bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forebrain projections to the periaqueductral gray in the monkey, with observations in the cat and rat
Authors: Mantyh Patrick W. 
Published: January 2005

AbstractThere is considerable evidence that the midbrain periaqueductal gray (PAG) is involved in visceral, emotive, and sexual responses and in endogenous analgesic effects. To see which of the forebrain areas directly influence the PAG, small injections of horseradish peroxidase were made into the various regions of monkey, cat, and rat PAG.Despite the fact that different regions of the PAG were injected in separate animals the majority of the forebrain areas labeled remained constant. Retrogradely filled pyramidal neurons in layer V were found in the frontal lobe in areas 6, 8, 9, 10, 13, and 24. Labeled neurons also appeared in the amygdala, preoptic area, and the anterior, dorsal, periventricular, ventromedial, periarcuate, lateral, and posterior hypothalamic nuclei. The main route for the hypothalamic → PAG projection appeared to be via the periaqueductal bundle which immediately borders on the cerebral aqueduct. Labeled neurons were also observed in the zona incerta, mesencephalic reticular formation, deep layers of the superior colliculus, and the nucleus cuneiformis. Most labeling was ipsilateral to the injection site although a small but consistent contralateral labeling was present. Therefore a strict subdivision of the PAG based on each subnucleus having its own unique set of connections seems inappropriate. There were few striking differences found in the forebrain areas that project to the PAG in the three species examined.These results are discussed in terms of the possible contribution these forebrain areas have in regulating the PAG with regard to its functions as a visceral, nociceptive, and cognitive integrator.
Retinal projections in the African cichlid fish, Haplochromis burtoni
Authors: Fernald Russell D. 
Published: January 2005

AbstractThe retinal projections of the African cichlid fish, Haplochromis burtoni, have been traced by two different methods. Following unilateral enucleation, a modified Nauta technique was used to demonstrate degenerating axons and terminals. Some degeneration was found after 5 days but optimal survival time was 20–25 days. Orthograde transport of horseradish peroxidase (HRP) into the cut optic nerve also was used to examine retinal fiber distribution in the brain. The optic nerve is completely crossed and gives rise to two major tracts, the tractus opticus dorsomedialis and the tractus opticus ventrolateralis, as well as minor fascicles. Projections were found in the suprachiasmatic nucleus, ventral thalamus, dorsal thalamus, the pretectal complex, and the tectum opticum. The optic tectum is large and laminated and the great majority of the optic fibers terminate there. Degeneration methods revealed projections in the tectum to the stratum opticum, stratum griseum et fibrosum superficiale, and stratum album centrale. HRP staining confirmed these projections and revealed another projection to the stratum griseum centrale.
Ventral lateral geniculate nucleus efferents to the rat suprachiasmatic nucleus exhibit avian pancreatic polypeptide‐like immunoreactivity
Authors: Card J. Patrick , Moore Robert Y. 
Published: January 2005

AbstractThe distribution of avian pancreatic polypeptide‐like (APP) immunoreactivity was investigated in the suprachiasmatic nucleus (SCN) of the rat hypothalamus with immunohistochemical methods. Specificity of the antisera was established by the absence of all immunoreactive staining in tissue incubated in antisera which had been preabsorbed with the pure APP antigen. In addition, the antisera exhibited no significant cross reactivity with vasoactive intestinal polypeptide, vasopressin, somatostatin, or secretin. Within the rat SCN, APP immunoreactivity is restricted to varicose axons in the ventral and lateral aspects of the nucleus; the dorsomedial component of the nucleus is totally devoid of immunoreactivity and immunoreactive perikarya are not present in any portion of the SCN. The immunoreactive axons in the ventrolateral portion of the nucleus form an extensive plexus which is distributed in a pattern closely corresponding to the distribution of retinal and ventral lateral geniculate (vLGN) efferents to the SCN. No immunoreactive perikarya are observed in the retina following immunoperoxidase staining for APP and neither unilateral nor bilateral enucleation causes an observable alteration in the pattern of APP axon distribution within the SCN, thus indicating that the fiber plexus is not of retinal origin. In contrast, APP immunoreactive neurons are present in the same area of the vLGN in which retrogradely filled neurons have been demonstrated following iontophoretic injection of HRP into the SCN. Bilateral electrolytic lesions of the vLGN result in a total loss of immunoreactive axons in both SCN. Unilateral vLGN lesions cause a loss of approximately 60 to 75% of the immunoreactive fibers in the ipsilateral SCN with a lesser contralateral loss. These observations provide further information on the organization of afferents to the rat SCN and demonstrate that the vLGN projection is chemically distinct from other SCN afferents.
Cytoarchitecture of auditory system in lower brainstem of the mustache bat, Pteronotus parnellii
Authors: Zook J. M. , Casseday J. H. 
Published: January 2005

