1
|
Zhao H, Guillaud L, Emily MF, Xu X, Moshniaha L, Hanayama H, Kabe R, Terenzio M, Narita A. Nanographene-Based Polymeric Nanoparticles as Near-Infrared Emissive Neuronal Tracers. ACS NANO 2024; 18:34730-34740. [PMID: 39668551 DOI: 10.1021/acsnano.4c10754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2024]
Abstract
Precise tracking of axonal transport is key to deciphering neuronal functions. To achieve long-term imaging at both ultrastructural and macroscopic resolutions, it is critical to develop fluorescent transport tracers with high photostability and biocompatibility. Herein, we report the investigation of nanographene (NG)-based polymeric nanoparticles (NPs) as near-infrared (NIR)-emissive neuronal tracers. Dibenzo[a,m]dinaphtho[3,2,1-ef:1',2',3'-hi]coronene (DBDNC) was employed as the NG, which exhibited a broad NIR emission with a maximum at 711 nm inside the NPs. DBDNC-NPs displayed high photostability and low cytotoxicity, enabling live tracing of retrograde axonal transport in mouse sensory neurons cultured in microfluidic chambers. We also elucidated how DBDNC-NPs undergo retrograde axonal transport following the endolysosomal pathway. This work provides a proof of concept for NIR-emissive, NG-based neuronal tracers with potential for applications in neurobiology.
Collapse
Affiliation(s)
- Hao Zhao
- Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Laurent Guillaud
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Maria Fransiska Emily
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Xiushang Xu
- Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Liliia Moshniaha
- Organic Optoelectronics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Hiroki Hanayama
- Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Ryota Kabe
- Organic Optoelectronics Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Marco Terenzio
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
| | - Akimitsu Narita
- Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa 904-0495, Japan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| |
Collapse
|
2
|
Guyenet PG, Stornetta RL, Souza GMPR, Abbott SBG, Brooks VL. Neuronal Networks in Hypertension: Recent Advances. Hypertension 2020; 76:300-311. [PMID: 32594802 DOI: 10.1161/hypertensionaha.120.14521] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurogenic hypertension is associated with excessive sympathetic nerve activity to the kidneys and portions of the cardiovascular system. Here we examine the brain regions that cause heightened sympathetic nerve activity in animal models of neurogenic hypertension, and we discuss the triggers responsible for the changes in neuronal activity within these regions. We highlight the limitations of the evidence and, whenever possible, we briefly address the pertinence of the findings to human hypertension. The arterial baroreflex reduces arterial blood pressure variability and contributes to the arterial blood pressure set point. This set point can also be elevated by a newly described cerebral blood flow-dependent and astrocyte-mediated sympathetic reflex. Both reflexes converge on the presympathetic neurons of the rostral medulla oblongata, and both are plausible causes of neurogenic hypertension. Sensory afferent dysfunction (reduced baroreceptor activity, increased renal, or carotid body afferent) contributes to many forms of neurogenic hypertension. Neurogenic hypertension can also result from activation of brain nuclei or sensory afferents by excess circulating hormones (leptin, insulin, Ang II [angiotensin II]) or sodium. Leptin raises blood vessel sympathetic nerve activity by activating the carotid bodies and subsets of arcuate neurons. Ang II works in the lamina terminalis and probably throughout the brain stem and hypothalamus. Sodium is sensed primarily in the lamina terminalis. Regardless of its cause, the excess sympathetic nerve activity is mediated to some extent by activation of presympathetic neurons located in the rostral ventrolateral medulla or the paraventricular nucleus of the hypothalamus. Increased activity of the orexinergic neurons also contributes to hypertension in selected models.
Collapse
Affiliation(s)
- Patrice G Guyenet
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Ruth L Stornetta
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - George M P R Souza
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Stephen B G Abbott
- From the Department of Pharmacology, University of Virginia, Charlottesville (P.G.G., R.L.S., G.M.P.R.S., S.B.G.A.)
| | - Virginia L Brooks
- Department of Chemical Physiology and Biochemistry, Oregon Health & Sciences University, Portland (V.L.B.)
| |
Collapse
|
3
|
Abstract
Our ability to understand the function of the nervous system is dependent upon defining the connections of its constituent neurons. Development of methods to define connections within neural networks has always been a growth industry in the neurosciences. Transneuronal spread of neurotropic viruses currently represents the best means of defining synaptic connections within neural networks. The method exploits the ability of viruses to invade neurons, replicate, and spread through the intimate synaptic connections that enable communication among neurons. Since the method was first introduced in the 1970s, it has benefited from an increased understanding of the virus life cycle, the function of viral genome, and the ability to manipulate the viral genome in support of directional spread of virus and the expression of transgenes. In this unit, we review these advances in viral tracing technology and the way in which they may be applied for functional dissection of neural networks.
