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Wu N, Sun T, Wu X, Chen H, Zhang Z. Modulation of GABA B receptors in the insula bidirectionally affects associative memory of epilectic rats in both spatial and non-spatial operant tasks. Front Behav Neurosci 2023; 16:1042227. [PMID: 36688127 PMCID: PMC9846148 DOI: 10.3389/fnbeh.2022.1042227] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/12/2022] [Indexed: 01/05/2023] Open
Abstract
Background Stimulation of gamma-aminobutyric acid (GABA) activity through GABA receptor agonists is the basic mechanism of many anticonvulsant drugs. Nevertheless, many of these GABergic drugs have adverse cognitive effects. We previously found that GABAB receptors (GABABRs) in the insula regulate operant associative memory in healthy rats. The present study aimed at investigating the effects of GABABR modulation in the insula on operant associative memory in epileptic rats, along with the underlying mechanisms. Methods The lithium-pilocarpine model of temporal lobe epilepsy (TLE) was established in male Sprague-Dawley rats. A 22-gauge stainless-steel guide cannula was surgically implanted into the granular insula cortex of the epileptic rats. Baclofen (125 ng/μl, 1 μl), CGP35348 (12.5 μg/μl, 1 μl), or saline (1 μl) was slowly infused through the guide cannula. The Intellicage automated behavioral testing system was used to evaluate operant associative memory of the epileptic rats, including non-spatial operant tasks (basic nosepoke learning and skilled nosepoke learning) and spatial operant tasks (chamber position learning). The expression of the GABABR subunits GB1 and GB2 in the insula was examined by immunofluorescence and Western blotting. Results The Intellicage tests demonstrated that baclofen significantly impaired basic nosepoke learning, skilled nosepoke learning and chamber position learning of the epileptic rats, while CGP35348 boosted these functions. Immunofluorescence staining revealed that GB1 and GB2 were expressed in the insula of the epileptic rats, and Western blotting analysis showed that baclofen enhanced while CGP35348 inhibited the expression of these subunits. Conclusion GABABRs in the insula bidirectionally regulate both spatial and non-spatial operant associative memory of epileptic rats. Effects of GABABRs on cognition should be taken into account when evaluating new possible treatments for people with epilepsy.
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Affiliation(s)
- Nan Wu
- Department of Neurosurgery, Tianjin Children’s Hospital (Children’s Hospital of Tianjin University), Tianjin, China
| | - Tao Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Xin Wu
- Department of Neurosurgery, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China
| | - Hongguang Chen
- Department of Neurosurgery, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China
| | - Zhen Zhang
- Department of Neurosurgery, The Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, Shandong, China,*Correspondence: Zhen Zhang,
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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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Gernert M, Feja M. Bypassing the Blood-Brain Barrier: Direct Intracranial Drug Delivery in Epilepsies. Pharmaceutics 2020; 12:pharmaceutics12121134. [PMID: 33255396 PMCID: PMC7760299 DOI: 10.3390/pharmaceutics12121134] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/18/2020] [Accepted: 11/21/2020] [Indexed: 02/06/2023] Open
Abstract
Epilepsies are common chronic neurological diseases characterized by recurrent unprovoked seizures of central origin. The mainstay of treatment involves symptomatic suppression of seizures with systemically applied antiseizure drugs (ASDs). Systemic pharmacotherapies for epilepsies are facing two main challenges. First, adverse effects from (often life-long) systemic drug treatment are common, and second, about one-third of patients with epilepsy have seizures refractory to systemic pharmacotherapy. Especially the drug resistance in epilepsies remains an unmet clinical need despite the recent introduction of new ASDs. Apart from other hypotheses, epilepsy-induced alterations of the blood-brain barrier (BBB) are thought to prevent ASDs from entering the brain parenchyma in necessary amounts, thereby being involved in causing drug-resistant epilepsy. Although an invasive procedure, bypassing the BBB by targeted intracranial drug delivery is an attractive approach to circumvent BBB-associated drug resistance mechanisms and to lower the risk of systemic and neurologic adverse effects. Additionally, it offers the possibility of reaching higher local drug concentrations in appropriate target regions while minimizing them in other brain or peripheral areas, as well as using otherwise toxic drugs not suitable for systemic administration. In our review, we give an overview of experimental and clinical studies conducted on direct intracranial drug delivery in epilepsies. We also discuss challenges associated with intracranial pharmacotherapy for epilepsies.
