bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of galaninlike immunoreactivity in the rat central nervous system
Authors: Melander Tor , Hökfelt Tomas , Rökaeus Ake 
Published: January 2005

AbstractThe localization of galanin (GAL) immunoreactive (IR) neuronal structures in the rat central nervous system has been investigated by using the indirect immunofluorescence technique. GAL‐IR structures were seen in high concentrations in the hypothalamus, medulla oblongata, and spinal cord. Less extensive systems were detected in the telencephalon, thalamus, mesencephalon, and pons, while virtually no GAL‐positive structures were seen in the olfactory bulb and cerebellum.Major populations of cell bodies staining for GAL‐like material were seen in many areas. In the telencephalon somata were revealed in the bed nucleus of stria terminalis, in the nucleus of the diagonal band, medial septum, and in the medial aspects of the central amygdaloid nucleus, and in small numbers in cortical areas. The anterodorsal and periventricular nuclei of the thalamus contained positive cell bodies. In the hypothalamus GAL‐IR somata were seen in the medial and lateral preoptic nuclei, arcuate nucleus, periventricular nucleus, in the dorsomedial nucleus, in the medial forebrain bundle area, in the tubular, caudal, accessory, supraoptic, and paraventricular magnocellular nuclei and lateral to the mammillary recess. The dorsal raphe nucleus hosted a large number of GAL‐positive somata. Locus coeruleus of the pons contained a large number of GAL‐IR perikarya. In the medulla oblongata positive somata were found in the caudal spinal trigeminal nucleus, the nucleus of the solitary tract, and in the ventral lateral area just rostral to area postrema. Small cell bodies were detected in the superficial layers of the dorsal horn of the spinal cord at all levels and in lamina X at lumbar levels.Analysis of GAL‐positive fibers in the telencephalon revealed highly or medium‐dense networks in the lateral septal nucleus, in the bed nucleus of stria terminalis, and in the central and medial amygdaloid nuclei. Positive fibers were found in the thalamus in and around the periventricular nucleus as well as to the lateral habenular nucleus and extending in a lateral, caudal direction from the third ventricle and fasciculus retroflexus to the lateral tip of the medial lemniscus. In the hypothalamus the external layer of the median eminence contained a very dense fiber network. Dense or medium‐dense GAL‐IR networks were detected in the periventricular nucleus, throughout the medial and lateral preoptic areas, in the medial forebrain bundle area, in the dorsomedial nucleus, and lateral to the mammillary recess. In the pons GAL‐IR fibers were seen in the parabrachial nuclei, dorsal to the superior olive, and in the periaqueductal central gray. The external layers of the caudal spinal trigeminal nucleus, the nucleus of the solitary tract, and the ventral portions of the medulla oblongata contained extensive positive fiber networks. In the spinal cord GAL‐IR fibers were noted in high numbers in the superficial layers (lamina I and II) of the dorsal horn and at lumbar and sacral levels in lamina X.
The accessory optic system in a prosimian primate (Microcebus murinus): Evidence for a direct retinal projection to the medial terminal nucleus
Authors: Cooper H. M. 
Published: January 2005

AbstractThe accessory optic system (AOS) was studied in the prosimian primate, Microcebus murinus, by using intraocular injections of the anterograde tracers 3H‐proline and horseradish peroxidase (HRP). Retinal fibers were found to terminate bilaterally in all three mesencephalic AOS nuclei as defined by Hayhow ('66, J. Comp. Neurol 126:653‐672). In contrast to previous reports in primates, we find that both the ventral and dorsal divisions of the medial terminal nucleus (MTN) receive projections from the retina. The ventral MTN is composed of a compact triangular group of cells, situated at the medial base of the cerebral peduncle, rostral to the rootlets of the third cranial nerve. The dorsal MTN extends dorsomedial to the substantia nigra and is composed of characteristic fusiform cells embedded in a fibrous neuropil. Although the cells of the dorsal MTN intermingle somewhat with the nigral cells, the nucleus is clearly distinguished by cytoand myeloarchitectural features. The large lateral terminal nucleus (LTN) receives a dense projection from the retina and forms a prominent bulge on the lateral surface of the cerebral peduncle. The dorsal terminal nucleus (DTN) is located between the brachia of the superior and inferior colliculi, near the origin of the superior fasciculus of the accessory optic tract (AOT). This fasciculus is composed of anterior, middle, and posterior branches. In addition, a ventral group of fibers, corresponding to the inferior fasciculus of the AOT previously described in nonprimates, was identified in all planes of section. The results confirm the existence of a common plan of AOS organization in mammals.
Lectins demarcate the barrel subfield in the somatosensory cortex of the early postnatal mouse
Authors: Cooper Nigel G. F. , Steindler Dennis A. 
Published: January 2005

