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Joghataei MT, Bakhtiarzadeh F, Dehghan S, Ketabforoush AHME, Golab F, Zarbakhsh S, Ahmadirad N. The role of neurotransmitters in glioblastoma multiforme-associated seizures. Int J Dev Neurosci 2023; 83:677-690. [PMID: 37563091 DOI: 10.1002/jdn.10294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/20/2023] [Accepted: 07/26/2023] [Indexed: 08/12/2023] Open
Abstract
GBM, or glioblastoma multiforme, is a brain tumor that poses a great threat to both children and adults, being the primary cause of death related to brain tumors. GBM is often associated with epilepsy, which can be debilitating. Seizures and the development of epilepsy are the primary symptoms that have a severe impact on the quality of life for GBM patients. It is increasingly apparent that the nervous system plays an essential role in the tumor microenvironment for all cancer types, including GBM. In recent years, there has been a growing understanding of how neurotransmitters control the progression of gliomas. Evidence suggests that neurotransmitters and neuromodulators found in the tumor microenvironment play crucial roles in the excitability, proliferation, quiescence, and differentiation of neurons, glial cells, and neural stem cells. The involvement of neurotransmitters appears to play a significant role in various stages of GBM. In this review, the focus is on presenting updated knowledge and emerging ideas regarding the interplay between neurotransmitters and neuromodulators, such as glutamate, GABA, norepinephrine, dopamine, serotonin, adenosine, and their relationship with GBM and the seizures induced by this condition. The review aims to explore the current understanding and provide new insights into the complex interactions between these neurotransmitters and neuromodulators in the context of GBM-related seizures.
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Affiliation(s)
| | - Fatemeh Bakhtiarzadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Samaneh Dehghan
- Eye Research Center, The Five Senses Institute, Rasool Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
- Stem Cell and Regenerative Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sam Zarbakhsh
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Nooshin Ahmadirad
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
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Bauer R, Clowry GJ, Kaiser M. Creative Destruction: A Basic Computational Model of Cortical Layer Formation. Cereb Cortex 2021; 31:3237-3253. [PMID: 33625496 PMCID: PMC8196252 DOI: 10.1093/cercor/bhab003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/13/2022] Open
Abstract
One of the most characteristic properties of many vertebrate neural systems is the layered organization of different cell types. This cytoarchitecture exists in the cortex, the retina, the hippocampus, and many other parts of the central nervous system. The developmental mechanisms of neural layer formation have been subject to substantial experimental efforts. Here, we provide a general computational model for cortical layer formation in 3D physical space. We show that this multiscale, agent-based model, comprising two distinct stages of apoptosis, can account for the wide range of neuronal numbers encountered in different cortical areas and species. Our results demonstrate the phenotypic richness of a basic state diagram structure. Importantly, apoptosis allows for changing the thickness of one layer without automatically affecting other layers. Therefore, apoptosis increases the flexibility for evolutionary change in layer architecture. Notably, slightly changed gene regulatory dynamics recapitulate the characteristic properties observed in neurodevelopmental diseases. Overall, we propose a novel computational model using gene-type rules, exhibiting many characteristics of normal and pathological cortical development.
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Affiliation(s)
- Roman Bauer
- Department of Computer Science, University of Surrey, Guildford, GU2 7XH, UK
| | - Gavin J Clowry
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Marcus Kaiser
- School of Computing, Newcastle University, Newcastle upon Tyne NE4 5TG, UK
- Precision Imaging Beacon, School of Medicine, University of Nottingham, Nottingham NG7 2UH, UK
- Rui Jin Hospital, Shanghai Jiao Tong University, Shanghai 200025, China
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Zhang J, Fan J. Prazosin inhibits the proliferation, migration and invasion, but promotes the apoptosis of U251 and U87 cells via the PI3K/AKT/mTOR signaling pathway. Exp Ther Med 2020; 20:1145-1152. [PMID: 32765662 DOI: 10.3892/etm.2020.8772] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/24/2020] [Indexed: 11/06/2022] Open
Abstract
Prazosin, an α-adrenergic receptor antagonist, is used to treat mild to moderate hypertension. It has recently been discovered that α-adrenergic receptors may have potential antitumor properties. Therefore, in the present study, the effect of prazosin on human glioblastoma and the underlying mechanism were investigated. Human glioblastoma U251 and U87 cells were treated with different concentrations of prazosin, and a Cell Counting Kit-8 assay was performed to investigate the effects of prazosin on cell proliferation. Transwell migration and invasion assays were used to assess the effects of prazosin on cell migration and invasion. Prazosin-induced apoptosis in U251 and U87 cells was detected by flow cytometry, and the protein expression levels of anti-apoptotic proteins and proteins related to the PI3K/AKT/mTOR signaling pathway were detected by western blotting. The results suggested that following treatment with prazosin, the proliferation, migration and invasion of U251 and U81 cells were decreased. By contrast, U251 and U81 cell apoptosis, as well as the protein expression levels of Bax and active Caspase-3 were increased after prazosin treatment (P<0.05). Bcl-2 levels were also decreased after prazosin treatment (P<0.05). Additionally, the expression of phosphorylated (p)-AKT and p-mTOR, P70 and cyclin D1 were decreased in U251 and U81 cells following prazosin treatment (P<0.05). The present study suggested that prazosin may suppress glioblastoma progression by downregulating the activity of the PI3K/AKT/mTOR signaling pathway.
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Affiliation(s)
- Jing Zhang
- Department of Pharmacy, Hebei Chemical and Pharmaceutical College, Shijiazhuang, Hebei 050026, P.R. China
| | - Jiye Fan
- Department of Pharmacy, Hebei Chemical and Pharmaceutical College, Shijiazhuang, Hebei 050026, P.R. China.,College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei 050024, P.R. China
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Zhu MY. Noradrenergic Modulation on Dopaminergic Neurons. Neurotox Res 2018; 34:848-859. [DOI: 10.1007/s12640-018-9889-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 12/24/2022]
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Kirischuk S, Sinning A, Blanquie O, Yang JW, Luhmann HJ, Kilb W. Modulation of Neocortical Development by Early Neuronal Activity: Physiology and Pathophysiology. Front Cell Neurosci 2017; 11:379. [PMID: 29238291 PMCID: PMC5712676 DOI: 10.3389/fncel.2017.00379] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/13/2017] [Indexed: 12/23/2022] Open
Abstract
Animal and human studies revealed that patterned neuronal activity is an inherent feature of developing nervous systems. This review summarizes our current knowledge about the mechanisms generating early electrical activity patterns and their impact on structural and functional development of the cerebral cortex. All neocortical areas display distinct spontaneous and sensory-driven neuronal activity patterns already at early phases of development. At embryonic stages, intermittent spontaneous activity is synchronized within small neuronal networks, becoming more complex with further development. This transition is accompanied by a gradual shift from electrical to chemical synaptic transmission, with a particular role of non-synaptic tonic currents before the onset of phasic synaptic activity. In this review article we first describe functional impacts of classical neurotransmitters (GABA, glutamate) and modulatory systems (e.g., acetylcholine, ACh) on early neuronal activities in the neocortex with special emphasis on electrical synapses, nonsynaptic and synaptic currents. Early neuronal activity influences probably all developmental processes and is crucial for the proper formation of neuronal circuits. In the second part of our review, we illustrate how specific activity patterns might interfere with distinct neurodevelopmental processes like proliferation, migration, axonal and dendritic sprouting, synapse formation and neurotransmitter specification. Finally, we present evidence that transient alterations in neuronal activity during restricted perinatal periods can lead to persistent changes in functional connectivity and therefore might underlie the manifestation of neurological and neuropsychiatric diseases.
