bluuebunny/crossref_metadata_2025_split huggingface dataset:
Afferent and efferent connections of the olfactory bulbs in the lizard Podarcis hispanica
Authors: Martinez‐Garcia Fernando , Olucha Francisco E. , Teruel Vicent , Lorente Maria J. , Schwerdtfeger Walter K. 
Published: January 2005

AbstractThe connections of the olfactory bulbs of Podarcis hispanica were studied by tract‐tracing of injected horseradish peroxidase. Restricted injections into the main olfactory bulb (MOB) resulted in bilateral terminallike labeling in the medial part of the anterior olfactory nucleus (AON) and in the rostral septum, lateral cortex, nucleus of the lateral olfactory tract, and ventrolateral amygdaloid nucleus. Bilateral retrograde labeling was found in the rostral lateral cortex and in the medial and dorsolateral AON. Ipsilaterally the dorsal cortex, nucleus of the diagonal band, lateral preoptic area, and dorsolateral amygdala showed labeled cell bodies. Retrogradely labeled cells were also found in the midbrain raphe nucleus.Results from injections into the rostral lateral cortex and lateral olfactory tract indicate that the mitral cells are the origin of the centripetal projections of the MOB.Injections in the accessory olfactory bulb (AOB) produced ipsilateral terminallike labeling of the ventral AON, bed nucleus of the accessory olfactory tract, central and ventromedial amygdaloid nuclei, medial part of the bed nucleus of the stria terminalis, and nucleus sphericus. Retrograde labeling of neurons was observed ipsilaterally in the bed nucleus of the accessory olfactory tract and stria terminalis, in the central amygdaloid nucleus, dorsal cortex, and nucleus of the diagonal band. Bilateral labeling of somata was found in the ventral AON, the nucleus sphericus (hilus), and in the mesencephalic raphe nucleus and locus coeruleus.Injections into the dorsal amygdala showed that the mitral neurons are the cells of origin of the AOB centripetal projections. Reciprocal connections are present between AOB and MOB.To our knowledge, this is the first study to address the afferent connections of the olfactory bulbs in a reptile. On the basis of the available data, a discussion is provided of the similarities and differences between the reptilian and mammalian olfactory systems, as well as of the possible functional role of the main olfactory connections in reptiles.
The fine structure of the Purkinje cell and its afferents in lurcher chimeric mice
Authors: Caddy Keith W. T. , Herrup Karl 
Published: January 2005

AbstractLurcher is an autosomal dominant mutation in the mouse. Heterozygote (+/Lc) animals lose 100% of their cerebellar Purkinje cells during the first postnatal month. Aggregation chimeras made between +/Lc and wild‐type embryos have been used to demonstrate that this neuronal cell death is a cell autonomous property of the +/Lc Purkinje cells. In lurcher chimeras, all +/Lc PCs die while wild‐type Purkinje cells survive in the numbers expected. Although they are normal in number, previous work from our laboratories has shown that when the genetically wild‐type Purkinje cells are present in the mosaic environment of the lurcher chimeric mouse they develop a very unusual morphology. Their dendritic trees are small, and the caliber of their dendrites is increased. This paper examines the fine structure of these unusual cells as well as their afferent fibers. Purkinje cell somas in the lurcher chimera have an increased number of lysosomes and the rough endoplasmic reticulum is improperly configured. In the majority of the Purkinje cell dendrites the organelles are disorganized; it is not certain whether this is a cause or a consequence of the increase in dendritic caliber previously reported. Presynaptic fibers have been examined and, while all classes of expected synapses can be observed, the numbers of synaptic profiles visible in any one thin section are reduced. Climbing fiber terminations on the Purkinje cells were smaller than normal with a greatly diminished number of constituent vesicles. Unexpectedly, we found unusual morphologies among the Bergmann glial fibers and the presence of unusual (or ectopic) astrocytic like glial cells near the pial surface. These changes in turn were accompanied by an increase in the number of glial‐like fibers near the pia in some parts of the chimeric cerebellar cortex. The results are discussed in light of our knowledge of other mutant mice, and a hypothesis is put forward to explain some of our results.
Expression of glial fibrillary acidic protein by müller cells in rd chick retina
Authors: Semple‐Rowland Susan L. 
Published: January 2005

