bluuebunny/crossref_metadata_2025_split huggingface dataset:
The vestibular nuclei in the domestic hen (Gallus domesticus): VI. Afferents from the cerebellum
Authors: Wold Jan Egil 
Published: May 2005

AbstractFollowing horseradish peroxidase (HRP) injections in the superior, in the Deiters', in the medial, and in the descending vestibular nuclei in the hen, labeled cells are found in lateral longitudinal zones in the ipsilateral cerebellar cortex, most numerously in the anterior lobe, the nodulus, the uvula, and the auricle. Furthermore, labeled cells are found bilaterally in the ventral parts of the medial and intermediate cerebellar nuclei. Lesions in the cerebellar cortex of the anterior lobe and in anterior parts of the posterior lobe result in terminal degeneration, mainly in the nucleus Deiters dorsalis, but also scantily, in peripheral regions of the superior nucleus, the nucleus Deiters ventralis, the ventrolateral part of the medial nucleus and, mainly medially, in the descending nucleus. Lesions in the posterior part of the uvula, in the nodulus, and in the auricle result in much denser degeneration, most heavily affecting the nucleus Deiters dorsalis, but also affecting peripheral regions of the superior nucleus, the nucleus Deiters ventralis, the entire descending and medial nuclei, and the tangential nucleus. Lesions in the medial cerebellar nucleus result in degeneration bilaterally in the vestibular complex, most heavily affecting the nucleus Deiters ventralis and cell group B, but also affecting peripheral regions of the superior nucleus, the medial nucleus—mainly in dorsomedial regions, lateral and caudal parts of the descending nucleus and, very scantily, in the nucleus Deiters dorsalis. The findings are discussed in the light of the data concerning the organization of the cerebellovestibular projections in mammals and the known connections of the vestibular nuclei in birds.
The neural pathway involved in “efferent inhibition” of chemoreceptors in the cat carotid body
Authors: McDonald Donald M. , Mitchell Robert A. 
Published: May 2005

AbstractThis study was done to determine whether a pathway of efferent axons in the carotid sinus nerve is necessary for the phenomenon of “efferent inhibition” (inhibition induced in carotid body chemoreceptors by electrical stimulation of the carotid sinus nerve). Our approach was to eliminate efferent axons in the carotid sinus nerve of cats without destroying the sensory axons. This was achieved by cutting the ipsilateral glossopharyngeal and vagus nerves central to their sensory ganglia and/or by removing the nodose and superior cervical ganglia. In neurophysiological studies we found that the response of chemoreceptors in cats 10 days after surgery was the same as that in controls. Chemoreceptor activity was decreased by electrical stimulation of the carotid sinus nerve and was increased by hypoxia and cyanide. In operated cats as in control animals, “efferent inhibition” was abolished by haloperidol and dihydroergotamine, drugs that block the inhibitory action of dopamine. Electron microscopic studies disclosed that the number of nerve endings in glomus cell/sheath cell complexes was not measurably different in control and experimental carotid bodies. By contrast, 10 days after the carotid sinus nerve was cut the number of nerve endings next to such cells was reduced by more than 99%. Cutting the nerve roots and excising the ganglia eliminated most nerve endings on blood vessels: The number of noradrenergictype nerve endings was reduced by 99% and other types of nerve endings (presumptive cholinergic and peptidergic types) were reduced by more than 90%. Our experiments indicate that “efferent inhibition” is not abolished by operations that destroy inputs to blood vessels and to carotid body glomus cells from (1) the nodose ganglion, (2) superior cervical ganglion, or from (3) neurons in the brain stem whose axons run in the glossopharyngeal or vagus nerves. We conclude that “efferent inhibition” may be caused by antidromic stimulation of sensory axons.
Postembryonic production and aging of inner ear hair cells in sharks
Authors: Corwin Jeffrey T. 
Published: May 2005

