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Barioni NO, Beduschi RS, da Silva AV, Martins MG, Almeida-Francia CCD, Rodrigues SA, López DE, Gómez-Nieto R, Horta-Júnior JAC. The role of the Ventral Nucleus of the Trapezoid Body in the auditory prepulse inhibition of the acoustic startle reflex. Hear Res 2024; 450:109070. [PMID: 38972084 DOI: 10.1016/j.heares.2024.109070] [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: 02/29/2024] [Revised: 05/28/2024] [Accepted: 06/13/2024] [Indexed: 07/09/2024]
Abstract
Cholinergic signaling is essential to mediate the auditory prepulse inhibition (PPI), an operational measure of sensorimotor gating, that refers to the reduction of the acoustic startle reflex (ASR) when a low-intensity, non-startling acoustic stimulus (the prepulse) is presented just before the onset of the acoustic startle stimulus. The cochlear root neurons (CRNs) are the first cells of the ASR circuit to receive cholinergic inputs from non-olivocochlear neurons of the ventral nucleus of the trapezoid body (VNTB) and subsequently decrease their neuronal activity in response to auditory prepulses. Yet, the contribution of the VNTB-CRNs pathway to the mediation of PPI has not been fully elucidated. In this study, we used the immunotoxin anti-choline acetyltransferase (ChAT)-saporin as well as electrolytic lesions of the medial olivocochlear bundle to selectively eliminate cholinergic VNTB neurons, and then assessed the ASR and PPI paradigms. Retrograde track-tracing experiments were conducted to precisely determine the site of lesioning VNTB neurons projecting to the CRNs. Additionally, the effects of VNTB lesions and the integrity of the auditory pathway were evaluated via auditory brain responses tests, ChAT- and FOS-immunohistochemistry. Consequently, we established three experimental groups: 1) intact control rats (non-lesioned), 2) rats with bilateral lesions of the olivocochlear bundle (OCB-lesioned), and 3) rats with bilateral immunolesions affecting both the olivocochlear bundle and the VNTB (OCB/VNTB-lesioned). All experimental groups underwent ASR and PPI tests at several interstimulus intervals before the lesion and 7, 14, and 21 days after it. Our results show that the ASR amplitude remained unaffected both before and after the lesion across all experimental groups, suggesting that the VNTB does not contribute to the ASR. The%PPI increased across the time points of evaluation in the control and OCB-lesioned groups but not in the OCB/VNTB-lesioned group. At the ISI of 50 ms, the OCB-lesioned group exhibited a significant increase in%PPI (p < 0.01), which did not occur in the OCB/VNTB-lesioned group. Therefore, the ablation of cholinergic non-olivocochlear neurons in the OCB/VNTB-lesioned group suggests that these neurons contribute to the mediation of auditory PPI at the 50 ms ISI through their cholinergic projections to CRNs. Our study strongly reinforces the notion that auditory PPI encompasses a complex mechanism of top-down cholinergic modulation, effectively attenuating the ASR across different interstimulus intervals within multiple pathways.
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Affiliation(s)
- N O Barioni
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - R S Beduschi
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - A V da Silva
- Medicine School, Federal University of Mato Grosso do Sul, UFMS-CPTL, Três Lagoas, Mato Grosso do Sul, Brazil
| | - M G Martins
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - C C D Almeida-Francia
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - S A Rodrigues
- Department of Bioprocesses and Biotechnology - Faculty of Agricultural Sciences, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil
| | - D E López
- Neuroscience Institute of Castilla y León (INCyL), Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain; Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
| | - R Gómez-Nieto
- Neuroscience Institute of Castilla y León (INCyL), Salamanca, Spain; Institute of Biomedical Research of Salamanca (IBSAL), University of Salamanca, Salamanca, Spain; Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain.
| | - J A C Horta-Júnior
- Department of Functional and Structural Biology - Anatomy Division, Institute of Biosciences of Botucatu, São Paulo State University-UNESP, Botucatu, São Paulo, Brazil.