Collapse
Affiliation(s)
- J Patrick Card
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | |
Collapse
|
4
|
Ugolini G. Advances in viral transneuronal tracing. J Neurosci Methods 2010; 194:2-20. [DOI: 10.1016/j.jneumeth.2009.12.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Revised: 11/28/2009] [Accepted: 12/03/2009] [Indexed: 10/20/2022]
|
5
|
Abstract
The middle ear muscle (MEM) reflex is one of two major descending systems to the auditory periphery. There are two middle ear muscles (MEMs): the stapedius and the tensor tympani. In man, the stapedius contracts in response to intense low frequency acoustic stimuli, exerting forces perpendicular to the stapes superstructure, increasing middle ear impedance and attenuating the intensity of sound energy reaching the inner ear (cochlea). The tensor tympani is believed to contract in response to self-generated noise (chewing, swallowing) and non-auditory stimuli. The MEM reflex pathways begin with sound presented to the ear. Transduction of sound occurs in the cochlea, resulting in an action potential that is transmitted along the auditory nerve to the cochlear nucleus in the brainstem (the first relay station for all ascending sound information originating in the ear). Unknown interneurons in the ventral cochlear nucleus project either directly or indirectly to MEM motoneurons located elsewhere in the brainstem. Motoneurons provide efferent innervation to the MEMs. Although the ascending and descending limbs of these reflex pathways have been well characterized, the identity of the reflex interneurons is not known, as are the source of modulatory inputs to these pathways. The aim of this article is to (a) provide an overview of MEM reflex anatomy and physiology, (b) present new data on MEM reflex anatomy and physiology from our laboratory and others, and (c) describe the clinical implications of our research.
Collapse
Affiliation(s)
- Sudeep Mukerji
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Alanna Marie Windsor
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Daniel J. Lee
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
- Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| |
Collapse
|
6
|
Klopfleisch R, Klupp BG, Fuchs W, Kopp M, Teifke JP, Mettenleiter TC. Influence of pseudorabies virus proteins on neuroinvasion and neurovirulence in mice. J Virol 2007; 80:5571-6. [PMID: 16699038 PMCID: PMC1472135 DOI: 10.1128/jvi.02589-05] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Neurotropism is a distinctive feature of members of the Alphaherpesvirinae. However, its molecular basis remains enigmatic. In the past, research has been focused mainly on the role of viral envelope proteins in modulating herpesvirus neuroinvasion and neurovirulence (T. C. Mettenleiter, Virus Res. 92:192-206, 2003). To further analyze the molecular requirements for neuroinvasion of the alphaherpesvirus pseudorabies virus (PrV), adult mice were infected intranasally with a set of single- or multiple-deletion mutants lacking the UL3, UL4, UL7, UL11, UL13, UL16, UL17, UL21, UL31, UL34, UL37, UL41, UL43, UL46, UL47, UL48, UL51, US3, US9, glycoprotein E (gE), gM, UL11/US9, UL11/UL16, UL16/UL21, UL11/UL16/UL21, UL11/gE, UL11/gM, UL43/gK, UL43/gM, or UL43/gK/gM genes. Neurovirulence was evaluated by measuring mean survival times compared to that after wild-type virus infection. Furthermore, by immunohistochemical detection of infected neurons, the kinetics of viral spread in the murine central nervous system was investigated.
Collapse
Affiliation(s)
- Robert Klopfleisch
- Institute of Molecular Biology, Friedrich-Loeffler-Institut, Boddenblick 5A, D-17493 Greifswald-Insel Riems, Germany
| | | | | | | | | | | |
Collapse
|
7
|
Breshears MA, Eberle R, Ritchey JW. Temporal progression of viral replication and gross and histological lesions in Balb/c mice inoculated epidermally with Saimiriine herpesvirus 1 (SaHV-1). J Comp Pathol 2005; 133:103-13. [PMID: 15964589 DOI: 10.1016/j.jcpa.2005.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Accepted: 01/25/2005] [Indexed: 11/27/2022]
Abstract
Saimiriine herpesvirus 1 (SaHV-1), an alphaherpesvirus enzootic in squirrel monkeys, is genetically related to monkey B virus and human herpes simplex virus (HSV). To study the temporal progression of viral spread and associated lesions, Balb/c mice were inoculated epidermally by scarification with a green fluorescent protein (GFP)-expressing recombinant strain of SaHV-1 and killed sequentially. Pinpoint ulcerative lesions in the inoculated epidermis progressed over a few days to unilateral or bilateral hindlimb paresis or paralysis, urinary and faecal incontinence, abdominal distension, hunched posture and eventual depression warranting euthanasia. Viral replication was present within epidermal keratinocytes, neurons of the dorsal root ganglia and thoracolumbar spinal cord, regional autonomic ganglia, lower urinary tract epithelium and colonic myenteric plexuses, as indicated by histological lesions and GFP expression. Almost all mice inoculated with 10(5) or 10(6) plaque-forming units (PFU) of SaHV-1 developed rapidly progressive disease. Two of eight mice given 10(4)PFU developed disease, but no mice receiving less than 10(4)PFU gave evidence of infection. Mice that showed no clinical signs also failed to develop an antiviral IgG response, indicating absence of active viral infection. For SaHV-1 inoculated epidermally, the ID(50), CNSD(50) and LD(50) values were identical (10(4.38)), indicating that successful infection by this route invariably resulted in lethal CNS (central nervous system) disease. Consistently severe disease in all infected animals, with regionally extensive distribution of viral replication, constituted a marked difference from the disease produced by intramuscular inoculation.
