bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rod‐signal interneurons in the rabbit retina: 2. AII amacrine cells
Authors: Vaney David I. , Gynther Ian C. , Young Heather M. 
Published: January 2005

AbstractAII amacrine cells, which are the third‐order neurons in the rod pathway, can be differentially labelled in rabbit retina by injecting Nuclear Yellow into the posterior chamber. Under ultraviolet excitation, the labelled retina appears strongly metachromatic, with the AII nuclei fluorescing silvery‐yellow and the nuclei of other amacrine cells fluorescing blue. Labelled AH cells were injected with Lucifer Yellow under direct microscopic control in a superfused retinal preparation, and the dye was later photoconverted to an opaque reaction produc.Rabbit AII amacrines, which number about 525,000 cells, reach a maximum density of 2,500–3,000 cells/mm2 on the peak visual streak, dropping to 400–500 cells/mm2 at the superior margin. These narrow‐field amacrines have a bistratified dendritic morphology, with distinctive “lobular appendages” in sublamina a of the inner plexiform layer and wider ranging “arboreal dendrites” in sublamina b. Although the lobular field area increases 10‐fold from the visual streak to the far periphery, the lobular field coverage is almost uniform across the retina, averaging 1.0 in inferior retina and 0.8 in superior retina. The dendritic field area of the arboreal dendrites also increases with eccentricity from the visual streak, but there are pronounced differences between inferior and superior retina. The arboreal fields are 2 to 3 times larger than the lobular fields throughout the inferior retina but up to 15 times larger in the superior retina. The arboreal field overlap is only 1.8 at the peak visual streak, increasing slightly to about 2.4 over most of the inferior retina; the overlap increases sharply in the superior retina, however, reaching values of 10 or more in the far periphery. Both the lobular and arboreal fields of AII cells are spaced more regularly than the somata, thus covering apparent gaps in the somatic arra.An analysis of the potential convergence and divergence between rod bipolar cells and AII amacrine cells in the rabbit retina indicates that the neuronal architecture of the rod circuit is not organized in a uniform module that is simply scaled‐up from central to peripheral retina. Moreover, peripheral fields in the superior and inferior retina that have equivalent densities of interneurons show markedly different rod bipolar → AII amacrine convergence ratios, with the result that many more rod photoreceptors converge on an AII amacrine cell in the superior retina than in the inferior retina. In the rabbit retina, much of the convergence in the rod circuit must occur in the outer retina, whereas, in the central cat retina, it is more evenly distributed between the inner and outer retin.
Ecdysteroid receptors in the central nervous system of Manduca sexta: Their changes in distribution and quantity during larval‐pupal development
Authors: Bidmon Hans‐Jürgen , Granger Noelle A. , Cherbas Peter , Maròy Peter , Stumpf Walter E. 
Published: January 2005

AbstractEcdysteroids act initially by binding to nuclear and possibly also extranuclear receptors. The presence and expression of these receptors in the insect brain was investigated in the present study as a means of defining these neurons involved in ecdysteroid‐regulated processes at different developmental stages. Early in the fifth larval stadium of Manduca sexta, when endogenous ecdysteroid levels are low, receptors for ecdysteroids in cerebral neurons are either absent or present at low levels. Receptors can be reliably detected only on day 0 and are not found again until day 3.5, at the beginning of the commitment peak in the ecdysteroid titer, when they occur in a small stage‐specific population of cells. At this time, ecdysteroid receptors are found mainly in nuclei but are also observed at low levels in cytoplasm. By day 4.8, ecdysteroid receptors are exclusively nuclear, and the number of target cells has increased dramatically in several brain regions, including those with known neurosecretory cell groups. This population and organization of ecdysteroid target cells is constant up to day 6, after which time the number of target neurons declines. By day 7.8, only 10% of the number of labelled neurons seen on days 4.8–6.8 remain in peripheral areas. In the pupal brains, ecdysteroid receptors reappear in a new population of neurons. The results indicate changes in the genomic regulation of a varying neuron population by ecdysteroids during fifth stadium developmen.
Organization of visceral and limbic connections in the insular cortex of the rat
Authors: Allen Gary V. , Saper Clifford B. , Hurley Karen M. , Cechetto David F. 
Published: January 2005