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Affiliation(s)
- Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Anne Sinning
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Oriane Blanquie
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Slotkin TA, Skavicus S, Seidler FJ. Prenatal drug exposures sensitize noradrenergic circuits to subsequent disruption by chlorpyrifos. Toxicology 2015; 338:8-16. [PMID: 26419632 DOI: 10.1016/j.tox.2015.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/11/2015] [Accepted: 09/24/2015] [Indexed: 11/20/2022]
Abstract
We examined whether nicotine or dexamethasone, common prenatal drug exposures, sensitize the developing brain to chlorpyrifos. We gave nicotine to pregnant rats throughout gestation at a dose (3mg/kg/day) producing plasma levels typical of smokers; offspring were then given chlorpyrifos on postnatal days 1-4, at a dose (1mg/kg) that produces minimally-detectable inhibition of brain cholinesterase activity. In a parallel study, we administered dexamethasone to pregnant rats on gestational days 17-19 at a standard therapeutic dose (0.2mg/kg) used in the management of preterm labor, followed by postnatal chlorpyrifos. We evaluated cerebellar noradrenergic projections, a known target for each agent, and contrasted the effects with those in the cerebral cortex. Either drug augmented the effect of chlorpyrifos, evidenced by deficits in cerebellar β-adrenergic receptors; the receptor effects were not due to increased systemic toxicity or cholinesterase inhibition, nor to altered chlorpyrifos pharmacokinetics. Further, the deficits were not secondary adaptations to presynaptic hyperinnervation/hyperactivity, as there were significant deficits in presynaptic norepinephrine levels that would serve to augment the functional consequence of receptor deficits. The pretreatments also altered development of cerebrocortical noradrenergic circuits, but with a different overall pattern, reflecting the dissimilar developmental stages of the regions at the time of exposure. However, in each case the net effects represented a change in the developmental trajectory of noradrenergic circuits, rather than simply a continuation of an initial injury. Our results point to the ability of prenatal drug exposure to create a subpopulation with heightened vulnerability to environmental neurotoxicants.
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Affiliation(s)
- Theodore A Slotkin
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Samantha Skavicus
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Frederic J Seidler
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Li F, Ohtani A, Senzaki K, Shiga T. Receptor-dependent regulation of dendrite formation of noradrenaline and dopamine in non-GABAergic cerebral cortical neurons. Dev Neurobiol 2012; 73:370-83. [PMID: 23135899 DOI: 10.1002/dneu.22065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 09/18/2012] [Accepted: 10/31/2012] [Indexed: 12/12/2022]
Abstract
The present study characterized the receptor-dependent regulation of dendrite formation of noradrenaline (NA) and dopamine (DA) in cultured neurons obtained from embryonic day 16 rat cerebral cortex. Morphological diversity of cortical dendrites was analyzed on various features: dendrite initiation, dendrite outgrowth, and dendrite branching. Using a combination of immunocytochemical markers of dendrites and GABAergic neurons, we focused on the dendrite morphology of non-GABAergic neurons. Our results showed that (1) NA inhibited the dendrite branching, (2) β adrenergic receptor (β-AR) agonist inhibited the dendrite initiation, while promoted the dendrite outgrowth, (3) β1-AR and β2-AR were present in all the cultured neurons, and both agonists inhibited the dendrite initiation, while only β1-AR agonist induced the dendrite branching; (4) DA inhibited the dendrite outgrowth, (5) D1 receptor agonist inhibited the dendrite initiation, while promoted the dendrite branching. In conclusion, this study compared the effects of NA, DA and their receptors and showed that NA and DA regulate different features on the dendrite formation of non-GABAergic cortical neurons, depending on the receptors.
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Affiliation(s)
- Fei Li
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8577, Ibaraki, Japan
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Abstract
The importance of adult neurogenesis has only recently been accepted, resulting in a completely new field of investigation within stem cell biology. The regulation and functional significance of adult neurogenesis is currently an area of highly active research. G-protein-coupled receptors (GPCRs) have emerged as potential modulators of adult neurogenesis. GPCRs represent a class of proteins with significant clinical importance, because approximately 30% of all modern therapeutic treatments target these receptors. GPCRs bind to a large class of neurotransmitters and neuromodulators such as norepinephrine, dopamine, and serotonin. Besides their typical role in cellular communication, GPCRs are expressed on adult neural stem cells and their progenitors that relay specific signals to regulate the neurogenic process. This review summarizes the field of adult neurogenesis and its methods and specifies the roles of various GPCRs and their signal transduction pathways that are involved in the regulation of adult neural stem cells and their progenitors. Current evidence supporting adult neurogenesis as a model for self-repair in neuropathologic conditions, adult neural stem cell therapeutic strategies, and potential avenues for GPCR-based therapeutics are also discussed.