AbstractTo begin an investigation of the auditory pathways in the brainstem of the mustache bat, we examined the cytoarchitecture of the cochlear nuclei, superior olivary complex, nuclei of the lateral lemniscus, and inferior colliculus. Although all of these auditory centers are hypertrophied in this echolocating bat, only some areas have unusual cytoarchitectural features: (1) In the anterior part of the anteroventral cochlear nucleus we do not find the large spherical cells seen in other mammals; instead, very small spherical cells are found in this area. (2) In the posterior part of the anteroventral cochlear nucleus there is a region containing a homogeneous population of very large multipolar cells. (3) The medial superior olive is unusually large for an animal with a small head. (4) The most striking observations are seen in the lateral lemniscus. The ventral nucleus of the lateral lemniscus has a distinct columnar organization. The intermediate area of the lateral lemniscus contains a large and very distinct nucleus. Each of these cytoarchitectural features distinguishes the auditory system of this bat from that of other mammals. The results raise questions about whether or not there are unique subdivisions in the auditory pathways of echolocating bats. The results also identify these unusual nuclei as candidates to play a role in the special auditory functions related to echolocation.
Origin of ascending projections to inferior colliculus in the mustache bat, Pteronotus parnellii
Authors: Zook J. M. , Casseday J. H. 
Published: January 2005

AbstractThe origins of pathways to the inferior colliculus of the mustache bat were identified by retrograde transport of horseradish peroxidase (HRP). A specific goal of this study was to obtain evidence that would help determine whether the nuclei, shown in the previous paper to have unusual cytoarchitectural features, are unique to bats, or whether they are homologous to areas that are not well differentiated in other mammals. The auditory pathways in the lower brain stem of Pteronotus appear to conform to the same basic organization as in other mammals: After injection of HRP into one inferior colliculus, labeled cells are located contralaterally in the cochlear nucleus, ipsilaterally in the medial superior olive, bilaterally in the lateral superior olive, ipsilaterally in the ventral and intermediate nuclei of the lateral lemniscus, and bilaterally in the dorsal nucleus of the lateral lemniscus. These patterns of labeling provide a basis for understanding how the specialized auditory areas of the bat may be organized within a basic plan of mammalian auditory systems. In the anteroventral cochlear nucleus the unusually small spherical cells seem to be homologous to stellate cells in the anteroventral cochlear nucleus of the cat. In the superior olive, differences in patterns of labeled cells distinguish the medial from the lateral superior olive. In the lateral lemniscus the pattern of labeled cells shows clear differences between the two special parts, intermediate and ventral nuclei, as well as between these and the dorsal nucleus of the lateral lemniscus. The results are consistent with the hypothesis that the unusual auditory nuclei of the bat have homologues in mammals whose auditory systems are not specialized for echolocation.
Neuropeptide proctolin (H‐Arg‐Try‐Leu‐Pro‐Thr‐Oh): Immunocytochemical mapping of neurons in the central nervous system of the cockroach
Authors: Bishop Cynthia A. , O'shea Michael 
Published: January 2005