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The distribution pattern of M2 and Adrenergic α2 receptors on inferior colliculi in male newborns of diabetic rats. Neurosci Lett 2022; 787:136820. [PMID: 35917839 DOI: 10.1016/j.neulet.2022.136820] [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: 06/13/2022] [Revised: 07/17/2022] [Accepted: 07/25/2022] [Indexed: 11/22/2022]
Abstract
AIMS Despite the high prevalence of diabetes in the world, its possible effects throughut pregnancy on neonatal auditory nervous system development are still unknown. In the present research, maternal diabetes' impact on the M2 and Adrenergicα2 receptors expression in the inferior colliculus (IC) of male newborn rats was investigated. Main methods Female rats were grouped into three: sham, insulin-treated diabetic, and diabetic. Diabetes was induced through streptozotocin (STZ) injection as one dose intraperitoneally (65 mg/kg). After mating and delivery, male rats were euthanized on P0, P7, and P14. Immunohistochemistry (IHC) was used to study the distribution pattern of receptors. Key findings The present study indicated that the expression of M2 receptors in the diabetic group was significantly increased in pairwise comparisons in the sham and diabetic treated with insulin groups (P<0.001, each). The highest M2 expression was for the diabetic group on P14 and the lowest one was for the sham group on P0. The Adrenergicα2a receptors expression in the diabetic group was significantly reduced in pairwise comparisons in the sham and diabetic treated with insulin groups (P <0.001, each). The highest Adrenergicα2a expression was for the sham group on P14 and the lowest one was for the diabetic group on P0. There was no significant difference between the sham and insulin groups regarding all receptors expression. SIGNIFICANCE This study demonstrated a time-dependent significant decrease in Adrenergicα2a but a time-dependent significant increase in M2 receptors expression.
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Butyrylcholinesterase is a potential biomarker for Sudden Infant Death Syndrome. EBioMedicine 2022; 80:104041. [PMID: 35533499 PMCID: PMC9092508 DOI: 10.1016/j.ebiom.2022.104041] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 11/30/2022] Open
Abstract
Background Autonomic dysfunction has been implicated in the pathophysiology of the Sudden Infant Death Syndrome (SIDS). Butyrylcholinesterase (BChE) is an enzyme of the cholinergic system, a major branch of the autonomic system, and may provide a measure of autonomic (dys)function. This study was undertaken to evaluate BChE activity in infants and young children who had died from Sudden Infant Death or Sudden Unexpected Death. Methods In this case-control study we measured BChE activity and total protein in the eluate of 5μL spots punched from the dried blood spots taken at birth as part of the newborn screening program. Results for each of 67 sudden unexpected deaths classified by the coroner (aged 1 week-104 weeks) = Cases, were compared to 10 date of birth - and gender-matched surviving controls (Controls), with five cases reclassified to meet criteria for SIDS, including the criterion of age 3 weeks to 1 year. Findings Conditional logistic regression showed that in groups where cases were reported as “SIDS death” there was strong evidence that lower BChE specific activity (BChEsa) was associated with death (OR=0·73 per U/mg, 95% CI 0·60-0·89, P=0·0014), whereas in groups with a “Non-SIDS death” as the case there was no evidence of a linear association between BChEsa and death (OR=1·001 per U/mg, 95% CI 0·89-1·13, P=0·99). Interpretation BChEsa, measured in dried blood spots taken 2-3 days after birth, was lower in babies who subsequently died of SIDS compared to surviving controls and other Non-SIDS deaths. We conclude that a previously unidentified cholinergic deficit, identifiable by abnormal -BChEsa, is present at birth in SIDS babies and represents a measurable, specific vulnerability prior to their death. Funding All funding provided by a crowd funding campaign https://www.mycause.com.au/p/184401/damiens-legacy
