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Brown T, McElroy T, Simmons P, Walters H, Ntagwabira F, Wang J, Byrum SD, Allen AR. Cognitive impairment resulting from treatment with docetaxel, doxorubicin, and cyclophosphamide. Brain Res 2021; 1760:147397. [PMID: 33705788 DOI: 10.1016/j.brainres.2021.147397] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 01/08/2023]
Abstract
Breast cancer is the most commonly diagnosed cancer among women and it is estimated that about 30% of newly diagnosed cancers in women will be breast cancers. While advancements in treating breast cancer have led to an average 5-year survival rate of 90%, many survivors experience cognitive impairments as a result of chemotherapy treatment. Doxorubicin, cyclophosphamide, and docetaxel (TAC) are commonly administered as breast cancer treatments; however, there are few studies that have tested the cognitive effects of TAC. In the current study, 12-week-old female C57BL/6 mice received 4 weekly intraperitoneal injections of either saline or a combination therapy of doxorubicin and cyclophosphamide followed by 4 weekly docetaxel injections. Four weeks after the last injection, mice were tested for hippocampus-dependent cognitive performance in the Y-maze and the Morris water maze. During Y-maze testing, mice exposed to TAC exhibited impairment. During the water maze assessment, all animals were able to locate the visible and hidden platform locations. However, mice that received the TAC presented with a significant impairment in spatial memory retention on the probe trial days. TAC treatment significantly decreases the dendritic complexity of arborization in the dentate gyrus region of the hippocampus. In addition, comparative proteomic analysis revealed downregulation of proteins within key metabolic and signaling pathways associated with cognitive dysfunction, such as oxidative phosphorylation, ephrin signaling, and calcium signaling.
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Affiliation(s)
- Taurean Brown
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Taylor McElroy
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Pilar Simmons
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Huddoy Walters
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Fabio Ntagwabira
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Jing Wang
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Arkansas Children's Research Institute, Little Rock, AR 72202, United States
| | - Antiño R Allen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States; Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States.
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Tan W, Zhang Q, Dong Z, Yan Y, Fu Y, Liu X, Zhao B, Duan X. Phosphatidylcholine Ameliorates LPS-Induced Systemic Inflammation and Cognitive Impairments via Mediating the Gut-Brain Axis Balance. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:14884-14895. [PMID: 33289390 DOI: 10.1021/acs.jafc.0c06383] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Systemic inflammation will cause an imbalance in the steady state of the gut-brain axis. Phosphatidylcholine (PC) is a phospholipid found in egg yolk that has anti-inflammatory and antioxidant properties. The present research proved that PC supplementation (60 mg/kg body weight) for 35 days prevented inflammatory responses and behavioral disturbances in lipopolysaccharide (LPS)-induced mice. PC could regulate the expression of neurotrophic factors and synaptic proteins, which effectively alleviated the nerve damage and synaptic dysfunction caused by LPS. In addition, PC supplementation ameliorated gut barrier damage, altered gut genes, and improved gut health by modulating the cell adhesion molecule (CAM) pathway. Furthermore, PC remodeled the gut microbiome structure in the mice of the LPS group by increasing the relative abundance of Rikenellaceae and Lachnospiraceae. PC also increased short-chain fatty acid (SCFA) production in LPS-induced mice, which in turn ameliorated brain inflammatory responses. In conclusion, PC supplementation may be a nutritional strategy for the prevention of systemic inflammation via the gut-brain axis.