Collapse
Affiliation(s)
- M A Breshears
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078, USA
| | | | | |
Collapse
|
8
|
Seiler MJ, Sagdullaev BT, Woch G, Thomas BB, Aramant RB. Transsynaptic virus tracing from host brain to subretinal transplants. Eur J Neurosci 2005; 21:161-72. [PMID: 15654853 DOI: 10.1111/j.1460-9568.2004.03851.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of this study was to establish synapses between a transplant and a degenerated retina. To tackle this difficult task, a little-known but well-established CNS method was chosen: trans-synaptic pseudorabies virus (PRV) tracing. Sheets of E19 rat retina with or without retinal pigment epithelium (RPE) were transplanted to the subretinal space in 33 Royal College of Surgeons (RCS) and transgenic s334ter-5 rats with retinal degeneration. Several months later, PRV-BaBlu (expressing E. colibeta-galactosidase) or PRV-Bartha was injected into an area of the exposed superior colliculus (SC), topographically corresponding to the transplant placement in the retina. Twenty normal rats served as controls. After survival times of 1-5 days, retinas were examined for virus by X-gal histochemistry, immunohistochemistry and electron microscopy. In normal controls, virus was first seen in retinal ganglion cells and Müller glia after 1-1.5 days, and had spread to all retinal layers after 2-3 days. Virus-labeled cells were found in 16 of 19 transplants where the virus injection had retrogradely labeled the topographically correct transplant area of the host retina. Electron microscopically, enveloped and nonenveloped virus could clearly be detected in infected cells. Enveloped virus was found only in neurons. Infected glial cells contained only nonenveloped virus. Neurons in retinal transplants are labeled after PRV injection into the host brain, indicating synaptic connectivity between transplants and degenerated host retinas. This study provides evidence that PRV spreads in the retina as in other parts of the CNS and is useful to outline transplant-host circuitry.
Collapse
Affiliation(s)
- Magdalene J Seiler
- Department of Ophthalmology & Visual Sciences, University of Louisville, Louisville, KY, USA.
| | | | | | | | | |
Collapse
|
9
|
Boldogköi Z, Sík A, Dénes A, Reichart A, Toldi J, Gerendai I, Kovács KJ, Palkovits M. Novel tracing paradigms--genetically engineered herpesviruses as tools for mapping functional circuits within the CNS: present status and future prospects. Prog Neurobiol 2004; 72:417-45. [PMID: 15177785 DOI: 10.1016/j.pneurobio.2004.03.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Accepted: 03/29/2004] [Indexed: 11/17/2022]
Abstract
The mammalian CNS is composed of an extremely complex meshwork of highly ordered interconnections among billions of neurons. To understand the diverse functions of this neuronal network we need to differentiate between functionally related and nonrelated elements. A powerful labeling method for defining intricate neural circuits is based on the utilization of neurotropic herpesviruses, including pseudorabies virus and herpes simplex virus type 1. The recent development of genetically engineered tracing viruses can open the way toward the conception of novel tract-tracing paradigms. These new-generation tracing viruses may facilitate the clarification of problems, which were inaccessible to earlier approaches. This article first presents a concise review of the general aspects of neuroanatomical tracing protocols. Subsequently, it discusses the molecular biology of alpha-herpesviruses, and the genetic manipulation and gene expression techniques that are utilized for the construction of virus-based tracers. Finally, it describes the current utilization of genetically modified herpesviruses for circuit analysis, and the future directions in their potential applications.
Collapse
Affiliation(s)
- Zsolt Boldogköi
- Laboratory of Neuromorphology, Department of Anatomy, Faculty of Medicine, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Cano G, Card JP, Sved AF. Dual viral transneuronal tracing of central autonomic circuits involved in the innervation of the two kidneys in rat. J Comp Neurol 2004; 471:462-81. [PMID: 15022264 DOI: 10.1002/cne.20040] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The neural control of renal function is exerted by the central nervous system via sympathetic innervation of the kidneys. To determine the extent to which the control of the two kidneys is provided by the same brain neurons, the central circuitry involved in the innervation of both kidneys was characterized in individual rats by dual viral transneuronal tracing using isogenic recombinant strains (PRV-152 and BaBlu) of pseudorabies virus. Prior to dual tracing, the neuroinvasive properties of PRV-152 and BaBlu were characterized by conducting parametric studies, using the two kidneys as an anatomical model, and comparing the pattern of infection with that obtained following injection of the parental strain, PRV-Bartha, into the left kidney. Once the optimal concentrations of virus required to obtain equivalent infection were established, PRV-152 and BaBlu were injected into the left and right kidney, respectively, in the same rats. Immunocytochemical localization of viral reporter proteins at different postinoculation times allowed us to determine the sequence of infection in the brain, as well as to quantify dual- and single-labeled neurons in each infected area. Neurons that influence autonomic outflow to one or both kidneys coexist in all brain areas involved in the control of the sympathetic outflow to the kidneys at every hierarchical level of the circuit. The proportions of dual-infected neurons with respect to the number of total infected neurons varied across regions, but they were maintained at different survival times. The pattern of infection suggests that the activity of each kidney is controlled independently by organ-specific neurons, whereas the functional coordination of the two kidneys results from neurons that collaterize to modulate the sympathetic outflow to both organs. The advantages of using an anatomical symmetrical system, such as the two kidneys, as an experimental approach to characterize PRV recombinants in general are also discussed.