AbstractIn many animals the sensory hair cells of the inner ear are ultrastructurally variable within individual epithelia. This variation has been hypothetically related to both the function and the age of the individual cells. In this study, growth‐related changes in hair cell populations were examined in the macula neglecta sensory epithelia of juvenile and adult sharks. Scanning electron microscopy demonstrated that more than 80% of the 200,000 hair cells in the adult's macula neglecta are produced postembryonically. Tritiated thymidine autoradiography and histological descriptions of the hair cells in this sound detector indicate that new sensory cells are produced in growth zones at the edges of the epithelia. The hair cells in those zones have small cell bodies, small and heterogeneous cilia complexes, and associations with small numbers of particularly thin nerve terminals. Their cytological features and their sparse innervation contrast with the features of the more numerous central cells in each epithelium, but appear to resemble the published descriptions of embryonically developing hair cells. Thus, a germinal zone at the leading edge of sensory epithelium growth appears to persist into adult life in sharks. Published reports reinterpreted in light of this evidence suggest that such hair cell population growth may be expected in other anamniotes and that latent growth zones might persist in the ears of amniotes.
Brainstem afferents to the torus semicircularis of the Queensland cane toad (Bufo marinus)
Authors: Pettigrew A. G. 
Published: May 2005

AbstractThe ascending projections to the major midbrain auditory center of anura, the torus semicircularis, have been examined using the technique of retrograde labeling with horseradish peroxidase (HRP). Localized iontophoretic injections of HRP were made in one torus semicircularis of Queensland cane toads (Bufo marinus). Visualization of HRP‐labeled neurons with tetramethyl benzidine revealed that the torus semicircularis receives its major afferent input from the ipsilateral superior olive. Other prominent projections arise in the contralateral dorsal nucleus of the eighth nerve and the contralateral torus semicircularis. HRP‐labeled neurons were also associated with the lateral lemniscus at a level ventral and lateral to the nucleus isthmi on both sides. It is suggested that these neurons constitute diffuse nuclei of the lateral lemnisci. Relatively minor projections to the torus semicircularis arise in the contralateral superior olive, ipsilateral dorsal nucleus of the eighth nerve, and the ventral division of both the ipsilateral and contralateral eighth nerve nuclei.
Topographic atlas of somatostatin‐containing neuron system in the avian brain in relation to catecholamine‐containing neuron system. I. Telencephalon and diencephalon
Authors: Takatsuki Kenichi , Shiosaka Sadao , Inagaki Shinobu , Sakanaka Masahiro , Takagi Hiroshi , Senba Emiko , Matsuzaki Takashi , Tohyama Masaya 
Published: May 2005

AbstractThe morphological organization of the somatostatin (SRIF)‐positive neurons in the forebrain (telencephalon and diencephalon) of the warbling grass parakeet (Melopsittacus undulatus) was studied using the indirect immunohistochemical technique of Coons and co‐workers ('58). In the telencephalon, a number of SRIF‐positive neurons was detected in the lobus paraolfactorius, hippocampus, and paleostriatum. Furthermore, scattered SRIF‐labeled cells were noticed in the area corticoidea dorsolateralis and area temporoparieto‐occipitalis. A moderate density of immunoreactive fibers was found in the above areas. In addition, although the septal area was devoid of SRIF‐positive neurons, this area contained a moderate number of SRIF‐positive fibers. A large number of SRIF‐positive neurons occurred in the following hypothalamic areas: (1) nucleus medialis hypothalami posterior, (2) lateral hypothalamus, and (3) mammillary nucleus. The bird hypothalamus also received a strikingly massive SRIF innervation. The heaviest concentration of SRIF‐labeled fibers was detected in the median eminence. Many SRIF‐labeled fibers were also observed in other hypothalamic regions. Their locations roughly corresponded in many cases to the areas in which SRIF‐positive neurons were disclosed.The overall distribution of the catecholamine system (CA) of the avian forebrain is also presented by means of histofluorescent technique. A possible interaction between SRIF and CA neuron systems is briefly discussed.
Topographic atlas of somatostatin‐containing neuron system in the avian brain in relation to catecholamine‐containing neuron system. II. Mesencephalon, rhombencephalon, and spinal cord
Authors: Shiosaka Sadao , Takatsuki Kenichi , Inagaki Shinobu , Sakanaka Masahiro , Takagi Hiroshi , Senba Emiko , Matsuzaki Takashi , Tohyama Masaya 
Published: May 2005

