bluuebunny/crossref_metadata_2025_split huggingface dataset:
Afferent influences on brain stem auditory nuclei of the chicken: Effects of conductive and sensorineural hearing loss on N. Magnocellularis
Authors: Tucci Debara L. , Rubel Edwin W 
Published: May 2005

AbstractNucleus magnocellularis is the avian homologue of the spherical cell region of the mammalian anteroventral cochlear nucleus. Its primary excitatory synaptic input is from large end bulbs of Held from the eighth nerve ganglion cells. We have examined the effects of three peripheral manipulations–middle ear ossicle (columella) removal (monaural and binaural), columella removal and oval window puncture (monaural), and monaural earplug–on cross‐sectional cell area (“cell size”) of second‐order auditory neurons in n. magnocellularis of the chicken. Manipulations were performed between embryonic day 19 and posthatch day 4. Survival time was varied from 2 to 60 days. Air conduction and bone conduction thresholds were determined to assess for conductive and sensorineural hearing loss associated with each of these manipulations. Hair cell counts were made from basilar papillae of each experimental group.We found that a columella removal alone, which produced a 50–55‐dB purely conductive hearing loss, was not associated with changes in cell size of n. magnocellularis neurons. Similarly, chronic monaural earplugging did not affect the cross‐sectional area of these second‐order auditory neurons. Conversely, a combined columella removal and oval window puncture, which produced a mixed hearing loss with a 15–40‐dB sensorineural component was associated with an 18–20% reduction in n. magnocellularis cell area. Hair cell counts for experimental ears were not significantly different from control ears. These results, in conjunction with measurements of multiunit activity recorded in n. magnocellularis, suggest that manipulations which markedly attentuate extrinsic auditory stimulation, but do not result in chronic change in the average activity levels, also do not influence the size of n. magnocellularis cell bodies. On the other hand, a manipulation which influences overall activity levels, but does not result in degeneration of receptor cells, resulted in marked changes in n. magnocellularis cell size.
Peptidergic and aminergic innervation of the facial nucleus of the rat with special reference to ontogenetic development
Authors: Senba Emiko , Tohyama Masaya , Shiotani Yahe , Kawasaki Yoshiyuki , Kubo Takeshi , Matsunaga Toru , Emson Piers C. , Steinbusch Harry W. M. 
Published: May 2005

AbstractThe distribution and ontogenetic development of several neuropeptides such as enkephalin, substance P, somatostatin, neuropeptide Y, and of monoamines such as serotonin and catecholamines in the facial nucleus of the rat were investigated with immunocytochemistry. The neuropeptides were concentrated in certain subnuclei. Enkephalin‐immunoreactive fibers were distributed in the medial and dorsal subnuclei, substance P in the intermediate and dorsal subnuclei, somatostatin in the intermediate subnucleus, and neuropeptide Y in the dorsal subnucleus. The amines were distributed evenly throughout the nucleus. These distribution patterns suggest that peptidergic fibers are closely related to the functions of different subnuclei, while fibers containing monoamines are more basic–not specific to individual muscles. Few of these fibers were observed in the prenatal stage of the rat, but they increased markedly in number during the first postnatal week, and had established their innervation pattern by the tenth postnatal day, which coincides with the establishment of nerve‐muscle innervation.The present study further showed that fibers containing serotonin are supplied mainly from the raphe nucleus, that catecholamine fibers are from neurons containing catecholamine surrounding the facial nucleus, and that fibers containing neuropeptide Y are from the lateral part of the caudal medullary reticular formation. These findings suggest that catecholamine and neuropeptide Y are not both present in the single neurons projecting to the facial nucleus.
Morphology of sympathetic preganglionic neurons in the thoracic spinal cord of the cat: An intracellular horseradish peroxidase study
Authors: Dembowsky K. , Czachurski J. , Seller H. 
Published: May 2005

