bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical analysis of magnocellular elements in rat hypothalamus: Distribution and numbers of cells containing neurophysin, oxytocin, and vasopressin
Authors: Rhodes C. H. , Morriell J. I. , Pfaff D. W. 
Published: January 2005

AbstractA cell‐by‐cell analysis of the magnocellular elements in hypothalami of fifty Long‐Evans (normal) and Brattleboro (diabetes insipidis) rats was done using the unlabeled antibody enzyme technique (PAP) with primary antisera directed against oxytocin (OXY), vasopressin (ADH), and the neurophysins.The magnocellular neurons of the hypothalamus were found in the supraoptic (SON), paraventricular (PVN), and anterior comissural (ACN) nuclei, a number of accessory nuclei, and as individual cells in the anterior hypothalamic area. SON was divided by the optic tract into the principal part and retrochiasmatic SON. In retrochiasmatic SON a majority of the cells contained vasopressin. Within the principal part of SON oxytocin‐producing cells tended to be found rostrally and dorsally, while the vasopressin cells were more common caudally and ventrally. PVN was divided into three subnuclei, the medial, lateral, and posterior subnuclei, on the basis of cellular morphology and peptide content. The magnocellular cells of the medial and lateral PVN were closely packed together and nearly round, while those of posterior PVN were more separated and fusiform in shape with their long axis running in a medio‐lateral direction. Medial PVN consisted primarily of oxytocin‐producing cells, while lateral PVN was formed by a core of vasopressin‐producing cells with a rim of oxytocin cells. Posterior PVN contained largely oxytocin‐producing cells. Both ADH and OXY cells were found in the accessory nuclei.In the Long‐Evans rat the SON had, on the average, 1443 OXY and 3236 ADH cells; the PVN had 1174 OXY and 976 ADH cells; and the accessory magnocellular groups in the hypothalamus (including the ACN) had 1286 OXY and 552 ADH cells. The Brattleboro strain animal had similar numbers of cells in these nuclei. (The cells which contain ADH in normal animals were identified in the Brattleboro rat as large, neurophysin‐negative cells.) Thus, a large fraction of the magnocellular oxytocin‐ and vasopressin‐producing cells in the rat were located outside of the PVN and SON. One accessory cell group in particular, ACN, had 616 OXY cells, or about 50% as many as PVN. In each nucleus the sum of the numbers of OXY and ADH cells was approximately the number of neurophysin cells.
Organization of afferent connections of the feline lateral habenular nucleus
Authors: McBride Russell L. 
Published: January 2005

AbstractThe organization of afferent projections to the lateral habenular nucleus (LHB) was studied in adult cats. In autoradiographic experiments, tritiated leucine injections were made into regions shown in retrograde transport studies to project to LHB (lateral hypothalamus, preoptic region, entopeduncular nucleus, and midbrain raphe) to determine the locations of axonal trajectories and terminal zones.The distribution of silver grains in the ipsilateral LHB differed according to the injection site. Entopeduncular nucleus projected to the ventrolateral part, raphe to the dorsomedial part, preoptic region to the central part, anterior hypothalamus to all but the ventrolateral part, and posterior hypothalamus to all but the dorsomedial part. The lateral hypothalamus, preoptic region, and anterior portion of the entopeduncular nucleus projected primarily through the inferior thalamic peduncle and stria medullaris, while the posterior portion of the entopeduncular nucleus projected more diffusely through thalamus to enter LHB from its ventral aspect. Raphe axons reached LHB through the fasciculus retroflexus.Entopeduncular and lateral hypothalamic axons passed through the habenular commissure to the contralateral stria medullaris to reach the contralateral LHB. Silver grains in LHB were distributed similarly bilaterally, but were much less dense contralateral to the injection.The major afferent projections to the feline LHB are therefore topographically organized. The significance of this organization in relation to the possible role of the LHB in integrating limbic and extrapyramidal motor systems is discussed.
Normal and abnormal retinal projections following the crush of one optic nerve in goldfish (Carrassius auratus)
Authors: Springer Alan D. 
Published: January 2005

