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Xia Y, Chen D, Xia H, Liao Z, Tang W, Yan Y. Serotonergic projections to lumbar levels and its plasticity following spinal cord injury. Neurosci Lett 2017; 649:70-77. [PMID: 28396282 DOI: 10.1016/j.neulet.2017.04.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 03/26/2017] [Accepted: 04/06/2017] [Indexed: 01/25/2023]
Abstract
The descending serotonergic pathway, which originates in various populations of brainstem neurons, plays an important role in generating the rhythmic motor pattern associated with locomotor movement. Although the development of its innervation has been studied in rodent spinal cord, it has not been clearly identified how the projection of serotonergic pathway is related to its function. Here, we evaluated the pattern of serotonergic innervation on the lumbar spinal cord from embryonic day 14.5 (E14.5) to adulthood. Before birth, we found that 5-hydroxytryptamine (5-HT) fibers invade the lumbar cord as early as E14.5, penetrate into the gray matter from lateral funiculus by E16.5, and then mainly occupied the ventral horn by E18.5 before localizing in the dorsal horn. After birth, we found that 5-HT invasion of both dorsal horn and ventral horn were present by the 7th postnatal day (P7). Additionally, the 5-HT innervation of these two areas evolved progressively from a diffuse network to a more restricted pattern, particularly at the ventral horn within the motoneuron area from P21 to adulthood. This 5-HT innervation pattern in the lumbar cord provides anatomical evidence that serotonergic fibers establish direct connections with lumbar motoneurons, which offers us a solid foundation that enhancing the plasticity of serotonergic pathway following SCI may facilitate locomotor functional recovery. Therefore, we employed treadmill training to activate serotonergic plasticity after SCI. We found that mice which underwent treadmill training exhibited a better locomotor functional recovery. Meanwhile, the density of 5-HT fibers in the ventral horn was significantly increased and the synaptic formation of 5-HT fibers with lumbar motoneurons was also significantly rescued in the training group mice after SCI. These findings demonstrate that the descending serotonergic projection is a robust and flexible parallel pathway for modulating spinal locomotor function.
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Affiliation(s)
- Yongzhi Xia
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Dan Chen
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Haijian Xia
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Zhengbu Liao
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Wenyuan Tang
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yi Yan
- Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
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Liang H, Schofield E, Paxinos G. Imaging Serotonergic Fibers in the Mouse Spinal Cord Using the CLARITY/CUBIC Technique. J Vis Exp 2016:53673. [PMID: 26967767 DOI: 10.3791/53673] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Long descending fibers to the spinal cord are essential for locomotion, pain perception, and other behaviors. The fiber termination pattern in the spinal cord of the majority of these fiber systems have not been thoroughly investigated in any species. Serotonergic fibers, which project to the spinal cord, have been studied in rats and opossums on histological sections and their functional significance has been deduced based on their fiber termination pattern in the spinal cord. With the development of CLARITY and CUBIC techniques, it is possible to investigate this fiber system and its distribution in the spinal cord, which is likely to reveal previously unknown features of serotonergic supraspinal pathways. Here, we provide a detailed protocol for imaging the serotonergic fibers in the mouse spinal cord using the combined CLARITY and CUBIC techniques. The method involves perfusion of a mouse with a hydrogel solution and clarification of the tissue with a combination of clearing reagents. Spinal cord tissue was cleared in just under two weeks, and the subsequent immunofluorescent staining against serotonin was completed in less than ten days. With a multi-photon fluorescent microscope, the tissue was scanned and a 3D image was reconstructed using Osirix software.