AbstractAccumulation of glial fibrillary acidic protein (GFAP) in Müller cells has been observed in retinas of several mammalian species secondary to genetically induced degeneration and neuronal injury. In the present series of experiments, I have examined the effects of the rd (retinal degeneration) mutation on the expression of GFAP in retinas of chicks homozygous for the mutation (rd/rd) prior to and following the onset of photoreceptor degeneration, which first appears approximately 7 days posthatch (7dph). Carrier (+/rd) and wild‐type (+/+) retinas served as controls.Retinas taken from 1, 7, 21, and 33 dph rd/rd, +/rd, and +/+ chicks were analyzed for the presence of GFAP by immunocytochemical and SDS‐PAGE/Western blot techniques. The following immunocytochemical observations were made: (1) GFAP immunostaining was limited to and located throughout the Müller cells. (2) The intensity of GFAP immunostaining increased with age in all three retina types in tissue sections, as well as on immunoblots. (3) The distribution of GFAP staining within rd/rd Müller cells following the onset of degeneration was slightly different from that observed in +/+ and +/rd retinas and was distinguished by increased staining of the cell bodies and the cell processes forming the outer limiting membrane.The results of these experiments show that Müller cells in chick retina contain GFAP. In addition, they suggest that, in contrast to Müller cells in degenerating mammalian retina, Müller cells in rd chick retina do not accumulate large amounts of GFAP in response to degeneration.
Somatosensory cortex of the neonatal pig: II. Topographic organization of the secondary somatosensory cortex (SII)
Authors: Craner Sandra L. , Ray Richard H. 
Published: January 2005

AbstractMultiunit microelectrode recording techniques were used to delineate the somatotopic organization of the secondary somatosensory cortex (SII) of the neonatal pig. Barbiturate anesthetized piglets ranging in age from 7 days preterm to 2 months postpartum were used. The SII area, located lateral to the rostral and middle suprasylvian sulci, was found to contain a complete somatotopic representation of the contralateral body surface with a significant proportion of bilateral input for all body regions except the forehoof and forelimb. The SII forelimb and hindlimb representations were found to possess a “striplike” orientation in a rostral to caudal sequence, and the trunk representation was located posterolateral to the hindlimb representation, giving SII an inverted appearance. Two apparently separate face representations were delineated; one posterolateral to the projection from the trunk and the other anterior to the forehoof region.Unlike SI, which possesses a disproportionately large representation of the rostrum, SII has no specialized representation of the rostrum. The overall organization of SII supports the contention that this cortical region provides a more generalized representation of the entire body surface than does SI.
Subregional topography of capillaries in the dorsal vagal complex of rats: I. Morphometric properties
Authors: Shaver Steven W. , Pang Judy J. , Wall Katharine M. , Sposito Nadine M. , Gross Paul M. 
Published: January 2005

AbstractCytoarchitectonic and neurochemical studies of the dorsal vagal complex in the caudal medulla oblongata of rats indicate the existence of distinct anatomical and functional compartments within its components. We applied morphometric methods to discern whether capillary networks differed quantitatively between subregions and zones of area postrema, nucleus tractus solitarii (NTS), and dorsal motor nucleus of the vagus nerve (DMN) of rats. Analysis of 11 subdivisions of area postrema identified both “true” (range in luminal diameter of 3–7.5 μm) and sinusoidal (luminal diameter > 7.5 μm) capillaries that, together, made the capillary density for most of area postrema 75% greater than that found in NTS and DMN (526/mm2 vs about 300/mm2). The rank order of true capillary density in area postrema along its rostracaudal axis was caudal > central < rostral, whereas the reverse order was true for sinusoidal capillaries. Dorsal (periventricular) and medial zones of area postrema throughout its rostrocaudal axis tended to have higher values for capillary density, volume, surface area, luminal diameter, and pericapillary space volume than lateral or ventral zones bordering NTS. Within 200 μm of obex, the ventral zone of rostral area postrema was distinct, having a relatively sparse capillary density that may indicate morphological specializations limiting blood‐tissue communication in this subregion. There were no quantitative differences in capillary dimensions between DMN and three subnuclei of NTS. These studies add to extant evidence that the dorsal vagal complex is differentiated for specific functions. Area postrema, especially, has topographical diversity in its capillary organization that likely corresponds to complex roles in neuroendocrine, autonomic, and chemosensory mechanisms.
Organization of the cerebellum in the pigeon (Columba livia): III. Corticovestibular connections with eye and neck premotor areas
Authors: Arends J. J. A. , Allan Robert W. , Zeigler H. Philip 
Published: January 2005