AbstractThe anterograde and retrograde transport of horseradish peroxidase was used to study the anatomical organization of visceral and limbic terminal fields in the insular cortex. Following injections into the ventroposterolateral parvicellular (VPLpc) and ventroposteromedial parvicellular (VPMpc) visceral relay nuclei of the thalamus, dense anterograde and retrograde labeling was present in the posterior granular and dysgranular insular cortices, respectively. The parabrachial nucleus had extensive connections with the posterior dysgranular cortex and to a lesser degree with the anterior dysgranular and granular cortices. In contrast, injections into the medial prefrontal cortex and mediodorsal nucleus of the thalamus resulted in dense anterograde and retrograde labeling primarily in the anterior agranular cortex, whereas injections in the amygdala resulted in axonal labeling in the agranular and dysgranular insular cortices. Injections into the lateral hypothalamic area resulted in dense anterograde and retrograde labeling mainly in the agranular and dysgranular cortices and moderate to light labeling in the granular cortex.Our results indicate that ascending visceral afferents, VPLpc, VPMpc, and parabrachial nuclei, are topographically organized in the granular and dysgranular fields of the insular cortex, whereas the agranular cortex appears to receive highly integrated limbic afferents from the infralimbic cortex and the mediodorsal nucleus of the thalamus. Although these visceral and limbic inputs to the insular cortex are segregated for the most part into different longitudinally oriented strips of cortex, limbic input from the lateral hypothalamic area and the amygdala, which have extensive autonomic as well as limbic connections, are more diffusely distributed over the different regions of the insular cortex. This organization may subserve a role for the insular cortex in integration of autonomic response with ongoing behaviour and emotion.
Distribution of FMRFamide‐related peptides in the blood‐feeding bug Rhodnius prolixus
Authors: Tsang Paul W. , Orchard Ian 
Published: January 2005

AbstractImmunohistochemistry was used to study the distribution of FMRFamide‐like material in the central and peripheral nervous systems and visceral tissues of 5th instar Rhodnius prolixus. Over 200 immunoreactive cell bodies and their processes as well as extensive neuropile regions were distributed throughout the nervous system. Immunoreactive processes were seen over the cephalic aorta, corpus cardiacum/corpus allatum complex, and in neurohaemal sites on the abdominal nerves. In visceral tissues, immunoreactive processes were seen innervating the salivary glands, the foregut, and the hindgut. Immunoreactive cells were also found in the anterior midgut (i.e., the crop and the anterior intestine). A radioimmunoassay specific for “RFamide” carboxy‐terminal peptides was used to quantify the amount and the distribution of FMRFamide‐like material. Reversed‐phase high performance liquid chromatography of nervous tissue extracts revealed several peaks of immunoreactive material. The results suggest the existence of a number of FMRFamide‐related peptides in Rhodnius which may have roles in both central and peripheral transmission, may be released as neurohormones and may have endocrine functions in the gut.
Superior paraolivary nucleus in the pigmented guinea pig: Separate classes of neurons project to the inferior colliculus and the cochlear nucleus
Authors: Schofield Brett R. 
Published: January 2005

AbstractThe superior paraolivary nucleus is a large component of the superior olivary complex in rodents and a major source of input to the inferior colliculi and the cochlear nuclei. In the present study, retrograde transport of the fluorescent tracers Fluoro‐Gold, Fluoro‐Ruby (tetramethyl rhodamine conjugated to dextran), fluorescein‐coated microspheres, and Fast Blue were used to reveal the morphology and collateral projection patterns of cells in the superior paraolivary nucleus.The ascending projections to the inferior colliculus from the superior paraolivary nucleus arise mainly from round, multipolar cells, including large cells that project exclusively to the inferior colliculi and not to the cochlear nuclei. Projections to the ipsilateral and contralateral inferior colliculi arise from cells with similar morphology and, in fact, many of the cells that project contralaterally project ipsilaterally as well. Projections to the ipsilateral and contralateral cochlear nuclei arise primarily from cells that do not have collicular projections. On average, the somas of these cells are significantly smaller and more elongated than those that project to the inferior colliculi. Overlap between these ascending and descending systems is restricted to a small percentage of cells that send collateral projections to both the ipsilateral cochlear nucleus and the ipsilateral inferior colliculus. These cells are small and moderately elongated. Thus the ascending and descending projections examined here arise largely from different cells that belong to different morphological classes.
Early development of the retinal line of decussation in normal and albino ferrets
Authors: Cucchiaro Josephine B. 
Published: January 2005