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Affiliation(s)
- Van A Doze
- Department of Molecular Cardiology, NB50, Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave., Cleveland, OH 44195, USA
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Kilb W, Kirischuk S, Luhmann HJ. Electrical activity patterns and the functional maturation of the neocortex. Eur J Neurosci 2011; 34:1677-86. [DOI: 10.1111/j.1460-9568.2011.07878.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Fan Y, Huang J, Duffourc M, Kao RL, Ordway GA, Huang R, Zhu MY. Transcription factor Phox2 upregulates expression of norepinephrine transporter and dopamine β-hydroxylase in adult rat brains. Neuroscience 2011; 192:37-53. [PMID: 21763404 PMCID: PMC3166407 DOI: 10.1016/j.neuroscience.2011.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 07/05/2011] [Accepted: 07/06/2011] [Indexed: 01/22/2023]
Abstract
Degeneration of the noradrenergic locus coeruleus (LC) in aging and neurodegenerative diseases is well documented. Slowing or reversing this effect may have therapeutic implications. Phox2a and Phox2b are homeodomain transcriptional factors that function as determinants of the noradrenergic phenotype during embryogenesis. In the present study, recombinant lentiviral eGFP-Phox2a and -Phox2b (vPhox2a and vPhox2b) were constructed to study the effects of Phox2a/2b over-expression on dopamine β-hydroxylase (DBH) and norepinephrine transporter (NET) levels in central noradrenergic neurons. Microinjection of vPhox2 into the LC of adult rats significantly increased Phox2 mRNA levels in the LC region. Over-expression of either Phox2a or Phox2b in the LC was paralleled by significant increases in mRNA and protein levels of DBH and NET in the LC. Similar increases in DBH and NET protein levels were observed in the hippocampus following vPhox2 microinjection. In the frontal cortex, only NET protein levels were significantly increased by vPhox2 microinjection. Over-expression of Phox2 genes resulted in a significant increase in BrdU-positive cells in the hippocampal dentate gyrus. The present study demonstrates an upregulatory effect of Phox2a and Phox2b on the expression of DBH and NET in noradrenergic neurons of rat brains, an effect not previously shown in adult animals. Phox2 genes may play an important role in maintaining the function of the noradrenergic neurons after birth, and regulation of Phox2 gene expression may have therapeutic utility in aging or disorders involving degeneration of noradrenergic neurons.
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Affiliation(s)
- Yan Fan
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
- Department of Biochemistry and Molecular Biology, Soochow University School of Medicine, Suzhou, China
| | - Jingjing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Michelle Duffourc
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Race L. Kao
- Department of Surgery, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Gregory A. Ordway
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
| | - Rui Huang
- Department of Biochemistry and Molecular Biology, Soochow University School of Medicine, Suzhou, China
| | - Meng-Yang Zhu
- Department of Pharmacology, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, USA
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Suárez J, Romero-Zerbo SY, Rivera P, Bermúdez-Silva FJ, Pérez J, De Fonseca FR, Fernández-Llebrez P. Endocannabinoid system in the adult rat circumventricular areas: An immunohistochemical study. J Comp Neurol 2010; 518:3065-85. [DOI: 10.1002/cne.22382] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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12
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Slotkin TA, Ryde IT, Wrench N, Card JA, Seidler FJ. Nonenzymatic role of acetylcholinesterase in neuritic sprouting: regional changes in acetylcholinesterase and choline acetyltransferase after neonatal 6-hydroxydopamine lesions. Neurotoxicol Teratol 2009; 31:183-6. [PMID: 19452616 DOI: 10.1016/j.ntt.2008.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acetylcholinesterase (AChE) is postulated to play a nonenzymatic role in the development of neuritic projections. We gave the specific neurotoxin, 6-OHDA to rats on postnatal day (PN) 1, a treatment that destroys noradrenergic nerve terminals in the forebrain while producing reactive sprouting in the brainstem. AChE showed profound decreases in the forebrain that persisted in males over the entire phase of major synaptogenesis, from PN4 through PN21; in the brainstem, AChE was increased. Parallel examinations of choline acetyltransferase, an enzymatic marker for cholinergic nerve terminals, showed a different pattern of 6-OHDA-induced alterations, with initial decreases in both forebrain and brainstem in males and regression toward normal by PN21; females were far less affected. The sex differences are in accord with the greater plasticity of the female brain and its more rapid recovery from neurotoxic injury; our findings indicate that these differences are present well before puberty. These results support the view that AChE is involved in neurite formation, unrelated to its enzymatic role in cholinergic neurotransmission. Further, the results for choline acetyltransferase indicate that early depletion of norepinephrine compromises development of acetylcholine systems, consistent with a trophic role for this neurotransmitter.
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Affiliation(s)
- Theodore A Slotkin
- Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, North Carolina, 27710, USA.
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Il’inykh FA, Kalinina TS, Dygalo NN. Effects of clonidine and yohimbine on the levels of bax, Bcl-XL, and caspase-3 mRNAs in the brain of neonatal rats. NEUROCHEM J+ 2008. [DOI: 10.1134/s1819712408040053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Il’inykh FA, Bannova AV, Kalinina TS, Dygalo NN. Effects of ligands of α2-adrenoceptors on mRNA level of apoptotic proteins in developing rat brain. BIOL BULL+ 2008. [DOI: 10.1134/s1062359008010135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Gandhi R, Luk KC, Rymar VV, Sadikot AF. Group I mGluR5 metabotropic glutamate receptors regulate proliferation of neuronal progenitors in specific forebrain developmental domains. J Neurochem 2007; 104:155-72. [PMID: 17944877 DOI: 10.1111/j.1471-4159.2007.04955.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Major classical neurotransmitters including GABA and glutamate play novel morphogenic roles during development of the mammalian CNS. During forebrain neurogenesis, glutamate regulates neuroblast proliferation in different germinal domains using receptor subtype-specific mechanisms. For example, ionotropic N-methyl-D-aspartate (NMDA) or alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) glutamate receptors mediate distinct proliferative effects in ventral or dorsal forebrain germinal domains, and regulate the correct number of neurons that populate the striatum or cerebral cortex. Recent work suggests metabotropic receptors may also mediate glutamate's proliferative effects. Group I mGluR5 receptor subtypes are highly expressed in forebrain germinal zones. Using in vitro and in vivo methods, we demonstrate mGluR5 receptor activation plays an important role in neuroblast proliferation in the ventral telencephalon, and helps determine the complement of striatum projection neurons. mGluR5 receptor-mediated effects on striatal neuronal progenitors are restricted mainly to early cycling populations in the ventricular zone, with little effect on secondary proliferative populations in the subventricular zone. In contrast to proliferative effects in the ventral telencephalon, mGluR5 receptors do not modulate proliferation of dorsal telencephalon-derived cortical neuroblasts. Heterogeneous domain-specific proliferative effects of glutamate-mediated by specific receptor subtypes provide an important developmental mechanism allowing generation of the correct complement of neuronal subtypes that populate the mammalian forebrain.