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Ye H, Liu ZX, He YJ, Wang X. Effects of M currents on the persistent activity of pyramidal neurons in mouse primary auditory cortex. J Neurophysiol 2022; 127:1269-1278. [PMID: 35294269 DOI: 10.1152/jn.00332.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neuronal persistent activity (PA) is a common phenomenon observed in many types of neurons. PA can be induced in neurons in the mouse auditory nucleus by activating cholinergic receptors with carbachol (CCh), a dual muscarinic and nicotinic receptor agonist. PA is presumed to be associated with learning-related auditory plasticity at the cellular level. However, the mechanism is not clearly understood. Many studies have reported that muscarinic cholinergic receptor agonists inhibit muscarinic-sensitive potassium channels (M channels). Potassium influx through M channels produces potassium currents, called M currents, which play an essential role in regulating neural excitability and synaptic plasticity. Further study is needed to determine whether M currents affect the PA of auditory central neurons and provide additional analysis of the variations in electrophysiological properties. We used in vitro whole-cell patch-clamp recordings in isolated mouse brain slices to investigate the effects of M currents on the PA in pyramidal neurons in layer V of the primary auditory cortex (AI-L5). We found that blocking M currents with XE991 depolarized the AI-L5 pyramidal neurons, which significantly increased the input resistance. The active threshold and threshold intensity were significantly reduced, indicating that the intrinsic excitability was enhanced. Our results also showed that blocking M currents with XE991 switched the neuronal firing patterns in the AI-L5 pyramidal neurons from regular-spiking to intrinsic-bursting. Blocking M currents facilitated PA by increasing the plateau potential and enhancing intrinsic excitability. Our results suggested that blocking M currents might facilitate the PA in AI-L5 pyramidal neurons, which underlies auditory plasticity.
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Affiliation(s)
- Huan Ye
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Zhen-Xu Liu
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Ya-Jie He
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Xin Wang
- Hubei Key Lab of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
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Mori C, Aoki N, Fujita T, Yamaguchi S, Matsushima T, Homma KJ. Gene expression profiles of the muscarinic acetylcholine receptors in brain regions relating to filial imprinting of newly-hatched domestic chicks. Behav Brain Res 2021; 420:113708. [PMID: 34902480 DOI: 10.1016/j.bbr.2021.113708] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/24/2021] [Accepted: 12/05/2021] [Indexed: 12/01/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs) in the central nervous system play an important role in regulating complex functions such as learning, memory, and selective attention. Five subtypes of the mAChRs (M1-M5) have been identified in mammals, and are classified into two subfamilies: excitatory (M1, M3, and M5) and inhibitory (M2 and M4) subfamilies. Filial imprinting of domestic chicks is a useful model in the laboratory to investigate the mechanisms of memory formation in early learning. We recently found that mAChRs in the intermediate medial mesopallium (IMM) are involved in the memory formation of imprinting. However, expression profiles of each mAChR subtype in the brain regions including the IMM remain unexplored. Here we show the unique gene expression of each mAChR subtype in the pallial regions involved in imprinting. In terms of the excitatory mAChRs, M5 was expressed in the IMM region and other parts of the pallium, whereas M3 was less expressed in the IMM but highly expressed in the hyperpallium and nidopallium. Regarding the inhibitory mAChRs, M2 was sparsely distributed but clearly in some cells throughout the pallial regions. M4 was highly expressed in the IMM region and other parts of the pallium. These expression profiles can be used as a basis for understanding cholinergic modulation in the memory formation of imprinting and other learning processes in birds, and compared to those of mammals.