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Affiliation(s)
- Huazheng Liang
- Brain Structure and Function Group, Neuroscience Research Australia; School of Medical Sciences, The University of New South Wales;
| | - Emma Schofield
- Brain Structure and Function Group, Neuroscience Research Australia
| | - George Paxinos
- Brain Structure and Function Group, Neuroscience Research Australia; School of Medical Sciences, The University of New South Wales
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Liang H, Wang S, Francis R, Whan R, Watson C, Paxinos G. Distribution of raphespinal fibers in the mouse spinal cord. Mol Pain 2015; 11:42. [PMID: 26173454 PMCID: PMC4502924 DOI: 10.1186/s12990-015-0046-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/03/2015] [Indexed: 12/13/2022] Open
Abstract
Background Serotonergic raphespinal neurons and their fibers have been mapped in large mammals, but the non-serotonergic ones have not been studied, especially in the mouse. The present study aimed to investigate the termination pattern of fibers arising from the hindbrain raphe and reticular nuclei which also have serotonergic neurons by injecting the anterograde tracer BDA into them. Results We found that raphespinal fibers terminate in both the dorsal and ventral horns in addition to lamina 10. There is a shift of the fibers in the ventral horn towards the dorsal and lateral part of the gray matter. Considerable variation in the termination pattern also exists between raphe nuclei with raphe magnus having more fibers terminating in the dorsal horn. Fibers from the adjacent gigantocellular reticular nucleus show similar termination pattern as those from the raphe nuclei with slight difference. Immunofluorescence staining showed that raphespinal fibers were heterogeneous and serotoninergic fibers were present in all laminae but mainly in laminae 1, 2, medial lamina 8, laminae 9 and 10. Surprisingly, immunofluorescence staining on clarified spinal cord tissue revealed that serotoninergic fibers formed bundles regularly in a short distance along the rostrocaudal axis in the medial part of the ventral horn and they extended towards the lateral motor neuron column area. Conclusion Serotonergic and non-serotonergic fibers arising from the hindbrain raphe and reticular nuclei had similar termination pattern in the mouse spinal cord with subtle difference. The present study provides anatomical foundation for the multiple roles raphe and adjacent reticular nuclei play. Electronic supplementary material The online version of this article (doi:10.1186/s12990-015-0046-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Huazheng Liang
- Neuroscience Research Australia, 139 Barker Street, Randwick, NSW, 2031, Australia. .,School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Shaoshi Wang
- Department of Neurology, Branch of Shanghai First People's Hospital, Shanghai, 200081, China.
| | - Richard Francis
- Biomedical Imaging Facility, The University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Renee Whan
- Biomedical Imaging Facility, The University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Charles Watson
- Health Sciences Dean Research, Faculty of Health Sciences, Curtin University, Shenton Park Campus, Perth, WA, 6102, Australia.
| | - George Paxinos
- Neuroscience Research Australia, 139 Barker Street, Randwick, NSW, 2031, Australia. .,School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia.
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Eaton MJ, Widerström-Noga E, Wolfe SQ. Subarachnoid Transplant of the Human Neuronal hNT2.19 Serotonergic Cell Line Attenuates Behavioral Hypersensitivity without Affecting Motor Dysfunction after Severe Contusive Spinal Cord Injury. Neurol Res Int 2011; 2011:891605. [PMID: 21799949 PMCID: PMC3135871 DOI: 10.1155/2011/891605] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Accepted: 03/21/2011] [Indexed: 11/21/2022] Open
Abstract
Transplant of cells which make biologic agents that can modulate the sensory and motor responses after spinal cord injury (SCI) would be useful to treat pain and paralysis. To address this need for clinically useful human cells, a unique neuronal cell line that synthesizes and secretes/releases the neurotransmitter serotonin (5HT) was isolated. Hind paw tactile allodynia and thermal hyperalgesia induced by severe contusive SCI were potently reversed after lumbar subarachnoid transplant of differentiated cells, but had no effect on open field motor scores, stride length, foot rotation, base of support, or gridwalk footfall errors associated with the SCI. The sensory effects appeared 1 week after transplant and did not diminish during the 8-week course of the experiment when grafts were placed 2 weeks after SCI. Many grafted cells were still present and synthesizing 5HT at the end of the study. These data suggest that the human neuronal serotonergic hNT2.19 cells can be used as a biologic minipump for receiving SCI-related neuropathic pain, but likely requires intraspinal grafts for motor recovery.