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Affiliation(s)
- Rina Gandhi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
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Ohashi H, Nishikawa K, Ayukawa K, Hara Y, Nishimoto M, Kudo Y, Abe T, Aoki S, Wada K. Alpha 1-adrenoceptor agonists protect against stress-induced death of neural progenitor cells. Eur J Pharmacol 2007; 573:20-8. [PMID: 17643416 DOI: 10.1016/j.ejphar.2007.06.060] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 06/18/2007] [Accepted: 06/26/2007] [Indexed: 11/19/2022]
Abstract
Here, we show that alpha(1)-adrenoceptor agonists suppress stress-induced death of mouse embryonic brain-derived neural progenitor cells (NPCs). NPCs highly expressed both alpha(1A)- and alpha(1B)-adrenoceptor genes, whereas the gene encoding alpha(1D)-adrenoceptor was expressed at low levels. Application of the alpha(1)-adrenoceptor agonists phenylephrine and cirazoline significantly promoted cell survival of embryonic NPCs that had been exposed to stress, as measured by a lactate dehydrogenase release assay, but had no remarkable effect on differentiation of the NPCs. Both phenylephrine and cirazoline protected NPCs from death induced by growth factor deprivation, N2 nutrient deprivation, tunicamycin treatment or staurosporine treatment. Phenylephrine and cirazoline treatments both maximally reduced stress-induced cell death by approximately 60% but did not change the percentage of undifferentiated cells as measured by nestin staining. Moreover, phenylephrine and cirazoline treatments did not affect the cellular activities of caspase-3 and caspase-7 but markedly reduced propidium iodide penetration into the cytoplasm, suggesting that alpha(1)-adrenoceptor agonists inhibit caspase-3/7-independent death of the embryonic NPCs.
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Affiliation(s)
- Hiroki Ohashi
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, NCNP, Kodaira, Tokyo 187-8502, Japan
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Karkoulias G, Mastrogianni O, Ilias I, Lymperopoulos A, Taraviras S, Tsopanoglou N, Sitaras N, Flordellis CS. Alpha 2-adrenergic receptors decrease DNA replication and cell proliferation and induce neurite outgrowth in transfected rat pheochromocytoma cells. Ann N Y Acad Sci 2007; 1088:335-45. [PMID: 17192578 DOI: 10.1196/annals.1366.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alpha 2-adrenergic receptors (alpha(2)-ARs) have a widespread distribution in the central nervous system (CNS) and affect a number of biochemical and behavioral functions, including stimulation of prefrontal cortex (PFC) and cognitive function. In addition to its role as a classical neurotransmitter, norepinephrine (NE) has been recently shown to exert an important influence on the plasticity in areas of the brain where neurogenesis persists in the adult, notably the subgranular zone (SGZ) within the dentate gyrus of the hippocampus and the olfactory bulb (OB). In regulating adult neurogenesis, the noradrenergic system is functionally integrated with chronic stress and depression. Chronic stress, depression, or depletion of NE in vivo suppress, and antidepressant treatments induce hippocampal neurogenesis by down- or upregulating, respectively, cell proliferation. In the present study we show that alpha(2)-AR subtypes promote the differentiation rather than cell proliferation of PC12 cells. It is conceivable that alpha(2)-ARs might contribute neurotrophic actions in vivo synergistically or in permutation with other neurotrophic factors.
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Affiliation(s)
- G Karkoulias
- Department of Pharmacology, School of Medicine, University of Patras-Rion, GR-26504, Greece
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18
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Chen MJ, Nguyen TV, Pike CJ, Russo-Neustadt AA. Norepinephrine induces BDNF and activates the PI-3K and MAPK cascades in embryonic hippocampal neurons. Cell Signal 2007; 19:114-28. [PMID: 16876982 DOI: 10.1016/j.cellsig.2006.05.028] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 05/29/2006] [Indexed: 11/19/2022]
Abstract
Both antidepressant treatment and physical exercise have been shown to increase circulating levels of norepinephine (NE) and hippocampal brain-derived neurotrophic factor (BDNF). Increases in BDNF have been shown to be associated with enhanced dendritic arborization and neuronal survival, which forms the theoretical basis of the Neurotrophin Hypothesis of antidepressant action. Using isolated embryonic hippocampal neurons and immunoblotting, we show that application of NE increases BDNF and phosphorylated Trk, and that these increases can be prevented by ERK and PI-3K inhibitors. In addition, NE-induced increases in phospho-ERK2 and PI-3K were each suppressed by a PI-3K and MAPK inhibitor, respectively. Furthermore, phosphorylation of cAMP-response element binding (CREB) protein was also increased by NE and brought down to baseline levels by MAPK and PI-3K inhibitors. And finally, because both the MAPK and PI-3K inhibitors suppress phosphorylation of both TrkB (upstream) and CREB (downstream), these results indicate that NE-induced BDNF expression follows a cyclic pathway, reminiscent of a positive feedback loop. The results of this study provide an in vitro model of the intracellular signaling mechanisms activated by NE, via ligand-G-protein-coupled receptor (GPCR)-to-BDNF-RTK transactivation, that is putatively thought to occur in vivo as a result of excitatory neural activity.
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Affiliation(s)
- M J Chen
- California State University, Los Angeles, Department of Biological Sciences, 5151 State University Dr., Los Angeles, CA 90032, USA.
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19
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Araki KY, Fujimura S, MacDonald ME, Bhide PG. Characterization of mouse striatal precursor cell lines expressing functional dopamine receptors. Dev Neurosci 2006; 28:518-27. [PMID: 17028429 PMCID: PMC1615710 DOI: 10.1159/000095114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Accepted: 01/16/2006] [Indexed: 11/19/2022] Open
Abstract
Dopamine and its receptors appear in the developing brain early in the embryonic period and dopamine receptor activation influences proliferation and differentiation of neuroepithelial precursor cells. Since dopamine D(1) and D(2) receptor activation produces opposing effects on precursor cell activity, dopamine's overall effects may correlate with relative numbers and activity of each receptor subtype on the precursor cells. Dopamine receptor expression and activity in individual precursor cells in the intact brain are difficult to ascertain. Therefore, cell lines with known receptor expression profiles can be useful tools to study dopamine's influence on neuroepithelial cells. We report characterization of dopamine receptor expression and activity profiles in three mouse striatal precursor cell lines and suggest that these cell lines can be valuable tools to study dopamine's effects on striatal precursor cell proliferation and differentiation.