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Affiliation(s)
- Manuela Gernert
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559 Hannover, Germany;
- Center for Systems Neuroscience, D-30559 Hannover, Germany
- Correspondence: ; Tel.: +49-(0)511-953-8527
| | - Malte Feja
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Bünteweg 17, D-30559 Hannover, Germany;
- Center for Systems Neuroscience, D-30559 Hannover, Germany
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Farokhnia M, Sheskier MB, Lee MR, Le AN, Singley E, Bouhlal S, Ton T, Zhao Z, Leggio L. Neuroendocrine response to GABA-B receptor agonism in alcohol-dependent individuals: Results from a combined outpatient and human laboratory experiment. Neuropharmacology 2018; 137:230-239. [PMID: 29665351 PMCID: PMC6050109 DOI: 10.1016/j.neuropharm.2018.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/05/2018] [Accepted: 04/10/2018] [Indexed: 12/13/2022]
Abstract
Gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the nervous system, plays an important role in biobehavioral processes that regulate alcohol seeking, food intake, and stress response. The metabotropic GABA-B receptor has been investigated as a potential therapeutic target for alcohol use disorder, by using orthosteric agonists (e.g., baclofen) and positive allosteric modulators. Whether and how pharmacological manipulation of the GABA-B receptor, in combination with alcohol intake, may affect feeding- and stress-related neuroendocrine pathways remains unknown. In the present randomized, double-blind, placebo-controlled study, thirty-four alcohol-dependent individuals received baclofen (30 mg/day) or placebo in a naturalistic outpatient setting for one week, and then performed a controlled laboratory experiment which included alcohol cue-reactivity, fixed-dose priming, and self-administration procedures. Blood samples were collected, and the following neuroendocrine markers were measured: ghrelin, leptin, amylin, glucagon-like peptide-1 (GLP-1), insulin, prolactin, thyroid-stimulating hormone, growth hormone, cortisol, and adrenocorticotropic hormone (ACTH). During the outpatient phase, baclofen significantly increased blood concentrations of acyl-ghrelin (p = 0.01), leptin (p = 0.01), amylin (p = 0.004), and GLP-1 (p = 0.02). Significant drug × time-point interaction effects for amylin (p = 0.001) and insulin (p = 0.03), and trend-level interaction effects for GLP-1 (p = 0.06) and ACTH (p = 0.10) were found during the laboratory experiment. Baclofen, compared to placebo, had no effect on alcohol drinking in this study (p's ≥ 0.05). Together with previous studies, these findings shed light on the role of the GABAergic system and GABA-B receptors in the shared neurobiology of alcohol-, feeding-, and stress-related behaviors.
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Affiliation(s)
- Mehdi Farokhnia
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Mikela B Sheskier
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Mary R Lee
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - April N Le
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Erick Singley
- Clinical Core Laboratory, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Sofia Bouhlal
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA
| | - Timmy Ton
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Zhen Zhao
- Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Lorenzo Leggio
- Section on Clinical Psychoneuroendocrinology and Neuropsychopharmacology, National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse, National Institutes of Health, Bethesda, MD, USA; Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University, Providence, RI, USA.
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Wu N, Wang F, Jin Z, Zhang Z, Wang LK, Zhang C, Sun T. Effects of GABA B receptors in the insula on recognition memory observed with intellicage. Behav Brain Funct 2017; 13:7. [PMID: 28416021 PMCID: PMC5392977 DOI: 10.1186/s12993-017-0125-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/05/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Insular function has gradually become a topic of intense study in cognitive research. Recognition memory is a commonly studied type of memory in memory research. GABABR has been shown to be closely related to memory formation. In the present study, we used intellicage, which is a new intelligent behavioural test system, and a bilateral drug microinjection technique to inject into the bilateral insula, to examine the relationship between GABABR and recognition memory. METHODS Male Sprague-Dawley rats were randomly divided into control, Sham, Nacl, baclofen and CGP35348 groups. Different testing procedures were employed using intellicage to detect changes in rat recognition memory. The expression of GABABR (GB1, GB2) in the insula of rats was determined by immunofluorescence and western blotting at the protein level. In addition, the expression of GABABR (GB1, GB2) was detected by RT-PCR at the mRNA level. RESULTS The results of the intellicage test showed that recognition memory was impaired in terms of position learning, punitive learning and punitive reversal learning by using baclofen and CGP35348. In position reversal learning, no significant differences were found in terms of cognitive memory ability between the control groups and the CGP and baclofen groups. Immunofluorescence data showed GABABR (GB1, GB2) expression in the insula, while data from RT-PCR and western blot analysis demonstrated that the relative expression of GB1 and GB2 was significantly increased in the baclofen group compared with the control groups. In the CGP35348 group, the expression of GB1 and GB2 was significantly decreased, but there was no significant difference in GB1 or GB2 expression in the control groups. CONCLUSIONS GABABR expression in the insula plays an important role in the formation of recognition memory in rats.
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Affiliation(s)
- Nan Wu
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
| | - Feng Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
| | - Zhe Jin
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Zhen Zhang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
| | - Lian-Kun Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
| | - Chun Zhang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
| | - Tao Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, Ningxia, China. .,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China.
