Vasoactive intestinal polypeptide immunoreactivity in the spinal cord of the guinea pig

Summary The distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the lower medulla oblongata and the spinal cord has been analyzed in guinea pigs. This study includes results obtained by colchicine treatment and transection experiments. In the spinal cord, numerous VIP-IR varicosities were observed in the substantia gelatinosa of the columna dorsalis; some were also found in the substantia intermedia and the columna anterior. The spinal VIP-IR nerve fibers were mainly of intraspinal origin and oriented segmentally. VIP-IR nuclei in the spinal cord extended dorsally into corresponding regions of the caudal medulla oblongata, namely from the substantia intermedia medialis and lateralis into the vagus-solitarius complex and from the nucleus spinalis lateralis into the area of the nucleus reticularis lateralis. Additional VIP-IR perikarya were observed in the pars caudalis of the nucleus spinalis nervi trigemini. The VIP-IR nuclei within the caudal medulla oblongata probably form a continuous system with those localized within the spinal cord. They may be involved functionally in the modulation of cardiovascular and respiratory regulation in the guinea pig.Supported by the DFG, Carvas SFB 90     

心外膜应用腺苷时c—fos在脊髓延髓和丘脑中的表达

在１２只切断两侧缓冲神经和迷走神经的麻醉大鼠,观察了心外膜应用腺苷对脊髓,延髓和丘脑ｃ－ｆｏｓ原部基因表达的影响。结果显示：心外膜应用腺苷组大鼠,动脉血压和心率无明显变化;脊髓Ｔ３节段背角,延髓巨细胞旁外侧核以及丘脑的腹后外侧核,后核,中央外侧核和束旁核等部位Ｆｏｓ蛋白样免疫阳性反应神经元显著增加;而在溶剂对照组大鼠,仅见少数ＦＬＩ细胞。     

Substance P in the ventrolateral medulla oblongata regulates ventilatory responses.

Local injection of substance P (SP) into the ventral portion of the nucleus gigantocellularis, nucleus reticularis lateralis, and nucleus retrofacialis of the ventrolateral medulla oblongata (VLM) or direct application on the ventral surface of the medulla oblongata caused marked stimulation of tidal volume (VT) and/or minute ventilation (VE). The ventilatory response to hypoxia was significantly blunted after SP in the VLM but not in the dorsal medulla oblongata (DM) (nucleus tractus solitarius). The SP antagonist [D-Pro2,D-Trp7,9]SP almost completely inhibited this response when applied locally to a wide area of the superficial layer of the VLM but not of the DM. Unilateral or bilateral application of 0.3-1.5 nmol of the SP antagonist in the VLM (corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment) markedly attenuated the response to a 5% CO2 inhalation. The inhibition of the CO2 response was seen after [D-Pro2,D-Trp7,9]SP in the rostral areas of the medulla oblongata corresponding to the corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment of the cervical cord. Electric somatosensory-induced ventilatory stimulation could be depressed by approximately 70% by [D-Pro2,D-Trp7,9]SP locally applied on the surface of the VLM. We conclude that SP is involved in the hypoxic, hypercapnic, and somatosensory ventilatory responses in the rat. However, these respiratory reflexes are mediated via different neuronal pools in the medulla oblongata, mainly the VLM.     

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata

The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus. The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.     

Developmental study of the shortened spinal cord in the adult tiger puffer fish, Takifugu rubripes (Teleostei)

