bluuebunny/crossref_metadata_2025_split huggingface dataset:
A wide field electron microscopic analysis of the fiber constituents of the major splanchnic nerve in cat
Authors: Kuo David C. , Yang Grace C. H. , Yamasaki Dwayne S. , Krauthamer George M. 
Published: January 2005

AbstractThe fiber compositio of the left major splanchnic nerve was studed in cats by electron microscopy. Comparisons were made between normal and partically degenerated nerve specimens following ventral rhizotomy (T3‐L1), or spinal nerve division (T3‐L1). Normal, major splanchnic nerves contained 2,500–4,000 myelinated and 10,000–15,000 unmyelinated fibers. Preganglionic fibers included approximately 90% of the finely myelinated (1–7μm) and over 50% of the unmyelinated fibers. Removal of the sensory and preganglionic components by spinal nerve division revealed a third, postganglionic fiber category. This included 13–38 small myelinated (1–5μm) and 1,645‐7,619 unmyelinated fibers. Finally, a comparison of normal and partially degenerated nerve specimens of both groups (ventral rhizotomy and spinal nerve cut) indicated that splanchnic afferents are made up of virtually all of the 120–350 large myelinated (8‐14μm) and 10% of the small myelinated (1–7μm) fibers. A preliminary estimate indicated that about 10–20% of the unmyelinated fibers were sensory. The implications of these findings are discussed.
Synapse‐to‐neuron ratios in the visual cortex of adult rats undernourished from about birth until 100 days of age
Authors: Warren M. A. , Bedi K. S. 
Published: January 2005

AbstractMale rats undernourished from the 18th day of gestation until 100 days of age were nutritionally rehabilitated until 200 days of age. Six control and six experimental rats at each of 100 and 200 days of age were killed by perfusion with buffered 2.5% glutaraldehyde. Pieces of visual cortex from each rat were postfixed in osmium tetroxide and embedded in resin. Stereological procedures at the light and electron microscope levels were used to estimate the synapse‐to‐neuron ratios in cortical layers II to IV.Rats undernourished until 100 days of age had a mean ± S.E. of 10,350 ± 470 synapses associated with each neuron. This represented a 13% deficit (P < 0.05) when compared to the control value of 11,950 ± 530.Following nutritional rehabilitation till 200 days of age it was found that the previously undernourished rats had about 23% more (P < 0.05) synapses‐per‐neuron than their age‐matched controls. This was due almost entirely to a substantial increase in the ratio in the previously undernourished animals; the value of controls did not alter significantly between the two age groups.It appears that the deficit in the synapse‐to‐neuron ratio seen after a lengthy period of undernutrition is not permanent, at least in rats subsequently allowed nutritional rehabilitation. In fact, such animals seem to be capable of not only “catching‐up” but “overshooting” the values found in age‐matched controls.
Distribution of cholinergic neurons in rat brain: Demonstrated by the immunocytochemical localization of choline acetyltransferase
Authors: Armstrong David M. , Saper Clifford B. , Levey Allan I. , Wainer Bruce H. , Terry Robert D. 
Published: January 2005

AbstractThe neuroanatomical location and cytological features of cholinergic neurons in the rat brain were determined by the immunocytochemical localization of the biosynthetic enzyme, choline acetyltransferase (ChAT). Perikarya labeled with ChAT were detected in four major cell groups: (1) the striatum, (2) the magnocellular basal nucleus, (3) the pontine tegmen‐tum, and (4) the cranial nerve motor nuclei. Labeled neurons in the striatum were observed scattered throughout the neostriatum (caudate, putamen) and associated areas (nucleus accumbens, olfactory tubercle). Larger ChAT‐labeled neurons were seen in an extensive cell system which comprises the magnocellular basal nucleus. This more or less continuous set of neuronal clusters consists of labeled neurons in the nucleus of the diagonal band (horizontal and vertical limbs), the magnocellular preoptic nucleus, the substantia innominata, and the globus pallidus. Labeled neurons in the pontine tegmentum were seen as a group of large neurons in the caudal midbrain, dorsolateral to the most caudal part of the substantia nigra, and extended in a caudodorsal direction through the midbrain reticular formation into the area surrounding the superior cerebellar peduncle. The neurons in this latter group constitute the pedunculopontine tegmental nucleus (PPT). An additional cluster of cells was observed medially adjacent to the PPT, in the lateral part of the central gray matter at the rostral end of the fourth ventricle. This group corresponds to the laterodorsal tegmental nucleus. Large ChAT‐labeled neurons were also observed in all somatic and visceral motor nerve nuclei. The correspondence of the distribution of ChAT‐labeled neurons identified by our methods to earlier immunocytochemical and acetylcholinesterase histochemical studies and to connectional studies of these groups argues for the specificity of the ChAT antibody used.
Projections of nucleus caudalis and spinal cord to rrainstem and diencephalon in the hedgehog (Erinaceus europaeus and Paraechinus aethiopicus): A degeneration study
Authors: Ring George , Ganchrow Donald 
Published: January 2005