AbstractOptic nerve regeneration was examined with [3H]proline radioautography in fish that had one nerve crushed. Fibers had not yet grown beyond the crush site at 2 days post‐crush (PC) and were at the optic chiasm by 4–5 days PC. By 6 days PC the fibers had reinnervated the rostral pole of the contralateral tectum, the lateral geniculate nucleus and area pretectalis dorsalis and ventralis. Area preopticus, nucleus opticus dorsolateralis and nucleus opticus commissurae posterior were partially reinnervated by 8 days PC. At this time numerous abnormal targets were labeled, including nucleus rotundus, nucleus isthmi, cerebellum, pituitary gland and ipsilateral optic tectum. Optic fibers also entered the posterior, intertectal and horizontal commissures, as well as tractus rotundus, the tectocerebellar, tectobulbar and mesencephalocerebellar tracts. In addition, fibers within the contralateral optic tectum were not restricted to their usual laminae. They were distributed from the superficial edge of the tectum to the ventricle. At 32 days PC only the normal retinal projections were evident, and all of the anomalous projections had disappeared. The anomalous projections may have either retracted or degenerated or become undetectable with radioautography.
Neurogenesis in the trigeminal ganglion of the albino rat: A quantitative autoradiographic study
Authors: Forbes Donna J. , Welt Carol 
Published: January 2005

AbstractThe time of neuron origin in the trigeminal ganglion was examined in autoradiograms of 60‐day‐old rats that were exposed to a single pulse of 3H‐thymidine on day 11, 12, 13, 14, or 15 of gestation. Heavily labeled neurons, representing cells in or near their last mitotic division at the time of the pulse label, were present in animals injected between embryonic days 11 and 13 with a peak on day 12. Within this time period, larger neurons were generated prior to smaller neurons with a peak for larger cells on day 12 and for smaller cells on day 13. Thus, the majority of trigeminal ganglion neurons are generated over a three‐day period just after the midpoint of gestation.Neuron number, size, type, and cytoarchitectural organization were also examined in the ganglion. The mean neuron count per ganglion was 52,372. The size distribution of these cells ranged continuously from 7–61 μm (mean diameter) with no evidence for clearly defined subpopulations. The staining intensity and distribution patterns of the Nissl substance varied greatly from cell to cell precluding the classification of cells as light or dark. Little correspondence between these Nissl features and cell size was found. Among the clusters and rows of neurons in the ganglion, we did not see consistent cytoarchitectonic patterns which might reflect specific sensory receptive fields.
A golgi‐electron microscopic study of goldfish optic tectum. I. description of afferents, cell types, and synapses
Authors: Meek J. 
Published: January 2005

AbstractA study of goldfish optic tectum was performed with conventional electron microscopy and with the Golgi‐EM technique described by Fairén et al. (1977). Five types of tectal afferents, three types of interneurons and three types of efferent neurons were investigated.Afferents from the torus longitudinalis, which terminate in the marginal layer, contain round synaptic vesicles with a mean diameter of 43 nm. Optic afferents, which terminate in the superficial gray and plexiform layer, are characterized by pale mitochondria with dilated cristae and round vesicles with a mean diameter of 49 nm. Afferents of unknown origin, terminating in several tectal layers, can be subdivided in three types; one containing round vesicles and two containing pleomorphic vesicles with different degrees of ellipticity.The three types of interneurons studied (type I, III and XIV, of Meek and Schellart, 1978) were selected on basis of their high frequency of occurrence. The apical dendrites of type I neurons make many synaptic contacts with the marginal axons. All three types have dendrites in the superficial gray and plexiform layer making contacts with optic nerve terminals. In addition, their dendrites and cell bodies make synaptic contacts with several types of unidentified presynaptic elements. The axon terminals of type I and of type XIV contain round vesicles with a mean diameter of 45 and 46 nm respectively.Three of the four types of efferent neurons present in the goldfish tectum were studied (type VI, XII and XIII). Two of them make contact with optic terminals (type VI and XII) and two make contact with tectal afferents of unknown origin in the central white layer or in the lower part of the central gray layer (type XII and XIII). The axons of all three types become myelinated at some distance from their origin. Their intial unmyelinated parts are covered with a so‐called “outer surface coating”, have no collaterals and are occasionally (type VI and XII) or frequently (type XIII1) postsynaptic to other elements. The archiform axons of type XIII1, and to a lesser extent also the shepherds‐crook shaped axons of type XII, have a close apposition to looping and narrowing dendrites in the inner plexiform layer.The present results concerning neuronal circuitry of the goldfish optic tectum are summarized in a tentative scheme.
Intracortical arborizations and receptive fields of identified ventrobasal thalamocortical afferents to the primary somatic sensory cortex in the cat
Authors: Landry Pierre , Deschênes Martin 
Published: January 2005