AbstractPlant lectins were used to examine the disposition of glycosylated molecules in vibratome sections through the barrel subfield of mouse somatosensory cortex at selected times during postnatal development. The peroxidase conjugates of peanut agglutinin (PNA, specific for N‐acetygalactosamine), concanavalin A (specific for mannose), and wheat germ agglutinin (specific for N‐acetylglucosamine and N‐acetylneuraminic acid) were used to study lectin binding in aldehyde‐fixed tissue sections of cortex. Following peroxidase cytochemistry and light microscopy, it was found that all three lectins bound in the region of the barrel subfield as early as postnatal day 3 (day of birth = postnatal day 1). The lectins bound to the prospective sides and/or septae of individual barrels in preference to the prospective hollows. This lectin demarcation of the barrel field occurred prior to the detection of this region with cresyl violet staining and was still demonstrable on postnatal day 6, when the individual barrels became discernible with cresyl violet. This suggests that the lectin binding material is present before tie barrel field becomes a fully formed and organized region. A decrease in lectin affinity for binding sites in these tissue sections occurs during postnatal development (Cooper and Steindler: Soc. Neurosci. (Abstr.) 10: 43a, '84) and this study demonstrates that lectins do not delineate the barrel field of more mature animals (2‐3 months old), whereas barrels can be detected with cresyl violet at this time. A preliminary electron microscope analysis of the postnatal day 6 somatosensory cortex demonstrates that the lectin PNA binds to elements of the forming neuropil and also to Golgi apparatus intermediate saccules in neuronal cells. The prospective barrel field can be detected with lectins during a critical period in development in which alterations can occur in the barrel field in response to peripheral deprivation (Jeanmonod et al: Neuroscience 6:1503‐35, '81) and therefore we suggest that the glycans visualized with lectin‐peroxidase conjugates denote possible candidates for molecules involved in shaping barrel structure.
Metamorphosis of the cerebral neuroendocrine system in the moth Manduca sexta
Authors: Copenhaver Philip F. , Truman James W. 
Published: January 2005

AbstractWe have examined the morphology and neuronal elements of the cerebral neuroendocrine system in the larval, pupal, and adult stages of the moth Manduca sexta with a variety of neuroanatomical techniques. The larval brain contains several discrete groups of neurosecretory and non‐neurosecretory cells that project to the associated neurohemal organs (the corpora cardiaca‐allata complex, or CC‐CA) and to a variety of more peripheral structures. A previously undescribed set of cells in the subesophageal ganglion have also been found that project out the neurosecretory nerves.During metamorphosis, the cerebral neuroendocrine system undergoes a dramatic structural reorganization, including the reduction or loss of many larval nerves and a repositioning of the cell groups and their dendritic fields. Despite these changes, most of its central elements are retained. In addition, by the completion of adult development a new cluster of cells can be found on either side of the dorsal midline of the brain. We have also determined the relative contributions of the different cell groups to the moth neuroendocrine system by intracellular iontophoresis of dye into individual cells. Within the dorsal protocerebrum, five separate morphological types of cells can be recognized, each with a distinctive pattern of dendritic arborization in the brain and terminal neurohemal processes that project to the CC, the CA, the aorta, or to a combination of these regions. The large intrinsic cells of the CC have also been filled, revealing an unusual set of morphological features in these peripheral neurosecretory cells.
Degeneration and regeneration of peripheral nerve in the rat trigeminal system. II. Response to nerve lesions
Authors: Renehan William E. , Munger Bryce L. 
Published: January 2005