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Affiliation(s)
- Kiyomi Y Araki
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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20
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Swinny JD, Valentino RJ. Corticotropin-releasing factor promotes growth of brain norepinephrine neuronal processes through Rho GTPase regulators of the actin cytoskeleton in rat. Eur J Neurosci 2006; 24:2481-90. [PMID: 17100837 DOI: 10.1111/j.1460-9568.2006.05129.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cognitive aspects of the acute stress response are partly mediated through activation of the locus coeruleus (LC)-norepinephrine (NE) system via corticotropin-releasing factor (CRF). Apart from mediating the acute responses to stress, CRF can mediate the long-term impact of stress on the brain through its potent modulation of neuronal morphology. Importantly, the cellular pathways engaged by stress in general, and CRF in particular, in remodeling neuronal structure are poorly understood. Here, we demonstrate that apart from its well-established acute effects on LC neuronal activity, CRF also stimulates growth and arborization of LC neuronal processes. By contrast, urocortin 2 (UCN 2), a related peptide, inhibits outgrowth of such processes. These opposing effects are transduced by a common receptor (CRF(1)) but distinct intracellular signaling pathways. The structural effects of CRF required protein kinase A and mitogen-activated protein kinase, as well as Rac1, a member of the Rho family of GTPases that regulates the actin and microtubule cytoskeleton. By contrast, the effects of UCN II were mediated by the protein kinase C and RhoA pathways. This is the first study to link stress-related substrates to molecular mediators of actin cytoskeletal remodeling in the LC. We propose a model of dynamic LC neuronal plasticity that is reciprocally controlled by CRF and UCN II, eventually determining actin rearrangement by Rho-specific pathways. By regulating the extension of processes into pericoerulear regions where limbic afferents terminate, these peptides may determine the degree to which the LC-NE system is influenced by limbic structures that mediate emotional expression.
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Affiliation(s)
- Jerome D Swinny
- Department of Pediatrics, 402C Abramson Bldg, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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21
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Hiramoto T, Ihara Y, Watanabe Y. α-1 Adrenergic receptors stimulation induces the proliferation of neural progenitor cells in vitro. Neurosci Lett 2006; 408:25-8. [PMID: 16989945 DOI: 10.1016/j.neulet.2006.02.052] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Revised: 01/24/2006] [Accepted: 02/12/2006] [Indexed: 10/24/2022]
Abstract
The proliferation of neural progenitor cells (NPCs) is regulated by classical neurotransmitters such as dopamine, serotonin and acetylcholine, via its own receptors. Previous studies have reported that the depletion of L-norepinephrine decreases the proliferation of NPCs in the adult rat hippocampus and it has been suggested that L-norepinephrine regulates the proliferation of NPCs. However, it remains unknown whether or not adrenergic receptors are involved in the increased proliferation of NPCs. In the present study, an MTT cell proliferation assay was carried out in order to investigate the roles played by adrenergic receptors in the proliferation of NPCs. We demonstrated that L-epinephrine enhanced the proliferation of embryonic NPCs in vitro. In addition, the alpha-1 adrenergic receptor agonist L-phenylephrine was found to enhance the proliferation of NPCs, whereas an alpha-adrenergic antagonist and selective alpha-1 antagonists significantly inhibited cell proliferation increases induced by L-epinephrine and L-phenylephrine. These results suggest that stimulation with alpha-1 adrenergic receptors induces the proliferation of embryonic NPCs.
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Affiliation(s)
- Takeshi Hiramoto
- Department of Pharmacology, National Defense Medical College, Tokorozawa 359-8513, Japan
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22
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Rizk P, Salazar J, Raisman-Vozari R, Marien M, Ruberg M, Colpaert F, Debeir T. The alpha2-adrenoceptor antagonist dexefaroxan enhances hippocampal neurogenesis by increasing the survival and differentiation of new granule cells. Neuropsychopharmacology 2006; 31:1146-57. [PMID: 16292321 DOI: 10.1038/sj.npp.1300954] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The generation of new neurons in the hippocampus is a dynamic process regulated by environmental, endocrine, and pharmacological factors. Since enhancement of hippocampal neurogenesis has been associated with learning and memory, and the locus coeruleus-noradrenergic system has been shown to modulate these cognitive functions, we hypothesized that activation of noradrenergic neurotransmission might enhance neurogenesis in the adult hippocampus. To test this hypothesis in vivo, we induced the release of noradrenaline in the hippocampus by blocking presynaptic inhibitory autoreceptors with the selective alpha2-adrenoceptor antagonist dexefaroxan. Confocal microscopy showed that noradrenergic afferents make contact with proliferating and differentiating cells, suggesting a direct noradrenergic influence on neurogenesis. Chronic systemic treatment of rats with dexefaroxan did not affect cell proliferation per se in the dentate gyrus (as monitored by bromodeoxyuridine-labeling), but promoted the long-term survival of newborn neurons by reducing apoptosis. Dexefaroxan treatment also enhanced the number and complexity of the dendritic arborizations of polysialated neural cell adhesion molecule-positive neurons. The trophic effects of dexefaroxan on newborn cells might involve an increase in brain-derived neurotrophic factor, which was upregulated in afferent noradrenergic fiber projection areas and in neurons in the granule cell layer. By promoting the survival of new endogenously formed neurons, dexefaroxan treatment represents a potential therapeutic strategy for maintaining adult neurogenesis in neurodegenerative conditions, such as Alzheimer's disease, that affect the hippocampus.
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Affiliation(s)
- Pamela Rizk
- INSERM U679, Neurology and Experimental Therapeutics, Paris, France
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23
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Slotkin TA, Seidler FJ. Anomalous regulation of β-adrenoceptor signaling in brain regions of the newborn rat. Brain Res 2006; 1077:54-8. [PMID: 16487945 DOI: 10.1016/j.brainres.2006.01.047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 01/10/2006] [Accepted: 01/15/2006] [Indexed: 11/27/2022]
Abstract
Desensitization, an essential homeostatic response to excessive or continued beta-adrenoceptor (betaAR) stimulation, is deficient in immature cells. To determine the mechanisms underlying anomalous betaAR responses in newborn rats, we administered terbutaline, a beta2AR agonist, on postnatal day 2 and evaluated signaling through adenylyl cyclase (AC) in cell membrane preparations 4 h later. Although a small decrement in isoproterenol-stimulated AC was obtained in the forebrain, robust sensitization was seen in the brainstem and cerebellum, in association with heterologous increases in AC catalytic activity: increased basal, dopamine-stimulated and forskolin-stimulated AC. Superimposed on this global increase, there was a small degree of betaAR and dopamine receptor desensitization, characterized by decreases in the isoproterenol/forskolin and dopamine/forskolin AC activity ratios. Our results indicate that, in some immature brain regions, betaAR desensitization is masked by more substantial increases in the activity of signaling elements downstream from the receptors, resulting in sustained responses in the face of continued receptor stimulation. These effects are likely responsible for the maintenance of betaAR activity associated with neurotrophic input during synaptogenesis but may also contribute to adverse effects of betaAR agonists used in preterm labor.