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Affiliation(s)
- Mary J. Eaton
- Miami VA Health System Center, D806C, 1201 NW 16th Street, Miami, FL 33125, USA
| | - Eva Widerström-Noga
- Miami VA Health System Center, D806C, 1201 NW 16th Street, Miami, FL 33125, USA
- The Miami Project to Cure Paralysis, Miller School of Medicine, University of Miami, 1095 NW 14th Terrace, Miami, FL 33136, USA
| | - Stacey Quintero Wolfe
- Department of Neurosurgery, Tripler Army Medical Center, 1 Jarrett White Road, Honolulu, HI 96859-5000, USA
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Duncan JR, Garland M, Myers MM, Fifer WP, Yang M, Kinney HC, Stark RI. Prenatal nicotine-exposure alters fetal autonomic activity and medullary neurotransmitter receptors: implications for sudden infant death syndrome. J Appl Physiol (1985) 2009; 107:1579-90. [PMID: 19729586 DOI: 10.1152/japplphysiol.91629.2008] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During pregnancy, exposure to nicotine and other compounds in cigarette smoke increases the risk of the sudden infant death syndrome (SIDS) two- to fivefold. Serotonergic (5-HT) abnormalities are found, in infants who die of SIDS, in regions of the medulla oblongata known to modulate cardiorespiratory function. Using a baboon model, we tested the hypothesis that prenatal exposure to nicotine alters 5-HT receptor and/or transporter binding in the fetal medullary 5-HT system in association with cardiorespiratory dysfunction. At 87 (mean) days gestation (dg), mothers were continuously infused with saline (n = 5) or nicotine (n = 5) at 0.5 mg/h. Fetuses were surgically instrumented at 129 dg for cardiorespiratory monitoring. Cesarean section delivery and retrieval of fetal medulla were performed at 161 (mean) dg for autoradiographic analyses of nicotinic and 5-HT receptor and transporter binding. In nicotine-exposed fetuses, high-frequency heart rate variability was increased 55%, possibly reflecting increases in the parasympathetic control of heart rate. This effect was more pronounced with greater levels of fetal breathing and age. These changes in heart rate variability were associated with increased 5-HT(1A) receptor binding in the raphé obscurus (P = 0.04) and increased nicotinic receptor binding in the raphé obscurus and vagal complex (P < 0.05) in the nicotine-exposed animals compared with controls (n = 6). The shift in autonomic balance in the fetal primate toward parasympathetic predominance with chronic exposure to nicotine may be related, in part, to abnormal 5-HT-nicotine alterations in the raphé obscurus. Thus increased risk for SIDS due to maternal smoking may be partly related to the effects of nicotine on 5-HT and/or nicotinic receptors.
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Affiliation(s)
- Jhodie R Duncan
- Dept. of Pathology, Enders 1112.1, Children's Hospital Boston, 300 Longwood Ave., Boston, MA 02115, USA
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Barreiro-Iglesias A, Villar-Cerviño V, Anadón R, Rodicio MC. Development and organization of the descending serotonergic brainstem-spinal projections in the sea lamprey. J Chem Neuroanat 2008; 36:77-84. [PMID: 18602462 DOI: 10.1016/j.jchemneu.2008.06.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 05/30/2008] [Accepted: 06/03/2008] [Indexed: 10/21/2022]
Abstract
The organization and development of the descending spinal projections from serotonergic rhombencephalic neurons in the larval sea lamprey were investigated by double labeling, tract-tracing methods and immunocytochemistry against serotonin. The results showed that two serotonergic populations of the isthmic and vagal reticular regions present reticulospinal neurons from the beginning of the larval period. Of the three serotonergic subpopulations recognized in the isthmic reticular group [Abalo, X.M., Villar-Cheda, B., Meléndez-Ferro, M., Pérez-Costas, E., Anadón, R., Rodicio, M.C., 2007. Development of the serotonergic system in the central nervous system of the sea lamprey. J. Chem. Neuroanat. 34, 29-46], only two - the medial and ventral subpopulations - project to the spinal cord, with most of the projecting cells in the caudal part of the medial isthmic subpopulation. Occasional cells projecting to the spinal cord were observed in the ventral subpopulation. The vagal reticular serotonergic nucleus situated in the caudal rhombencephalon also presents cells with descending projections. The early development of the brainstem serotonergic projections to the spinal cord appears to be a conserved trait in all vertebrates studied. Although a serotonergic hindbrain-spinal projection system appears to have been present before the divergence of agnathans and gnathostomes, no serotonergic cells were observed in the raphe region in lamprey. Moreover, proportionally more rostral hindbrain serotonergic cells contribute to the spinal serotonergic projections in the sea lamprey than in jawed vertebrates.