AbstractProctolinlike immunoreactivity was mapped in the central nervous system of the cockroach, Periplaneta americana, by using whole‐ganglion immunoreacted preparations. The procedure for this immunohistochemical staining of whole‐mounts is described. Immunoreactivity was confined to neuronal cell bodies and processes. These were found in all ganglia of the CNS. The cells varied in the consistency and intensity of their staining. The occurrence and variability of staining is described in detail.Cell bodies were found in the dorsal, ventral, and lateral regions of the ganglia. The highest number of cell bodies was found in the terminal ganglion and the lowest number in the cerebral ganglion. Those in the cerebral ganglion occurred mainly in the tritocrebral lobes. The distribution of immunoreactive cell bodies correlated with results previously obtained by radioimmunoassay. Immunoreactive processes were detected in all interganglionic connectives and many ganglionic nerve roots. Dense ramifications of immunoreactive processes and variocosities were detected in many of the ganglia. The widespread presence of immunoreactivity suggests that proctolin has diverse central and peripheral functions. The mapping of immunoreactive neuronal somata provides a valuable step in the identification of putative proctolin‐containing neurons suitable for further biochemical, anatomical, and physiological analysis.
Ascending lateral line pathways to the midbrain of the clearnose skate, Raja eglanteria
Authors: Boord Robert L. , Northcutt R. Glenn 
Published: January 2005

AbstractEfferent projections of the electroreceptive dorsal and the mechanoreceptive intermediate octavolateralis nuclei were revealed, in the brain of the clearnose skate Raja eglanteria, by means of silver degeneration and autoradiographic methods. Efferents from each nucleus give rise to ipsilateral and contralateral lemnisci and commissural components. Commissural fibers terminate within their respective nuclei of the opposite side. The lemnisci from each nucleus parallel each other as they course from medullary to mesencephalic levels; those from the dorsal nucleus assume a lateral position and terminate within the lateral part of the nucleus of the lateral line lemniscus and the lateral nucleus of the midbrain; those from the intermediate nucleus assume a medial position and terminate within the medial part of the lateral line lemniscal nucleus and the dorsomedial mesencephalic nucleus. A substantial number of fibers of each class course through the mesencephalic nuclei and terminate bilaterally within the central tectal zone. The segregation of electroreceptive and mechanoreceptive information is maintained from medullary to mesencephalic levels although there probably is convergence within the central tectal zone and the magnocellular nucleus, the only octaval center to receive terminals from secondary lateral line fibers.
Crossed connections of the substantia nigra in the rat
Authors: Gerfen Charles R. , Staines William A. , Fibiger Hans C. , Arbuthnott Gordon W. 
Published: January 2005

AbstractThe existence of crossed multisynaptic pathways that allow for the interdependent control of activity in one substantia nigra and its contralateral counterpart has been inferred from a number of recent biochemical and neurophysiological investigations. This prompted a reexamination of the connections of the substantia nigra with an emphasis on crossed inputs to and crossed projections from that nucleus. Male albino rats received 20–50‐nl pressure injections of a 1% wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP) solution into the substantia nigra or into surrounding areas as controls. Following a 24‐hour survival period the animals were processed according to the tetramethylbenzidine protocol for the visualization of HRP.The pattern of anterograde transport of WGA‐HRP after substantia nigra injections, confirming for the most part previous reports, demonstrated ipsilateral nigral efferent projections to the striatum; globus pallidus; subthalamic nucleus; the lateral dorsal, paralamellar mediodorsal, ventromedial, and parafascicular thalamic nuclei; central gray, midbrain reticular formation; superior colliculus; and peribrachial area, including the pedunculopontine nucleus. Additionally, the nigral projections to the paralamellar mediodorsal and ventromedial thalamic nuclei and to the superior colliculus were demonstrated to be bilateral. Most of these connections were confirmed by the complementary retrograde experiment.In accordance with previous reports, intranigral WGA‐HRP injections retrogradely labeled neurons located in the ipsilateral prefrontal cortex, motor cortex, striatum, globus pallidus, central nucleus of the amygdala, anterior hypothalamic area, subthalamic nucleus, and dorsal raphe. Additionally, labeled perikarya were observed in the ipsilateral parafascicular thalamic nucleus, in the contralateral posterior lateral hypothalamic area, and in the ipsilateral and contralateral peribrachial‐pedunculopontine area. These latter nigral afferents were confirmed with complementary WGA‐HRP injections into each of the regions of origin. While bilateral peribrachial‐pedunculopontine innervation of the substantia nigra has been reported in the cat there has been no previous demonstration of a crossed nigral afferent system from the contralateral posterior lateral hypothalamic area. The results are discussed with reference to the pathways that may mediate the interdependent control of the activity of neurons in the left and right substantia nigra. Additionally, the association of the substantia nigra with a variety of neuronal circuits, including the cerebellofugal, tectothalamic, thalamocortical, thalamostriatal, and basal ganglia pathways, are discussed.
The morphological relationships between substance P immunoreactive processes and ventral horn neurons in the human and monkey spinal cord
Authors: De Lanerolle Nihal C. , Lamotte Carole C. 
Published: January 2005