Collapse
Affiliation(s)
- Georgina Cano
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | | | | |
Collapse
|
11
|
Horváth M, Ribári O, Répássy G, Tóth IE, Boldogkõi Z, Palkovits M. Intracochlear injection of pseudorabies virus labels descending auditory and monoaminerg projections to olivocochlear cells in guinea pig. Eur J Neurosci 2003; 18:1439-47. [PMID: 14511324 DOI: 10.1046/j.1460-9568.2003.02870.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pseudorabies virus was used to label transneuronally descending auditory projections following intracochlear injections. At different time points after injection, virus-infected cells were detected immunohistochemically in the central nervous system. Initially (25 h), virus was transported retrogradely to olivocochlear cells in the pons. At 32-72 h after injection, labelling occurred in higher order auditory brainstem nuclei as well as in the locus coeruleus and pontine dorsal raphe. At 90-108 h, virus-infected neurons were found bilaterally in the medial geniculate body and in layer V of the auditory cortex. Viral transneuronal labelling in the auditory cortex after intracochlear application confirms the existence of a continuous descending chain of neurons from the auditory cortex to the cochlea, via the medial and lateral olivocochlear systems. The transneuronal labelling of the locus coeruleus and pontine dorsal raphe suggests that noradrenergic and serotonergic inputs may substantially influence the activity of olivocochlear cells, and thus the cochlea.
Collapse
Affiliation(s)
- Miklós Horváth
- Department of Otolaryngology, Head and Neck Surgery, Semmelweis University, Szigony u. 36., 1083 Budapest, Hungary.
| | | | | | | | | | | |
Collapse
|
12
|
Flamand A, Bennardo T, Babic N, Klupp BG, Mettenleiter TC. The absence of glycoprotein gL, but not gC or gK, severely impairs pseudorabies virus neuroinvasiveness. J Virol 2001; 75:11137-45. [PMID: 11602753 PMCID: PMC114693 DOI: 10.1128/jvi.75.22.11137-11145.2001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Penetration and propagation of herpesviruses in the nervous system require the action of several glycoproteins. To assay for a function of glycoproteins gC, gK, and gL in the neuroinvasiveness of pseudorabies virus (PrV), deletion mutants lacking one of these glycoproteins and corresponding rescuants were inoculated in the nasal cavity of adult mice. We demonstrate that the lack of gL almost prevented the virus from penetrating and propagating in trigeminal, sympathetic, and parasympathetic tracks innervating the nasal cavity, while the lack of gC and gK only slowed the invasion of the nervous system. The conclusion of this and previous studies is that only gB, gD, gH, and gL are indispensable for penetration into neurons, while gB, gH, and gL (and, in some categories of neurons, also gE and gI) are necessary for transneuronal transfer in the mouse model. The deletion of other glycoprotein genes has little effect on PrV neuroinvasiveness although it may affect the dissemination of the virus.
Collapse
Affiliation(s)
- A Flamand
- Laboratoire de Génétique des Virus, CNRS, F-91198 Gif-sur-Yvette Cedex, France.
| | | | | | | | | |
Collapse
|
13
|
Waldbaum S, Hadziefendic S, Erokwu B, Zaidi SI, Haxhiu MA. CNS innervation of posterior cricoarytenoid muscles: a transneuronal labeling study. ACTA ACUST UNITED AC 2001; 126:113-25. [PMID: 11348639 DOI: 10.1016/s0034-5687(01)00200-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The CNS cell groups that project to neurons, which innervate the posterior cricoarytenoid muscles (PCA), were identified by the viral retrograde transneuronal labeling method. Pseudorabies virus (PRV) was injected into the PCA of C8 spinal rats and after 5 days survival, brain tissue sections were processed for immunohistochemical detection of PRV. Retrogradely labeled motor neurons innervating the PCA were seen in the nucleus ambiguus and in the area ventral to it. Neurons innervating the PCA motoneurons were found throughout the ventral aspect of the medulla oblongata, in the nucleus tractus solitarius, and in the pons. Labeling was present in the midbrain periaquaductal gray, in the lateral and paraventricular hypothalamic nuclei, in the amygdaloid complex, in the hippocampus, and within the piriform cortex. In summary, the motor neurons that control PCA activity are innervated predominantly by a network of neurons that lie along the neuraxis, in the regions known to be involved in regulation of respiratory output and autonomic functions.
Collapse
Affiliation(s)
- S Waldbaum
- Department of Pediatrics, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | | | | | | | | |
Collapse
|
14
|
Bartness TJ, Song CK, Demas GE. SCN efferents to peripheral tissues: implications for biological rhythms. J Biol Rhythms 2001; 16:196-204. [PMID: 11407779 DOI: 10.1177/074873040101600302] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The suprachiasmatic nucleus (SCN) is the principal generator of circadian rhythms and is part of an entrainment system that synchronizes the animal with its environment. Here, we review the possible communication of timing information from the SCN to peripheral tissues involved in regulating fundamental physiological functions as revealed using a viral, transneuronal tract tracer, the pseudorabies virus (PRV). The sympathetic nervous system innervation of the pineal gland and the sympathetic outflow from brain to white adipose tissue were the first demonstrations of SCN-peripheral tissue connections. The inclusion of the SCN as part of these and other circuits was the result of lengthened postviral injection times compared with those used previously. Subsequently, the SCN has been found to be part of the sympathetic outflow from the brain to brown adipose tissue, thyroid gland, kidney, bladder, spleen, adrenal medulla, and perhaps the adrenal cortex. The SCN also is involved in the parasympathetic nervous system innervation of the thyroid, liver, pancreas, and submandibular gland. Individual SCN neurons appear connected to more than one autonomic circuit involving both sympathetic and parasympathetic innervation of a single tissue, or sympathetic innervation of two different peripheral tissues. Collectively, the results of these PRV studies require an expansion of the traditional roles of the SCN to include the autonomic innervation of peripheral tissues and perhaps the modulation of neuroendocrine systems traditionally thought to be controlled solely by hypothalamic stimulating/inhibiting factors.