AbstractThis work describes the retinal origin of the crossed and uncrossed projections in newborn, 9‐day‐old and adult normally pigmented and albino ferrets. Horseradish peroxidase (HRP) was injected unilaterally into the thalamic and midbrain visual centers of ferrets to label retinal ganglion cells retrogradely.In normally pigmented adults, the retinal line of decussation was sharp and passed through the area centralis. Ganglion cells with uncrossed axons occupied the entire temporal retina. In albino adults, ganglion cells with uncrossed axons were distributed in the periphery of the temporal retina away from the area centralis. In the normally pigmented adults, about 11% of the retinal ganglion cells had uncrossed axons compared to about 4% in the albinos. At birth, normally pigmented ferrets had a sharp line of decussation with most (about 98%) uncrossed ganglion cells found in the temporal retina. In the newborn albinos, most uncrossed ganglion cells were in the temporal retina (about 89%), but there were many fewer than in the normal neonates and, as in the albino adults, the uncrossed ganglion cells were distributed along the temporalmost margin of the retina. In the normal neonates, about 11% of the ganglion cells had uncrossed axons, compared to about 3% in the albino neonates. The area centralis and visual streak were not evident until 9 days after birth.From these results we conclude that the retinal line of decussation is essentially mature by birth in the ferret, and the degree of t he albino's abnormality is as extreme in neonates as in adults. The retinal decussation is virtually mature at a stage of development when the crossed and uncrossed retinal afferent axons are completely intermingled in their target nuclei and prior to the onset of significant retinal ganglion cell loss.
Neuromuscular organization of the buccal system in Aplysia californica
Authors: Scott Marsha L. , Govind C. K. , Kirk Mark D. 
Published: January 2005

AbstractThe intrinsic muscles and peripheral nerves in the buccal system of the sea hare Aplysia californica were studied to build a foundation on which to base future investigations of feeding in intact animals. A detailed description of the bilaterally paired intrinsic muscles is given identifying previously unreported muscles. Each of the six buccal nerves (n1‐n6) and the cerebrobuccal connective (CBC) have been characterized in several respects. Cell bodies in the buccal ganglion with projections into each of the buccal nerves have been identified via the cobalt backfilling technique. All nerves contain axons of cell bodies in the ipsilateral as well as the contralateral ganglia. For each nerve, there is a consistent pattern in the distribution of cell bodies in the paired ganglia with the number of cell bodies in the contralateral ganglion being less than or equal to the number in the ipsilateral ganglion. Although the total number of backfilled cell bodies varies among the nerves, their size ranges are similar with the majority being small. Nerves 1, 2, 4, 5, and 6 provide motor innervation to the intrinsic buccal muscles in varying degrees with nerve 4 supplying all the intrinsic muscles; nerve 2 supplies only one. The axon composition of each nerve was scrutinized and revealed large numbers of axon profiles, the majority of which were less than 2 μm in diameter. The present study provides a framework for analysis of feeding behavior in Aplysia californica.
Comparison of serotonin 5‐HT1 receptors and innervation in the visual cortex of normal and dark‐reared cats
Authors: Mower George D. 
Published: January 2005