AbstractHorseradish peroxidase was intracellularly injected into sympathetic preganglionic neurons (SPN) of the third thoracic segment in cats. Seven neurons were reconstructed from serial horizontal or parasagittal sections of the spinal cord.The cell bodies of all neurons were located in the n. intermediolateralis pars principalis (ILp). They were spindle‐shaped with the long axis in craniocaudal direction or large and multipolar or small and oval in shape. Preferentially on the cranial and caudal pole of the cell body, five to eight primary dendrites arose from the cell body. Dendritic branches were traced to their terminations at distances up to 1,330 μm from the cell body. The dendritic fields of all SPNs were strictly oriented in the longitudinal direction with a total length of 1,500–2,540 μm. The cranial and caudal dendritic fields were about equal in length but, with one exception, the degree of branching was always greater in the cranial than in the caudal dendritic field. The dendritic fields of all SPNs were primarily restricted to the ILp. In the mediolateral direction it extended from 130 to 360 μm and in the dorsoventral direction from 50 to 180 μm. Only rarely, a higher‐order dendrite left the boundaries of the ILp and projected dorsolaterally or laterally into the white matter or ventromedially or medially into the adjacent n. intercalatus. All dendrites showed various forms of spines. At a distance of 132–437 μm from the cell body the axon arose as a direct extension of a process which closely resembled a primary or second‐order dendrite. The axons projected ventrally and mostly caudally along the lateral border of the gray matter until they turned laterally at the end of the ventral horn. No axon collaterals were observed.
NADPH diaphorase cells in the mammalian inner retina
Authors: Sandell J. H. 
Published: May 2005

AbstractThe distribution of the enzyme NADPH diaphorase was examined histochemically in the retina of the rat, rabbit, cat, owl monkey, squirrel monkey, rhesus macaque, and human being. In all species tested the enzyme was concentrated in cells 10–12 μm in diameter at the vitread margin of the inner nuclear layer. The population was sparse (< 2,000 cells/rat retina). In several species additional minor populations were observed. While a clear function for NADPH diaphorase has yet to be described, an abundance of the enzyme characterizes a similar subpopulation of retinal cells in a wide variety of mammals.
The central organization of the vagus nerve innervating the stomach of the rat
Authors: Shapiro Robert E. , Miselis Richard R. 
Published: May 2005

AbstractWe employed the neural tracers cholera toxin‐norseradish peroxidase and wheat germ agglutinin‐horseradisn peroxidase to examine the organization of the afferent and efferent connections of the stomach within the medulla oblongata of the rat. The major finding of this study is that gastric motoneurons of the dorsal motor nucleus (DMN) possess numerous dendrites penetrating discrete regions of the overlying nucleus of the solitary tract (NTS). In particular, dendritic labelling was present in areas of NTS which also received terminals of gastric vagal afferent fibers such as the subnucleus gelatinosus, nucleus commissuralis, and medial nucleus of NTS. This codistribution of afferent and efferent elements of the gastric vagus may provide loci for monosynaptic vagovagal interactions. A small number of dendrites of DMN neurons penetrated the ependyma of the fourth ventricle and a few others entered the ventral aspect of the area postrema, thus making possible the direct contact of preganglionic neurons with humoral input from the cerebrospinal fluid and/or the peripheral plasma. Nucleus ambiguus neurons projecting to the stomach predominantly innervate the forestomach. The dendrites of these cells, when labelled, were generally short, and extended beyond the compact cluster of ambiguus neurons in a ventrolateral direction, parallel to the fascicles of vagal efferent fibers traversing the medulla.
The fine structural organization of tyrosine hydroxylase immunoreactive neurons in rat arcuate nucleus
Authors: Piotte M. , Beaudet A. , Joh T. H. , Brawer J. R. 
Published: May 2005

AbstractThe fine structure of the tyrosine hydroxylase (TH) immunoreactive neurons of the hypothalamic arcuate nucleus was examined by means of immunocytochemistry [peroxidase‐antiperoxidase (PAP) method], utilizing an antibody against TH. Immunolabeled axon terminals were observed infrequently and were located predominantly in the lateral region, whereas numerous labeled perikarya and dendrites were found throughout the nucleus. The labeled terminals, containing primarily clear and occasionally dense core vesicles, were never observed in synaptic contact. On the other hand, unlabeled axon terminals were frequently seen synapsing on labeled dendrites. In addition, the labeled dendrites were often seen in direct apposition to other neuronal elements such as both labeled and unlabeled perikarya. In contrast, unlabeled dendrites were never seen apposed to labeled perikarya. Labeled dendrites also occurred in direct contact with one another and with unlabeled dendrites. Moreover, numerous labeled dendrites were encountered along tanycytic processes. Dendrites engaged in tanycytic appositions were occasionally partially encompassed by thin sheaths emanating from the tanycytic process. The extensive contact made by the labeled dendritic profiles on both labeled perikarya and dendrites suggests that tubero‐infundibular dopaminergic (TIDA) cells may communicate with each other by means of dendritic release of dopamine. The presence of appositions between labeled dendrites and both unlabeled perikarya and dendrites suggests that the TIDA system also influences other neuronal populations through its dendrites. Finally, the dendrotanycytic relationship suggests that the TIDA system may play some role in the regulation of tanycytic function.
Population dynamics of adult‐formed granule neurons of the rat olfactory bulb
Authors: Kaplan Michael S. , McNelly Nancy A. , Hinds James W. 
Published: May 2005