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Affiliation(s)
- Chihiro Mori
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Naoya Aoki
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Toshiyuki Fujita
- Department of Biological Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Shinji Yamaguchi
- Department of Biological Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
| | - Toshiya Matsushima
- Department of Biology, Faculty of Science, Hokkaido University, Hokkaido 060-0810, Japan
| | - Koichi J Homma
- Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi-ku, Tokyo 173-8605, Japan
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Neurotoxic Effects of Neonicotinoids on Mammals: What Is There beyond the Activation of Nicotinic Acetylcholine Receptors?-A Systematic Review. Int J Mol Sci 2021; 22:ijms22168413. [PMID: 34445117 PMCID: PMC8395098 DOI: 10.3390/ijms22168413] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 02/07/2023] Open
Abstract
Neonicotinoids are a class of insecticides that exert their effect through a specific action on neuronal nicotinic acetylcholine receptors (nAChRs). The success of these insecticides is due to this mechanism of action, since they act as potent agonists of insect nAChRs, presenting low affinity for vertebrate nAChRs, which reduces potential toxic risk and increases safety for non-target species. However, although neonicotinoids are considered safe, their presence in the environment could increase the risk of exposure and toxicity. On the other hand, although neonicotinoids have low affinity for mammalian nAChRs, the large quantity, variety, and ubiquity of these receptors, combined with its diversity of functions, raises the question of what effects these insecticides can produce in non-target species. In the present systematic review, we investigate the available evidence on the biochemical and behavioral effects of neonicotinoids on the mammalian nervous system. In general, exposure to neonicotinoids at an early age alters the correct neuronal development, with decreases in neurogenesis and alterations in migration, and induces neuroinflammation. In adulthood, neonicotinoids induce neurobehavioral toxicity, these effects being associated with their modulating action on nAChRs, with consequent neurochemical alterations. These alterations include decreased expression of nAChRs, modifications in acetylcholinesterase activity, and significant changes in the function of the nigrostriatal dopaminergic system. All these effects can lead to the activation of a series of intracellular signaling pathways that generate oxidative stress, neuroinflammation and, finally, neuronal death. Neonicotinoid-induced changes in nAChR function could be responsible for most of the effects observed in the different studies.
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Sherman SP, Bang AG. High-throughput screen for compounds that modulate neurite growth of human induced pluripotent stem cell-derived neurons. Dis Model Mech 2018; 11:dmm.031906. [PMID: 29361516 PMCID: PMC5894944 DOI: 10.1242/dmm.031906] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/29/2017] [Indexed: 01/01/2023] Open
Abstract
Development of technology platforms to perform compound screens of human induced pluripotent stem cell (hiPSC)-derived neurons with relatively high throughput is essential to realize their potential for drug discovery. Here, we demonstrate the feasibility of high-throughput screening of hiPSC-derived neurons using a high-content, image-based approach focused on neurite growth, a process that is fundamental to formation of neural networks and nerve regeneration. From a collection of 4421 bioactive small molecules, we identified 108 hit compounds, including 37 approved drugs, that target molecules or pathways known to regulate neurite growth, as well as those not previously associated with this process. These data provide evidence that many pathways and targets known to play roles in neurite growth have similar activities in hiPSC-derived neurons that can be identified in an unbiased phenotypic screen. The data also suggest that hiPSC-derived neurons provide a useful system to study the mechanisms of action and off-target activities of the approved drugs identified as hits, leading to a better understanding of their clinical efficacy and toxicity, especially in the context of specific human genetic backgrounds. Finally, the hit set we report constitutes a sublibrary of approved drugs and tool compounds that modulate neurites. This sublibrary will be invaluable for phenotypic analyses and interrogation of hiPSC-based disease models as probes for defining phenotypic differences and cellular vulnerabilities in patient versus control cells, as well as for investigations of the molecular mechanisms underlying human neurite growth in development and maintenance of neuronal networks, and nerve regeneration. Summary: High-throughput, small molecule screening of hiPSC-derived neurons using a high-content, image-based approach focused on neurite growth identified hit compounds, including approved drugs, which target molecules or pathways known to regulate neurite growth.