AbstractThe connections of the cerebellar cortex with vestibular premotor neurons of the oculomotor and collimotor systems in the pigeon were delineated in experiments using WGA‐HRP as an anterograde and retrograde tracer. Putative premotor neuron pools were identified by injections into the oculomotor (mIII) and trochlear nuclei (mIV) and into the most rostral portion of the cervical neck motor nucleus, nucleus supraspinalis (SSp). The retrograde data indicate that ipsilateral projections upon oculomotor neurons arise from the medial portions of the superior (VeS) and tangential (Ta) nuclei. Contralateral projections originate from the infracerebellar nucleus, the interstitial vestibular region including the main (lateral) portion of the tangential nucleus, and from the descending and medial vestibular nuclei (VeD, VeM). These projections were confirmed in anterograde studies that also denned the connections of these vestibular premotor regions with specific subnuclear divisions of the pigeon's “oculomotor” nuclei (mill, mIV, mVI). The organization of projections from the vestibular nuclei to the pigeon's extraocular motoneurons is similar to that reported in mammals.Projections upon neck premotor neurons arise primarily from neurons in the interstitial region of the vestibular nuclear complex. After injections in SSp, retrogradely labeled neurons were found, contralaterally, in the lateral part of the tangential and superior vestibular nuclei and in the dorsolateral vestibular nucleus (VDL). Ipsilateral labeling was seen in the medial interstitial region (VeM, VeD, and medial Ta). These projections were confirmed in anterograde experiments. With the exception of VDL, vestibular nuclei projecting to neck motoneurons also project to extraocular motoneurons. Thus the infracerebellar nucleus projects exclusively, and the superior vestibular nucleus predominantly, upon oculomotor (mill, mIV) nuclei; VDL projects predominantly upon the neck motor nucleus, whereas the interstitial vestibular regions (medial Ta, rostral VeD, intermediate VeM) project upon both collimotor and oculomotor neurons.The pattern of retrograde labeling seen in the cerebellar cortex after injections into vestibular premotor nuclei was used to define the projections of specific cerebellar cortical zones upon vestibular eye and neck premotor neurons. Corticovestibular projections upon these regions arise from the auricle and lateral unfoliated cortex, the posterior lobe components of cortical zones B and E, and from the vestibulocerebellum. Each of these cortical zones projects upon components of the vestibular nuclear complex, which are premotor to either oculomotor nuclei or collimotor nuclei.The hodological findings are related to the functional organization of the oculomotor and collimotor systems in the pigeon and compared with the mammalian data.
Dendritic morphology of pyramidal neurones of the visual cortex of the rat: III. Spine distributions
Authors: Larkman Alan U. 
Published: January 2005