ABSTRACT The spinal cords of vertebrates are generally divided into the cord proper and the minute filum terminale. While the spinal cord extends the entire length of the vertebral canal in the adult tiger puffer, Takifugu rubripes, the cord proper is greatly reduced in length and almost all of the canal is occupied by the filum terminale, which is tape-like rather than thread-like. The dorsal and ventral roots of the spinal nerves extend, respectively, above and below the filum terminale; as a whole, these form a massive cauda equina. Supramedullary cells are found in the rostral half of the medulla oblongata caudal to the cerebellum. In 4-mm long tiger puffers, the spinal cord is cylindrical and supramedullary cells are found in the rostral half of the cord. In 7-mm puffers, the longitudinally arranged ventral roots appear ventrally in the middle portion of the spinal cord. In 15-mm puffers, the dorsal and ventral roots run longitudinally along the spinal cord and have noticeably increased in number. Supramedullary cells are located in the rostral 15% of the cord. In 21-mm puffers, the spinal cord in large part becomes dorsoventrally flattened. In 30-mm puffers, the spinal cord becomes much flatter, and supramedullary cells now are located mainly in the medulla oblongata. These observations indicate that formation of the shortened spinal cord proper is due to at least two developmental processes. First, the elongation of the spinal cord proper is remarkably less than that of the vertebral canal. Second, the bulk of the spinal cord proper is translocated to the cranial cavity, where it is transformed into part of the medulla oblongata.     

Neurons of the medulla oblongata and hypothalamus projecting on the sympathetic neurons of the ventral horn of the spinal cord]

Connections of the neurons of the spinal cord ventral horn with the structures, situating above have been investigated. After injection of uranyl acetate into the TIII segment of the spinal cord, labelled neurons are found in various reticular nuclei of the medulla oblongata. At the level of the roots of the XII pair of the cranial nerves they are revealed in the reticular paramedian, ventral, parvocellular and lateral nuclei. The formations mentioned participate in regulation of the cardio-vascular system. More rostral (2 and 4 mm relatively to the roots of the XII pair of the cranial nerves) the neurons are observed in the reticular giant cellular nucleus, in nuclei of the raphe and in the group of the P-substance reactive neurons. Besides, labelled neurons are revealed in the posterior, lateral fields and in the dorso- and ventromedial nuclei of the hypothalamus.     

Distribution of choline acetyltransferase and acetylcholinesterase in the nervous system of the dog

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity were determined in 23 selected parts of the dog CNS and 4 parts of the peripheral nervous system. Maximum ChAT activity was found in the caudate nucleus and the ventral roots of the spinal cord. High activity was also present in the thalamus, the pons, the cerebral cortex, the medulla oblongata, the ventral spinal horns and the sciatic nerve. The lowest activity was measured in the cerebellum, the dorsal cord roots and the spinal ganglia. Maximum AChE activity was found in the caudate nucleus and the cerebellum. Relatively high activity was also present in the thalamus, the pons, the medulla oblongata, the grey matter of the spinal cord and the spinal ganglia. The lowest AChE activity was measured in the ventral and dorsal spinal roots.     

Localization of three types of arginine vasotocin receptors in the brain and pituitary of the newt Cynops pyrrhogaster

The distribution of three types of arginine vasotocin (AVT) receptors in the brain and pituitary of the newt Cynops pyrrhogaster, namely, the V1a-, V2-, and V3/V1b-type receptors, was studied by means of in situ hybridization and immunohistochemistry. mRNA signals and immunoreactive cells for the V1a-type receptor were observed in the telencephalon (mitral layer of the olfactory bulb, dorsal and medial pallium, lateral and medial amygdala, bed nucleus of the decussation of the fasciculus telencephali, bed nucleus of the stria terminalis), diencephalon (anterior preoptic area, magnocellular preoptic nucleus, suprachiasmatic nucleus, ventral thalamus, dorsal and ventral hypothalamic nucleus), mesencephalon (tegmentum, interpeduncular nucleus), and medulla oblongata (median reticular formation, nucleus motorius tegmenti). Cells expressing the V2-type receptor were found in the telencephalon (medial pallium, lateral and medial amygdala, bed nucleus of the decussation of the fasciculus telencephali), and mesencephalon (tegmentum trigemini and facialis). In the paraphysis (possibly the main site of cerebrospinal fluid production), only V2-type receptor mRNA signal and immunoreactivity were detected. V3/V1b-type receptor mRNA was expressed in the diencephalon (dorsal hypothalamic nucleus, nucleus tuberculi posterioris), mesencephalon (tegmentum, interpeduncular nucleus), and medulla oblongata (raphe nucleus), whereas V3/V1b-type-receptor-like immunoreactivity was scarcely detectable in the entire brain. The V3/V1b-type receptor was predominantly expressed in the anterior pituitary. V3/V1b-type receptor and proopiomelanocortin mRNAs were co-localized in the distal lobe of the pituitary. This is the first report of the distribution of three types of AVT receptor in the brain and pituitary of non-mammalian vertebrates.     