AbstractWith the indirect immunofluorescence technique of Coon's and collaborators, overall distribution of the somatostatin (SRIF)‐positive neuron system in the avian lower brain stem was explored. Numerous cell somata containing SRIF were identified in the interpeduncular nucleus and substantia grisea centralis (GCT) at the level of the nucleus nervi trochlearis. Furthermore, a moderate number of SRIF‐positive neurons were seen in the tectum opticum, nucleus tractus solitarii, and spinal cord. Scattered labeled cells were noticed in the rhombencephalon. A dense network of SRIF‐positive fibers was distributed widely in the lower brain stem of birds. Their locations corresponded in many cases to the areas where SRIF‐positive neurons were found.The present study also presents the distribution of the catecholamine (CA) neuron system in the avian lower brain stem.Possible interactions between SRIF and CA neuron systems are briefly discussed.
Structural and histochemical features of the avian blood‐brain barrier
Authors: Stewart P. A. , Wiley M. J. 
Published: May 2005

AbstractWe have investigated the structural and histochemical features of the blood‐brain barrier (b‐bb) in both adults and embryos of chicken (Gallus domesticus, White Leghorn) and quail (Corturnix coturnix japonica). We found that brain endothelial cells of both species are characterized structurally by tight junctions, a low density of pinocytotic vesicles, and a moderately elevated density of mitochondria. Both alkaline phosphatase and butyryl cholinesterase were found in adult quail brain capillaries, but only alkaline phosphatase was found in adult chick brain capillaries. Aromatic amino acid decarboxylase was not found in brain capillaries of either species.In the chick embryo alkaline phsophatase appeared during the time when b‐bb matures functionally; i.e., during the third week of development. However, an elevation in mitochondrial density was not apparent until after hatching.In the quail, alkaline phosphatase and butyrl cholinesterase appeared during the last week of embryonic development. By 2 days posthatching the structural characteristics of the brain capillaries were similar to those in the adult.
Localization of sympathetic postganglionic neurons of physiologically identified cardiac nerves in the dog
Authors: Armour J. Andrew , Hopkins David A. 
Published: May 2005

AbstractCardiac nerves were identified physiologically and injected with horseradish peroxidase in 38 dogs. Retrogradely labeled neurons were present in the greatest number in the middle cervical ganglion, whereas fewer labeled neurons were present in the stellate ganglion. Only occasional neurons in the superior cervical ganglion were labeled, and no labeled cells were found in the T3 to T6 paravertebral ganglia or in the ganglia contralateral to the nerve injected. Following injections into specific cardiac nerves, retrograde labeling was widespread within the middle cervical ganglion, and the distributions of labeled neurons from different nerves overlapped considerably. In the middle cervical ganglion there was little or no regional grouping of cells projecting to specific cardiac nerves. Within the stellate ganglion, however, the cardiac‐sympathetic cells were clustered primarily at the cranial pole near the origin of the ventral and dorsal ansae. Mediastinal ganglia and ganglia located in cardiac nerves were frequently as heavily labeled as the ipsilateral stellate ganglion. The occurrence of heavy labeling in mediastinal and cardiac nerve ganglia indicates that these hitherto unreported ganglia play a significant role in cardiac neural regulation. These data imply that the organization of sympathetic neurons controlling the heart is much more complex than has previously been considered.
Origin of the parallel fibers in the cerebellar crest overlying the intermediate nucleus of the elasmobranch hindbrain
Authors: Montgomery John C. 
Published: May 2005

AbstractThis study utilizes anterograde transport of horseradish peroxidase (HRP), Golgi staining, and electrophysiological techniques to demonstrate the origin of the parallel fibers which constitute the molecular layer overlying the intermediate nucleus of the dogfish hindbrain. The parallel fibers are shown to arise from granule cells of the auricle. The majority come from the granular area of the lower leaf of the auricles, which is termed the lateral granule cell area of the auricle. A band of parallel fibers at the ventrolateral extent of the molecular layer arises from the ipsilateral and contralateral granule cell layers of the upper leaf of the auricle. The functional continuity of the molecular layer between vestibular and lateral‐line areas may provide an additional basis for interactions between these two sense modalities.
Changing retinal ganglion cell distribution in the frog Heleioporus eyrei
Authors: Dunlop S. A. , Beazley L. D. 
Published: May 2005