Collapse
Affiliation(s)
- T J Bartness
- Department of Biology, Center for Behavioral Neuroscience, Georgia State University, Atlanta 30303-3083, USA.
| | | | | |
Collapse
|
15
|
Gerendai I, Tóth IE, Boldogkoi Z, Medveczky I, Halász B. Central nervous system structures labelled from the testis using the transsynaptic viral tracing technique. J Neuroendocrinol 2000; 12:1087-95. [PMID: 11069124 DOI: 10.1046/j.1365-2826.2000.00560.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present study, the transneuronal transport of neurotrophic virus technique was used to identify cell groups of the spinal cord and the brain that are transsynaptically connected with the testis. Pseudorabies virus was injected into the testis and after survival times of 3-6 days, the spinal cord and brain were processed immunocytochemically using a polyclonal antibody against the virus. Virus-infected perikarya were detected in the preganglionic neurones of the spinal cord (T10-L1, L5-S1) and in certain cell groups and areas of the brain stem, the hypothalamus and the telencephalon. In the brain stem, the cell groups and areas in which labelled neurones were present included, among others, the nucleus of the solitary tract, the caudal raphe nuclei, the locus coeruleus and the periaqueductal grey of the mesencephalon. In the hypothalamus, virus infected perikarya were observed in the paraventricular nucleus and in certain other cell groups. Telencephalic structures containing labelled neurones included the preoptic area, the bed nucleus of the stria terminalis, the central amygdala and the insular cortex. These data identify a multisynaptic circuit of neurones in the spinal cord and in the brain which may be involved in the control of testicular functions.
Collapse
Affiliation(s)
- I Gerendai
- Hungarian Academy of Sciences and Semmelweis University, Department of Human Morphology and Developmental Biology, Budapest
| | | | | | | | | |
Collapse
|
16
|
Ter Horst GJ. Transneuronal retrograde dual viral labelling of central autonomic circuitry: possibilities and pitfalls. Auton Neurosci 2000; 83:134-9. [PMID: 11593764 DOI: 10.1016/s1566-0702(00)00170-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Viral retrograde transneuronal labelling has become an important neuroanatomical tract-tracing tool for characterization of limbic neuronal networks. Recently, dual viral retrograde transneuronal labelling has been introduced; a method employing differential transgene expression of two genetically engineered virus strains to identify double infected cells with selective antibodies. In this way, interactions of parallel networks can be revealed. The use of this method will increase the understanding of the function of the limbic system, for example in the maintenance of metabolic homeostasis, but is associated with limitations related to the use of genetically engineered virus strains. Virulence, speed of replication and retrograde transport may be affected by the insertion or deletion of genes in the viral genome. Moreover, the rate of replication and transport can be affected by the immune system of the host and competition between the two viruses. There may be selective affinity of the virus strain for the sympathetic or parasympathetic systems. False negative results are the most important risk in dual viral labelling addressed in this review. Several control experiments are presented that can help to reduce the risk of obtaining false negative results.
Collapse
Affiliation(s)
- G J Ter Horst
- Biological Psychiatry, University Groningen, Hanzeplein 1, PO Box 30.001, Rm 7.15, 9700 RB Groningen, The Netherlands.