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Affiliation(s)
- Wen Tan
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Qinjun Zhang
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Zhijian Dong
- Xi'an Gaoxin Hospital, Xi'an 710000, Shaanxi, China
| | - Yubin Yan
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Yukun Fu
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Xuebo Liu
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Beita Zhao
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
| | - Xiang Duan
- College of Food Science and Engineering, Northwest A&F University, 22 Xi-nong Road, Yangling 712100, China
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Zhao Z, Ren Y, Jiang H, Huang Y. Dexmedetomidine inhibits the PSD95-NMDA receptor interaction to promote functional recovery following traumatic brain injury. Exp Ther Med 2020; 21:4. [PMID: 33235613 PMCID: PMC7678629 DOI: 10.3892/etm.2020.9436] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 10/10/2019] [Indexed: 01/02/2023] Open
Abstract
The present study examined the effects of dexmedetomidine (Dex) on cognitive and motor recovery in mice following traumatic brain injury (TBI). TBI induces synaptic damage, which leads to motor dysfunction and cognitive decline. Although Dex is known to induce neuroprotection, its role following TBI remains unknown. In the present study, male C57BL/6 mice (8 weeks old; n=72) were subjected to cortical impact injury to generate a TBI mice model. Mice were divided into four groups: TBI, sham, TBI + vehicle, and TBI + Dex. Mice in the TBI + vehicle and TBI + Dex groups received intraperitoneal injections of saline (n=18) and 100 µg/kg Dex (n=18), respectively, at 1 and 12 h following surgery. At 24 h post-injury, 10 animals from each group were sacrificed, and brain tissue was isolated for Fluoro-Jade B staining and RNA and protein extraction. At 72 h post-TBI, motor function was evaluated. Furthermore, cognitive impairment was assessed between day 14 and 19 using the Morris water maze. The results demonstrated that the mRNA and protein expression of post-synaptic density 95 (PSD95) was reduced post-TBI. In addition, neuronal degeneration was evaluated using FJB staining, where PSD95 formed a complex with the N-methyl-D-aspartic acid (NMDA) receptor subunit (NR2B) and neuronal nitric oxide synthase (nNOS) inducing neuronal death post-TBI. Treatment with Dex efficiently decreased the PSD95-NR2B-nNOS interaction, which reduced the TBI-induced neuronal death. Furthermore, Dex treatment contributed to the enhanced cognitive and motor recovery following TBI. The results from the present study reported a potential mechanistic action of Dex treatment post-TBI, which may be associated with the inhibition of PSD95-NMDA interaction.
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Affiliation(s)
- Zhongbai Zhao
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, P.R. China
| | - Yu Ren
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai 200032, P.R. China
| | - Hong Jiang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, P.R. China
| | - Yan Huang
- Department of Anesthesiology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200011, P.R. China
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So LY, Miller JE. Social context-dependent singing alters molecular markers of synaptic plasticity signaling in finch basal ganglia Area X. Behav Brain Res 2020; 398:112955. [PMID: 33031871 DOI: 10.1016/j.bbr.2020.112955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/14/2020] [Accepted: 09/30/2020] [Indexed: 12/23/2022]
Abstract
Vocal communication is a crucial skill required throughout life. However, there is a critical gap in our understanding of the underlying molecular brain mechanisms, thereby motivating our use of the zebra finch songbird model. Adult male zebra finches show differences in neural activity patterns in song-dedicated brain nuclei when they sing in two distinct social contexts: a male singing by himself (undirected, UD) and a male singing to a female (female-directed, FD). In our prior work, we showed that in song-dedicated basal ganglia Area X, protein levels of a N-methyl-D-aspartate receptor subtype 2B (NMDAR2B) increased with more UD song and decreased with more FD song. We hypothesized that molecules downstream of this receptor would show differential protein expression levels in Area X between UD and FD song. Specifically, we investigated calcium/calmodulin dependent protein kinase II beta (CaMKIIB), homer scaffold protein 1 (HOMER1), serine/threonine protein kinase (Akt), and mechanistic target of rapamycin kinase (mTOR) following singing and non-singing states in Area X. We show relationships between social context and protein levels. HOMER1 protein levels decreased with time spent singing FD song, and mTOR protein levels decreased with the amount of and time spent singing FD song. For both HOMER1 and mTOR, there were no differences with the amount of UD song. With time spent singing UD, CaMKIIB protein levels trended in a U-shaped curve whereas Akt protein levels trended down. Both molecules showed no change with FD song. Our results support differential involvement of molecules in synaptic plasticity pathways between UD and FD song behaviors.