AbstractThe number and distribution of retinal ganglion cells were examined in the burrowing frog Heleioporus eyrei. Retinae of midlarval tadpoles, animals at metamorphic climax, 2‐month postmetamorphic juveniles, and adults were flat‐mounted and stained with cresyl violet.The identity of retinal ganglion cells was established in the adult using retrograde transport of horseradish peroxidase applied to the optic nerve. Horseradish peroxidase‐filled cells, identified as neurons, had an axon hillock and contained Nissl substance within a pale‐staining cytoplasm. Glial cells, which never filled with horseradish peroxidase, had very dark nuclei and a thin film of cytoplasm lacking Nissl. The diameter of horseradish peroxidase‐filled neurons ranged from 7 to 16 m̈m. Cells identified as glia, which represented less than 1% of cells in the ganglion layer, were 3–8 m̈m in diameter. There were, however, a proportion (14%) of cells which did not fill with horseradish peroxidase. These small cells (5–7 m̈m diameter) had a similar appearance to the horseradish peroxidase‐filled cells and may be neuronal.The total number of ganglion cells rose almost 6‐fold, being approximately 61,000–83,000 for the tadpole, 100,000–118,000 at metamorphic climax, 170,000–184,000 in juveniles, and 454,000–495,000 in adults. Estimates for left and right sides in the same animal were within 1.9% for the tadpole, 1.6% at metamorphic climax, and 7.5% in the juvenile. Fiber counts were made by electron microscopy and were within 11% of ganglion cell estimates for the adult and within 5% for the remaining stages. Overall ganglion cell densities dropped from tadpoles to adults as retinal area increased 20‐fold.The topography of retinal ganglion cells changed at each stage. In the tadpole there was a radial anisotropy, the lowest density being in central retina. Anisotropy was still characteristically radial in animals at metamorphic climax but was less extreme since cell densities had dropped, particularly at the periphery. In contrast, the juvenile was beginning to form a visual streak with higher density patches appearing in nasal and temporal retina. The adult topography was similar, the highest densities still being in the nasal and temporal retina, but now a complete band of intermediate density extended across the horizontal axis of the eye. The transition of retinal ganglion cell topography to produce a visual streak after metamorphosis presumably reflects a change in life‐style from an aquatic, browsing tadpole to an animal which actively seeks its prey.The striking changes in retinal ganglion cell number and distribution provide an experimental model to study the continual development of the amphibian eye. The implications of this finding in terms of neuronal plasticity of connections formed within the visual centers are discussed.
Primary afferent distribution pattern in the marginal zone (Lamina I) of adult monkey and cat lumbosacral spinal cord
Authors: Beal John A. , Bicknell H. Ryan 
Published: May 2005

AbstractUsing Golgi preparations from adult cat and monkey, the present study describes the general arborization pattern of primary afferent collaterals to the marginal layer (lamina I) of the dorsal horn. The dorsal root origin of the Golgi‐impregnated afferents was verified in the cat by matching the structural properties of these fibers with horseradish peroxidase (HRP)‐stained primary afferents which were filled with HRP via anterograde transport through dorsal rootlets. The marginal afferents, in both the cat and the monkey, are relatively fine‐caliber fibers which emanate from the dorsolateral fasciculus of Lissauer. Superficially they form a transverse plexus of fibers which runs across the surface of the dorsal horn and is especially dense in the lateral portion of the dorsal aspect of the marginal layer where lamina I is thickest. In deeper regions of the marginal layer, marginal afferents are longitudinally oriented and have collaterals within the outer zone of lamina II. In both superficial and deep regions of the marginal layer the afferents run parallel with large numbers of marginal cell dendrites. Most marginal afferents give rise to collaterals with widely spaced, round to oval “boutons en passant” and “boutons terminaux” which are 1.5–2.0 m̈m in diameter. Structural correlation with previous physiological and anatomical studies suggests that most of these fibers are finely myelinated, A‐delta, high‐threshold mechanoreceptive fibers.
The tectopontine projection in the rat with comments on visual pathways to the basilar pons
Authors: Burne R. A. , Azizi S. A. , Mihailoff G. A. , Woodward D. J. 
Published: May 2005