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Affiliation(s)
- Antón Barreiro-Iglesias
- Department of Cell Biology and Ecology, Faculty of Biology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
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7
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Jensen I, Llewellyn-Smith IJ, Pilowsky P, Minson JB, Chalmers J. Serotonin inputs to rabbit sympathetic preganglionic neurons projecting to the superior cervical ganglion or adrenal medulla. J Comp Neurol 1995; 353:427-38. [PMID: 7751440 DOI: 10.1002/cne.903530310] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The input from serotonin-containing nerve fibres to rabbit sympathetic preganglionic neurons projecting to either the superior cervical ganglion or the adrenal medulla was investigated by combining retrograde tracing with the B subunit of cholera toxin and immunocytochemistry for serotonin. There were pronounced rostrocaudal variations in the density of serotonin fibres in the rabbit intermediolateral cell column from T1 to L4; maximum numbers of fibres were found in T3-6 and L3-4 and minimum numbers in T1 and T10-12. By light microscopy, retrogradely labelled sympathetic preganglionic neurons projecting to the superior cervical ganglion or the adrenal medulla received variable densities of close appositions from serotonin-immunoreactive fibres. Some neurons from each population received many close appositions, whereas others received moderate numbers or few appositions. Appositions occurred on the cell bodies, dendrites, and occasionally axons of sympathetic preganglionic neurons. Rare neurons in both groups of retrogradely labelled cells received no appositions from serotonin-containing nerve fibres. At the ultrastructural level, synapses were found between serotonin-positive boutons and sympathetic preganglionic neurons projecting either to the superior cervical ganglion or to the adrenal medulla. These results indicate that, through direct synaptic contacts, serotonin-immunoreactive, presumably bulbospinal, nerve fibres affect the activity of the vast majority of sympathetic preganglionic neurons that send axons either to the superior cervical ganglion or to the adrenal medulla. This serotonin input may be sympathoexcitatory and could mediate increases in sympathetic nerve activity and in the release of catecholamines from the adrenal medulla.
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Affiliation(s)
- I Jensen
- Department of Medicine, School of Medicine, Flinders University, Bedford Park, Australia
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8
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Westlund KN, Sorkin LS, Ferrington DG, Carlton SM, Willcockson HH, Willis WD. Serotoninergic and noradrenergic projections to the ventral posterolateral nucleus of the monkey thalamus. J Comp Neurol 1990; 295:197-207. [PMID: 2358512 DOI: 10.1002/cne.902950204] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the present study, serotoninergic and noradrenergic varicosities were identified in the ventral posterolateral nucleus of the macaque monkey. Monoaminergic neurons projecting to the ventral posterolateral nucleus of the thalamus were identified by using retrograde labeling with horseradish peroxidase combined with immunocytochemical staining for serotonin or dopamine-beta-hydroxylase. The midbrain nucleus raphe dorsalis was the major site of origin for neurons providing a serotoninergic projection to the ventral posterolateral nucleus. A few retrogradely labeled serotonin-containing neurons were also observed in the central superior and the raphe pontis nuclei. Noradrenergic cells with projections to the thalamus were primarily located in the nucleus locus coeruleus with some projection neurons in the nucleus subcoeruleus, and the A5 catecholamine cell group of the pons.
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Affiliation(s)
- K N Westlund
- Department of Anatomy, Marine Biomedical Institute, University of Texas Medical Branch, Galveston 77550-2772
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9
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Combined axonal transport tracing and immunocytochemistry for mapping pathways of peptide-containing nerves in the peripheral nervous system. ACTA ACUST UNITED AC 1989. [DOI: 10.1007/978-3-0348-9136-3_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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10
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Newton BW, Burkhart AB, Hamill RW. Immunohistochemical distribution of serotonin in spinal autonomic nuclei: II. Early and late postnatal ontogeny in the rat. J Comp Neurol 1989; 279:82-103. [PMID: 2913063 DOI: 10.1002/cne.902790108] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
These studies reveal that the postnatal ontogeny of serotonin (5HT) in the sympathetic nuclei of the rat spinal cord is protracted; the adult complement of 5HT-immunoreactive fibers is not achieved until at least 60 days of age. As descending serotonin fibers innervate and demarcate the distribution of preganglionic sympathetic nuclei, rostral-caudal and temporal gradients exist. Additionally, a heterogeneous segmental 5HT ontogenetic pattern is observed in sympathetic nuclei. Most serotonin fibers in laminae VII and X are unorganized at birth except for some sympathetic nuclei in high thoracic regions where the 5HT sympathetic pattern is being initiated. By postnatal day 6 the framework of the 5HT pattern is established in all sympathetic nuclei, and by postnatal day 16 a pattern is formed, which develops into the compact adult state by postnatal day 60. The protracted period of sympathetic 5HT development corresponds with the length of time it takes for the autonomic nervous system to mature. In addition, 5HT intraspinal cell bodies are observed at all time points examined, except for the day of birth, and are found in the same regions as adult 5HT neurons, i.e., dorsal or lateral to the central canal in laminae VII and X and in all spinal segments except cervical levels. Many of the 5HT neurons are pericanalicular and bipolar in appearance. Multipolar 5HT neurons are first observed on postnatal day 45.
