. We also synthesize recent evidence, including evidence from our laboratory, suggesting that overeating impairs hippocampal functioning and that impaired hippocampal functioning, in turn, contributes to the development and/or maintenance of diet-induced obesity. Finally, we identify critical questions and challenges for future research investigating neural controls of meal onset.
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Affiliation(s)
- Marise B Parent
- Neuroscience Institute, Georgia State University, Atlanta, Georgia; and Department of Psychology, Georgia State University, Atlanta, Georgia
| | - Jenna N Darling
- Neuroscience Institute, Georgia State University, Atlanta, Georgia; and
| | - Yoko O Henderson
- Neuroscience Institute, Georgia State University, Atlanta, Georgia; and
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