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Affiliation(s)
- Sean P Sherman
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute La Jolla, CA 92037, USA
| | - Anne G Bang
- Conrad Prebys Center for Chemical Genomics, Sanford Burnham Prebys Medical Discovery Institute La Jolla, CA 92037, USA
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Bojić T, Perović VR, Senćanski M, Glišić S. Identification of Candidate Allosteric Modulators of the M1 Muscarinic Acetylcholine Receptor Which May Improve Vagus Nerve Stimulation in Chronic Tinnitus. Front Neurosci 2017; 11:636. [PMID: 29184482 PMCID: PMC5694542 DOI: 10.3389/fnins.2017.00636] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 11/02/2017] [Indexed: 12/20/2022] Open
Abstract
Chronic tinnitus is characterized by neuroplastic changes of the auditory cortex. A promising method for therapy of chronic tinnitus is vagus nerve stimulation (VNS) combined with auditory stimulation. The principle of VNS is reversal of pathological neuroplastic changes of the auditory cortex toward physiological neural activity and synchronicity. The VNS mechanism of action in chronic tinnitus patients is prevailingly through the muscarinic neuromodulation of the auditory cortex by the activation of nc. basalis Meynerti. The aim of this study is to propose potential pharmaceutics which may improve the neuromodulatory effects of VNS. The working hypothesis is that M1 receptors have a dominant role in the neural plasticity of the auditory cortex. We propose that allosteric agonists of the muscarinic receptor type 1 (M1) receptor could improve specificity and selectivity of the neuromodulatory effect of VNS on the auditory cortex of chronic tinnitus patients even in the circumstances of lower acetylcholine brain concentration. This intervention would also reinforce the re-learning process of tinnitus (sub)networks by acting on cholinergic memory and learning mechanisms. We performed in silico screening of drug space using the EIIP/AQVN filter and selected 50 drugs as candidates for allosteric modulators of muscarinic receptors. Further filtering of these compounds by means of 3D QSAR and docking revealed 3 approved drugs-bromazepam, estazolam and flumazenil as the most promising candidates for combined chronic tinnitus therapy. These drugs should be further evaluated by biological tests and clinical trials.
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Affiliation(s)
- Tijana Bojić
- Laboratory of Radiobiology and Molecular Genetics, Institute of Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
| | - Vladimir R Perović
- Center for Multidisciplinary Research, Institute of Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
| | - Milan Senćanski
- Center for Multidisciplinary Research, Institute of Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
| | - Sanja Glišić
- Center for Multidisciplinary Research, Institute of Nuclear Sciences Vinča, University of Belgrade, Belgrade, Serbia
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Beltrán-Castillo S, Morgado-Valle C, Eugenín J. The Onset of the Fetal Respiratory Rhythm: An Emergent Property Triggered by Chemosensory Drive? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1015:163-192. [PMID: 29080027 DOI: 10.1007/978-3-319-62817-2_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The mechanisms responsible for the onset of respiratory activity during fetal life are unknown. The onset of respiratory rhythm may be a consequence of the genetic program of each of the constituents of the respiratory network, so they start to interact and generate respiratory cycles when reaching a certain degree of maturation. Alternatively, generation of cycles might require the contribution of recently formed sensory inputs that will trigger oscillatory activity in the nascent respiratory neural network. If this hypothesis is true, then sensory input to the respiratory generator must be already formed and become functional before the onset of fetal respiration. In this review, we evaluate the timing of the onset of the respiratory rhythm in comparison to the appearance of receptors, neurotransmitter machinery, and afferent projections provided by two central chemoreceptive nuclei, the raphe and locus coeruleus nuclei.
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Affiliation(s)
- Sebastián Beltrán-Castillo
- Laboratorio de Sistemas Neurales, Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile
| | - Consuelo Morgado-Valle
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Campus Xalapa, Berlin 7, Fracc., Monte Magno Animas, C.P. 91190, Xalapa, Veracruz, Mexico.
| | - Jaime Eugenín
- Laboratorio de Sistemas Neurales, Facultad de Química y Biología, Departamento de Biología, Universidad de Santiago de Chile, USACH, PO 9170022, Santiago, Chile.