| |
Collapse
|
17
|
Gerdts V, Beyer J, Lomniczi B, Mettenleiter TC. Pseudorabies virus expressing bovine herpesvirus 1 glycoprotein B exhibits altered neurotropism and increased neurovirulence. J Virol 2000; 74:817-27. [PMID: 10623744 PMCID: PMC111602 DOI: 10.1128/jvi.74.2.817-827.2000] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Herpesvirus glycoproteins play dominant roles in the initiation of infection of target cells in culture and thus may also influence viral tropism in vivo. Whereas the relative contribution of several nonessential glycoproteins to neurovirulence and neurotropism of Pseudorabies virus (PrV), an alphaherpesvirus which causes Aujeszky's disease in pigs, has recently been uncovered in studies using viral deletion mutants, the importance of essential glycoproteins is more difficult to assess. We isolated an infectious PrV mutant, PrV-9112C2, which lacks the gene encoding the essential PrV glycoprotein B (gB) but stably carries in its genome and expresses the homologous gene of bovine herpesvirus 1 (BHV-1) (A. Kopp and T. C. Mettenleiter, J. Virol. 66:2754-2762, 1992). Apart from exhibiting a slight delay in penetration kinetics, PrV-9112C2 was similar in its growth characteristics in cell culture to wild-type PrV. To analyze the effect of the exchange of these homologous glycoproteins in PrV's natural host, swine, 4-week-old piglets were intranasally infected with 10(6) PFU of either wild-type PrV strain Kaplan (PrV-Ka), PrV-9112C2, or PrV-9112C2R, in which the PrV gB gene was reinserted instead of the BHV-1 gB gene. Animals infected with PrV-Ka and PrV-9112C2R showed a similar course of disease, i.e., high fever, marked respiratory symptoms but minimal neurological disorders, and excretion of high amounts of virus. All animals survived the infection. In contrast, animals infected with PrV-9112C2 showed no respiratory symptoms and developed only mild fever. However, on day 5 after infection, all piglets developed severe central nervous system (CNS) symptoms leading to death within 48 to 72 h. Detailed histological analyses showed that PrV-9112C2R infected all regions of the nasal mucosa and subsequently spread to the CNS preferentially by the trigeminal route. In contrast, PrV-9112C2 primarily infected the olfactory epithelium and spread via the olfactory route. In the CNS, more viral antigen and significantly more pronounced histological changes resulting in more severe encephalitis were found after PrV-9112C2 infection. Thus, our results demonstrate that replacement of PrV gB by the homologous BHV-1 glycoprotein resulted in a dramatic increase in neurovirulence combined with an alteration in the route of neuroinvasion, indicating that the essential gB is involved in determining neurotropism and neurovirulence of PrV.
Collapse
Affiliation(s)
- V Gerdts
- Institutes of Molecular Biology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, D-17498 Insel Riems, Germany
| | | | | | | |
Collapse
|
18
|
Masse MJ, Jöns A, Dijkstra JM, Mettenleiter TC, Flamand A. Glycoproteins gM and gN of pseudorabies virus are dispensable for viral penetration and propagation in the nervous systems of adult mice. J Virol 1999; 73:10503-7. [PMID: 10559368 PMCID: PMC113105 DOI: 10.1128/jvi.73.12.10503-10507.1999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Glycoproteins gM and gN are conserved throughout the herpesviruses but are dispensable for viral replication in cell cultures. To assay for a function of these proteins in infection of an animal, deletion mutants of pseudorabies virus lacking gM or gN and corresponding revertants were analyzed for the ability to penetrate and propagate in the nervous systems of adult mice after intranasal inoculation. We demonstrate that neither of the two glycoproteins is required for infection of the nervous systems of mice by pseudorabies virus.
Collapse
Affiliation(s)
- M J Masse
- Laboratoire de Génétique des Virus, CNRS, F-91198 Gif-sur-Yvette Cedex, France
| | | | | | | | | |
Collapse
|
19
|
Tóth IE, Boldogkoi Z, Medveczky I, Palkovits M. Lacrimal preganglionic neurons form a subdivision of the superior salivatory nucleus of rat: transneuronal labelling by pseudorabies virus. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1999; 77:45-54. [PMID: 10494749 DOI: 10.1016/s0165-1838(99)00032-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Transneuronal viral tracing was applied to localize preganglionic parasympathetic neurons in the brainstem which innervate the extraorbital lacrimal gland in the rat. The Bartha strain of pseudorabies virus was injected into the lacrimal gland, and after different survival times, the superior cervical and Gasserian ganglia, the upper thoracic spinal cords and the brainstems were immunostained by antiviral antiserum. Virus-labelled neurons appeared in the ganglia and in the ventrolateral part of the ipsilateral brainstem at the pontomedullary junction 45 h after inoculation. The virus-labelled brainstem neurons comprised a subgroup of the superior salivatory nucleus (SSN) located between the root fibers of the facial nerve and the nuclei of the superior olive, and were clearly distinguished from the tyrosine hydroxylase (TH)-immunopositive, A5 catecholaminergic neurons by double immunostaining. The number of infected cells in the ipsilateral SSN was increased by 72 h, and labelled neurons appeared in the intermediolateral cell column (IML) of the ipsilateral thoracic spinal cord. In rats with cervical ganglionectomy prior to the virus injection in the lacrimal gland, virus-infected cells appeared in the SSN, but not in the thoracic spinal cord, indicating that preganglionic SSN cells were infected via parasympathetic axons of the facial nerve. A double-virus tracer labelling technique was applied to determine the topographical relationship between the preganglionic parasympathetic neurons of the lacrimal gland and those of the submandibular gland within the SSN. Simultaneous injection of Bartha strain of pseudorabies virus into the submandibular gland, and a lacZ gene-containing Bartha-derived virus strain into the lacrimal gland (and vice versa) demarcated a ventral lacrimal and a dorsal submandibular subgroup in the SSN.