AbstractThe visual cortical serotoninergic system was compared in normal and dark‐reared cats to determine whether visual experience is necessary for its normal development. In vitro receptor binding of [3H]5‐HT indicated an increase in 5‐HT1 receptor number in dark‐reared cats with no change in affinity. This elevation was specific to the visual cortex and no changes were found in the frontal cortex as a result of dark rearing. Autoradiographic histology revealed that in the normal cat visual cortex, 5‐HT1 receptors were present in all cortical layers and were slightly more dense in supragranular and infragranular layers. In dark‐reared cats, there was a marked elevation in receptor density in supragranular and infragranular layers and little change within layer IV.Immunohistochemical techniques (anti‐5‐HT) were used to compare serotoninergic innervation in the visual cortex of normal and dark‐reared cats. In normal cat visual cortex, serotonin fibers were most dense in the superficial layers (I‐III), least dense in layers IV and VI, and intermediate in layer V. No differences were found between normal and dark‐reared cats in the laminar distribution or density of serotoninergic innervation.These results indicate that visual experience is necessary for the normal development of the visual cortical serotonin system. The findings that the effects of dark rearing were specific to the visual cortex and that within the visual cortex these effects were specific to supra‐ and infragranular layers are consistent with a possible role for serotonin in the prolonged physiological plasticity that occurs in the visual cortex of dark‐reared cats.
Auditory, electrosensory, and mechanosensory lateral line pathways through the forebrain in channel catfishes
Authors: Striedter Georg F. 
Published: January 2005

AbstractThe forebrain auditory, electrosensory, and mechanosensory lateral line pathways in the channel catfish, Ictalurus punctatus, were examined by applying the fluorescent tracer DiI to (1) the auditory part of the torus semicircularis, (2) the electrosensory part of the torus semicircularis, (3) the lateral preglomerular nucleus, and (4) the anterior tuberal nucleus. Three distinct pathways ascend from the torus semicircularis to the telencephalon; they course through either (1) the lateral preglomerular nucleus of the posterior tuberculum, (2) the anterior tuberal nucleus of the hypothalamus, or (3) the central posterior nucleus of the dorsal thalamus. The anatomical data suggest that each of these ascending pathways carries information from more than one sensory modality. The lateral preglomerular nucleus receives an electrosensory input from nucleus electrosensorius in the diencephalon, but it also receives auditory and mechanosensory inputs directly from the torus semicircularis. The anterior tuberal and central posterior nuclei receive primarily auditory and mechanosensory, but also minor electrosensory, inputs. The efferent projections of the central posterior nucleus are presently unknown, but the lateral preglomerular and anterior tuberal nuclei project to nonoverlapping portions of the telencephalon.A cladistic analysis of these indirect torotelencephalic pathways reveals that (1) the pathway through the dorsal thalamus is probably a primitive character for gnathostomes, (2) a well‐developed pathway through the posterior tuberculum is probably a derived character for actinopterygian fishes, (3) the pathway through nucleus electrosensorius is probably a derived character for catfishes and gymnotoid teleosts, and (4) auditory pathways through the hypothalamus probably evolved independently in catfishes and frogs.
Calbindin‐like immunoreactivity in the central auditory system of the mustached bat, Pteronotus parnellii
Authors: Zettel M. L. , Carr C. E. , O'Neill W. E. 
Published: January 2005