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Kara M, Yumrutas O, Demir CF, Ozdemir HH, Bozgeyik I, Coskun S, Eraslan E, Bal R. Insecticide imidacloprid influences cognitive functions and alters learning performance and related gene expression in a rat model. Int J Exp Pathol 2015; 96:332-7. [PMID: 26568164 DOI: 10.1111/iep.12139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 07/18/2015] [Indexed: 01/11/2023] Open
Abstract
The potential toxic effects of several pesticides, including imidacloprid on non-target organisms have not been clearly established. Also, the chronic effects of non-toxic doses on cognitive function in mammals are unknown. In this study, the effects of different doses of imidacloprid on learning and memory of infant and adult rats were evaluated, and the expressions of genes synthesizing proteins known to be associated with learning in brain tissues were also documented. 0.5, 2 and 8 mg/kg doses of imidacloprid were administered to newborn infant and adult Wistar albino rats by gavage. Their learning activities were evaluated, and the expression levels of the inotropic glutamate receptor GRIN1, synoptophysin, growth-associated protein 43 and the muscarinic receptor M1 in hippocampus were determined by real-time PCR method. Learning activities were diminished significantly at 2 and 8 mg/kg doses in the infant model groups and at 8 mg/kg dose in adult rats. Also, expression levels of GRIN1, SYP and GAP-43 were found to be insignificantly altered. Only the expression of M1 were significantly changed in high doses of adult group. Thus imidacloprid in high doses causes deterioration in cognitive functions particularly in infant rats, and this deterioration may be associated with changes in the expressions of related genes.
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Affiliation(s)
- Murat Kara
- Department of Medical Genetics, Faculty of Medicine, Mugla Sitki Kocman University, Mugla, Turkey
| | - Onder Yumrutas
- Department of Medical Biology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
| | - Caner F Demir
- Department of Neurology, Faculty of Medicine, Fırat University, Elazıg, Turkey
| | | | - Ibrahim Bozgeyik
- Department of Medical Biology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey
| | - Salih Coskun
- Department of Medical Genetics, Faculty of Medicine, Dicle University, Diyarbakır, Turkey
| | - Ersen Eraslan
- Department of Physicology, Faculty of Medicine, Ataturk University, Erzurum, Turkey
| | - Ramazan Bal
- Department of Physicology, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey
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Miller DJ, Lackey EP, Hackett TA, Kaas JH. Development of myelination and cholinergic innervation in the central auditory system of a prosimian primate (Otolemur garnetti). J Comp Neurol 2014; 521:3804-16. [PMID: 23749337 DOI: 10.1002/cne.23379] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 11/07/2022]
Abstract
Change in the timeline of neurobiological growth is an important source of biological variation, and thus phenotypic evolution. However, no study has to date investigated sensory system development in any of the prosimian primates that are thought to most closely resemble our earliest primate ancestors. Acetylcholine (ACh) is a neurotransmitter critical to normal brain function by regulating synaptic plasticity associated with attention and learning. Myelination is an important structural component of the brain because it facilitates rapid neuronal communication. In this work we investigated the expression of acetylcholinesterase (AChE) and the density of myelinated axons throughout postnatal development in the inferior colliculus (IC), medial geniculate complex (MGC), and auditory cortex (auditory core, belt, and parabelt) in Garnett's greater galago (Otolemur garnetti). We found that the IC and MGC exhibit relatively high myelinated fiber length density (MFLD) values at birth and attain adult-like values by the species-typical age at weaning. In contrast, neocortical auditory fields are relatively unmyelinated at birth and only attain adult-like MFLD values by the species-typical age at puberty. Analysis of AChE expression indicated that, in contrast to evidence from rodent samples, the adult-like distribution of AChE in the core area of auditory cortex, dense bands in layers I, IIIb/IV, and Vb/VI, is present at birth. These data indicate the differential developmental trajectory of central auditory system structures and demonstrate the early onset of adult-like AChE expression in primary auditory cortex in O. garnetti, suggesting the auditory system is more developed at birth in primates compared to rodents.