AbstractThe population dynamics of internal granule cells in the rat olfactory bulb during adult life were analyzed in histological sections and in autoradiograms with (1) counts of granule cells, (2) counts of labeled granule cells 1 month after injection of 3H‐thymidine at various ages, and (3) counts of labeled granule cells at varying survival times (up to 18 months) after injection at 3 months and 24 months. The total number of granule cells increases linearly throughout life, approximately doubling between 3 and 31 months. Autoradiographic studies show that the rate of production of new granule cells decreases from 3 to 12 months and then is approximately constant during the rest of the life span. The number of labeled cells found 6 months after injection at 3 and 24 months is about one‐fourth and one‐half, respectively, that of the number at a 1‐month survival, suggesting that many of the cells produced to do not survive. However, at least some granule cells labeled at 3 months survive for 18 months. A model is suggested in which granule cells are produced continuously throughout life and control of the total number of granule cells is effected chiefly through the rate of cell death.
Nigral inhibitory termination on efferent neurons of the superior colliculus: An intracellular horseradish peroxidase study in the cat
Authors: Karabelas A. B. , Moschovakis A. K. 
Published: May 2005

AbstractIntracellularly recorded responses of deeper tectal neurons to stimulation of the substantia nigra and the cerebral peduncle were obtained to demonstrate the monosynaptic inhibitory nature of the nigrotectal pathway in the cat. We also employed antidromic stimulation (contralateral predorsal bundle and superior colliculus) and intracellular labeling with HRP to demonstrate which types of tectal efferent neurons are nigrorecipient. The response to nigral stimulation in 61% of the cells studied was a monosynaptic IPSP of short duration. Recovered HRP‐labeled nigrorecipient neurons include X1 (large multipolar radiating), X2 (tufted), X4 (mediumsize vertical), X5 (mediumsize horizontal), T1 (mediumsize trapezoid radiating), T2 (small ovoid vertical), I (small sparsely ramified), and A (small horizontal) neurons. Nigrorecipient cells participate in all four of the major efferent axonal systems of the deeper tectal layers: crossed descending (X and T neurons), ipsilateral descending (I and T neurons), ascending (A, X, and T neurons), and commissural (T neurons). EPSPs accompanied by long‐lasting hyperpolarizing potentials were recorded from the remaining tectal neurons in response to stimulation of the substantia nigra, cerebral peduncle, and pericruciate cortex. Collision experiments indicate that at least part of the excitatory responses of tectal neurons to nigral and penduncular stimulation are mediated by corticotectal fibers traversing the cerebral peduncle and the substantia nigra. Excitatory effects of nigral, peduncular, and cortical stimulation were disclosed in X neurons including the non‐nigrorecipient large vertical neurons of the X3 subgroup. Cortical excitatory and nigral inhibitory inputs converge only on X neurons (X1, X2, X4, X5). In this case, nigrally evoked IPSPs were preceded by a brief EPSP. Collectively, these results demonstrate the inhibitory termination of tne nigrotectal pathway on a wide variety of deeper tectal efferent neurons. Such findings imply the versatility of the nigral involvement in tectal mechanisms of gaze control. We suggest that the substantia nigra pars reticulata contacts tectal neurons differing as to their response properties and shapes the signal carried by all the major tectofugal bundles.
Ascending projections of the mammillary region in the pigeon: Emphasis on telencephalic connections
Authors: Berk Mitchell L. , Hawkin Randall K. 
Published: May 2005