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Affiliation(s)
- Lisa Y So
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States
| | - Julie E Miller
- Graduate Interdisciplinary Program in Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Neuroscience, University of Arizona, Gould-Simpson Building, Tucson, AZ, 85721, United States; Department of Speech, Language, and Hearing Sciences, University of Arizona, Speech, Language, and Hearing Sciences Building, Tucson, AZ, 85721, United States.
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Bawari S, Tewari D, Argüelles S, Sah AN, Nabavi SF, Xu S, Vacca RA, Nabavi SM, Shirooie S. Targeting BDNF signaling by natural products: Novel synaptic repair therapeutics for neurodegeneration and behavior disorders. Pharmacol Res 2019; 148:104458. [DOI: 10.1016/j.phrs.2019.104458] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/13/2019] [Accepted: 09/15/2019] [Indexed: 12/12/2022]
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Dong Q, Teng SW, Wang Y, Qin F, Li Y, Ai LL, Yu H. Sitagliptin protects the cognition function of the Alzheimer's disease mice through activating glucagon-like peptide-1 and BDNF-TrkB signalings. Neurosci Lett 2018; 696:184-190. [PMID: 30597232 DOI: 10.1016/j.neulet.2018.12.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 12/13/2018] [Accepted: 12/27/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Sitagliptin is an anti-diabetic drug and its effects on Alzheimer's disease (AD) remain controversial. This study aimed to investigate the protective effect of sitagliptin on the cognition in AD and its underlying molecular mechanism. METHODS The APP/PS1 (a model of AD) mice received daily gastric gavage administration of sitagliptin (20 mg/kg) for 8 weeks. Then animals were subjected to behavioral experiment or sacrificed to histological staining and protein level analysis. RESULTS The MWM test showed that sitagliptin treatment significantly reduced the escape latency times in APP/PS1 mice in the learning phase (day 3-5) and elongated the time spent in the target quadrant in the probe test. Sitagliptin significantly reduced amyloid plaque deposition and elevated the spine density and the protein levels of synaptoneurosome GluA1- and GluA2-containing AMPA receptor (GluA1R and GluA2R) in the brain of the APP/PS1 mice. Sitagliptin treatment significantly up-regulated the brain BNDF protein and phosphorylation of tyrosine receptor kinase B (TrkB). Furthermore, exendin-(9-39) (a glucagon-like peptide-1 [GLP-1] receptor antagonist) and K252a (a Trk tyrosine kinase inhibitor) treatment significantly abolished the cognitive protective effect of sitagliptin in the MWM test. CONCLUSION Sitagliptin treatment effectively protected the cognition function of the AD mice by regulating synaptic plasticity, at least partially, through activating GLP-1 and BDNF-TrkB signalings.
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Affiliation(s)
- Qing Dong
- Department of Neurology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, People's Republic of China.
| | - Shuai-Wen Teng
- Shandong Provincial Key Laboratory of Mental Disorders, Department of Cell and Neurobiology, School of Basic Medicine, Shandong University, Jinan, Shandong, 250012, People's Republic of China
| | - Yue Wang
- Shandong Provincial Key Laboratory of Mental Disorders, Department of Cell and Neurobiology, School of Basic Medicine, Shandong University, Jinan, Shandong, 250012, People's Republic of China
| | - Feng Qin
- Department of Neurosurgery, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Yue Li
- Department of Traditional Chinese Medicine, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Lu-Lu Ai
- Department of Neurology, the Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, 510630, People's Republic of China
| | - Hui Yu
- Shandong Provincial Key Laboratory of Mental Disorders, Department of Cell and Neurobiology, School of Basic Medicine, Shandong University, Jinan, Shandong, 250012, People's Republic of China.