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Affiliation(s)
- Daniel J Miller
- Department of Psychology, Vanderbilt University, Nashville, Tennessee, 37205
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Ma Y, Li X, Fu J, Li Y, Gao L, Yang L, Zhang P, Shen J, Wang H. Acetylcholine affects osteocytic MLO-Y4 cells via acetylcholine receptors. Mol Cell Endocrinol 2014; 384:155-64. [PMID: 24508663 DOI: 10.1016/j.mce.2014.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/21/2014] [Accepted: 01/28/2014] [Indexed: 02/06/2023]
Abstract
The identification of the neuronal control of bone remodeling has become one of the many significant recent advances in bone biology. Cholinergic activity has recently been shown to favor bone mass accrual by complex cellular regulatory networks. Here, we identified the gene expression of the muscarinic and nicotinic acetylcholine receptors (m- and nAChRs) in mice tibia tissue and in osteocytic MLO-Y4 cells. Acetylcholine, which is a classical neurotransmitter and an osteo-neuromediator, not only influences the mRNA expression of the AChR subunits but also significantly induces the proliferation and viability of osteocytes. Moreover, acetylcholine treatment caused the reciprocal regulation of RANKL and OPG mRNA expression, which resulted in a significant increase in the mRNA ratio of RANKL:OPG in osteocytes via acetylcholine receptors. The expression of neuropeptide Y and reelin, which are two neurogenic markers, was also modulated by acetylcholine via m- and nAChRs in MLO-Y4 cells. These results indicated that osteocytic acetylcholine receptors might be a new valuable mediator for cell functions and even for bone remodeling.
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Affiliation(s)
- Yuanyuan Ma
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xianxian Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jing Fu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Yue Li
- Chongqing Key Laboratory for Oral Diseases and Biomedical Sciences, Chongqing 400016, China; The Affiliated Hospital of Stomatology, Chongqing Medical University, Chongqing 400016, China
| | - Li Gao
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Ling Yang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou 510055, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Ping Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jiefei Shen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China
| | - Hang Wang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China; Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
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Jiang S, Li Y, Zhang C, Zhao Y, Bu G, Xu H, Zhang YW. M1 muscarinic acetylcholine receptor in Alzheimer's disease. Neurosci Bull 2014; 30:295-307. [PMID: 24590577 DOI: 10.1007/s12264-013-1406-z] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 10/28/2013] [Indexed: 01/31/2023] Open
Abstract
The degeneration of cholinergic neurons and cholinergic hypofunction are pathologies associated with Alzheimer's disease (AD). Muscarinic acetylcholine receptors (mAChRs) mediate acetylcholine-induced neurotransmission and five mAChR subtypes (M1-M5) have been identified. Among them, M1 mAChR is widely expressed in the central nervous system and has been implicated in many physiological and pathological brain functions. In addition, M1 mAChR is postulated to be an important therapeutic target for AD and several other neurodegenerative diseases. In this article, we review recent progress in understanding the functional involvement of M1 mAChR in AD pathology and in developing M1 mAChR agonists for AD treatment.