AbstractIn the light of hypotheses related to the evolution of pain‐carrying systems in mammals, terminal projection fields in brainstem and diencephalon of efferents of nucleus caudalis (NC) of the spinal trigeminal complex and spinal cord were determined in hedgehog by using Nauta‐Gygax and Fink‐Heimer silver techniques for degeneration.Unilateral NC lesions resulted in medullary degeneration in the ventral portion of NC contral a ter ally and bilaterally in cuneate nucleus (CU) and reticular formation. Pontine degeneration was noted ipsilaterally in medial (PBM) and lateral (PBL) parabrachial, facial motor (VII), and interpolar, oral, and main sensory trigeminal nuclei; degeneration in reticular formation was bilateral. Midbrain degeneration was seen bilaterally in caudal superior colliculus (SO), inferior colliculus (IC), periaqueductal gray, and tegmentum. In thalamus, projections to ventroposterior nucleus (VP) were contralateral and concentrated in a crescent extending along the lateral one‐third‐to‐one‐halfand ventral border of the nucleus. Bilateral degeneration fields were noted in a dorsomedial sector of the “ventral nuclear field,” posterior complex (PO), and mediodorsal nucleus (MD), the degeneration always heavier contralaterally in these nuclei. Sparse degeneration was noted in the medialmost portions of the medial geniculate nuclei bordering PO and VP. In rostral diencephalon, bilateral degeneration was traced from the inferior thalamic peduncle to the lateral hypothalamic area (LH).Unilateral spinal cord lesions made between C7 and Tl vertebrae resulted in medullary degeneration in NC contralaterally, ipsilaterally in CU and lateral cuneate nucleus, and bilaterally in gracile nucleus, inferior olivary complex, and reticular formation. Pontine degeneration was limited to ipsilateral PBL and bilaterally to VII. Midbrain degeneration was found bilaterally in IC, SC, nucleus sagulum, and tegmentum; a minor projection was noted in interpeduncular nucleus. In thalamus, projections were confined to ipsilateral PO and zona incerta. In rostral diencephalon bilateral fields were noted in LH.NC terminations in PO and VP parallel results of research in hedgehogs on thalamic projections of the dorsal column nuclei (Jane and Schroeder, 1971), and particularly the location in VP of most cells responsive to stimulation of the face (Erickson et al., 1967). This suggests that somatic input from NC, some of which may be pain‐specific, reaches thalamic areas, a portion of whose neurons are characterized as polymodal and at least partially convergent for somatotopy. These results are consistent with the thesis that specific sensothalamic nuclei evolved from a diffuse sensory region. Response properties of neurons in the dorsomedial portion of the ventral nuclear field, an area which also received NC efferents, are not known. Last, NC projections to MD and LH implicate the role of “limbic” aspects of nociception.
The acoustic and lateral line nuclei are distinct inthe premetamorphic frog, Rana catesbeiana
Authors: Jacoby Jean , Rubinson Kalman 
Published: January 2005