AbstractThe course of vibrissa sensory receptor denervation and subsequent reinnervation was studied following transection or crush of the rat infraorbital nerve. Eighteen hours after nerve lesion, the large‐diameter myelinated nerves supplying the lanceolate receptors of the intermediary zone and the Merkel cells of the stratum basale contained areas of focal axoplasmic abnormalities, and some of the nerve terminals exhibited vacuolization, mitochondrial swelling, and disruption of the neurofilament pattern. The Merkel cells and lanceolate receptors of the intermediary zone were completely deafferented by 24 hours after the nerve injuries. The Ruffini complex, free nerve endings and lanceolate receptors of the inner conical body, as well as the free nerve endings and lanceolate receptors of the connective tissue below the Ringwulst, were completely normal 24 hours after crush or transection of the nerve. These receptors underwent progressive degeneration from days 2 through 6 and the vibrissa was totally denervated by day 7. Regenerating axons were first seen entering the vibrissae 2 weeks after the crush lesion and 1 month following nerve transection. Except for a slight decrease in the percentage of Merkel cells innervated, vibrissae from postcrush animals were virtually indistinguishable from normal by 3 months. In contrast, vibrissae from rats subjected to the transection lesion exhibited evidence of misdirected axons and abnormally reinnervated receptors throughout the course of regeneration. Axons entering the hairs with the main vibrissal nerve were observed contributing to the innervation of the inner conical body, an area normally supplied exclusively by the conus nerve. Many of the lanceolate receptors contained multiple unmyelinated axons, and the usually highly ordered circular innervation of the inner conical body was markedly abnormal. It is suggested that these results may help explain the faulty sensory localization and abnormal sensations reported by patients suffering a peripheral nerve injury.
The distribution of choline acetyltransferase in the rat amygdaloid complex and adjacent cortical areas, as determined by quantitative micro‐assay and immunohistochemistry
Authors: Hellendall R. P. , Godfrey D. A. , Ross C. D. , Armstrong D. M. , Price J. L. 
Published: January 2005

AbstractThe distribution of choline acetyltransferase (ChAT) within the amygdaloid complex has been studied to evaluate what should primarily represent the terminal field of the cholinergic projection from the basal forebrain. Two currently available methods have been combined for the comparison: immunohistochemistry with a monoclonal antibody against ChAT, by a double peroxidase‐antiperoxidase procedure, and quantitative histochemistry involving micro‐assay of the ChAT activity of contiguous microdissected samples. Both methods indicate prominent ChAT activity in the basolateral amygdaloid nucleus (especially rostrally), the nucleus of the lateral olfactory tract (especially layer II), and the amygdalohippocampal area. Regions of lower ChAT activity were not accurately represented, by the immunohistochemistry, but could be discriminated by the quantitative assays. Lowest activity was found in the medial nucleus of the amygdala. Most other regions had activities at least as high as average brain or neocortex. Gradients of enzyme activity were found within several regions, including the basolateral and lateral amygdaloid nuclei and the nearby posterior piriform cortex. In the piriform cortex, a region of particularly high ChAT activity was found at its medial edge near the nucleus of the lateral olfactory tract. The immunohistochemical method shows a few intensely reactive somata in layer III within this zone. Comparison of the results seen with immunohistochemistry and quantitative histochemistry suggests an advantage in using them together, since their respective strengths and weaknesses tend to complement each other.
The organization of the motoneurons innervating the axial musculature of vertebrates: II. Florida water snakes (Nerodia fasciata pictiventris)
Authors: Fetcho Joseph R. 
Published: January 2005