AbstractThe projection from the superior and inferior colliculi to the basilar pons in the rat was studied with the technique of orthograde transport of labeled amino acids and autoradiography. Injections restricted to the medial or lateral regions of the superior colliculus gave rise to grain labeling representing terminal fields over the ipsilateral peduncular, dorsolateral, and ventrolateral regions of the caudal basilar pons and over the dorsomedial area of the contralateral nucleus reticularis tegmenti pontis (NRTP). The pontine projection from the superior colliculus to the lateral basilar pons is topographically organized; the medial superior colliculus projects primarily to the peduncular region, wheras the lateral superior colliculus terminates chiefly in ventrolateral pontine areas. A projection from the superior colliculus to the contralateral dorsomedial pontine and medial peduncular pontine regions, a previously undescribed finding, has also been shown. Descending fibers from the inferior colliculus do not appear to terminate extensively within the basilar pons but rather course adjacent to pontine cells of the dorsolateral region in the caudal pons. Pretectal nuclei project ipsilaterally to medial and lateral nuclei in the rostral and middle basilar pons, respectively. A rostrocaudal topography exists in the tectopontine projection; the pretectum projects to rostromiddle basilar pons, the superior colliculus to more caudal pontine regions, and the inferior colliculus (although sparsely) to further caudal areas.The pontine projection pattern from the colliculi and pretectum differs from the pontine afferents from the visual cortices. The findings of this study, when compared to our results from previous investigations on the pontocerebellar projection system, suggest that the tectal inputs to certain lateral cerebellar lobules are relayed primarily through NRTP rather than the basilar pons. The collicular projections to midvermal lobules of the cerebellum appear to be mediated in part by both NRTP and lateral pontine nuclei.
Neurogenetic gradients in the superior and inferior colliculi of the rhesus monkey
Authors: Lee Cooper Michael , Rakic Pasko 
Published: May 2005

AbstractThe spatiotemporal patterns of neurogenesis in the superior colliculus (SC) and inferior colliculus (IC) were analyzed by plotting the positions of heavily labeled neurons in autoradiograms from a series of rhesus monkeys that had been exposed to 3H‐thymidine at various embryonic (E) days and killed either shortly thereafter or at 2–3 months postnatally. Tectal neurons in this species are generated in the ventricular and subventricular zones surrounding the mesocoele (future Sylvian aqueduct) within the first third of the 165‐day gestation period. Cells destined for the SC undergo final mitosis from E30 to E56, with peak proliferation from E38 to E43. These cells exhibit only a weak ventrodorsal gradient of neurogenesis and virtually no mediolateral or rostrocaudal gradients. Genesis of the neurons of the central nucleus (CN) of the IC also occurs between E30 and E56 and peaks around E43; but in contrast to cells of the SC, CN cells exhibit distinct rostrocaudal, lateromedial, and ventrodorsal gradients of genesis. Quantitative analysis revealed that whereas neurogenesis of the SC proceeds with about equal strength along the three cardinal axes, in the CN the lateral‐medial gradient is significantly stronger than the anterior‐posterior gradient. In addition, both the lateral‐medial and ventral‐dorsal IC gradients are significantly stronger than any SC gradients. Analysis of embryos sacrified at short intervals following 3H‐thymidine injection shows that the gradients are not caused by secondary lateral cell movement or by selective cell death. Thus, these findings suggest that within the generative zone of the midbrain tectum significant regional differences exist which result in distinctive spatiotemporal patterns of proliferation for the neurons of the primate superior and inferior colliculi.
Neurons and glia in cat superior colliculus accumulate [3H] gamma‐aminobutyric acid (GABA)
Authors: Mize R. Ranney , Spencer Robert F. , Sterling Peter 
Published: May 2005

AbstractWe have examined by autoradiography the labeling pattern in the cat superior colliculus following injection of tritiated gamma‐aminobutyric acid (GABA). Silver grains were heavily distributed within the zonal layer and the upper 200 m̈m of the superficial gray. Fewer grains were observed deeper within the superficial gray, and still fewer were found within the optic and in‐termediate gray layers. The accumulation of label was restricted to certain classes of neuron and glia. Densely labeled neurons were small (8—12 m̈m in diameter) and located primarily within the upper 200 m̈m. Dark oligodendrocytes and as‐trocytes showed a moderate accumulation of label while pale oligodendrocytes and microglia were unlabeled. Label was also selectively accumulated over sev‐eral other types of profile within the neuropil, including presynaptic dendrites, axons, and axon terminals.