1
|
Barbaresi P, Fabri M, Lorenzi T, Sagrati A, Morroni M. Intrinsic organization of the corpus callosum. Front Physiol 2024; 15:1393000. [PMID: 39035452 PMCID: PMC11259024 DOI: 10.3389/fphys.2024.1393000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 05/16/2024] [Indexed: 07/23/2024] Open
Abstract
The corpus callosum-the largest commissural fiber system connecting the two cerebral hemispheres-is considered essential for bilateral sensory integration and higher cognitive functions. Most studies exploring the corpus callosum have examined either the anatomical, physiological, and neurochemical organization of callosal projections or the functional and/or behavioral aspects of the callosal connections after complete/partial callosotomy or callosal lesion. There are no works that address the intrinsic organization of the corpus callosum. We review the existing information on the activities that take place in the commissure in three sections: I) the topographical and neurochemical organization of the intracallosal fibers, II) the role of glia in the corpus callosum, and III) the role of the intracallosal neurons.
Collapse
Affiliation(s)
- Paolo Barbaresi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Mara Fabri
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Teresa Lorenzi
- Department of Experimental and Clinical Medicine, Section of Neuroscience and Cell Biology, Marche Polytechnic University, Ancona, Italy
| | - Andrea Sagrati
- Department of Life and Environmental Sciences, Marche Polytechnic University, Ancona, Italy
| | - Manrico Morroni
- Electron Microscopy Unit, Azienda Ospedaliero-Universitaria, Ancona, Italy
| |
Collapse
|
2
|
Burnstock G, Fredholm BB, North RA, Verkhratsky A. The birth and postnatal development of purinergic signalling. Acta Physiol (Oxf) 2010; 199:93-147. [PMID: 20345419 DOI: 10.1111/j.1748-1716.2010.02114.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The purinergic signalling system is one of the most ancient and arguably the most widespread intercellular signalling system in living tissues. In this review we present a detailed account of the early developments and current status of purinergic signalling. We summarize the current knowledge on purinoceptors, their distribution and role in signal transduction in various tissues in physiological and pathophysiological conditions.
Collapse
Affiliation(s)
- G Burnstock
- Autonomic Neuroscience Centre, Royal Free and University College Medical School, London, UK.
| | | | | | | |
Collapse
|
3
|
Abstract
This review is focused on purinergic neurotransmission, i.e., ATP released from nerves as a transmitter or cotransmitter to act as an extracellular signaling molecule on both pre- and postjunctional membranes at neuroeffector junctions and synapses, as well as acting as a trophic factor during development and regeneration. Emphasis is placed on the physiology and pathophysiology of ATP, but extracellular roles of its breakdown product, adenosine, are also considered because of their intimate interactions. The early history of the involvement of ATP in autonomic and skeletal neuromuscular transmission and in activities in the central nervous system and ganglia is reviewed. Brief background information is given about the identification of receptor subtypes for purines and pyrimidines and about ATP storage, release, and ectoenzymatic breakdown. Evidence that ATP is a cotransmitter in most, if not all, peripheral and central neurons is presented, as well as full accounts of neurotransmission and neuromodulation in autonomic and sensory ganglia and in the brain and spinal cord. There is coverage of neuron-glia interactions and of purinergic neuroeffector transmission to nonmuscular cells. To establish the primitive and widespread nature of purinergic neurotransmission, both the ontogeny and phylogeny of purinergic signaling are considered. Finally, the pathophysiology of purinergic neurotransmission in both peripheral and central nervous systems is reviewed, and speculations are made about future developments.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neurscience Centre, Royal Free and University College Medical School, London, UK.
| |
Collapse
|
4
|
Hussl S, Boehm S. Functions of neuronal P2Y receptors. Pflugers Arch 2006; 452:538-51. [PMID: 16691392 DOI: 10.1007/s00424-006-0063-8] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2006] [Accepted: 03/06/2006] [Indexed: 01/05/2023]
Abstract
Within the last 15 years, at least eight different G protein-coupled nucleotide receptors, i.e., P2Y receptors, have been characterized by molecular means. While ionotropic P2X receptors are mainly involved in fast synaptic neurotransmission, P2Y receptors rather mediate slower neuromodulatory effects. This P2Y receptor-dependent neuromodulation relies on changes in synaptic transmission via either pre- or postsynaptic sites of action. At both sites, the regulation of voltage-gated or transmitter-gated ion channels via G protein-linked signaling cascades has been identified as the predominant underlying mechanisms. In addition, neuronal P2Y receptors have been found to be involved in neurotoxic and neurotrophic effects of extracellular adenosine 5-triphosphate. This review provides an overview of the most prominent actions mediated by neuronal P2Y receptors and describes the signaling cascades involved.