AbstractThe vast majority of excitatory synaptic inputs to neocortical pyramidal cells terminate on dendritic spines, which can thus serve as markers, visible by light microscopy, for the locations of these synapses. The aim of this study was to provide estimates of the total numbers and distributions of spines on the dendrites of individual pyramidal neurones from layers 2/3 and 5 of the visual cortex of the rat. High magnification camera lucida drawings were made of dendritic segments lying close to the plane of section and the number of spines per unit length of dendrite calculated for each. These spine densities were used to estimate the numbers of spines on the other dendritic segments and the results were entered to a computer program that calculated various statistics.Mean total numbers of spines per cell were 7,965 ± 2,723 (S.D.) for layer 2/3 cells, 8,647 ± 3,097 for slender layer 5 cells, and 14,932 ± 3,371 for thick layer 5 cells; these figures are in good agreement with previous stereological estimates. For all cell classes, 70% or more of spines were located on the basal and apical oblique dendrites. The distribution of spines with respect to cortical layers was also explored. Most cells had most of their spines in the layer containing the soma, but there were differences within and between cell classes. Layer 2/3 cells showed a progressive reduction in the proportion of their spines in layers 1 and 2 with increasing depth of their soma in the cortex. Thick layer 5 cells had substantial contributions from layers 4, 3, 2, and especially layer 1. Slender layer 5 cells had small contributions from layers 6 and 4, but relatively few spines in layers 3 and 2.The distribution of spines with path distance from the soma was explored by estimating the numbers of spines contained within a series of concentric shells centred on the soma. All cells showed a rapid increase in the number of spines per shell for the proximal 100 μm or so, followed by a sharp decline to approximately 250 μm, beyond which the number remained relatively constant until the end of the terminal arbor. In each case, the majority of spines were located within a path length of 150 μm from the soma.
Localization of NADPH‐diaphorase‐containing neurons in sensory ganglia of the rat
Authors: Aimi Yoshinari , Fujimura Masaki , Vincent Steven R. , Kimura Hiroshi 
Published: January 2005

AbstractThe presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH)‐diaphorase activity was studied histochemically in the sensory ganglia of the rat. Supraspinally, the trigeminal ganglion possessed only a few cells positively stained for NADPH‐diaphorase, while a large number of positive neurons was found in the nodose ganglion. In the dorsal root ganglia, the distribution of positive cells showed a peculiar pattern in relation to spinal levels. Very minor populations (less than 2% of the total ganglionic cells) exhibited positive reaction in ganglia at levels ranging from the first cervical (C1) to fourth thoracic (T4) and from the second lumber (L2) through the entire sacral levels. In the middle to lower thoracic levels (from T5 to L1), however, abundant diaphorase‐positive cells were observed. From these positive neurons it was possible to trace intensely stained nerve fibers. In the lower thoracic level, for example, dense positive fibers were seen in the ramus communicans. Retrograde tracing studies revealed that diaphorase‐containing neurons in the lower thoracic level project at least partly to the gastric wall and the celiac ganglion. These results indicate that the diaphorase‐positive ganglionic neurons in the thoracicolumbar levels may carry autonomic visceral afferent information. Double staining with NADPH‐diaphorase histochemistry and peptide immunohistochemistry revealed that NADPH‐diaphorase colocalizes with calcitonin gene‐related peptide and substance P in many of these visceral afferent neurons.
Neurofilament antibodies and spiral ganglion neurons of the mammalian cochlea
Authors: Berglund A. M. , Ryugo D. K. 
Published: January 2005

AbstractThe spiral ganglia of the cat, gerbil, mouse, rat, and human were immunohistochemically stained with various monoclonal neurofilament antibodies. Three antibodies to the 200‐kD neurofilament protein (R‐3, Dräger et al., '84; ICN anti‐200, clone NE14, Debus et al., '83; RT‐97, Wood and Anderton, '81) labeled the somata of type II spiral ganglion neurons but not those of type I ganglion neurons. In the extreme base of the cochlea of cats, mice and rats, there was intense labeling of a few (< 0.5% of the total ganglion population) large neurons resembling type I ganglion neurons.Several other neurofilament antibodies (Amtersham anti‐68, Amersham and ICN anti‐160, and SMI‐32) did not specifically label type II ganglion neurons but instead labeled all neurons of the spiral ganglion. These two patterns of labeling prompted us to investigate the cause for this difference. Because antibodies against the 200‐kD neurofilament protein preferentially labeled type II neurons and because 200‐kD neurofilament is highly phosphorylated, we treated cochlear tissue with alkaline phosphatase in order to remove phosphate groups. This treatment eliminated the intense labeling of type II neurons with R‐3, ICN anti‐200, and RT‐97, but had no effect on the intense labeling of ganglion cell bodies observed with the other neurofilament antibodies tested. This evidence suggests that labeling occurs because of the cytoplasmic presence of phosphorylated 200‐kD neurofilament protein in type II ganglion neurons. Populations of neurons may thus differ in their neurofilament epitopes and monoclonal antibodies can be used to mark such differences.
Axonal regeneration in the adult lamprey spinal cord
Authors: Lurie Diana I. , Selzer Michael E. 
Published: January 2005