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Affiliation(s)
- Shangtong Jiang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, College of Medicine, Xiamen University, Xiamen, 361102, China
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Liu X, Wang C, Pan C, Yan J. Physiological Correspondence Dictates Cortical Long-Term Potentiation and Depression by Thalamic Induction. Cereb Cortex 2013; 25:545-53. [DOI: 10.1093/cercor/bht259] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Widespread decreases in cortical muscarinic receptors in a subset of people with schizophrenia. Int J Neuropsychopharmacol 2013; 16:37-46. [PMID: 22338582 DOI: 10.1017/s1461145712000028] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
These studies were undertaken to investigate the selectivity of cortical muscarinic receptor radioligand binding in muscarinic M(1) and M(4) receptor knockout mice and to determine whether a marked decrease in [(3)H]pirenzepine binding in Brodmann's area (BA) 9 from a subset of people with schizophrenia was predictive of decreased muscarinic receptors in other central nervous system (CNS) regions. Our data show that, under the conditions used, [(3)H]pirenzepine binding was highly selective for the muscarinic M(1) receptor whereas both [(3)H]AF-DX 386 and [(3)H]4DAMP had less discriminatory power. In addition, the data suggest that a marked decrease in [(3)H]pirenzepine binding in BA 9 from a subset of people with schizophrenia is predictive of decreases in muscarinic receptors in other CNS regions. However, there were some region-specific decreases in muscarinic receptors in tissue from people with schizophrenia who were outside this subset. These data add to a growing body of evidence suggesting there are widespread decreases in muscarinic receptors in the CNS of some subjects with schizophrenia, as demonstrated by neuroimaging. Our data have implications for understanding the potential clinical utility of drugs directed at the orthosteric and allosteric sites of muscarinic receptors to treat schizophrenia.
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Zhang G, Gao Z, Guan S, Zhu Y, Wang JH. Upregulation of excitatory neurons and downregulation of inhibitory neurons in barrel cortex are associated with loss of whisker inputs. Mol Brain 2013; 6:2. [PMID: 23286328 PMCID: PMC3548736 DOI: 10.1186/1756-6606-6-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 12/28/2012] [Indexed: 11/10/2022] Open
Abstract
Loss of a sensory input causes the hypersensitivity in other modalities. In addition to cross-modal plasticity, the sensory cortices without receiving inputs undergo the plastic changes. It is not clear how the different types of neurons and synapses in the sensory cortex coordinately change after input deficits in order to prevent loss of their functions and to be used for other modalities. We studied this subject in the barrel cortices from whiskers-trimmed mice vs. controls. After whisker trimming for a week, the intrinsic properties of pyramidal neurons and the transmission of excitatory synapses were upregulated in the barrel cortex, but inhibitory neurons and GABAergic synapses were downregulated. The morphological analyses indicated that the number of processes and spines in pyramidal neurons increased, whereas the processes of GABAergic neurons decreased in the barrel cortex. The upregulation of excitatory neurons and the downregulation of inhibitory neurons boost the activity of network neurons in the barrel cortex to be high levels, which prevent the loss of their functions and enhances their sensitivity to sensory inputs. These changes may prepare for attracting the innervations from sensory cortices and/or peripheral nerves for other modalities during cross-modal plasticity.
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Affiliation(s)
- Guanjun Zhang
- Department of Physiology, Bengbu Medical College, Bengbu, Anhui Province 233000, China
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Liu X, Basavaraj S, Krishnan R, Yan J. Contributions of the thalamocortical system towards sound-specific auditory plasticity. Neurosci Biobehav Rev 2011; 35:2155-61. [DOI: 10.1016/j.neubiorev.2011.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 02/14/2011] [Accepted: 02/16/2011] [Indexed: 10/18/2022]
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Xiong Y, Liu X, Han L, Yan J. The ongoing balance of cortical excitation and inhibition during early development. Neurosci Biobehav Rev 2011; 35:2114-6. [PMID: 21334375 DOI: 10.1016/j.neubiorev.2011.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 02/08/2011] [Accepted: 02/08/2011] [Indexed: 11/26/2022]
Abstract
Two papers recently published in Nature propose that the balance between excitation and inhibition is important for the maturation of cortical function. Their conclusions however, are contradictory; one study suggests that balance is established before hearing onset, whereas the other proposes that balance is established after hearing onset. We carefully examined the data and found that the differences between the two groups are less dramatic than they first appear. Despite their methodological differences, both studies provide evidence that an ongoing balance between cortical excitation/inhibition accounts for the maturation and refinement of cortical function during early development.
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Affiliation(s)
- Ying Xiong
- Department of Neurobiology, Third Military Medical University, Chongqing, PR China
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