Collapse
Affiliation(s)
- Simon Hussl
- Center of Biomolecular Medicine and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstrasse 13a, Vienna, 1090, Austria
| | | |
Collapse
|
5
|
Coomber BL, Mitchell GB, Starr AE, Minhas K, Tamblyn A, Shewen PE, Gentry PA. Clopidogrel induced suppression of bovine platelet activation in vitro and a preliminary study of its effect on the development of Mannheimia haemolytica induced pneumonia. Vet J 2006; 171:126-34. [PMID: 16427590 DOI: 10.1016/j.tvjl.2004.09.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2004] [Indexed: 11/17/2022]
Abstract
We report here on the influence of the platelet antagonist clopidogrel (Plavix) on bovine platelet function. We first evaluated the capacity of clopidogrel to inhibit adenosine diphosphate (ADP)-stimulated platelet function in the bovine species, using an ex vivo approach with blood from treated animals. Platelets isolated from treated calves displayed rapid and consistent reduction in function (aggregation, thromboxane production) upon ADP, but not platelet activating factor (PAF), stimulation. We then examined the possibility that clopidogrel could influence Mannheimia haemolytica pneumonia pathobiology using an experimental challenge model. We were unable to detect significant differences between clopidogrel treated and untreated animals when challenged with intra-tracheal inoculation of M. haemolytica. There was a trend towards inhibition of platelet degranulation in the affected regions of lungs from clopidogrel treated calves, and pre-treated challenged animals had similar amounts of fibrin deposition and enhanced fibrous tissue formation in their lungs when compared with control counterparts.
Collapse
Affiliation(s)
- Brenda L Coomber
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ont., Canada N1G 2W1.
| | | | | | | | | | | | | |
Collapse
|
6
|
Burnstock G, Knight GE. Cellular Distribution and Functions of P2 Receptor Subtypes in Different Systems. INTERNATIONAL REVIEW OF CYTOLOGY 2004; 240:31-304. [PMID: 15548415 DOI: 10.1016/s0074-7696(04)40002-3] [Citation(s) in RCA: 581] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This review is aimed at providing readers with a comprehensive reference article about the distribution and function of P2 receptors in all the organs, tissues, and cells in the body. Each section provides an account of the early history of purinergic signaling in the organ?cell up to 1994, then summarizes subsequent evidence for the presence of P2X and P2Y receptor subtype mRNA and proteins as well as functional data, all fully referenced. A section is included describing the plasticity of expression of P2 receptors during development and aging as well as in various pathophysiological conditions. Finally, there is some discussion of possible future developments in the purinergic signaling field.
Collapse
Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Institute, Royal Free and University College Medical School, London NW3 2PF, United Kingdom
| | | |
Collapse
|
7
|
|
8
|
Sak K, Webb TE. A retrospective of recombinant P2Y receptor subtypes and their pharmacology. Arch Biochem Biophys 2002; 397:131-6. [PMID: 11747319 DOI: 10.1006/abbi.2001.2616] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since the first cloning of P2Y receptor sequences in 1993 it has become apparent that this family of G-protein-coupled receptors is omnipresent. At least 25 individual sequences entered in the GenBank sequence database encode P2Y receptors from a variety of species ranging from the little skate Raja erinacea to man. In man, six receptor subtypes have been cloned and found to be functionally active (P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(11), and P2Y(12)). In this article a review of the P2Y receptor subtypes is presented considering both their sequences and the pharmacological profiles of the encoded receptors expressed in heterologous expression systems.