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Zhang Y, Chopp M, Rex CS, Simmon VF, Sarraf ST, Zhang ZG, Mahmood A, Xiong Y. A Small Molecule Spinogenic Compound Enhances Functional Outcome and Dendritic Spine Plasticity in a Rat Model of Traumatic Brain Injury. J Neurotrauma 2018; 36:589-600. [PMID: 30014757 DOI: 10.1089/neu.2018.5790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The tetra (ethylene glycol) derivative of benzothiazole aniline (SPG101) has been shown to improve dendritic spine density and cognitive memory in the triple transgenic mouse model of Alzheimer disease (AD) when administered intraperitoneally. The present study was designed to investigate the therapeutic effects of SPG101 on dendritic spine density and morphology and sensorimotor and cognitive functional recovery in a rat model of traumatic brain injury (TBI) induced by controlled cortical impact (CCI). Young adult male Wistar rats with CCI were randomly divided into the following two groups (n = 7/group): (1) Vehicle, and (2) SPG101. SPG101 (30 mg/kg) dissolved in vehicle (1% dimethyl sulfoxide in phosphate buffered saline) or Vehicle were intraperitoneally administered starting at 1 h post-injury and once daily for the next 34 days. Sensorimotor deficits were assessed using a modified neurological severity score and adhesive removal and foot fault tests. Cognitive function was measured by Morris water maze, novel object recognition (NOR), and three-chamber social recognition tests. The animals were sacrificed 35 days after injury, and their brains were processed for measurement of dendritic spine density and morphology using ballistic dye labeling. Compared with the vehicle treatment, SPG101 treatment initiated 1 h post-injury significantly improved sensorimotor functional recovery (days 7-35, p < 0.0001), spatial learning (days 32-35, p < 0.0001), NOR (days 14 and 35, p < 0.0001), social recognition (days 14 and 35, p < 0.0001). Further, treatment significantly increased dendritic spine density in the injured cortex (p < 0.05), decreased heterogeneous distribution of spine lengths in the injured cortex and hippocampus (p < 0.0001), modifications that are associated with the promotion of spine maturation in these brain regions. In summary, treatment with SPG101 initiated 1 h post-injury and continued for an additional 34 days improves both sensorimotor and cognitive functional recovery, indicating that SPG101 acts as a spinogenic agent and may have potential as a novel treatment of TBI.
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Affiliation(s)
- Yanlu Zhang
- 1 Department of Neurosurgery, Henry Ford Hospital , Detroit, Michigan
| | - Michael Chopp
- 2 Department of Neurology, Henry Ford Hospital , Detroit, Michigan.,3 Department of Physics, Oakland University , Rochester, Michigan
| | | | | | | | - Zheng Gang Zhang
- 2 Department of Neurology, Henry Ford Hospital , Detroit, Michigan
| | - Asim Mahmood
- 1 Department of Neurosurgery, Henry Ford Hospital , Detroit, Michigan
| | - Ye Xiong
- 1 Department of Neurosurgery, Henry Ford Hospital , Detroit, Michigan
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Aberrant protein phosphorylation in Alzheimer disease brain disturbs pro-survival and cell death pathways. Biochim Biophys Acta Mol Basis Dis 2016; 1862:1871-82. [PMID: 27425034 DOI: 10.1016/j.bbadis.2016.07.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/22/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022]
Abstract
Protein phosphorylation of serine, threonine, and tyrosine residues is one of the most prevalent post-translational modifications fundamental in mediating diverse cellular functions in living cells. Aberrant protein phosphorylation is currently recognized as a critical step in the pathogenesis and progression of Alzheimer disease (AD). Changes in the pattern of protein phosphorylation of different brain regions are suggested to promote AD transition from a presymptomatic to a symptomatic state in response to accumulating amyloid β-peptide (Aβ). Several experimental approaches have been utilized to profile alteration of protein phosphorylation in the brain, including proteomics. Among central pathways regulated by kinases/phosphatases those involved in the activation/inhibition of both pro survival and cell death pathways play a central role in AD pathology. We discuss in detail how aberrant phosphorylation could contribute to dysregulate p53 activity and insulin-mediated signaling. Taken together these results highlight that targeted therapeutic intervention, which can restore phosphorylation homeostasis, either acting on kinases and phosphatases, conceivably may prove to be beneficial to prevent or slow the development and progression of AD.