AbstractThe motor pools of axial muscles in Florida water snakes (Nerodia fasciata pictiventris) were studied by applying horseradish peroxidase (HRP) to branches of spinal nerves innervating individual muscles or groups of muscles. Motor pools of different muscles or muscle groups were located in characteristic positions in both the transverse and the longitudinal extent of the motor column. Epaxial pools were located ventromedially in the column, segregated from most hypaxial ones, which were dorsolateral. The only exception to this general rule was the motoneurons innervating the levator costae muscle. Some of the motoneurons innervating this hypaxial muscle were located in the ventral part of the motor column, like epaxial motoneurons, but they were segregated longitudinally from epaxial ones.The arrangement of the motor pools was strikingly similar to the motor pools of presumptive homologous muscles in rats Smith and Hollyday: J. Comp. Neurol. 220:29–43, '83), even though the locomotor mechanics in the two animals are very different. The similarities may reflect a comparable relationship between the location of motoneurons in. The motor column and the location, in embryonic life, of the muscles they innervate. They also suggest that differences in the locomotor mechanics in the two species are accomplished without any dramatic reorganization of the medial motor column, in marked contrast to the substantial reorganization necessary to account for differences in the motor columns of amniotes and anamniotes.
The topography of expanded uncrossed retinal projections following neonatal enucleation of one eye: Differing effects in dorsal lateral geniculate nucleus and superior colliculus
Authors: Reese B. E. 
Published: January 2005

AbstractThe topographic organization of the uncrossed retinal projections to the dorsal lateral geniculate nucleus (dLGN) and superior colliculus (SC) was studied in normal adult hooded rats and in rats subjected to unilateral ocular enucleation on the day of birth. Sections were stained for anterograde degeneration products following discrete retinal lesions at various locations. The projection from the temporal crescent to the dLGN in neonatally enucleated rats had an expanded but topographically normal organization, with the nasotemporal and dorsoventral retinal axes displaying polarities identical to those in normal adults. Neonatal enucleation permits the remaining uncrossed retinogeniculate projection to extend primarily along the “lines of projection” into neuropil normally recipient of binocularly conjugate crossed projections. In the SC, the dorsoventral axis of the temporal crescent showed a normal polarity, but the nasotemporal axis failed to display any topographic organization. Retinal loci in the temporal crescent projected throughout the rostrocaudal extent of the ipsilateral SC. Retinal lesions placed outside the temporal crescent failed to produce any substantial degeneration in ipsilateral dLGN or SC.These topographically distinct effects in dLGN and SC following unilateral eye removal on the day of birth are discussed in the context of differing constraints upon axonal ingrowth and connectivity during early development, which may normally bring about the characteristically distinct features of retinogeniculate and retinocollicular organization.
A light and electron microscopic analysis of the sacral parasympathetic nucleus after labelling primary afferent and efferent elements with HRP
Authors: Mawe Gary M. , Bresnahan Jacqueline C. , Beattie Michael S. 
Published: January 2005

AbstractPrimary afferent input to the cat sacral parasympathetic nucleus (SPN) has been examined by injury filling sacral dorsal roots, ventral roots, or both with horseradish peroxidase (HRP). Appropriate spinal segments were processed for the demonstration of HRP with diaminobenzidine and prepared for sequential light (LM) and electron (EM) microscopy.At the LM level, a large fascicle of primary afferent fibers was observed passing ventrally along the lateral edge of the dorsal horn into the region of the SPN. Varicosities were seen throughout the course of the axons but were particularly abundant within the SPN. Injury filling of the ventral roots with HRP resulted in a Golgi‐like labelling of preganglionic neurons and their dendritic arbors, as well as ventral root afferent fibers. Swellings on both dorsal and ventral root afferent axons were observed in close apposition to labelled preganglionic neurons and their dendrites.At the ultrastructural level, labelled afferent terminals were found to contain clear spherical vesicles; 66% of these terminals also contained at least one dense‐cored vesicle. Of particular interest was the presence of labelled dorsal and ventral root afferent terminals synapsing on labelled preganglionic neurons. Preganglionic neurons were also pestsynaptic to unlabelled terminals containing clear spherical (79.7%) or pleomorphic vesicles (20.3%). These data indicate that preganglionic neurons receive direct input from several sources, and provide the first demonstration of direct input to these cells from sensory fibers in the dorsal and ventral roots. The connections described in the present study provide interesting and, as yet, unexplored possibilities for sensory and autonomic reflex integration.
Axonal regeneration in spinal cord injury: A perspective and new technique
Authors: Borgens Richard B. , Blight Andrew R. , Murphy D. J. 
Published: January 2005