Collapse
Affiliation(s)
- Katrin Sak
- Hematology-Oncology Clinic, Tartu University, Ulikooli 18, Tartu 50090, Estonia
| | | |
Collapse
|
9
|
Lenz G, Gonçalves D, Luo Z, Avruch J, Rodnight R, Neary JT. Extracellular ATP stimulates an inhibitory pathway towards growth factor-induced cRaf-1 and MEKK activation in astrocyte cultures. J Neurochem 2001; 77:1001-9. [PMID: 11359865 DOI: 10.1046/j.1471-4159.2001.00299.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ATP, acting via P2Y, G protein-coupled receptors (GPCRs), is a mitogenic signal and also synergistically enhances fibroblast growth factor-2 (FGF-2)-induced proliferation in astrocytes. Here, we have examined the effects of ATP and FGF-2 cotreatment on the main components of the extracellular-signal regulated protein kinase (ERK) cascade, cRaf-1, MAPK/ERK kinase (MEK) and ERK, key regulators of cellular proliferation. Surprisingly, ATP inhibited activation of cRaf-1 by FGF-2 in primary cultures of rat cortical astrocytes. The inhibitory effect did not diminish MEK and ERK activation; indeed, cotreatment resulted in a greater initial activation of ERK. ATP inhibition of cRaf-1 activation was not mediated by an increase in cyclic AMP levels or by protein kinase C activation. ATP also inhibited the activation of cRaf-1 by other growth factors, epidermal growth factor and platelet-derived growth factor, as well as other MEK1 activators stimulated by FGF-2, MEK kinase 1 (MEKK1) and MEKK2. Serotonin, an agonist of another GPCR coupled to ERK, did not inhibit FGF-2-induced cRaf-1 activation, thereby indicating specificity in the ATP-induced inhibitory cross-talk. These findings suggest that ATP stimulates an inhibitory activity that lays upstream of MEK activators and inhibits growth factor-induced activation of cRaf-1 and MEKKS: Such a mechanism might serve to integrate the actions of receptor tyrosine kinases and P2Y-GPCRS:
Collapse
Affiliation(s)
- G Lenz
- Departments of Biofísica and Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | | | | | | | | | | |
Collapse
|
10
|
Aguilar JS, Reyes R, Asensio AC, Oaknin S, Rotllán P, Miledi R. Ectoenzymatic breakdown of diadenosine polyphosphates by Xenopus laevis oocytes. EUROPEAN JOURNAL OF BIOCHEMISTRY 2001; 268:1289-97. [PMID: 11231280 DOI: 10.1046/j.1432-1327.2001.01987.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Xenopus laevis oocytes exhibit ectoenzymatic activity able to hydrolytically cleave extracellular diadenosine polyphosphates (Ap(n)A). The basic properties of this ectoenzyme were investigated using as substrates di-(1,N(6)-ethenoadenosine) 5',5"'-P(1),P(4)-tetraphospate [epsilon-(Ap(4)A)] and di-(1,N(6)-ethenoadenosine) 5',5"'-P(1),P(5)-pentaphospate [epsilon-(Ap(5)A)], fluorogenic derivatives of Ap(4)A and Ap(5)A, respectively. epsilon-(Ap(4)A) and epsilon-(Ap(5)A) are hydrolysed by folliculated oocytes according to hyperbolic kinetics with K(m) values of 13.4 and 12.0 microM and Vmax values of 4.8 and 5.5 pmol per oocyte per min, respectively. The ectoenzyme is activated by Ca(2+) and Mg(2+), reaches maximal activity at pH 8--9 and is inhibited by suramin. Defolliculated oocytes also hydrolyse both substrates with similar K(m) values but V(max) values are approximately doubled with respect to folliculated controls. Chromatographic analysis indicates that extracellular epsilon-(Ap(4)A) and epsilon-(Ap(5)A) are first cleaved into 1,N(6)-ethenoAMP (epsilon-AMP) + 1,N(6)-ethenoATP (epsilon-ATP) and epsilon-AMP + 1,N(6)-ethenoadenosine tetraphosphate (epsilon-Ap(4)), respectively, which are catabolized to 1,N(6)-ethenoadenosine (epsilon-Ado) as the end product by folliculated oocytes. Denuded oocytes, however, show a drastically reduced rate of epsilon-Ado production, epsilon-AMP being the main end-product of extracellular epsilon-(Ap(n)A) catabolism. Results indicate that, whereas the Ap(n)A-cleaving ectoenzyme appears to be located mainly in the oocyte, ectoenzymes involved in the dephosphorylation of mononucleotide moieties are located mainly in the follicular cell layer.
Collapse
Affiliation(s)
- J S Aguilar
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | | | | | | | | | | |
Collapse
|
11
|
Morán-Jiménez MJ, Matute C. Immunohistochemical localization of the P2Y(1) purinergic receptor in neurons and glial cells of the central nervous system. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 78:50-8. [PMID: 10891584 DOI: 10.1016/s0169-328x(00)00067-x] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study reports the characterization of a polyclonal antiserum to a carboxy-terminal epitope of the P2Y(1) receptor and its use in immunolocalization studies of this receptor in the CNS. The antibody recognized a major band of 42 kDa in Western blot of tissue homogenates from rat and bovine brain. Immunohistochemical studies confirmed early reports about the presence of the P2Y(1) receptor in the corpus callosum, habenula and ductal cells of the salivary gland. In addition, we found that the P2Y(1) receptor is intensely expressed in Purkinje cells, in deep layers of the cerebral cortex and in ischemic-sensitive areas of the hippocampus. Moreover, oligodendrocytes and astrocytes in brain white matter tracts and optic nerve were also immunoreactive. The intense expression of the P2Y(1) peptide in the aforementioned cell types suggests that this receptor may play fundamental roles in glial physiology. This antiserum should be a useful tool to study the presence of the P2Y(1) receptor in different tissues and cell cultures as well as in expression systems, and to distinguish the P2Y(1) from other subtypes of P2Y receptors.
Collapse
Affiliation(s)
- M J Morán-Jiménez
- Departamento de Neurociencias, Facultad de Medicina y Odontología, Universidad del País Vasco, 48940 Leioa, Vizcaya, Spain
| | | |
Collapse
|