AbstractThe transition from aquatic to terrestrial hearing in the frog occurs during metamorphosis and during the disappearance of the lateral line system. The coincidence in time of these two processes and morphological similarities between the acoustic and lateral line systems has led to the suggestion (Larsell, 1934) that the lateral line nuclei are transformed into the acoustic nuclei. The relation between the acoustic and lateral line systems was investigated by studying the distribution of primary afferents, the dendritic patterns of the cells in the primary nuclei, and the development of the nuclei in the premetamorphic bullfrog, Rana catesbeianaThe posterior and anterior lateral line roots distribute to a neuropil located medial to the dorsal medullary nucleus. Horseradish peroxidase (HRP) injections into the contralateral tegmentum fill cells in the periventricular region whose dendrites ramify within the neuropil. These cells constitute the lateral line nuclei. The amphibian and basilar papillary roots of the acoustic system distribute to the more lateral nuclear region. The dendrites of these cells arborize within the nucleus and not in the lateral line neuropil. The dorsal medullary nucleus is, therefore, the acoustic nucleus (AcN). [3H]‐thymidine labeling reveals that newly generated cells occupy the AcN within a few hours of their formation throughout the period when anatomical analysis shows the parallel growth and diminution of the lateral line neuropil and nucleiThis study indicates that the lateral line and acoustic systems are morphologically independent at the level of the primary afferents and primary nuclei throughout early development.
Nucleus rotundus in a snake, Thamnophis sirtalis: An analysis of a nonretinotopic projection
Authors: Dacey Dennis M. , Ulinski Philip S. 
Published: January 2005

AbstractNucleus rotundus, a tectorecipient thalamic nucleus in reptiles and birds, is described for the first time in a snake. The morphology of rotunda neurons and tectorotundal axons was studied at the light microscopic level by using anterograde and retrograde filling with horseradish peroxidase (HRP)Injections of HRP in the dorsal ventricular ridge retrogradely fill neurons in rotundus. Rotundus is situated centrally in the caudal diencephalon medial to the cell plate of the retinorecipient geniculate complex and ventrolateral to the lentiform thalamic nucleus. The dendrites of rotundal neurons are long and radiate, but are confined within the cytoarchitectonically defined borders of the nucleus. Injections of HRP into the optic tectum anterogradely fill axons that project to rotundus bilaterally via the tectothalamic tract. Small injections show that axons arising from a single tectal locus distribute to all sectors of rotundus. Thus, this projection may not be retinotopically organized. However, single axons reconstructed through serial sections form spatially restricted, sheetlike terminal fields that pass caudorostrally through the entire extent of rotundus.Several hypotheses on the functional significance of such organized but nonretinotopic visual projections are discussed.
Anatomy and electrophysiology of individual neurosecretory cells of an insect brain
Authors: Zaretsky Malcolm , Loher Werner 
Published: January 2005

AbstractThe structure and electrophysiological properties of individual neurose‐cretory cells of the pars intercerebralis, medial neurosecretory cells (MNSCs), in the brain of an insect, the cricket Teleogryllus commodus, were investigated by means of intracellular injections of the dye Lucifer Yellow and electrophysiological recordings. Action potentials recorded from these cells were of long duration, 8–50 msec. In the pars intercerebralis there are both neurosecretory cells with axons that join one of the tracts of the nervi corpori cardiaci I (NCC I) and cells without an axon or collateral that leaves the brain, local neurosecretory cells. MNSCs with axons that join NCC I and terminate in the anterior corpus cardiacum arborize extensively in the proto‐cerebrum and to a lesser degree in the deutocerebrum. Other MNSCs have axons that pass through the corpus cardiacum and hypocerebral ganglion and join one of the oesophageal nerves. These MNSCs have sparse collateral arborizations in the protocerebrum but do have extensive terminal arborizations in the tritocerebrum. This type of cell is dye‐coupled to other MNSCs. Among the local MNSCs, some have an unusual loop shape. These cells branch extensively in the protocerebrum and have massive terminal arborizations in a posterior ventromedial region of the brain. Both the long curved axons of the loop‐shaped cells and their ventromedial branches are of large diameter, suitable for storage of neurosecretory material.
Central organization of the electrosensory lateral line system in bullhead catfish Ictalurus nebulosus
Authors: Tong Shang‐Liang , Finger Thomas E. 
Published: January 2005