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Affiliation(s)
- B W Newton
- Neurology Unit, Monroe Community Hospital, Rochester, New York
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11
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Pretel S, Guinan MJ, Carstens E. Inhibition of the responses of cat dorsal horn neurons to noxious skin heating by stimulation in medial or lateral medullary reticular formation. Exp Brain Res 1988; 72:51-62. [PMID: 3169196 DOI: 10.1007/bf00248500] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Responses of single lumbar dorsal horn units to noxious radiant heating (50 degrees C, 10 s) of glabrous footpad skin were recorded in cats anesthetized with sodium pentobarbital and 70% nitrous oxide. The heat-evoked responses of 37/40 units were reduced during electrical stimulation (100 ms trains, 100 Hz, 3/s, 25-600 microA) in the medullary nucleus raphe magnus (NRM) and/or in laterally adjacent regions of the medullary reticular formation (MRF). Inhibition was elicited by stimulation in widespread areas of the medulla, but with greatest efficacy at ventrolateral sites. The magnitude of inhibition increased with graded increases in medullary stimulation intensity. Mean current intensities at threshold for inhibition or to produce 50% inhibition were higher for NRM than for MRF sites. Units' responses to graded noxious heat stimuli increased linearly from threshold (42-43 degrees C) to 52 degrees C. During NRM (5 units) or ipsilateral MRF stimulation (7 units), responses were inhibited such that the mean temperature-response functions were shifted toward higher temperatures with increased thresholds (1.5 degrees and 1 degree C, respectively) and reduced slopes (to 60% of control). Contralateral MRF stimulation had a similar effect in 4 units. Inhibitory effects of NRM and MRF stimulation were reduced (by greater than 25%) or abolished in 4/6 and 5/12 units, respectively, following systemic administration of the serotonin antagonist methysergide. Inhibitory effects from NRM, ipsi- and contralateral MRF were reduced or abolished in 2/9, 4/8 and 6/9 cases, respectively, following systemic administration of the noradrenergic antagonist phentolamine. These results confirm and extend previous studies of medullospinal inhibition and the role of monoamines, and are discussed in terms of analgesic mechanisms.
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Affiliation(s)
- S Pretel
- Department of Animal Physiology, University of California, Davis 95616
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12
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Edwards DL, Poletti CE, Foote WE. Evidence for leucine-enkephalin immunoreactive neurons in the medulla which project to spinal cord in squirrel monkey. Brain Res 1987; 437:197-203. [PMID: 2827868 DOI: 10.1016/0006-8993(87)91546-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Rhodamine-labeled latex microsphere injections were combined with horseradish peroxidase immunohistochemistry in squirrel monkeys to reveal neurons in the medullary raphe and medial reticular formation which projected to spinal cord and were positive for leucine-enkephalin-like immunoreactivity. Double-labeled cells were found primarily in nucleus raphe magnus, the reticular nucleus magnocellularis, and the lateral reticular nucleus. These results provide evidence for a descending projection from enkephalin-containing cells of the rostral ventral medulla, a region which has been strongly implicated in antinociception.
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Affiliation(s)
- D L Edwards
- Department of Psychiatry, Massachusetts General Hospital, Boston 02114
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13
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Affiliation(s)
- R L Kenigsberg
- Department of Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada
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14
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Su HC, Polak JM. Combined axonal transport tracing and immunocytochemistry for mapping pathways of peptide-containing nerves in the peripheral nervous system. EXPERIENTIA 1987; 43:761-7. [PMID: 2439365 DOI: 10.1007/bf01945353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The various combinations of axonal transport tracing and immunocytochemistry used for mapping pathways of peptide-containing nerves, and in particular those of the peripheral nervous system, are reviewed. The advantages and disadvantages of these methods are discussed. The applications and results presented illustrate the future potential value of this approach.