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van der Zee EA. Synapses, spines and kinases in mammalian learning and memory, and the impact of aging. Neurosci Biobehav Rev 2014; 50:77-85. [PMID: 24998408 DOI: 10.1016/j.neubiorev.2014.06.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/21/2014] [Accepted: 06/24/2014] [Indexed: 02/04/2023]
Abstract
Synapses are the building blocks of neuronal networks. Spines, the postsynaptic elements, are morphologically the most plastic part of the synapse. It is thought that spine plasticity underlies learning and memory processes, driven by kinases and cytoskeleton protein reorganization. Spine strength depends primarily on the number of incorporated glutamatergic receptors, which are more numerous in larger spines. Intrinsic and circadian fluctuations, occurring independently of presynaptic stimulation, demonstrate the native instability of spines. Despite innate spine instability some spines remain intact lifelong. Threats to spine survival are reduced by physical and mental activity, and declining sensory input, conditions characteristic for aging. Large spines are considered less vulnerable than thin spines, and in the older brain large spines are more abundant, whereas the thin spines are functionally weaker. It can be speculated that this shift towards memory spines contributes to enhanced retention of remote memories typically seen in the elderly. Gaining further insight in spine plasticity regulation, its homeostatic nature and how to maintain spine health will be important future research topics in Neuroscience.
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Affiliation(s)
- Eddy A van der Zee
- Department of Molecular Neurobiology, Centre for Behaviour and Neurosciences, University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
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Caruso V, Lagerström MC, Olszewski PK, Fredriksson R, Schiöth HB. Synaptic changes induced by melanocortin signalling. Nat Rev Neurosci 2014; 15:98-110. [PMID: 24588018 DOI: 10.1038/nrn3657] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The melanocortin system has a well-established role in the regulation of energy homeostasis, but there is growing evidence of its involvement in memory, nociception, mood disorders and addiction. In this Review, we focus on the role of the melanocortin 4 receptor and provide an integrative view of the molecular mechanisms that lead to melanocortin-induced changes in synaptic plasticity within these diverse physiological systems. We also highlight the importance of melanocortin peptides and receptors in chronic pain syndromes, memory impairments, depression and drug abuse, and the possibility of targeting them for therapeutic purposes.
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Ampuero E, Stehberg J, Gonzalez D, Besser N, Ferrero M, Diaz-Veliz G, Wyneken U, Rubio FJ. Repetitive fluoxetine treatment affects long-term memories but not learning. Behav Brain Res 2013; 247:92-100. [DOI: 10.1016/j.bbr.2013.03.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 02/28/2013] [Accepted: 03/04/2013] [Indexed: 10/27/2022]
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Melanocortin-4 receptor regulates hippocampal synaptic plasticity through a protein kinase A-dependent mechanism. J Neurosci 2013; 33:464-72. [PMID: 23303927 DOI: 10.1523/jneurosci.3282-12.2013] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Learning and memory require orchestrated regulation of both structural and functional synaptic plasticity in the hippocampus. While a neuropeptide alpha-melanocyte-stimulating hormone, α-MSH, has been implicated in memory acquisition and retention, the functional role of its cognate receptor, melanocortin-4 receptor (MC4R), in hippocampal-dependent synaptic plasticity has not been explored. In this study, we report that activation of MC4R enhances synaptic plasticity through the regulation of dendritic spine morphology and abundance of AMPA receptors. We show that activation of postsynaptic MC4R increases the number of mature dendritic spines and enhances surface expression of AMPA receptor subunit GluA1, resulting in synaptic accumulation of GluA1-containing AMPA receptors. Moreover, MC4R stimulates surface GluA1 trafficking through phosphorylation of GluA1 at Ser845 in a Gα(s)-cAMP/PKA-dependent manner. Blockade of protein kinase A (PKA) signaling abolishes the MC4R-mediated enhancement of neurotransmission and hippocampal long-term potentiation. Importantly, in vivo application of MC4R agonists increases LTP in the mouse hippocampal CA1 region. These findings reveal that MC4R in the hippocampus plays a critical role in the regulation of structural and functional plasticity.
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