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Affiliation(s)
- Theodore A Slotkin
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Box 3813 DUMC, Duke Univ. Med. Ctr., Durham, NC 27710, USA.
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24
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Quaglia W, Santoni G, Pigini M, Piergentili A, Gentili F, Buccioni M, Mosca M, Lucciarini R, Amantini C, Nabissi MI, Ballarini P, Poggesi E, Leonardi A, Giannella M. Structure-activity relationships in 1,4-benzodioxan-related compounds. 8.(1) {2-[2-(4-chlorobenzyloxy)phenoxy]ethyl}-[2-(2,6-dimethoxyphenoxy)ethyl]amine (clopenphendioxan) as a tool to highlight the involvement of alpha1D- and alpha1B-adrenoreceptor subtypes in the regulation of human PC-3 prostate cancer cell apoptosis and proliferation. J Med Chem 2006; 48:7750-63. [PMID: 16302814 DOI: 10.1021/jm0580398] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of new alpha1-adrenoreceptor antagonists (5-18) was prepared by introducing various substituents (Topliss approach) into the ortho, meta, and para positions of the benzyloxy function of the phendioxan open analogue 4 ("openphendioxan"). All the compounds synthesized were potent antagonists and generally displayed, similarly to 4, the highest affinity values at alpha1D- with respect to alpha1A- and alpha1B-AR subtypes and 5-HT1A subtype. By sulforhodamine B (SRB) assay on human PC-3 prostate cancer cells, the new compounds showed antitumor activity (estimated on the basis of three parameters GI50, TGI, LC50), at low micromolar concentration, with 7 ("clopenphendioxan") exhibiting the highest efficacy. Moreover, this study highlighted for the first time alpha1D- and alpha1B-AR expression in PC3 cells and also demonstrated the involvement of these subtypes in the modulation of apoptosis and cell proliferation. A significant reduction of alpha1D- and alpha1B-AR expression in PC3 cells was associated with the apoptosis induced by 7. This depletion was completely reversed by norepinephrine.
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Affiliation(s)
- Wilma Quaglia
- Dipartimento di Scienze Chimiche, Università degli Studi di Camerino, via S. Agostino 1, 62032 Camerino, Italy
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25
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Kreider ML, Aldridge JE, Cousins MM, Oliver CA, Seidler FJ, Slotkin TA. Disruption of rat forebrain development by glucocorticoids: critical perinatal periods for effects on neural cell acquisition and on cell signaling cascades mediating noradrenergic and cholinergic neurotransmitter/neurotrophic responses. Neuropsychopharmacology 2005; 30:1841-55. [PMID: 15841102 DOI: 10.1038/sj.npp.1300743] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glucocorticoids are the consensus treatment for the prevention of respiratory distress in preterm infants, but there is evidence for increased incidence of neurodevelopmental disorders as a result of their administration. We administered dexamethasone (Dex) to developing rats at doses below or within the range of those used clinically, evaluating the effects on forebrain development with exposure in three different stages: gestational days 17-19, postnatal days 1-3, or postnatal days 7-9. At 24 h after the last dose, we evaluated biomarkers of neural cell acquisition and growth, synaptic development, neurotransmitter receptor expression, and synaptic signaling mediated by adenylyl cyclase (AC). Dex impaired the acquisition of neural cells, with a peak effect when given in the immediate postnatal period. In association with this defect, Dex also elicited biphasic effects on cholinergic presynaptic development, promoting synaptic maturation at a dose (0.05 mg/kg) well below those used therapeutically, whereas the effect was diminished or lost when doses were increased to 0.2 or 0.8 mg/kg. Dex given postnatally also disrupted the expression of adrenergic receptors known to participate in neurotrophic modeling of the developing brain and evoked massive induction of AC activity. As a consequence, disparate receptor inputs all produced cyclic AMP overproduction, a likely contributor to disrupted patterns of cell replication, differentiation, and apoptosis. Superimposed on the heterologous AC induction, Dex impaired specific receptor-mediated cholinergic and adrenergic signals. These results indicate that, during a critical developmental period, Dex administration leads to widespread interference with forebrain development, likely contributing to eventual, adverse neurobehavioral outcomes.
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Affiliation(s)
- Marisa L Kreider
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Research Drive, Durham, NC 27710, USA
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26
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Veyrac A, Didier A, Colpaert F, Jourdan F, Marien M. Activation of noradrenergic transmission by alpha2-adrenoceptor antagonists counteracts deafferentation-induced neuronal death and cell proliferation in the adult mouse olfactory bulb. Exp Neurol 2005; 194:444-56. [PMID: 16022870 DOI: 10.1016/j.expneurol.2005.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 03/02/2005] [Accepted: 03/07/2005] [Indexed: 11/20/2022]
Abstract
The olfactory bulb is the target of neural progenitor cells that are generated in the subventricular zone of the lateral ventricle in the adult brain. This permanent neurogenesis is likely influenced by olfactory input to the bulb since previous studies have shown that cell proliferation and/or apoptotic death are stimulated by naris closure or surgical transection of the olfactory nerve. Since the olfactory bulb is densely innervated by noradrenergic afferents originating in the locus coeruleus, we have studied the impact of pharmacologically activating this noradrenergic system on cell death and proliferation following unilateral olfactory axotomy in the adult mouse olfactory bulb. We found that noradrenaline release in the olfactory bulb was significantly increased by intraperitoneal injections of the selective alpha(2)-adrenoceptor antagonists, dexefaroxan (0.63 mg/kg) and 5-fluoro-methoxyidazoxan (F 14413; 0.16 mg/kg). A chronic treatment with either compound for 7 days following olfactory axotomy significantly reduced neuronal death, glial activation and cell proliferation in the deafferented olfactory bulb. These data (1) confirm that alpha(2)-adrenoceptor antagonists, presumably by facilitating central noradrenergic transmission, afford neuroprotection in vivo, as previously shown in models of cerebral ischemia, excitotoxicity and devascularization-induced neurodegeneration, and (2) support a role of the locus coeruleus noradrenergic system in promoting survival of neurons in areas of the brain where neurogenesis persists in the adult.