AbstractThe ascending projections of the mammillary region of the hypothalamus and adjacent posterolateral hypothalamus were investigated by autoradiographic and horseradish peroxidase histochemical techniques. Analysis of the anterograde data revealed that the main contingent of mammillary fibers ascends in the medial forebrain bundle (MFB) in the lateral hypothalamic area. These fibers distribute to a number of telencephalic regions via three pathways. (1) Fibers course dorsomedially into the medial and lateral parts of the septum and continue into the hippocampus with a dense terminal field in the parahippocampal area. (2) Laterally coursing fibers project to area corticoidea dorsolateralis, area temporo%parieto%occipitalis, cortex piriformis, and the posterior part of archistriatum. (3) The fibers remaining in the MFB ascend into the “ventral paleostriatum,” olfactory tubercle, and into the lateral and ventral borders of the rostral portion of lobus parolfactorius (LPO). Numerous fibers leave the LPO region and course dorsally into the deep layer of the Wulst, hyperstriatum dorsale (HD). Many fibers continue dorsolaterally through the HD and enter an unnamed region of the dorsolateral telencephalon (lateral to the vallecula) at the level of the olfactory bulb. Retrograde transport experiments revealed that the perikarya of origin‐of‐fiber projections to the parahippocampal area and to the rostral, dorsolateral telencephalon reside not only in nucleus mammillaris lateralis but also in posterolateral hypothalamic cells rostral and dorsal to this nucleus. The projection of these hypothalamic cells to the hippocampal formation and many other telencephalic regions in birds suggests that these cells are similar to the mammalian supramammillary nucleus and posterolateral hypothalamus rather than the mammillary nuclei.
GABAergic neurons containing CCK‐8‐like and/or VIP‐like immunoreactivities in the rat hippocampus and dentate gyrus
Authors: Kosaka Toshio , Kosaka Katsuko , Tateishi Kayoko , Hamaoka Yoshiyuki , Yanaihara Noboru , Wu Jan‐Yen , Hama Kiyoshi 
Published: May 2005

AbstractThe coexistence of cholecystokinin‐octapeptide‐like (CCK‐L) and/or vasoactive‐intestinal‐polypeptide‐like immunoreactive (VIP‐LI) materials and glutamate decarboxylase (GAD) was studied in the rat hippocampus and dentate gyrus by means of immunohistochemistry. Consecutive 40‐μm‐thick sections were incubated in different antisera and those cells which were bisected by the plane of sectioning so as to be included at the paired surfaces of two adjacent sections were identified. The coexistence of the immunoreactivities for these peptides and GAD in the same cell could thus be determined by observing the immunoreactivity of the two halves of the cell, incubated in two different antisera.Almost all of the CCK‐LI neurons were also GAD immunoreactive, whereas only about 10% of the GAD‐immunoreactive neurons were CCK‐LI. The percentages of GAD‐immunoreactive neurons which were also immunoreactive for CCK were dependent on the laminar area in which they were found: i.e., 15–20% in the stratum radiatum of the hippocampus, about 10% in the stratum pyramidale, and about 6% in the stratum oriens.In contrast to the CCK‐LI neurons, only about 40% of the VIP‐LI neurons were identified to be also GAD immunoreactive, which might correspond to only part of the GAD‐immunoreactive neurons. Furthermore the coexistence of VIP‐LI and CCK‐LI materials was recognized in about 10% of the CCK‐LI neurons or about 35% of the VIP‐LI neurons, indicating that some GABAergic neurons (presumably about 1%) in the rat hippocampus and dentate gyrus may contain both CCK‐LI and VIP‐LI materials.
Morphology of terminations of small and large myelinated trigeminal primary afferent fibers in the cat
Authors: Hayashi Haruhide 
Published: May 2005