AbstractThe intracortical arborizations of neurons from the ventroposterolateral thalamic nucleus (VPL) in the cat were studied by intraaxonal injections of horseradish peroxidase (HRP) following identification of their receptive fields. In the primary somatic sensory cortex (SI) VPL cells terminated in different cytoarchitectonic areas according to their receptive field modality. Fibers excited by deep tissues or joint rotation arborized preferentially in area 3a. Those responding tonically to cutaneous stimuli were located in the anterior part of area 3b; hairdriven cells terminated in area 3b and in the rostral pole of area 1. All fibers had a similar laminar distribution within SI. Axons terminated mostly in layers VI, IV, and the lower part of layer III. None terminated in layers I and II. Most terminal arbors were oriented along the mediolateral axis of the brain. The main arborization of a single VPL cell formed a bush of about 500 μm in diameter. Some fibers generated two such bushes with an uninvaded region of about 300 μm between them. It is proposed that this patchy organization underlies in part the columnar organization of area SI. Many VPL cells had secondary projection sites in SI. These were issued from smaller‐sized collaterals and were located in a different cytoarchitectonic area than that of the main terminal plexuses. A significant number of these collaterals projected to area 4. Insufficient filling of the collaterals by HRP prevented a more complete characterization of the secondary arbors.
Metabolic response of optic centers to visual stimuli in the albino rat: Anatomical and physiological considerations
Authors: Toga Arthur W. , Collins Robert C. 
Published: January 2005

AbstractThe functional organization of the visual system was studied in the albino rat. Metabolic differences were measured using the 14‐C‐2‐deoxyglucose (DG) autoradiographic technique during visual stimulation of one entire retina in unrestrained animals. All optic centers responded to changes in light intensity but to different degrees. The greatest change occurred in the superior colliculus, less in the lateral geniculate, and considerably less in second‐order sites such as layer IV of visual cortex. These optic centers responded in particular to on/off stimuli, but showed no incremental change during pattern reversal or movement of orientation stimuli. Both the superior colliculus and lateral geniculate increased their metabolic rate as the frequency of stimulation increased, but the magnitude was twice as great in the colliculus. The histological pattern of metabolic change in the visual system was not homogenous. In the superior colliculus glucose utilization increased only in stratum griseum superficiale and was greatest in visuotopic regions representing the peripheral portions of the visual field. Similarly, in the lateral geniculate, only the dorsal nucleus showed an increased response to greater stimulus frequencies. Second‐order regions of the visual system showed changes in metabolism in response to visual stimulation, but no incremental response specific for type or frequency of stimuli.To label proteins of axoplasmic transport to study the terminal fields of retinal projections 14C‐amino acids were used. This was done to study how the differences in the magnitude of the metabolic response among optic centers were related to the relative quantity of retinofugal projections to these centers. Fast and slow axoplasmic transport were studied using three separate amino acids. In each case over 64% of the radioactivity projecting contralateral from the eye was found in superior colliculus. Considerably less isotope was found in dorsal lateral geniculate (11–17%), ventral lateral geniculate (3.7–6.2%), pretectal nuclei (5–12%), and the accessory optic system (3–7%). The greatest concentration of radioactivity within each optic center was found in the visuotopic aspect subserving the superior visual field; particularly the medial aspects of the superior colliculus, olivary pretectal nucleus, and posterior pretectal nucleus, and the anterior portion of the nucleus of the optic tract. The representation of central vision in the colliculus was relatively pale, as was a zone within the middle of the contralateral dorsal lateral geniculate.The anatomical and physiological results of this study suggest that differences in deoxyglucose metabolism among optic centers are primarily related to the number of retinofugal endings and the kind of visual stimulation. Changes within any one center primarily reflect the density of retinal endings subserving the visual field.
Distribution of methionine‐enkephalin immunoreactivity in the chick brain: An immunohistochemical study
Authors: De Lanerolle N. C. , Elde R. P. , Sparber S. B. , Frick M. 
Published: January 2005