Primary and secondary somatosensory projections in direct-developing Plethodontid Salamanders

In three species of plethodontid salamanders (Plethodon jordani, Hydromantes italicus, and Bolitoglossa subpalmata), primary and secondary somatosensory pathways were investigated by means of tract-tracing in vivo and in vitro using biocytin, horseradish peroxidase, and neurobiotin. Afferent sensory fibers of cranial nerves V, VII, and X and the brachial nerve run in the dorsal funiculus of the medulla oblongata and spinal cord. Fibers ascend to the level of, but do not enter, the cerebellum. In the caudal medulla oblongata, sensory tracts of the cranial nerves descend in a dorsal and a dorsolateral bundle and reach the level of the fourth spinal nerve. Two bundles are likewise formed by spinal afferent fibers, which descend to the level of the seventh spinal nerve. Secondary somatosensory projections ascend in contralateral ventral, contralateral lateral, and ipsilateral lateral tracts, the latter two corresponding to the spinal lemniscal tracts of Herrick. These tracts reach the cerebellum, mesencephalic, and diencephalic targets (tegmentum, torus, tectum, tuberculum posterius, pretectum, and ventral thalamus) ipsi- and contra-laterally. The projection to the tectum is confined to fiber layer 4. Fibers of the ascending tracts cross in the cerebellar and tectal commissure. Our study demonstrates that the ascending secondary somatosensory pathways of plethodontid salamanders differ remarkably from those of other amphibians. J. Morphol. 238:307–326, 1998. © 1998 Wiley-Liss, Inc.     

PKCγ免疫反应定位小鼠皮质脊髓束的实验研究

目的探讨显示皮质脊髓束在成年小鼠脑和脊髓中定位分布的简便有效方法。方法运用蛋白激酶Cγ（PKCγ）免疫组织化学染色法,观察成年ICR小鼠脑和脊髓中皮质脊髓束的定位和分布情况。结果PKCγ免疫阳性产物分布于大脑运动皮层第V层锥体细胞胞体和轴突中,锥体细胞的阳性纤维经内囊、中脑大脑脚底、脑桥基底部、下行至延髓锥体中。在延髓下段,PKCγ阳性纤维经锥体交叉后进入对侧脊髓灰质后联合背侧,形成背侧皮质脊髓束,在脊髓白质的后索腹侧深层下行,至骶髓3-4节段以下逐渐消失。在整个脊髓前索和外侧索中未见有PKCγ阳性纤维。结论PKCγ特异地表达于脊髓后索皮质脊髓束中,提示PKCγ免疫组织化学法是一种显示和观察皮质脊髓束精确定位的有效方法。     

大鼠延髓尾端加压区对外周血管紧张的影响

本文以血管的灌流压变化反映血管紧张性,观察Ｌ－谷氨酸及肾上腺素能受体阻断剂微量注射于大鼠延髓腹面心血管活动调控区对骨骼肌血管和肾血管紧张的影响。实验观察到,Ｌ－－ｇｌｕ兴奋延髓尾端加压区（ＣＰＡ）在动脉直升的同时,双后肢骨骼肌灌流压上升３７．５９％,左肾灌流压上升１７．０４％,如预先在延髓腹面加我注入普萘少尔或酚妥拉明均能明显减小Ｌ－ｇｌｕ兴奋ＣＰＡ时的灌流压和肾灌流压升高效应。提示ＣＰＡ对外周血     

The distribution of neural crest-derived Schwann cells from subsets of brachial spinal segments into the peripheral nerves innervating the chick forelimb.