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Affiliation(s)
- Alexandra Veyrac
- Laboratoire Neurosciences et Systèmes Sensoriels, CNRS-UMR 5020, Université Claude Bernard-Lyon 1, 50 Avenue Tony Garnier, F-69366 Lyon, France
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27
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Bhatt R, Bhatt S, Hameed M, Rameshwar P, Siegel A. Amygdaloid kindled seizures can induce functional and pathological changes in thymus of rat: role of the sympathetic nervous system. Neurobiol Dis 2005; 21:127-37. [PMID: 16084731 DOI: 10.1016/j.nbd.2005.06.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 06/03/2005] [Accepted: 06/15/2005] [Indexed: 12/15/2022] Open
Abstract
The present study sought to determine the effects of long-term kindled seizures of the basal amygdala upon immune function in rat, utilizing the thymus, as a principal target for study. Histopathology from kindled Sprague-Dawley rats revealed the presence of epithelial cell thymoma in 70% of these rats. The results revealed an increased rate of apoptosis and proliferation in thymic epithelial cells. Analysis of thymocytes indicated a decrease in the ratio of CD4 to CD8 positive T cells and reduced proliferative response to T-cell mitogens. To determine whether these effects were mediated through the sympathetic nervous system, animals were treated with guanethidine, which blocked the development of epithelial cell thymomas, while mifepristone treatment, employed to determine the possible role of the hypothalamic-pituitary axis, was ineffective in attenuating thymoma development. Thus, the present study demonstrated that functional and pathological changes in the thymus during kindled seizures are mediated through the sympathetic nervous system.
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Affiliation(s)
- Rekha Bhatt
- Department of Neurology and Neurosciences, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA
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28
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Popolo M, McCarthy DM, Bhide PG. Influence of dopamine on precursor cell proliferation and differentiation in the embryonic mouse telencephalon. Dev Neurosci 2005; 26:229-44. [PMID: 15711063 PMCID: PMC1215465 DOI: 10.1159/000082140] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Accepted: 06/28/2004] [Indexed: 11/19/2022] Open
Abstract
Dopamine and its receptor binding sites appear in the brain early in the embryonic period raising the possibility that dopamine may influence brain development. We show that one component of dopamine's role in brain development is its ability to influence proliferation and differentiation of progenitor cells in the neostriatum and the dorsomedial prefrontal cortex on embryonic day 15 in mice. Dopamine and a D1-like receptor agonist reduce the relative proportion of progenitor cells incorporating the S phase marker bromodeoxyuridine. A D2-like agonist produces the opposite effect. Both the effects are evident in the lateral ganglionic eminence, neuroepithelial precursor of the neostriatum and in the neuroepithelium of the dorsomedial prefrontal cortex. Neostriatal progenitor cells are more responsive than cortical progenitor cells to the effects of dopamine receptor activation. Furthermore, progenitor cells in the ventricular zone are more responsive to D1-like agonists and progenitors in the subventricular zone more so to D2-like agonists. Thus, dopamine's developmental effects show regional and progenitor cell type specificity, presumably due to heterogeneity in the distribution of its receptor binding sites.
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Affiliation(s)
| | | | - Pradeep G. Bhide
- Dr. Pradeep G. Bhide Developmental Neurobiology, Massachusetts General Hospital 149, 13th Street Charlestown, MA 02129 (USA) Tel. +1 617 726 5763, Fax +1 617 726 6656, E-Mail
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29
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Meyer A, Seidler FJ, Aldridge JE, Slotkin TA. Developmental exposure to terbutaline alters cell signaling in mature rat brain regions and augments the effects of subsequent neonatal exposure to the organophosphorus insecticide chlorpyrifos. Toxicol Appl Pharmacol 2005; 203:154-66. [PMID: 15710176 DOI: 10.1016/j.taap.2004.08.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2004] [Accepted: 08/12/2004] [Indexed: 11/25/2022]
Abstract
Exposure to apparently unrelated neurotoxicants can nevertheless converge on common neurodevelopmental events. We examined the long-term effects of developmental exposure of rats to terbutaline, a beta-adrenoceptor agonist used to arrest preterm labor, and the organophosphorus insecticide chlorpyrifos (CPF) separately and together. Treatments mimicked the appropriate neurodevelopmental stages for human exposures: terbutaline on postnatal days (PN) 2-5 and CPF on PN11-14, with assessments conducted on PN45. Although neither treatment affected growth or viability, each elicited alterations in CNS cell signaling mediated by adenylyl cyclase (AC), a transduction pathway shared by numerous neuronal and hormonal signals. Terbutaline altered signaling in the brainstem and cerebellum, with gender differences particularly notable in the cerebellum (enhanced AC in males, suppressed in females). By itself, CPF exposure elicited deficits in AC signaling in the midbrain, brainstem, and striatum. However, sequential exposure to terbutaline followed by CPF produced larger alterations and involved a wider spectrum of brain regions than were obtained with either agent alone. In the cerebral cortex, adverse effects of the combined treatment intensified between PN45 and PN60, suggesting that exposures alter the long-term program for development of synaptic communication, leading to alterations in AC signaling that emerge even after adolescence. These findings indicate that terbutaline, like CPF, is a developmental neurotoxicant, and reinforce the idea that its use in preterm labor may create a subpopulation that is sensitized to long-term CNS effects of organophosphorus insecticides.
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Affiliation(s)
- Armando Meyer
- Centro de Estudos da Saúde do Trabalhador e Ecologia Humana (AM), Escola Nacional de Saúde Pública, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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30
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31
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Marien MR, Colpaert FC, Rosenquist AC. Noradrenergic mechanisms in neurodegenerative diseases: a theory. ACTA ACUST UNITED AC 2004; 45:38-78. [PMID: 15063099 DOI: 10.1016/j.brainresrev.2004.02.002] [Citation(s) in RCA: 313] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/11/2004] [Indexed: 11/26/2022]
Abstract
A deficiency in the noradrenergic system of the brain, originating largely from cells in the locus coeruleus (LC), is theorized to play a critical role in the progression of a family of neurodegenerative disorders that includes Parkinson's disease (PD) and Alzheimer's disease (AD). Consideration is given here to evidence that several neurodegenerative diseases and syndromes share common elements, including profound LC cell loss, and may in fact be different manifestations of a common pathophysiological process. Findings in animal models of PD indicate that the modification of LC-noradrenergic activity alters electrophysiological, neurochemical and behavioral indices of neurotransmission in the nigrostriatal dopaminergic system, and influences the response of this system to experimental lesions. In models related to AD, noradrenergic mechanisms appear to play important roles in modulating the activity of the basalocortical cholinergic system and its response to injury, and to modify cognitive functions including memory and attention. Mechanisms by which noradrenaline may protect or promote recovery from neural damage are reviewed, including effects on neuroplasticity, neurotrophic factors, neurogenesis, inflammation, cellular energy metabolism and excitotoxicity, and oxidative stress. Based on evidence for facilitatory effects on transmitter release, motor function, memory, neuroprotection and recovery of function after brain injury, a rationale for the potential of noradrenergic-based approaches, specifically alpha2-adrenoceptor antagonists, in the treatment of central neurodegenerative diseases is presented.