AbstractHorseradish peroxidase was injected intra‐axonally into functionally identified cutaneous primary afferent fibers in the cat's spinal trigeminal nucleus in order to study the morphology of their central terminations. They were determined physiologically to be large, myelinated primary afferents including vibrissa, G1‐hair, and slowly adapting type I afferents, as well as small, myelinated primary afferents including D‐hair and A‐delta high‐threshold mechanoreceptive (HTM) afferents. The axons were stained for distances of 4–12 mm at the levels of the subnuclei interpolaris (Vi) and caudalis (Vc) of the spinal trigeminal nucleus. The collaterals of large, myelinated primary afferents formed terminal arbors in the outer part of the spinal trigeminal nucleus when they were rostral to or near the obex (rostral‐type collaterals), in lamina V when in the rostral part of Vc (caudalis‐type collaterals), and in lamina III/IV when in the caudal part of Vc (spinal dorsal horn‐type collaterals). There were no transitional forms between the rostral and caudalis types, but there was a transitional type which terminated in laminae III/IV and V between the caudalis and spinal dorsal horn types. Major morphological differences were not observed among the three functional types of large, myelinated primary afferents. The collaterals of D‐hair afferents showed the same types of collaterals as were seen in the large, myelinated primary afferents, except that terminal arbors of the spinal dorsal horn‐type collaterals were distributed in lamina IIb in addition to lamina III/IV. Collaterals of A‐delta HTM afferents formed extensive terminal arbors in the superficial part of Vi. In Vc they were distributed mainly in lamina I and few terminals existed in lamina IIa. The frequency of collaterals of A‐delta HTM afferents was less than that of the other types of afferents. The collaterals of A‐delta HTM afferents in Vi were distributed less frequently than those in Vc. The terminal arbors of A‐delta HTM afferents were less extensive than those of the other types of afferents. The average size of varicosities of A‐delta HTM afferents was smaller and that of vibrissa afferents was larger than that of the other types of afferents. This study demonstrated that there are large differences in the terminations of nociceptive and non‐nociceptive primary afferents and that Vi receives direct nociceptive input from facial skin. However, the sparse distribution of collaterals of HTM afferents in Vi suggests that the rostral trigeminal nucleus contributes partially to sensory processing of facial pain.
Segmental distribution of peptide‐like immunoreactivity in cell bodies of the thoracolumbar sympathetic nuclei of the cat
Authors: Krukoff Teresa L. , Ciriello John , Calaresu Franco R. 
Published: May 2005

AbstractThe distribution of leucine‐enkephalin, methionine‐enkephalin, neurotensin, somatostatin, substance P. oxytocin, vasopressin, and neurophysin II in cell bodies of sympathetic autonomic nuclei of the thoracolumbar (T‐L) spinal cord was studied immunohistochemically in cats after intrathecal administration of colchicine. Neurons containing only enkephalin‐, neurotensin‐, somatostatin‐, and substance P‐like immunoreactivity (ENK, NT, SS, SP, respectively) were found in the intermediolateral nucleus pars principalis (IMLp) and pars funicularis (IMLf), the nucleus intercalatus (IC), and the central autonomic area (CA). The size, shape, location, and numbers of the peptide‐positive neurons in the IMLp, IMLf, and IC suggested that they were sympathetic preganglionic neurons (SPN). This was confirmed by a combined retrograde tracing/immunohistochemical study showing that most of these neurons at the levels of the T‐L cord known to provide preganglionic fibers to the stellate ganglion were SPN. On the other hand, the functional identification of the neurons in the CA is uncertain as neurons were not observed which were both retrogradely labelled and contained ENK, NT, SS, or SP. Immunoreactive neurons in each area were counted in ten sections from each segment from C8 to L4. In the IMLp, the SPN with ENK were greatest in number (up to 25) in segments T4–T7 and L2–L3. The maximum number of SPN containing NT was found in segments T4–T7 (45 neurons). Of the four peptides, neurons containing SS were found in the greatest number (up to 48 in segments T2–T6); neurons containing SP were found in the smallest number (15 or fewer per segment). Few SPN containing each of the four peptides were found in the IC; CA neurons with ENK and NT were also few in number. A comparison of the numbers of immunoreactive neurons in the IML with earlier estimates for the total numbers of SPN in the IML at each level showed that the proportions of IML neurons containing each of the four peptides were fairly consistent throughout the T‐L cord, with some exceptions. These results suggest that the innervation of visceral organs is not obviously peptide‐specific, although some organs may be innervated by a greater proportion of SPN containing one of these peptides. Finally, the presence of ENK, NT, SS, and SP in SPN suggests that these four peptides act as neurotransmitters in preganglionic pathways to sympathetic ganglia.