AbstractThe distribution of Met‐enkephalin‐like immunoreactivity in the brains of 2‐week‐old domestic chicks was studied with immunohistofluorescence and the unlabeled antibody peroxidase‐antiperoxidase technique, using antibodies to Met‐enkephalin generated in rabbits. Immunoreactive cell bodies were found in the telencephalon, diencephalon, and mesencephalon in areas as yet uncharacterized as discrete nuclei in birds (E‐1, E‐2, E‐3, E‐4, E‐5); further cells were located in the diencephalic nucleus spiriformis lateralis, the midbrain medial intercollicular nucleus (E‐6), the nucleus mesencephalicus lateralis, pars dorsalis, the Edinger‐Westphal nucleus and dorsal occulomotor nucleus; and in the nucleus of cranial nerve X and an uncharacterized area in the dorsolateral medulla (E‐7). Immunoreactive fibers and/or terminals were located around the immunoreactive cell bodies and, in addition in the lateral septal area of the telencephalon; in the preoptic and hypothalamic areas of the diencephalon; in the anterior intercollicular area, periaqueductal central gray, area C, and the midventral tegmentum of the mesencephalon; in the nucleus solitarius, nucleus IX‐X, nucleus intercalatus, nucleus intermedius, and ventrolateral areas of the rhombencephalon. The pattern of distribution of met‐enkephalin in the chick is compared with that in the rat. A possible functional role for Met‐enkephalin in neural mechanisms mediating some behaviors of the chick is suggested.
Thin‐section and freeze‐fracture studies of crayfish stretch receptor synapses including the reciprocal inhibitory synapse
Authors: Hirosawa Kazushige , Tao‐Cheng Jung‐Hwa , Nakajima Yasuko , Tisdale Ann D. 
Published: January 2005

AbstractThe crayfish slow‐adapting abdominal stretch receptor organ is innervated by three inhibitory and several excitatory axons. A previous study by Tisdale and Nakajima ('76) showed that under certain fixation conditions inhibitory and excitatory synapses can be distinguished on the basis of synaptic vesicle structure. Using this morphological criterion we describe six types of synapses in the receptor: (1) the inhibitory axo‐dendritic synapse, (2) the excitatory neuromuscular synapse, (3) the inhibitory neuromuscular synapse, (4) the axo‐axonic synapse which suggests presynaptic inhibition on the excitatory synapse, (5) the axo‐axonic synapse which suggests presynaptic inhibition on the inhibitory synapse, (6) the reciprocal inhibitory axo‐axonic synapse, which is a new type of synapse. The presence of these six types of synapse suggests that inhibitory and excitatory axons interact synaptically in a complicated manner, resulting in a delicate control of receptor function. In freeze fracture we have observed the presynaptic membrane structures of inhibitory and excitatory synapses. The active zone of the inhibitory synapse has ridges with loosely aggregated particles on the tops of the ridges and indentations (vesicle attachment sites) along their sides. The active zone of the excitatory neuromuscular synapse consists of bands of particle aggregates which are situated on slightly elevated membrane regions and surrounded by wide, relatively particle‐free, flat membrane areas.
Generation of the ocular motor nuclei and their cell types in the rabbit
Authors: Shaw Marjorie D. , Alley Keith E. 
Published: January 2005