AbstractLarval sea lampreys recover from complete spinal transection by a process involving directionally specific axonal regeneration. In order to determine whether this is also true of adults, 14 adult lampreys were transected at the level of the 5th gill and allowed to recover for 10 weeks. Müller and Mauthner cells and their giant reticulospinal axons (GRAs) were impaled with microelectrodes and injected with horseradish peroxidase (HRR) The tissue was processed for HRP histochemistry and wholemounts of brain and spinal cord were prepared.All animals recovered coordinated swimming; 61 of 121 (50%) neurites emanating from 30 axons regenerated caudal to the scar into the distal stump. Of the neurites which had grown beyond the scar, 92% were correctly oriented, i.e., caudalward and ipsilateral to the parent axon. Retransection in two additional animals eliminated the recovered swimming. Thus, behavioral recovery in adult sea lampreys is accompanied by directionally specific axonal regeneration.
The edinger‐westphal nucleus: Sources of input influencing accommodation, pupilloconstriction, and choroidal blood flow
Authors: Gamlin Paul D. R. , Reiner Anton 
Published: January 2005

AbstractThis study used neuroanatomical techniques to investigate sources of afferents to the Edinger‐Westphal nucleus (EW) of the pigeon. The EW contains the parasympathetic preganglionic neurons that, by way of the oculomotor nerve, project to the ciliary ganglion (Narayanan and Narayanan, '76; Lyman and Mugnaini, '80). The ciliary ganglion, in turn, innervates the internal musculature of the eye; the ciliary body, the iris sphincter muscle, and the smooth muscle of choroidal blood vessels (Marwitt et al., '71; Pilar and Tuttle, '82), In the bird, the neurons in the ciliary ganglion that innervate the iris sphincter muscle and the ciliary body receive input specifically from cells in the lateral EW (EWl), whereas those that innervate choroidal blood vessels receive input from cells in the medial EW (EWm) (Reiner et al., '83). Thus neurons in the EWl mediate pupilloconstriction and accommodation, whereas neurons in the EWm modulate choroidal blood flow.To study the afferents to EW, injections of horseradish peroxidase (HRP) were placed in this nucleus. These injections resulted in labeled cells in the area pretectalis, a retinorecipient pretectal nucleus and the suprachiasmatic nucleus, a retinorecipient hypothalamic nucleus. We have previously identified both these areas as being sources of afferents to EW (Gamlin et al., '82, '84). In addition, these HRP injections into EW resulted in labeled cells in the medial mesencephalic reticular formation (MRF) lateral and ventral to the oculomotor nucleus and in a localized area of the rostral lateral mesencephalic reticular formation (LRF) dorsolateral to nucleus subpretectalis. Injections of tritiated amino acids into the MRF labeled the entire EW, while such injections into the LRF labeled only the lateral EW. Both of these projections were predominantly contralateral.This study has identified the sources of two previously undocumented inputs to the avian EW. Both sources of input, the MRF and rostral LRF, receive afferents from visuomotor areas of the telencephalon and visual structures in the midbrain. The MRF input to EW could have either direct or modulatory influences on pupil diameter, accommodation, and choroidal blood flow, The LRF input to EW could play a role in controlling accommodation and possibly the pupillary near response.