AbstractThe connections of the electrosensory lateral line lobe (ELL) of ictalurid catfish were examined by means of horseradish peroxidase tracing methods. The ELL receives direct input from the anterior and posterior lateral line nerves. Some of these nerve fibers continue through the ELL to end as mossy fibers in the lateral portion of the eminentia granularis. Granule cells in this area as well as those in lobus caudalis of the cerebellum project back to the ELL as parallel fibers in the upper molecular layer. The lower molecular layer of the ELL receives its input from the n. praeeminentialis.The ELL projects via the lateral lemniscus to the n. praeeminentialis and torus semicircularis bilaterally, but more heavily on the contralateral side. In addition, the n. praeeminentialis receives the bulk of its input from the ipsilateral torus semicircularis. The caudal lobe of the cerebellum both projects to the electrosensory portion of the torus semicircularis and receives indirect input from the torus semicircularis via the inferior olivary nucleus. In summary, the central organization of this ampullary receptor electrosensory system in catfish is similar to that of the ampullary‐tuberous receptor elec‐trosense of mormyrids and gymnotids.
Immunohistochemical localization of avian pancreatic polypeptide‐like immunoreactivity in the rat hypothalamus
Authors: Card J. Patrick , Brecha Nicholas , Moore Robert Y. 
Published: January 2005

AbstractThe distribution of avian pancreatic polypeptide‐like (APP) immuno‐reactivity within the rat hypothalamus was investigated with the indirect immunoperoxidase method. APP immun ore active perikarya are found in largest numbers in the retrochiasmatic area, the arcuate nucleus, and the supracommissural portion of the interstitial nucleus of the stria terminalis. Small clusters of immunoreactive neurons are also consistently observed in the ventral aspect of the medial preoptic area and lateral hypothalamic area, immediately dorsolateral to the optic chiasm and tracts. These neurons are apparent in all animals but are more intensely stained and occur in larger numbers following colchicinepretreatment. Other immunoreactive neurons are visible only in colchicine‐treated rats and are scattered throughout the anterior and lateral hypothalamic areas and the supramammillary nucleus. Immunoreactive axons and terminal fields present an extensive and highly characteristic distribution throughout the hypothalamus, which in many instances exhibits differential distribution within specific subfields of hypo‐thalamic nuclei and areas. The heaviest concentrations of APP immuno‐reactive axons are present in the periventricular nucleus throughout the ros‐trocaudal extent of the hypothalamus, the ventrolateral portion of the suprachiasmatic nucleus, the retrochiasmatic area, the parvocellular para‐ventricularnucleus, the ventral supraopticnucleus, theperifornical nucleus, the ventral dorsomedial nucleus, and the arcuate nucleus. Moderate plexuses of immunoreactive fibers are also present in the medial preoptic area, the anterior and lateral hypothalamic areas, the nucleus circularis, the median eminence, and the ventral premammillary area. Other areas, such as the ventromedial nucleus, contain virtually no immunoreactive axons but are encapsulated by a dense plexus of immunoreactive terminals. The distribution of a major component of APP immunoreactive fibers exhibits a marked similarity to that of previously described norepinephrine‐containing hypothalamic afferents. Other groups of APP immunoreactive perikarya and fibers appear to represent components of intrinsic diencephalic systems.
Localization of cholecystokininlike immunoreactivity in the rat spinal cord, with particular reference to the autonomic innervation of the pelvic organs
Authors: Daa Schrøder Henrik 
Published: January 2005