AbstractThe distribution of substance P (SP)‐containing neural processes in the ventral horn region of the human and monkey spinal cord was studied by staining for SP by the indirect antibody peroxidase‐antiperoxidase technique and by light and electron microscopic examination of stained material. Immunoreactive fibers and terminals were found in all major cell columns of the ventral horn in the human and monkey spinal cord, with the immunoreactive profiles in close apposition to motoneurons. The immunoreactivity was contained in synaptic knoblike (bouton) structures, in which the label was associated with small agranular vesicles, dense‐core vesicles, and mitochondria. The immunoreactive synaptic knobs formed synaptic junctions predominantly with dendrites. The labeled knobs were similar to “S” (agranular spheroid vesicles) and “G” (dense‐core vesicles) type bulbs described previously in the monkey ventral horn. Their location, mainly on the neuron dendrites and soma supports the physiological evidence that SP‐produced membrane depolarization is mediated primarily by a direct action of the neurochemical on the neuron rather than by a transynaptic mechanism.
Tonotopic organization in the central auditory pathway of the mongolian gerbil: A 2‐deoxyglucose study
Authors: Ryan Allen F. , Woolf Nigel K. , Sharp Frank R. 
Published: January 2005

AbstractThe uptake of 2‐deoxyglucose (2‐DG) was employed to map functional activation of the central auditory pathway in the mongolian gerbil, during 85 dB SPL stimulation with pure tonal stimuli at frequencies of 0.75, 3.0, or 12.0 kHz. Pure tones produced foci of very high 2‐DG uptake, when compared to adjacent tissue, in the cochlear nucleus, superior olivary complex, and inferior colliculus. Less distinct areas of elevated 2‐DG uptake were seen in the dorsal and ventral nuclei of the lateral lemniscus, medial geniculate nucleus, and auditory cortex. Little or no change in the distribution of 2‐DG uptake was noted in the nucleus of the trapezoid body. The location of discrete regions of relatively high 2‐DG uptake varied systematically with stimulus frequency. The tonotopic organization demonstrated by 2‐DG mapping agreed well with the results of previous electrophysiological studies for most structures. However, in the inferior colliculus, stimulus‐evoked increases in 2‐DG uptake were found to occur in a fixed pattern of three to four bands across the central nucleus, which did not correspond to any previously reported anatomical or physiological organization. Pure tonal stimuli activated discrete portions of this banding pattern. Also, a small area at the ventromedial edge of the colliculus was more broadly tuned than other regions of the nucleus. It is concluded that 2‐DG uptake is well suited to theinvestigation of tonotopic organization. This technique reveals patterns ofactivation which have not been observed with other methodologies.
Morphology and laminar distribution of nonpyramidal neurons in the auditory cortex of the rabbit
Authors: McMullen Nathaniel T. , Glaser Edmund M. 
Published: January 2005