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Ghamkhari Nejad G, Shahabi P, Alipoor MR, Ghaderi Pakdel F, Asghari M, Sadighi Alvandi M. Ethosuximide Affects Paired-Pulse Facilitation in Somatosensory Cortex of WAG\Rij Rats as a Model of Absence Seizure. Adv Pharm Bull 2016; 5:483-9. [PMID: 26819920 DOI: 10.15171/apb.2015.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/28/2015] [Accepted: 07/27/2015] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The interaction between somatosensory cortex and thalamus via a thalamocortical loop is a theory behind induction of absence epilepsy. Inside peri-oral somatosensory (S1po) and primary somatosensory forelimb (S1fl) regions, excitatory and inhibitory systems are not balanced and GABAergic inhibitory synapses seem to play a fundamental role in short-term plasticity alterations. METHODS We investigated the effects of Ethosuximide on presynaptic changes by utilizing paired-pulse stimulation that was recorded from somatosensory cortex in 18 WAG\Rij rats during epileptic activity. A twisted tripolar electrode including two stimulating electrodes and one recording electrode was implanted into the S1po and S1FL according to stereotaxic landmarks. Paired-pulses (200 µs, 100-1000 µA, 0.1 Hz) were applied to somatosensory cortex at 50, 100, 400, 500 ms inter-pulse intervals for 50 min period. RESULTS The results showed that paired-pulse facilitation was significantly reduced at all intervals in all times, but compared to the control group of epileptic WAG/Rij rats (p<0.05), it was exceptional about the first 10 minutes after the injection. At the intervals of 50 and 100 ms, a remarkable PPD was found in second, third, fourth and fifth 10-min post injection. CONCLUSION These experiments indicate that Ethosuximide has effects on presynaptic facilitation in somatosensory cortex inhibitory loops by alteration in GABA levels that leads to a markedly diminished PPF in paired-pulse stimulation.
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Affiliation(s)
| | - Parviz Shahabi
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohamad Reza Alipoor
- Neurosciences Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Firouz Ghaderi Pakdel
- Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Mohammad Asghari
- Road Traffic Injury Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mina Sadighi Alvandi
- Drug Applied Research Center, Tabriz University of Medical Sciences,Tabriz, Iran
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Omrani H, Alipour MR, Mohaddes G. Ghrelin Improves Antioxidant Defense in Blood and Brain in Normobaric Hypoxia in Adult Male Rats. Adv Pharm Bull 2015; 5:283-8. [PMID: 26236669 DOI: 10.15171/apb.2015.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 09/30/2014] [Accepted: 10/18/2014] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Hypoxia is one of the important factors in formation of reactive oxygen species (ROS). Ghrelin is a peptide hormone that reduces oxidative stress. However, antioxidant effect of ghrelin on blood and brain in normobaric hypoxia condition has not yet been investigated. METHODS thirty-two animals were randomly divided into four (n=8) experimental groups: Control (C), ghrelin (Gh), hypoxia (H), hypoxic animals that received ghrelin (H+Gh). Normobaric systemic hypoxia (11% O2) was induced in rats for 48 hours. Effect of ghrelin (80 μg/kg, i.p) on serum TAC and MDA and brain SOD, CAT, GPx and MDA were assessed. RESULTS Hypoxia significantly (p<0.001) increased both blood and brain MDA Levels. Ghrelin treatment significantly (p<0.001) decreased blood MDA levels both in control and hypoxia, and brain MDA levels in hypoxia conditions. Brain SOD, CAT and GPx variations were not significant in two days of hypoxia. Ghrelin treatment also could not significantly increase activity of SOD, CAT and GPx in brain. Total antioxidant capacity of serum increased in ghrelin treatment both in control and hypoxic conditions, although it was only significant (p<0.01) in control conditions. CONCLUSION Our findings showed that administration of ghrelin may be useful in reducing blood and brain oxidative stress in normobaric hypoxia condition.
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Affiliation(s)
- Hasan Omrani
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Alipour
- Tuberculosis and Lung Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Gisou Mohaddes
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Wang D, Ren M, Guo J, Yang G, Long X, Hu R, Shen W, Wang X, Zeng K. The inhibitory effects of Npas4 on seizures in pilocarpine-induced epileptic rats. PLoS One 2014; 9:e115801. [PMID: 25536221 PMCID: PMC4275263 DOI: 10.1371/journal.pone.0115801] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 11/26/2014] [Indexed: 01/22/2023] Open
Abstract
To explore the effects of neuronal Per-Arnt-Sim domain protein 4 (Npas4) on seizures in pilocarpine-induced epileptic rats, Npas4 expression was detected by double-label immunofluorescence, immunohistochemistry, and Western blotting in the brains of pilocarpine-induced epileptic model rats at 6 h, 24 h, 72 h, 7 d, 14 d, 30 d, and 60 d after status epilepticus. Npas4 was localized primarily in the nucleus and in the cytoplasm of neurons. The Npas4 protein levels increased in the acute phase of seizures (between 6 h and 72 h) and decreased in the chronic phases (between 7 d and 60 d) in the rat model. Npas4 expression was knocked down by specific siRNA interference. Then, the animals were treated with pilocarpine, and the effects on seizures were evaluated on the 7th day. The onset latencies of pilocarpine-induced seizures were decreased, while the seizure frequency, duration and attack rate increased in these rats. Our study indicates that Npas4 inhibits seizure attacks in pilocarpine-induced epileptic rats.
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Affiliation(s)
- Dan Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Min Ren
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Jiamei Guo
- Department of Psychiatry, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guang Yang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xianghua Long
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Rong Hu
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Wenjing Shen
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xuefeng Wang
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Kebin Zeng
- Department of Neurology, the First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
- * E-mail:
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