Neural crest cells from brachial levels of the neural tube populate the ventral roots, spinal nerves, and peripheral nerves of the chick forelimb where they give rise to Schwann cells. The distribution of neural crest cells in the developing forelimb was examined using homotopic and heterotopic chick-quail chimeras to label neural crest cells from subsets of the brachial spinal segments. Neural crest cells from particular regions of the spinal cord populated ventral roots and spinal nerves adjacent to or immediately posterior to the graft. Crest cells also populated the brachial plexus in accord with their segmental origins. In the forelimb, neural crest cells populated muscle nerves with anterior brachial spinal segments populating nerves to anterior musculature of the forelimb and posterior brachial spinal segments populating nerves to posterior musculature. Similar patterns were seen following both homotopic and heterotopic transplantation. In both types of grafts, the distribution of neural crest cells largely matched the sensory and motor projection pattern from the same spinal segmental level. This suggests that neural crest-derived Schwann cells from a particular spinal segment may use sensory and motor fibers emerging from the same segmental level as substrates to guide their migration into the periphery.     

Study of neuronal structures of the brain stem which produce rapid reactions in reticulo-spinal pathways

The total electrical discharges of the ventral and ventrolateral funiculi of the 11th thoracic segment of the spinal cord in response to stimulation of different points of the pons varolii and the medulla oblongata between frontal planes P-2 and P-12 were investigated in decerebrated cats. Regions were found corresponding to the location of the oral and caudal reticular nuclei of the pons and the rostral section of the reticular giant cell nucleus whose stimulation caused a short-latent discharge in the ventral funiculus (latent period 1.6–1.9 msec) with maximum amplitude. It was concluded that such a discharge is due to the direct stimulation of a rather homogeneous group of fast-conducting reticulo-spinal fibers which terminate mainly in the ventral funiculus and which have an average rate of conduction of 131 m /sec. When the same regions were stimulated, the short-latet discharge of the ventro-lateral funiculus had a considerably lower amplitude and was accompanied by a powerful, late discharge with a latent period of about 3.3 msec. It was assumed that this funiculus consists mainly of fibers with a lower rate of conduction which originate in a broader region of the medial RF of the brain stem. Stimulation of contralateral regions of the reticular formation of the medulla oblongata evoked only a weak short-latent discharge in the ventral funiculus; the late component of the discharge in this case was considerably stronger.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 3, No. 3, pp. 274–283, May–June, 1971.     

Double central projection of VIIIth cranial nerve in the frog (Rana esculenta L.)]

In the frog we have cut the anterior or the posterior root of the VIIIth nerve between Scarpa's ganglion and the medulla oblongata. The degenerations show that both roots project onto the ventral and the dorsal vestibular nuclei.     