AbstractA set of techniques is described for determining the response of mammalian spinal axons to transection. The logical‐selection and the advantages of these techniques are discussed. The dorsal column of guinea pig thoracic spinal cord was transected with a tungsten needle and the position of the lesion was marked by a staple‐shaped wire device (Foerster: J. Comp. Neurol 210:335–356, '82). The morphology of dorsal column axons projecting rostrally toward the lesion was examined between 1 and 50 days postlesion by anterograde staining with horseradish peroxidase, applied to a second lesion of the dorsal column two to three vertebral segments caudal to the first. Axons damaged by the original lesion were found to die back 1–2 mm from the plane of transection and at 18–20 hours were characterized by terminal club‐shaped swellings attached to the proximal axon by a thin connection. At 50 days postlesion there was some evidence of limited regenerative responses in terms of growth‐cone‐like axon terminals, and the presence of aberrant axonal branching, but no evidence of regenerating axons approaching close to the plane of transection. These findings are in agreement with previous studies indicating little or no effective regrowth of myelinated axons in the mammalian spinal cord. These same techniques were used in a succeeding study to examine the effects of applied electric fields on the axonal response to transection.
Transected dorsal column axons within the guinea pig spinal cord regenerate in the presence of an applied electric field
Authors: Borgens Richard B. , Blight Andrew R. , Murphy D. J. , Stewart Lygia 
Published: January 2005

AbstractUsing an implanted battery and electrodes, we have imposed a weak, steady electrical field across partially severed guinea pig spinal cords. We have analyzed regeneration of dorsal column axons in experimental animals and sham‐treated controls at 50‐60 days postirjury by anterograde filling of these axons with the intracellular marker horseradish peroxidase and by employing a marking device to identify precisely the original plane of transection (J. Comp. Neurol. 250: 157‐167, '86). In response to electric field applications, axons grew into the glial scar, as far as the plane of transection in most experimental animals. In a few animals axons could be traced around the margins of the lesion (but never through it). Moreover, these fibers returned to their approximate positions within the rostral spinal cord before turning toward the brain.In sham‐treatede controls, ascending axons were found to terminate caudal to the glial scar, and rarely were any fibers found within the scar itself. Axons were never observed to cross into the rostral cord segment. These findings suggest that an imposed electrical field promotes growth of axons within the partially severed mammalian spinal cord, that a steady voltage gradient may e an environmental component necessary for axonal development and regeneration, and that some component(s) of the scar impede or deflect axonal growth and projection.
Alterations of the blood‐brain barrier after transplantation of autonomic ganglia into the mammalian central nervous system
Authors: Rosenstein Jeffrey M. , Brightman Milton W. 
Published: January 2005

AbstractAutonomic (superior cervical) ganglia, the vessels of which are freely permeable to macromolecules, from mature rat donors (allografts or autografts) were transplanted to different sites in the central nervous system (CNS). Minimal trauma was caused by grafts into the IVth ventricle while grafts to intraparenchymal locations such as cerebral cortex and spinal cord were necessarily traumatic and produced glial scarring. Postoperative periods were between 4 weeks and 30 months. A potentially significant aspect of neural transplantation is the functional vascular connections between host and graft. It is highly likely that grafting procedures alter the bloodbrain barrier (BBB) in the recipient brain. In order to determine permanent BBB changes, the glycoprotein horseradish peroxidase (HRP) (M.W. 40,000) was injected intravascularly for circulation periods ranging between 50 seconds and 90 minutes. Protein exudatation was monitored by using the chromagens DAB and the highly sensitive TMB.All autonomic ganglia transplants, regardless of postoperative or HRP circulation times, were permeable to the injected protein; no qualitative differences were found between allografts and autografts. The blood‐borne protein traversed the autonomic graft and infiltrated into the host brain for distances between 200 μm in intraparenchymal grafts to over 1 mm in intraventricular grafts; a smaller exudate was found in the intraparenchymal model than in the intraventricular site probably due to glial scarring, that impeded the protein movement in the interstitial spaces. Significantly, TMB demonstrated that the systemic protein entered the cerebrospinal fluid. HRP was detected on the ventricular floor and in the perivascular spaces of the microvasculature.Transplantation of an autonomic ganglion into the brain provides a biological portal that bypasses normal barriers to macromolecules. The vascular and extracellular confluences between host and graft could provide direct access for systemically administered substances to enter brain regions where they, normally, would be excluded.