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15
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Ehret M, Gobaille S, Cash CD, Mandel P, Maitre M. Regional distribution in rat brain of tryptophan hydroxylase apoenzyme determined by enzyme-linked immunoassay. Neurosci Lett 1987; 73:71-6. [PMID: 3561858 DOI: 10.1016/0304-3940(87)90033-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Tryptophan hydroxylase apoenzyme was measured in 21 regions of the rat brain by a competitive enzyme-linked immunoassay (ELISA) technique using a recently developed antiserum from the sheep to this protein. Highest apoenzyme levels were found in the pineal gland and in the dorsal raphé. An insignificant level was observed in the cerebellum. In general, the distribution of tryptophan hydroxylase apoenzyme follows the distribution of serotonin previously detected by immunocytochemistry. A turnover number for tryptophan hydroxylase in a rat brain supernatant fraction of 7.5 s-1 was estimated, a value far higher than that estimated for serotonin turnover in vivo. This result confirms that serotonin biosynthesis is additionally regulated by factors other than tryptophan hydroxylase apoenzyme concentration.
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Abstract
Serotonin (5HT) immunoreactive neurons were identified in the late-term fetal spinal cord of normal non-human primates. These neurons were distributed throughout the spinal cord, being concentrated in lamina X and the subjacent ventral median fissure, while their immunoreactive fibers and terminals innervated the zone surrounding the central canal and the ventral spinal artery. Even at this late fetal stage, the dorsal and ventral spinal gray matter was virtually devoid of any positive 5HT immunoreactivity, in contrast to that seen in the adult primate. These findings suggest that the intrinsic 5HT neurons of the primate during development may modulate CSF composition or provide cues for spinal cord differentiation rather than regulate sensorimotor functions as they do in the adult.
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17
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Brodin L, Buchanan JT, Hökfelt T, Grillner S, Verhofstad AA. A spinal projection of 5-hydroxytryptamine neurons in the lamprey brainstem; evidence from combined retrograde tracing and immunohistochemistry. Neurosci Lett 1986; 67:53-7. [PMID: 3725200 DOI: 10.1016/0304-3940(86)90207-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
To investigate whether there is a descending contribution to the spinal 5-hydroxytryptamine (5-HT) innervation in the lamprey, a primitive vertebrate, a study using retrograde transport of the fluorescent tracer Fast blue combined with 5-HT immunohistochemistry was conducted. Two to 4 weeks after an injection of Fast blue into the rostral spinal cord, retrogradely labelled cells were seen throughout the brainstem. Two groups of these cells, one within the posterior reticular nucleus of the rhombencephalon and another rostral to the trigeminal motor nucleus, were labelled after incubation with 5-HT antiserum. These findings suggest that in addition to the well-described local intraspinal 5-HT system, there is also, as in higher vertebrates, a descending 5-HT projection from the brainstem which extends at least 20 segments into the spinal cord.
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18
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Carlton SM, Chung JM, Leonard RB, Willis WD. Funicular trajectories of brainstem neurons projecting to the lumbar spinal cord in the monkey (Macaca fascicularis): a retrograde labeling study. J Comp Neurol 1985; 241:382-404. [PMID: 4086662 DOI: 10.1002/cne.902410310] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Brainstem nuclei projecting to the lumbar spinal cord in the monkey were identified by using horseradish peroxidase and the fluorescent dye granular blue. These retrogradely transported tracers were used in fluid and/or gel forms to determine the funicular trajectories of the brainstem-spinal projections. The major descending components of the dorsal funiculus arose from the n. gracilis, n. cuneatus, and the n. of the solitary tract. Major components of the dorsolateral funiculus (DLF) came from the raphe complex, medullary and pontine reticular formation, locus coeruleus, Edinger-Westphal n., and red n. Other nuclei giving rise to minor contributions to the DLF included n. gracilis, n. cuneatus, n. of the solitary tract, medial and spinal vestibular n., subcoeruleus, periaqueductal gray, interstitial n. of Cajal, n. of Darkschewitsch, and the anteromedian n. The major components of ventral cord paths (ventrolateral and ventral funiculi) arose from the raphe complex, the medullary and pontine reticular formation, lateral and spinal vestibular n., and the coerulean complex. Minor contributions to the ventral paths descended from the dorsal motor n. of X, n. of the solitary tract, medial vestibular n., paralemniscal reticular formation, dorsal parabrachial n., n. cuneiformis, periaqueductal gray, Kölliker-Fuse n., and red n. The possible functional implications of the funicular distribution of these descending pathways are discussed from the perspective of descending inhibition and pain modulation.