AbstractA study of the morphology and laminar distribution of nonpyramidal neurons in Goldi‐Nissl prepartions of electrophysiology verified auditory cortex was carried out in the adult rabbit. Nonpyramidal neurons were located primarily within laminae I‐IV and were only infrequently seen in lamina V and Vi. In lamina I, four nonpyramidal cell types were observed: (1) small, spine‐free horizontal neurons, (2) small, sparserly spined multipolar neurons with radiate dendrites, (3) large, multipolar neurons with fusiform somata and vertically aligned, sparsely spined dendrites, and (4) small, spine‐free neurogliform neurons. The horizontal and small multipolar neurons had tagentially running axons confined to lamina I. The large, fusiform cells had descending axons which arborized in lamina II and occasionally reached lamina III. In lamina II and the upper part of lamina III, seven nonpyramidal cell types were observed: (1) spine‐free bipolar neurons with vertically alined denddrites and axonal arbors; (2) large, (3) medium, and (4) small, spine‐free and sparsely spined multipolar neurons, all with locally ramifying axons; (5) pear‐shaped cells with highly oriented dendrites which branched toward the pial surface and vertically arborizing axons; (6) multipolar cells with tangentially and vertically oriented dendrites and ascending axons which entered lamina I, and (7) tufted cells with local axons. Three types of nonpyramidal cells were observed in lamina IV and the lower part of lamina III: (1) large, multipolar cells with radiate, spine‐free dendrites and stout axons which arborized locally, (2) spiny multipolar cells with vertically aligned dendrites and ascending axons which arborized in lamina II and III via long horizontal collaterals, and (3) spine‐free bipolar cells with vertical dendrites and axons which arborized in a narrow vertical column adjacent to the dendrites. Nonpyramidal neurons in lamina V and VI were primarily multipolar cells with sparsely spined and spine‐free dendrites. A comparison of these data with those of other species indicates that the neuronal organization of the rabbit auditory cortex is similar to the of the sensory cortex of the rodent butis strikingly differnt from that of cernivores and primates.
Ontogeny of the neurotensin‐containing neuron system of the rat: Immunohistochemical analysis. I. Forebrain and diencephalon
Authors: Hara Yoshinobu , Shiosaka Sadao , Senba Emiko , Sakanaka Masahiro , Inagaki Shinobu , Takagi Hiroshi , Kawai Yuriko , Takatsuki Kenichi , Matsuzaki Takashi , Tohyama Masaya 
Published: January 2005

AbstractThe ontogeny of the neurotensin (NT) neuron system in the forebrain and diencephalon of the rat was investigated by means of indirect immunofluorescence. NT‐positive structures first appear in the primordium of the olfactory bulb, anterior amygdaloid area, piriform cortex, amygdaloid complex, nucleus tractus diagonalis, lateral preoptic area, and lateral hypothalamus, etc., of the fetus of gestational day 16. From this day, NT‐positive structures appear gradually in various areas of the forebrain and diencephalon and reach their maximum content on postnatal day 7. In contrast, NT‐positive structures decrease slightly in number as the rat grows. However, even in adult rats, numerous NT‐positive structures are still identifiable in various areas of the forebrain and diencephalon.
A golgi study of the medial geniculate body in the tree shrew (Tupaia glis)
Authors: Oliver Douglas L. 
Published: January 2005

AbstractThe subdivisions of the medial geniculate body in Tupaia recognized in previous connectional and cytoarchitectural studies are identified in Golgi‐impregnated material. They may be distinguished by the organization of the neuropil, especially the dendrites, and, in many cases, by differences in the neurons. The ventral nucleus contains tufted cells with disc‐shaped dendritic fields which are aligned to form laminae. The caudomarginal and deep dorsal nuclei have less tufted, less precisely arranged cells with longer, thin appendages. Neurons in the suprageniculate and dorsal nuclei are similar except that they apparently are arranged more randomly and tend to have more spherically shaped dendritic fields. The medial division is characterized rostrally by the presence of stellate cells and caudally by large cells which appear to be the neurons, observed in previous studies to have widespread connections.The results of this Golgi study suggest that the subdivisions of the medial geniculate body might be grouped differently than in previous reports. When combined with data from previous studies of connections, the results show that the medial geniculate body of even distantly related species may follow a common plan. The ventral nucleus is the medial geniculate component of the central pathway which extends from the central nucleus of the inferior colliculus to the primary auditory cortex. Most of the other medial geniculate subdivisions participate in either pericentral pathways originating in the cortex and other nuclei which surround the central nucleus of the inferior colliculus or in the pathways of the lateral midbrain tegmentum. Pericentral and lateral tegmental pathways terminate in nonprimary auditory cortex. The widespread pathway involves only the caudal nucleus of the medial division. It receives afferents from most, if not all, of the midbrain regions that give rise to the other pathways and distributes to all parts of the auditory cortex where it terminates in layers other than layer III‐IV.