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Affiliation(s)
- Marc R Marien
- Centre de Recherche Pierre Fabre, Neurobiology I, 17 Avenue Jean Moulin, 81106 Castres Cedex, France.
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32
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Antonopoulos J, Latsari M, Dori I, Chiotelli M, Parnavelas JG, Dinopoulos A. Noradrenergic innervation of the developing and mature septal area of the rat. J Comp Neurol 2004; 476:80-90. [PMID: 15236468 DOI: 10.1002/cne.20205] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The noradrenergic innervation of the developing and mature septal area of the rat was examined with light and electron microscopic immunocytochemistry using an antibody against dopamine-beta-hydroxylase. At birth, a small number of relatively thick noradrenergic fibers were found to innervate the lateral septum (mainly its intermediate part) and the nuclei of the vertical and horizontal limbs of the diagonal band of Broca. By postnatal day 7, a substantial increase in their density was observed. At this age some labeled fibers left the medial forebrain bundle and invaded the nucleus of the horizontal limb of the diagonal band. These fibers then ran in a ventrodorsal direction and innervated the nucleus of the vertical limb before entering the medial septum. Immunoreactive fibers were finer and more varicose than at birth. In the subsequent 2 weeks, the density of labeled fibers in the septal area was further increased. By postnatal day 21, the distribution pattern and density of the noradrenergic innervation appeared similar to the adult. In the adult, noradrenergic fibers exhibited more varicosities than in younger rats. Electron microscopic analysis revealed a low proportion (peaked at P7) of noradrenergic varicosities engaged in synaptic contacts throughout development. The overwhelming majority of these synapses were symmetrical, predominantly with small or medium-sized dendrites. The present findings provide the morphological basis for the functional interactions between noradrenergic afferents and neuronal elements in the septal area. The low proportion of synaptic contacts found in this study suggests that noradrenaline may exert its action in the septal area mainly through transmission by diffusion (volume transmission), as has been suggested for other areas of the developing and adult brain.
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Affiliation(s)
- John Antonopoulos
- Department of Anatomy, School of Veterinary Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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33
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Bauer S, Moyse E, Jourdan F, Colpaert F, Martel JC, Marien M. Effects of the alpha 2-adrenoreceptor antagonist dexefaroxan on neurogenesis in the olfactory bulb of the adult rat in vivo: selective protection against neuronal death. Neuroscience 2003; 117:281-91. [PMID: 12614670 DOI: 10.1016/s0306-4522(02)00757-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A dysfunction of noradrenergic mechanisms originating in the locus coeruleus has been hypothesised to be the critical factor underlying the evolution of central neurodegenerative diseases [Colpaert FC (1994) Noradrenergic mechanism Parkinson's disease: a theory. In: Noradrenergic mechanisms in Parkinson's disease (Briley M, Marien M, eds) pp 225-254. Boca Raton, FL, USA: CRC Press Inc.]. alpha(2)-Adrenoceptor antagonists, presumably in part by facilitating central noradrenergic transmission, afford neuroprotection in vivo in models of cerebral ischaemia, excitotoxicity and devascularization-induced neurodegeneration. The present study utilised the rat olfactory bulb as a model system for examining the effects of the selective alpha(2)-adrenoceptor antagonist dexefaroxan upon determinants of neurogenesis (proliferation, survival and death) in the adult brain in vivo. Cell proliferation (5-bromo-2'-deoxyuridine labelling) and cell death associated with DNA fragmentation (terminal dideoxynucleotidyl transferase-catalysed 2'-deoxyuridine-5'-triphosphate nick end-labelling assay) were quantified following a 7-day treatment with either vehicle or dexefaroxan (0.63 mg/kg i.p., three times daily), followed by a 3-day washout period. The number of terminal dideoxynucleotidyl transferase-catalysed 2'-deoxyuridine-5'-triphosphate nick end-labelling-positive nuclei in the olfactory bulb was lower in dexefaroxan-treated rats, this difference being greatest and significant in the subependymal layer (-52%). In contrast, 5-bromo-2'-deoxyuridine-immunoreactive nuclei were more numerous (+68%) in the bulbs of dexefaroxan-treated rats whilst no differences were detected in the proliferating region of the subventricular zone. Terminal dideoxynucleotidyl transferase-catalysed 2'-deoxyuridine-5'-triphosphate nick end-labelling combination with glial fibrillary acidic protein or neuronal-specific antigen immunohistochemistry revealed that terminal dideoxynucleotidyl transferase-catalysed 2'-deoxyuridine-5'-triphosphate nick end-labelling-positive nuclei were associated primarily with a neuronal cell phenotype. These findings suggest that dexefaroxan increases neuron survival in the olfactory bulb of the adult rat in vivo, putatively as a result of reducing the apoptotic fate of telencephalic stem cell progenies.
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Affiliation(s)
- S Bauer
- Laboratoire Neurosciences et Systèmes Sensoriels, CNRS-UMR 5020, Université Claude Bernard-Lyon 1, Boulevard 11 novembre 1918, 69622 Villeurbanne, France
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34
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Kulkarni VA, Jha S, Vaidya VA. Depletion of norepinephrine decreases the proliferation, but does not influence the survival and differentiation, of granule cell progenitors in the adult rat hippocampus. Eur J Neurosci 2002; 16:2008-12. [PMID: 12453065 DOI: 10.1046/j.1460-9568.2002.02268.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The dentate gyrus region retains the ability to generate neurons throughout adulthood. A few studies have examined the neurotransmitter regulation of adult hippocampal neurogenesis and have shown that this process is regulated by serotonin and glutamate. Given the strong noradrenergic innervation of the adult hippocampus and the ability of norepinephrine to influence proliferation during development, we examined the influence of norepinephrine on adult hippocampal neurogenesis. Our study indicates that depletion of norepinephrine by the selective noradrenergic neurotoxin, N-(2-chloroethyl)-N-ethyl-2-bromo benzylamine hydrochloride (DSP-4), results in a 63% reduction in the proliferation of dentate gyrus progenitor cells identified through 5-bromo-2'-deoxyuridine (BrdU) labelling. In contrast, the survival of BrdU-positive cells labelled prior to treatment with DSP-4 is not influenced by norepinephrine depletion. The differentiation of BrdU labelled progenitors into neurons or glia was also not sensitive to noradrenergic depletion. These results indicate that the proliferation, but not the survival or differentiation, of adult hippocampal granule cell progenitors is affected by norepinephrine depletion.
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Affiliation(s)
- Vaishali A Kulkarni
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400005, India
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