AbstractThe distribution of cholecystokinin in the spinal cord was investigated by immunohistochemistry. Throughout the length of the spinal cord cholecystokinin immunoreactivity was found in laminae I and II, in the spinal re‐ticular nucleus, and in the surroundings of the central canal. On the basis of the cholecystokinin pattern lamina II could be divided into a dorsal and ventral part.In the lumbar and sacral spinal cord additional terminal fields of cholecystokinin immunoreactive boutons unique to these levels were found. They corresponded to the intermediolateral nucleus and to the medial lumbar sympathetic nucleus dorsal to the central canal in the first and second lumbar segment. Also the intermediolateral nucleus in L6–S1 received a dense cholecystokinin positive input. Moreover, the area surrounding the central canal in L6–S1, contained many cholecystokinin immunoreactive structures. Combined retrograde tracing and immunocytochemistry revealed that the two cholecystokinin terminal fields characteristic for L1–L2 and that sur‐rounding the intermediolateral nucleus in L6–S1 were situated corresponding to preganglionic neurons innervating pelvic organs through the hypo‐gastric nerve or the pelvic nerves.It thus appears that the unique lumbosacral cholecystokinin is related to nuclei influencing pelvic structures, pointing to a special need for regulation of the organs involved in evacuation and sexual functions. Moreover, it is demonstrated that the caudal part of the spinal sympathetic system differs from the more cranial part with respect to type of afferent connections.The origin of the spinal cholecystokinin was investigated and it was found that neither complete transection of the spinal cord nor ipsilateral sectioning of three or four dorsal roots induced visible changes in the cholecystokinin staining pattern. Treatment of the caudal spinal cord with colchicine revealed the presence of cholecystokinin immunoreactive neurons in the intermediate gray, at the lateral border of the dorsal horn, in the dorsal horn proper, and in the substantia gelatinosa. These findings indicate that the majority of spinal cholecystokinin has a spinal origin.
Modifications in the laminar organization of peptide‐like immunoreactivity in the anuran optic tectum following retinal deafferentation
Authors: Kuljis Rodrigo O. , Karten Harvey J. 
Published: January 2005

AbstractSubstance P (SP)‐, leucine‐enkephalin (LENK)‐, cholecystokinin octa‐peptide (CCK8)bombesin (BOM)‐, and avian pancreatic polypeptide (APP)‐like immunoreactiyities were analyzed in the optic tectum of Rana pipiens 5–99 days after unilateral eye enucleation, or optic nerve ligation, by means of the peroxidase‐antiperoxidase and indirect fluorescence single and double labeling methods. The normal pattern (Kuljis and Karten, 1981, 1982c) of peptide‐like immunoreactivity was observed ipsilaterally to the operation. Contralateral deafferented tectae displayed conspicuous modifications in the normal pattern of peptide‐like immunoreactivity unique to each of the substances studied. The modifications of peptide‐like immunoreactivity observed varied depending both on the survival time and on the particular peptide analyzed, with either increment or diminution or disappearance–or combinations thereof–in the staining intensity of some of the peptide‐positive bands in the superficial one‐third (superficial neuropil) of the tectum. The onset of these changes is detectable immunocytochemicahy between the sixth and tenth day following deafferentation. By 2–4 weeks full expression of the long‐term changes is reached with no apparent further modification up to the 99th postoperative day. The rapid onset of these phenomena suggests the existence of a previously unrecognized retinal ganglion cell terminal peptidergic contribution to the tectum and/or rapid transsynaptic effects. The former possibility is suggested by recent observations demon‐strating peptide‐like immunoreactivity for SP, LENK, CCK8 and BOM in the retinal stump of ligated optic nerves (Kuljis and Karten, 1982b). The fact that no vertebrate retinal ganglion cells have been shown to contain any of these peptides (Brecha et al., 79; Famiglietti et al., 1980; Eldred and Karten, 1981; Karten et al., 1982), however, argues against the possibility of a retinal terminal contribution to peptide‐like immunoreactivity in the tectum and suggests that transsynaptic phenomena are involved.
Comparisons of directionally selective with other ganglion cells of the turtle retina: Intracellular recording and staining
Authors: Jensen Ralph J. , Devoe Robert D. 
Published: January 2005

AbstractDirectionally selective (DS) and other ganglion cells of the turtle retina were studied in in vitro eyecup preparations by using intracellular recording and staining techniques. DS ganglion cells responded to moving gratings with periodic, depolarizing synaptic potentials in both preferred and null directions. Although depolarizations were usually larger in the preferred than in the null directions, in a few cells spike discharges were directional but depolarizations were not. Directionality could disappear if inappropriate field sizes or grating spatial frequencies were used.Unlike non‐DS cells, one‐half of the DS cells penetrated showed two sizes of action potentials upon photostimulation. It is proposed that the smaller spikes originated at axonal initial segments and failed to invade the somas actively. DS cells also exhibited postspike depolarizations (PSDs).Three types of DS ganglion cells (ON‐OFF, OFF center, and ON center) were identified morphologically with Lucifer yellow injection. Other ganglion cells, which were also recorded from and stained intracellularly, are compared to the DS cells.