Collapse
Affiliation(s)
- I E Tóth
- Joint Research Laboratory of Neuromorphology, Semmelweis University of Medicine and Hungarian Academy of Sciences, Budapest.
| | | | | | | |
Collapse
|
20
|
Barbeau H, McCrea DA, O'Donovan MJ, Rossignol S, Grill WM, Lemay MA. Tapping into spinal circuits to restore motor function. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1999; 30:27-51. [PMID: 10407124 DOI: 10.1016/s0165-0173(99)00008-9] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Motivated by the challenge of improving neuroprosthetic devices, the authors review current knowledge relating to harnessing the potential of spinal neural circuits, such as reflexes and pattern generators. If such spinal interneuronal circuits could be activated, they could provide the coordinated control of many muscles that is so complex to implement with a device that aims to address each participating muscle individually. The authors' goal is to identify candidate spinal circuits and areas of research that might open opportunities to effect control of human limbs through electrical activation of such circuits. David McCrea's discussion of the ways in which hindlimb reflexes in the cat modify motor activity may help in developing optimal strategies for functional neuromuscular stimulation (FNS), by using knowledge of how reflex actions can adapt to different conditions. Michael O'Donovan's discussion of the development of rhythmogenic networks in the chick embryo may provide clues to methods of generating rhythmic activity in the adult spinal cord. Serge Rossignol examines the spinal pattern generator for locomotion in cats, its trigger mechanisms, modulation and adaptation, and suggests how this knowledge can help guide therapeutic approaches in humans. Hugues Barbeau applies the work of Rossignol and others to locomotor training in human subjects who have suffered spinal cord injury (SCI) with incomplete motor function loss (IMFL). Michel Lemay and Warren Grill discuss some of the technical challenges that must be addressed by engineers to implement a neuroprosthesis using electrical stimulation of the spinal cord, particularly the control issues that would have to be resolved.
Collapse
Affiliation(s)
- H Barbeau
- School of Physical and Occupational Therapy, McGill University, Montreal, QC, Canada
| | | | | | | | | | | |
Collapse
|
21
|
Card JP, Enquist LW, Moore RY. Neuroinvasiveness of pseudorabies virus injected intracerebrally is dependent on viral concentration and terminal field density. J Comp Neurol 1999; 407:438-52. [PMID: 10320223 DOI: 10.1002/(sici)1096-9861(19990510)407:3<438::aid-cne11>3.0.co;2-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Pseudorabies virus (PRV), a neurotropic swine alpha herpesvirus, has been used extensively for transneuronal analysis ofmultisynaptic circuitry after peripheral injection. In the present analysis, we examined the influence of viral concentration and neuronal architecture on the invasiveness, replication, and transynaptic passage of an attenuated strain of PRV (PRV-Bartha) injected into rat striatum. Different concentrations of PRV-Bartha were injected into the striatum at a constant rate of infusion (10 nl/minute), and animals were killed 50 hours later. Viral concentration was manipulated by either altering the volume of the inoculum (100, 50, 20 nl) or by diluting the inoculum within a constant volume of 100 nl. Immunohistochemical localization of infected neurons revealed dramatic differences in the progression of infection that were dependent directly on the concentration of injected virus. In every case, the pattern of infection was consistent with preferential uptake of virions by axon terminals and retrograde transynaptic passage of virus from the injection site. The known topographically organized corticostriatal projections permitted a precise definition of the zone of viral uptake. This analysis demonstrated that the "effective zone of viral uptake" (i.e., the zone within which viral uptake led to productive replication of virus) varied in relation to the concentration of injected virus, with the highest concentration of PRV invading terminals within a 500 microm radius of the canula. Concentration-dependent changes in the progression of retrograde transynaptic infection also were observed. The highest concentration of virus produced the most extensive infection. The distribution of infected neurons in these cases included those with known afferent projections to striatum as well as those that became infected by retrograde transynaptic infection. Lesser concentrations of PRV-Bartha produced an increasingly restricted infection of the same circuitry within the same postinoculation interval. It is noteworthy that neurons known to elaborate dense striatal terminal fields were less sensitive to reduction in viral concentration than those giving rise to terminal fields of lesser density. Collectively, the data indicate that the onset of viral replication after intracerebral injection of PRV is directly dependent on virus concentration and terminal field density at the site of virus injection.
Collapse
Affiliation(s)
- J P Card
- Department of Neuroscience, University of Pittsburgh, Pennsylvania 15260, USA.
| | | | | |
Collapse
|
22
|
Enquist LW, Husak PJ, Banfield BW, Smith GA. Infection and spread of alphaherpesviruses in the nervous system. Adv Virus Res 1999; 51:237-347. [PMID: 9891589 DOI: 10.1016/s0065-3527(08)60787-3] [Citation(s) in RCA: 255] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- L W Enquist
- Department of Molecular Biology, Princeton University, NJ 08544, USA.
| | | | | | | |
Collapse
|
23
|
Abstract
There have been substantial advances in methods for defining connections among neurons over the past quarter century. However, most tracers have been limited in their ability to define populations of functionally related neurons that contribute to a multisynaptic circuit because they are not transported across synapses. As a result, the large body of literature that has employed these tracers has established regional associations between regions that must be further explored with electron microscopy and electrophysiological methods to define the synaptic relations among constituent neurons. Recently, neurotropic alpha herpesviruses have been used to visualize ensembles of neurons that contribute to polysynaptic networks. These pathogens invade permissive cells, replicate, and pass transynaptically to infect other neurons. In effect, the viruses become self-amplifying tracers whose natural tropism and invasiveness define populations of functionally related neurons. The recent increase in the use of this experimental approach has emerged from advances in our understanding of the life cycle of these viruses and the resulting evidence in support of specific transynaptic passage of progeny virus rather than infection by lytic release into the extracellular space. This article reviews the advances that have made this a viable experimental approach and considers ways in which this method has been creatively used to illuminate aspects of nervous system circuit organization that could not be defined with conventional tracers.