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19
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Henschen A, Verhofstad AA, Olson L. Intraocular grafts of nucleus raphe dorsalis provide cografted spinal cord with a serotonergic innervation. Brain Res Bull 1985; 15:335-42. [PMID: 3902153 DOI: 10.1016/0361-9230(85)90160-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Nucleus raphe dorsalis was sequentially cografted with spinal cord to the anterior chamber of the eye of adult rats. After maturation in oculo, the double grafts were examined histologically and immunohistologically utilizing an antiserum to serotonin (5HT). No 5HT-like immunoreactivity could be detected in grafts of single spinal cord or in irides of nongrafted eyes. In single raphe grafts, positive cell bodies and a dense terminal plexus were found. 5HT-positive fibers also penetrated into the irides forming dense networks in the walls of blood vessels and elsewhere in the irides. When spinal cord was cografted to maturated nucleus raphe dorsalis grafts, the raphe graft provided the spinal cord graft with a serotonergic innervation. Interestingly, when the grafting procedure was done in reversed order, i.e., the spinal cord was grafted first and left to mature before immature raphe grafts were added to the eye, the average density of 5HT-positive nerve terminals in the spinal cord part was clearly higher. It is concluded that immature as well as mature isolated spinal cord tissue can become innervated by adjacent central 5HT-neurons. Thus isolated replicas of descending serotonergic pathways to the spinal cord, suitable for electrophysiological analysis, are obtained in oculo.
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Wolters JG, ten Donkelaar HJ, Steinbusch HW, Verhofstad AA. Distribution of serotonin in the brain stem and spinal cord of the lizard Varanus exanthematicus: an immunohistochemical study. Neuroscience 1985; 14:169-93. [PMID: 3883229 DOI: 10.1016/0306-4522(85)90172-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The distribution of serotonin-containing nerve cell bodies, fibers and terminals in the lizard Varanus exanthematicus was studied with the indirect immunofluorescence technique, using antibodies to serotonin. Most of the serotonin-containing cell bodies were found in the midline, in both of the raphe nuclei, i.e. the nuclei raphes superior and inferior. A considerable number of more laterally shifted serotonergic neurons was found particularly at three levels of the brain stem, viz. in the caudal mesencephalic tegmentum, at the isthmic level, and over a long distance in the medulla oblongata. These laterally situated serotonin-positive neurons were partly found within the confines of the substantia nigra, the nucleus reticularis superior and the lateral part of the nucleus reticularis medius and ventrolateral part of the nucleus reticularis inferior, respectively. No serotonergic cell bodies were found in the spinal cord. In the brain stem a dense serotonergic innervation was observed in all of the motor nuclei of the cranial nerves, in two layers of the tectum mesencephali, in the nucleus interpeduncularis pars ventralis, the nucleus profundus mesencephali pars rostralis, the periventricular grey, the nucleus parabrachialis, the vestibular nuclear complex, the nucleus descendens nervi trigemini, the nucleus raphes inferior, and parts of the nucleus tractus solitarii. Descending serotonergic pathways could be traced into the spinal cord via the dorsolateral, ventral and ventromedial funiculi, and were found to innervate mainly three parts of the spinal grey throughout the spinal cord, i.e. the dorsal part of the dorsal horn, the motoneuron area in the ventral horn, and the intermediate zone just lateral to the central canal. The results obtained in the present study suggest a close resemblance of the organization of the serotonergic system in reptiles and mammals, especially as to the serotonergic innervation of the spinal cord.