Neurophysin pathways in the normal and hypophysectomized rat

Summary The hypothalamo-extrahypophyseal neurophysin pathways (HEH) and the three hypothalamic nuclei secreting neurophysins, the supraoptic (SON), paraventricular (PVN) and suprachiasmatic (SCN) nuclei, of normal and hypophysectomized rats were studied by application of the immunoperoxidase procedure. Eight well-defined HEH pathways were recognized. Their main sites of projection were: lateral septum and subfornical organ (1 and 2); tractus diagonalis (3); medial nucleus of the amygdala and lateral ventricle (4); nucleus periventricularis thalami, nucleus habenulae lateralis and periaqueductal gray (5); periaqueductal gray, pineal organ, collicular recess and subependymal region of the fourth ventricle (6); dorsomedial nucleus and premammillary area (7); perimammillary region, corpus trapezoideum, ventral surface of medulla oblongata, nucleus tractus solitarii, nucleus commissuralis, substantia gelatinosa and formatio reticularis lateralis of the medulla oblongata and spinal cord (8).Neurophysin fibers of unknown origin were found in the frontal cerebral cortex.It was noted that in pathway 5 the amount of immunostainable material undergoes changes with age.The three neurophysin-secreting nuclei reacted differently following hypophysectomy. Among the HEH pathways the only one that seemed to be affected by hypophysectomy was that innervating the lateral septum.It is suggested that the neurons that survive hypophysectomy either do not project to the neural lobe or, alternatively, display axon collaterals projecting outside the neural lobe. Such a neuronal population could be the origin of the HEH pathways.Supported by Grant RSM-80-13 from the Directión de Investigaciones, Universidad Austral de Chile.The authors wish to acknowledge the valuable help of Mrs. Elizabeth Santibá~nez and Mr. Genaro Alvial.     

The posterior inferior cerebellar artery

The posterior inferior cerebellar artery has a curved course in the region of the medulla oblongata. Besides its frequent individual variations, this vessel exhibits three morphological types: in type 1 (the commonest type, i.e. more than 50% of the cases) it curves with its vertex turned upwards; in type 2, the posterior inferior cerebellar artery turns in a gentle arch on to the posterior surface of the medulla oblongata, so there is no real curve; in type 3, the posterior inferior cerebellar artery curves but its vertex turns downwards. In all of these cases, the artery is in close relationship with the last four cranial nerves. This relationship is most characteristic in the 1st and 3rd types. The morphological types could be recognised on the angiograms.     

Fos protein expression in the medulla oblongata and changes in size of spinal lateral horn neurons after 4-wk simulated weightlessness in rats

Responses of the neurons in medulla oblongata and C8-T1 spinal cord lateral horn of rats induced by simulated weightlessness were investigated using anti-Fos protein and anti-tyrosine hydroxylase (TH) double staining immunohistochemical methods, and Nissl-staining technique respectively. After four weeks of tail-suspension, many Fos-like positive neurons were localized in the medullary visceral zone (MVZ), predominantly in the nucleus of tractus solitarii and ventrolateral medulla, and some of them showed TH-like immunoreactivity. Sizes of the cell bodies of the lateral horn neurons in C8-T1 segment were significantly increased in 4-wk tail-suspended rats (P<0.05) as compared with that in controls. The results suggest that the neurons in MVZ and the spinal lateral horn may be involved in the adaptation of central cardiovascular regulation during weightlessness.     

Distribution of NT-IR perikarya in the brain of the guinea pig with special reference to cardiovascular centers in the medulla oblongata