Collapse
Affiliation(s)
- J P Card
- Department of Neuroscience, University of Pittsburgh, PA 15260, USA.
| |
Collapse
|
24
|
Abstract
Determining the connections of neural systems is critical for determining how they function. In this review, we focus on the use of HSV-1 and HSV-2 as transneuronal tracers. Using HSV to examine neural circuits is technically simple. HSV is injected into the area of interest, and after several days, the animals are perfused and processed for immunohistochemistry with antibodies to HSV proteins. Variables which influence HSV infection include species of host, age of host, titre of virus, strain of virus and phenotype of infected cell. The choice of strain of HSV is critically important. Several strains of HSV-1 and HSV-2 have been utilized for purposes of transneuronal tract-tracing. HSV has been used successfully to study neuronal circuitry in a variety of different neuroanatomical systems including the somatosensory, olfactory, visual, motor, autonomic and limbic systems.
Collapse
Affiliation(s)
- R B Norgren
- Department of Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha 68198, USA
| | | |
Collapse
|
25
|
Card JP. Practical considerations for the use of pseudorabies virus in transneuronal studies of neural circuitry. Neurosci Biobehav Rev 1998; 22:685-94. [PMID: 9809304 DOI: 10.1016/s0149-7634(98)00007-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of neurotrophic alpha herpesviruses for transneuronal analysis of neuronal circuitry has emerged from interdisciplinary characterizations of the viral life cycle and the defense response mounted by the nervous system to contain and eliminate the infection. Important findings from a number of fields have combined to provide compelling evidence that these viruses, when used appropriately, are powerful probes of multisynaptic circuits. These studies have also revealed that a number of variables can influence the outcome of infection and should be considered in designing and interpreting data derived from studies employing this experimental approach. The purpose of this paper is to review the literature that has established this experimental approach as a viable method for transynaptic analysis of neuronal circuitry and to define the factors that should be considered in applying this technology.
Collapse
Affiliation(s)
- J P Card
- Department of Neuroscience, University of Pittsburgh, PA 15217, USA.
| |
Collapse
|
26
|
Affiliation(s)
- W M Cowan
- Howard Hughes Medical Institute, Chevy Chase, Maryland 20815, USA
| |
Collapse
|
27
|
Nadelhaft I, Vera PL. Neurons in the rat brain and spinal cord labeled after pseudorabies virus injected into the external urethral sphincter. J Comp Neurol 1996; 375:502-17. [PMID: 8915845 DOI: 10.1002/(sici)1096-9861(19961118)375:3<502::aid-cne11>3.0.co;2-n] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Male Sprague-Dawley rats, with their pelvic and hypogastric nerves transected, were infected with pseudorabies virus (PRV) injected into the external urethral sphincter. Animals were sacrificed at 2, 2.5, 3, and 4 days postinfection. Spinal cord and brain tissue were sectioned and processed by immunohistochemical techniques with antisera against PRV and choline acetyl transferase (CAT). At 2 days postinfection, virus-labeled neurons were found in the ventrolateral divisions of Onuf's nucleus and in the dorsal gray commissure (DGC). At progressively later incubation times, labeled neurons were found in the intermediolateral regions, the superficial layer of the dorsal horn, and the brainstem, in particular, the pontine micturition center. PRV/CAT-positive neurons were only found in Onuf's nucleus. Preganglionic neurons in the L6-S1 intermediolateral regions were CAT positive but PRV negative, thus suggesting that they are interneurons, not sacral parasympathetic preganglionic neurons. After 4 days, virus had spread to neurons in the paraventricular, preoptic, and even cortical regions. The distribution of these PRV-labeled brain neurons strongly resembled that obtained after the injection of PRV into the urinary bladder (Nadelhaft et al. [1992] Neurosci. Lett. 143:271-274). In both cases, neurons were labeled in the DGC in the spinal cord. The data therefore suggest that neurons in the DGC may be involved in the integrated control of the bladder and the external urethral sphincter.
Collapse
Affiliation(s)
- I Nadelhaft
- Veterans Administration Medical Center, Bay Pines, Florida 33504, USA.
| | | |
Collapse
|
28
|
Jansen AS, Nguyen XV, Karpitskiy V, Mettenleiter TC, Loewy AD. Central command neurons of the sympathetic nervous system: basis of the fight-or-flight response. Science 1995; 270:644-6. [PMID: 7570024 DOI: 10.1126/science.270.5236.644] [Citation(s) in RCA: 474] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
During stress, the activity of the sympathetic nervous system is changed in a global fashion, leading to an increase in cardiovascular function and a release of adrenal catecholamines. This response is thought to be regulated by a common set of brain neurons that provide a dual input to the sympathetic preganglionic neurons regulating cardiac and adrenal medullary functions. By using a double-virus transneuronal labeling technique, the existence of such a set of central autonomic neurons in the hypothalamus and brainstem was demonstrated. These neurons innervate both of the sympathetic outflow systems and likely function in circumstances where parallel sympathetic processing occurs, such as in the fight-or-flight response.
Collapse
Affiliation(s)
- A S Jansen
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | | | | | |
Collapse
|