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Wolters JG, ten Donkelaar HJ, Verhofstad AA. Distribution of catecholamines in the brain stem and spinal cord of the lizard Varanus exanthematicus: an immunohistochemical study based on the use of antibodies to tyrosine hydroxylase. Neuroscience 1984; 13:469-93. [PMID: 6151148 DOI: 10.1016/0306-4522(84)90243-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Antibodies to tyrosine hydroxylase were used to study the distribution of nerve cells, fibers and terminals, containing catecholamines, in the lizard Varanus exanthematicus, by means of the indirect immunofluorescence technique. Tyrosine hydroxylase-containing cell bodies occurred in the hypothalamus, the ventral and dorsal tegmentum mesencephali, the substantia nigra, the isthmic reticular formation, in and ventrolaterally to the locus coeruleus, in the nucleus tractus solitarii and in a lateral part of the nucleus reticularis inferior. In addition tyrosine hydroxylase-containing cell bodies were found throughout the spinal cord, ventral to the central canal. Tyrosine hydroxylase-immunoreactive terminal areas in the brain stem were seen in the nucleus interstitialis of the fasciculus longitudinalis medialis, the nucleus raphes superior, the locus coeruleus, several parts of the reticular formation and the nucleus descendens nervi trigemini. Ascending catecholaminergic pathways could be traced from the ventral mesencephalic tegmentum as well as from the dorsal isthmic tegmentum rostralwards, through the lateral hypothalamus. These pathways correspond to the mesostriatal and isthmocortical projections respectively, as described in mammals. Furthermore, ascending catecholaminergic fibers could be traced from the catecholaminergic cell groups in the medulla oblongata to the isthmus, where they intermingle with the locus coeruleus neurons. These pathways correspond to the medullohypothalamic projection and to the dorsal periventricular system in mammals. Descending catecholaminergic fibers to the spinal cord pass via the dorsomedial part of the lateral funiculus, and mainly terminate in the dorsal horn. The results obtained in the present study have been placed in a comparative perspective, which illustrates the constancy of catecholaminergic innervation throughout phylogeny.
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Ritchie TC, Roos LJ, Williams BJ, Leonard RB. The descending and intrinsic serotoninergic innervation of an elasmobranch spinal cord. J Comp Neurol 1984; 224:395-406. [PMID: 6715586 DOI: 10.1002/cne.902240307] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The descending and the intrinsic components of the serotoninergic (5HT) innervation of the Atlantic stingray spinal cord were described by comparing the distributions of neuronal elements exhibiting 5HT-like immunoreactivity (peroxidase-antiperoxidase method) in sections caudal and rostral to spinal transections. The cells of origin of the descending 5HT system were located with a double labeling method for both retrogradely transported horseradish peroxidase (HRP) and 5HT staining. The descending system provides virtually the entire 5HT innervation of the dorsal horn, the intermediate zone, and the dorsal and lateral portions of the ventral horn. Fibers of the descending 5HT system course in the lateral funiculus, the dorsal portion of the ventral funiculus, and in the submeningeal zones of the dorsal and lateral aspects of the spinal cord. This projection primarily originates from the 5HT cell groups of the caudal rhombencephalon (groups II and III; Ritchie et al., '83), with a minor contribution from group IV in the rostral rhombencephalon. The organization of the descending 5HT system in stingrays is remarkably similar to that of mammals. The intrinsic spinal 5HT system consists of cells distributed in the ventromedial spinal cord that have processes extending longitudinally in a ventral submeningeal fiber network. Fibers were traced from the submeningeal system to the ventral horn, where varicose processes were restricted largely to the neuropil ventral to the somata of the fin motoneurons. The existence of a well-defined intrinsic 5HT system in stingrays supports the hypothesis that such a system exists in the spinal cords of a variety of vertebrates.
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Steindler DA, Isaacson LG, Trosko BK. Combined immunocytochemistry and autoradiographic retrograde axonal tracing for identification of transmitters of projection neurons. J Neurosci Methods 1983; 9:217-28. [PMID: 6363827 DOI: 10.1016/0165-0270(83)90084-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A double labeling method is described which combines immunocytochemistry for identification of the neurotransmitter serotonin with autoradiographic retrograde axonal tracing using wheat germ agglutinin (WGA), N-[acetyl-3H]. The permanence, sensitivity, and distinctness of the two labels provide a valuable means for analyzing transmitter-identified projection neurons in the central nervous system. Combined immunohistochemical/autoradiographic preparations, following injections of WGA, N-[acetyl-3H] in the caudate-putamen of mice, revealed large numbers of serotonergic and fewer non-serotonergic raphe-striatal projection neurons.
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