Summary The occurrence and distribution of neurotensin-immunoreactive (NT-IR) perikarya was studied in the central nervous system of the guinea pig using a newly raised antibody (KN 1). Numerous NT-IR perikarya were found in the nuclei amygdaloidei, nuclei septi interventriculare, hypothalamus, nucleus parafascicularis thalami, substantia grisea centralis mesencephali, ventral medulla oblongata, nucleus solitarius and spinal cord. The distribution of NT-IR perikarya was similar to that previously described in the rat and monkey. In the gyrus cinguli, hippocampus and nucleus olfactorius, though, no NT-IR neurons were detected in this investigation. Additional immunoreactive perikarya, however, were observed in areas of the ventral medulla oblongata, namely in the nucleus paragigantocellularis, nucleus retrofacialis and nucleus raphe obscurus.The relevance of the NT-IR perikarya within the ventral medulla oblongata is discussed with respect to other neuropeptides, which are found in this area, and to cardiovascular regulation.Abbreviations abl nucleus amygdaloideus basalis lateralis - abm nucleus amygdaloideus basalis medialis - acc nucleus amygdaloideus centralis - aco nucleus amygdaloideus corticalis - ahp area posterior hypothalami - ala nucleus amygdaloideus lateralis anterior - alp nucleus amygdaloideus lateralis posterior - ame nucleus amygdaloideus medialis - atv area tegmentalis ventralis - bst nucleus proprius striae terminalis - CA commissura anterior - CC corpus callosum - cgld corpus geniculatum laterale dorsale - cglv corpus geniculatum laterale ventrale - cgm corpus geniculatum mediale - CHO chiasma opticum - CI capsula interna - co nucleus commissuralis - cod nucleus cochlearis dorsalis - cp nucleus caudatus/Putamen - cs colliculus superior - cu nucleus cuneatus - dmh nucleus dorsomedialis hypothalami - DP decussatio pyramidum - em eminentia mediana - ent cortex entorhinalis - epi epiphysis - FLM fasciculus longitudinalis medialis - fm nucleus paraventricularis hypothalami pars filiformis - FX fornix - gd gyrus dentatus - gp globus pallidus - gr nucleus gracilis - hl nucleus habenulae lateralis - hm nucleus habenulae medialis - hpe hippocampus - ift nucleus infratrigeminalis - io oliva inferior - ip nucleus interpeduncularis - LM lemniscus medialis - MT tractus mamillo-thalamicus - na nucleus arcuatus - nls nucleus lateralis septi - nms nucleus medialis septi - npca nucleus proprius commissurae anterioris - ns nucleus solitarius - n III nucleus nervi oculomotorii - nt V nucleus tractus spinalis nervi trigemini - ntm nucleus mesencephalicus nervi trigemini - osc organum subcommissurale - P tractus cortico-spinalis - PC pedunculus cerebri - PCI pedunculus cerebellaris inferior - pir cortex piriformis - pol area praeoptica lateralis - pom area praeoptica medialis - prt area praetectalis - pt nucleus parataenialis - pvh nucleus paraventricularis hypothalami - pvt nucleus paraventricularis thalami - r nucleus ruber - re nucleus reuniens - rgi nucleus reticularis gigantocellularis - rl nucleus reticularis lateralis - rm nucleus raphe magnus - ro nucleus raphe obscurus - rp nucleus raphe pallidus - rpc nucleus reticularis parvocellularis - rpgc nucleus reticularis paragigantocellularis - sch nucleus suprachiasmaticus - SM stria medullaris thalami - snc substantia nigra compacta - snl substantia nigra lateralis - snr substantia nigra reticularis - ST stria terminalis - tad nucleus anterior dorsalis thalami - tam nucleus anterior medialis thalami - tav nucleus anterior ventralis thalami - tbl nucleus tuberolateralis - tc nucleus centralis thalami - tl nucleus lateralis thalami - tmd nucleus medialis dorsalis thalami - TO tractus opticus - TOL tractus olfactorium lateralis - tpo nucleus posterior thalami - tr nucleus reticularis thalami - trs nucleus triangularis septi - TS tractus solitarius - TS V tractus spinalis nervi trigemini - tvl nucleus ventrolateralis thalami - vmh nucleus ventromedialis hypothalami - vh ventral horn, Columna anterior - zi zona incerta Supported by the Deutsche Forschungsgesellschaft (DFG) SFB 90, Carvas     

Chemosensitive structures of the medulla oblongata participate in blood pressure regulation and belong to APUD-system

It was shown in 25 experiments on anesthetized spontaneously breathing and immobilized artificially ventilated cats that the cooling of the intermediate chemosensitive area of the ventral surface of medulla oblongata to 20-22 degrees C is followed by depressor reaction that is more pronounced after preliminary occlusion of the sinocarotid and vagus nerves. Two types of apudocytes were revealed in this brain area with the use of the histochemical and immunohistochemical techniques. The first type cells are typically nervous and contain noradrenaline. The second type apudocytes adjacent to the microvascular wall showed melatonin and its precursors. It is assumed that the cells detected participate in the arterial pressure control.