AbstractWith the aid of a polyclonal antibody specific for Calbindin D‐28k, we studied the distribution of this calcium‐binding protein in the central auditory system of the mustached bat, Pteronotus parnellii. Components of the cochlear nucleus (CN) that were calbindin‐positive (cabp(+)) included the root of the auditory nerve, multipolar and globular bushy cells in the anteroventral CN, multipolar and octopus cells in the posteroventral CN, and small and medium‐size cells in the dorsal CN. Not stained were spherical bushy cells of the anteroventral CN and pyramidal/fusiform cells in the dorsal CN.In the superior olivary complex, labeled cells were found in the lateral and medial nuclei of the trapezoid body, the ventral and ventromedial periolivary nuclei, and the anterolateral periolivary nucleus. No cellular labeling was seen in the lateral superior olive. In the medial superior olive, only marginal cells were cabp(−). Labeled fibers could be seen surrounding the ghosts of unlabeled cells in both the latter nuclei.Most cells in the intermediate nucleus and the columnar division of the ventral nucleus of the lateral lemniscus were cabp(+). However, the dorsal nucleus was cabp(−). A group of cabp(+) cells was also seen in the paralemniscal zone.The inferior colliculus had a relatively low density of cabp(+) cells. Labeled cells were more common in the caudal half of the central nucleus, and in the external nucleus and dorsal cortex.In the auditory thalamus, nearly every cell in the medial geniculate body was cabp(+), but those in the suprageniculate nucleus and in the posterior group did not stain.Small cells in the intermediate layer and giant cells in the deep layers of the superior colliculus were densely cabp(+). In the pons, cabp(+) cells and neuropil could be seen in the medial and lateral pontine nuclei (pontine gray).In conclusion, calbindin‐like immunoreactivity was found in most of the brainstem auditory system, as well as in regions associated with acoustic orientation or control of vocalization. However, except for a minority of cells of the medial superior olive, it is conspicuously absent from the nuclei receiving binaural input below the level of the inferior colliculus.
Differential expression of mRNAs for the NGF family of neurotrophic factors in the adult rat central olfactory system
Authors: Guthrie Kathleen M. , Gall Christine M. 
Published: January 2005

AbstractThe cellular localization of mRNAs for nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), and neurotrophin‐3 (NT3), in the rat central olfactory system was evaluated with in situ hybridization of 35S‐labeled cRNA probes. In the main olfactory bulb, low levels of NGF and BDNF mRNA expression were detected. NGF mRNA was restricted to the glomerular region while BDNF mRNA was predominantly localized to the granule cell layer. No cellular hybridization to NT3 cRNA was seen. The accessory olfactory bulb did not express detectable levels of mRNA for any of the three related neurotrophic factors. Areas which receive olfactory nucleus and in layers 2 and 3 of rostal piriform cortex. BDNF mRNA expression in these areas appeared more robust than that of NGF mRNA, while NT3 mRNA was not detectable. In contrast, tenia tecta exhibited dense labeling with the cRNAs for all three neurotrophic factors. The localization of NGF mRNA to primary target neurons of the olfactory nerve in the periglomerular region of the main olfactory bulb suggests that bulb cells may influence the ingrowth and continual turnover of olfactory sensory afferents. However, as there is a strong correlation between the distribution of neurotrophic factor mRNAs within rostral olfactory structures and the distribution of centrifugal cholinergic neurons of the basal forebrain.
Functional regions within the map of a single digit in raccoon primary somatosensory cortex
Authors: Rasmusson D. D. , Webster H. H. , Dykes R. W. , Biesold D. 
Published: January 2005

AbstractElectrophysiological recordings were made at a large number of sites in the primary somatosensory cortex of six anesthetized raccoons. A high density of penetrations (110–229 per animal), within or near the representation of the fourth digit, allowed identification of three cortical regions with different physiological properties: a glabrous zone, containing a highly detailed, somatotopically ordered representation of the glabrous surface of the digit; rostral to this a claw‐dominant zone, in which the neurons at most penetrations respond to stimulation of the claw of the fourth digit, but may also receive input from the hairy skin or surrounding glabrous skin; and a more rostral multidigit zone, in which the neurons respond to stimulation of two to five digits, with the dominant digit usually being the one represented caudally (i.e., the fourth digit at most of the sites sampled here). Claw‐dominant zones with receptive fields restricted to digit three or five are also found rostral to the representations of the glabrous skin of the corresponding digit. The glabrous and claw‐dominant zones constitute a complete map of the fourth digit. The multidigit region presumably is a separate map, since its neurons have different spatial convergence, higher thresholds, and a lower incidence of slowly adapting inputs than those in the claw‐dominant and glabrous zones. A comparison between animals with lesions of the basal forebrain and intact animals found no differences in the organization of these zones or in the responses to peripheral input, suggesting that cholinergic inputs to the cortex are not essential to these properties. The detailed description of these regions and the proposed terminology should resolve some inconsistencies in the use of the term “heterogeneous zone” in this species.