AbstractAutoradiography of 3H‐thymidine incorporation was combined with horseradish peroxidase (HRP) transport to distinguish the birthdates of motoneurons and internuclear neurons of the abducens nucleus, and of specific motor pools within the oculomotor nucleus. Motoneurons were identified by their retrograde transport of HRP from the extraocular muscles. In other experiments, internucleur neuron types may be controlled by the local environment. The motor pools ofthe oculomotor nucleus are generated sequentially. This may reflect the mechanism whereby nuclei are constructed.
GABAergic synapses in the goldfish retina: An autoradiographic study of 3H‐muscimol and 3H‐GABA binding
Authors: Yazulla Stephen 
Published: January 2005

AbstractThe localization of synaptic receptor sites for γ‐amino butyric acid (GABA) in the goldfish retina was studied by light microscopic (LM) and electron microscopic autoradiography (EM‐ARG) of 3H‐muscimol and 3H‐GABA binding. Sodium‐independent binding of both 3H‐muscimol and 3H‐GABA was localized to a uniform band throughout the inner plexiform layer (IPL) by LM‐ARG of cryostat sections incubated in these compounds. No binding was observed over the outer plexiform layer. This binding pattern differs from the uptake pattern of 3H‐GABA in the IPL, which shows very heavy labeling in the most proximal IPL and little labeling throughout the rest of the IPL. Statistical analysis of EM‐ARGs of 3H‐muscimol (i.e., make GABAergic synapses). Labeled amacrine‐to‐amacrine synapses are mostly concentrated in the 20–80% levels of the IPL, whereas amacrine‐to‐bipolar synapses are concentrated at about the 70–90% depth. Maximal 3H‐GABA uptake, however, occurs at the 90–100% depth. This difference in the location of GABAergic synaptic binding and GABAergic uptake leads to the conclusion that the density of uptake label provides little information about the density of synaptic contacts. Thus, in order to localize GABAergic interactions, synaptic binding rather than neuronal uptake appears to provide the more appropriate description.
Organization of thalamic afferents to anterior dorsal ventricular ridge in turtles. I. Projections of thalamic nuclei
Authors: Balaban Carey D. , Ulinski Philip S. 
Published: January 2005

AbstractDorsal ventricular ridge (DVR) is a thalamorecipient, subcortical telencephalic structure in reptiles and birds. Although there is a fair amount of information about sources of afferents to DVR, little is known about the relationship of projections from individual thalamic nuclei to the organization of the structure. This study examines the relationship between thalamic projections and both areal and zonal divisions of anterior DVR (ADVR; Balaban,'78a) of emydid turtles with orthograde degeneration, and horseradish peroxidase techniques.Individual thalamic nuclei contribute either a diffuse or a restricted projection to ADVR. Diffuse projections arise primarily from the dorsomedial anterior nucleus. These fine‐caliber axons distribute bilaterally over a wide region of the telencephalon via both medial and lateral thalamotelencephalic pathways. The terminal regions include septum, striatum and the medial bank of cortex caudal to the lamina terminalis. In ADVR, the fibers are distributed sparsely in zones 2–4 of dorsal, medial and ventral areas. Restricted projections to ADVR originate in nucleus rotundus, nucleus reuniens and nucleus caudalis. They ascend ipsilaterally in the lateral thalamotelencephalic pathway (lateral forebrain bundle), and enter ADVR rostral to the anterior commissure. Nucleus rotundus projects to zone 4 of dorsal area, nucleus caudalis projects to zones 2–4 of the dorsal division of medial area, and nucleus reuniens projects to zones 2–4 of both the ventral division of medial area and the ventral area.Comparison of these results with thalamotelencephalic projections in mammals suggests that diffuse and restricted thalamic projection systems are a common feature of both groups. Restricted thalamic projections in reptiles, birds and mammals, terminating in anatomically distinct regions, also appear to be associated with different sensory modalities. The significance of diffuse systems is not clear.