bluuebunny/crossref_metadata_2025 huggingface dataset:
Rostrocaudal expression of antibody HNK‐1‐reactive glycolipids in mouse cerebellum: Relationship to developmental compartments and leaner mutation
Authors: Nair Sukumaran M. , Prasadarao Nemani , Tobet Stuart A. , Jungalwala Firoze B.
Published: January 2005

Sulfoglucuronylglycolipids (SGGLs) and glycoproteins, reacting with monoclonal antibody HNK‐1, are developmentally and spatially regulated in the mammalian cortex and cerebellum. It has been proposed that the HNK‐1 carbohydrate epitope is involved in intercellular adhesion and cell‐cell interactions. Biochemical analysis and immunocytochemical localization of SGGLs and other neolacto series glycolipids were studied in the leaner mutant mouse cerebellum, where a slow and progressive rostral to caudal degeneration occurs with a gradual loss of both granule cells and Purkinje cells. Biochemical analyses showed that SGGLs and other neolacto series of glycolipids were significantly decreased in the adult leaner cerebellum; however, HNK‐1‐reactive glycoproteins were not affected. By an immunocytochemical method which selectively localizes the lipid antigens, it is shown that SGGLs are primarily associated with Purkinje cell bodies and their dendrites in the molecular layer and in cerebellar nuclei where Purkinje cell axons terminate. At postnatal day 30 (P30), SGGL immunoreactivity (rSGGL‐ir) in the leaner cerebellum was reduced moderately compared to normal littermates, which correlated with the minimal degree of Purkinje cell degeneration at this age in leaner and with the biochemical data. At P67 and P90, the SGGL‐ir was significantly more reduced in the leaner as Purkinje cell degeneration proceeded. There was a direct correlation between loss of Purkinje cells and SGGL‐ir in the cerebellar molecular layer. In both normal and young leaner cerebella, the SGGL‐ir in different lobules was not uniform; there were distinct rostrocaudal and mediolateral differences. SGGL‐ir was markedly more intense in rostral than in caudal lobules in the vermis, the dividing line being the region immediately caudal to the primary fissure and rostral to the declival sulcus. In the lateral cerebellum, the SGGL‐ir was less intense than in the vermis and the rostrocaudal difference was not as pronounced. There was also nonuniformity in the intensity of staining in different folia. The rostrocaudal as well as mediolateral differences in the intensity of SGGL‐ir were confirmed independently by biochemical analysis. The differential phenotypic expression of SGGLs and the selective susceptibility to Purkinje cell death in leaner mutant are discussed in relation to the known embryologic and ontogenetic compartmentation of cerebellum. © 1993 Wiley‐Liss, Inc.
Distribution of synapses on identified cell types in a gustatory subdivision of the nucleus of the solitary tract
Authors: Whitehead Mark C.
Published: January 2005

Two morphological types of neurons in the rostral nucleus of the solitary tract (NST) in the hamster send axons to the parabrachial nucleus (PBN). Elongate cells have oval cell bodies and 2 mediolaterally oriented primary dendrites. Large stellate cells have polygonal cell bodies and 3–5 radiating primary dendrites. Both cell types are located in the rostral central subdivision of the NST, surrounded by primary afferent axons from the oral cavity. This study uses electron microscopy to evaluate the synaptic inputs to horseradish peroxidase (HRP)‐labelled elongate and stellate PBN projection cells.

Three types of axon terminals provide most of the synapses on the labelled cells. Primary‐like terminals contain large, clear, round vesicles and engage in asymmetrical synaptic junctions; they resemble gustatory (facial) afferent terminals identified previously (Whitehead, J. Comp. Neurol. 244:72, 1986). Axon terminals containing small, pleomorphic vesicles (SP terminals), form symmetrical junctions, and resemble Golgi II endings. Terminals containing medium‐sized pleomorphic vesicles (MP terminals) form asymmetrical junctions. These types of axon terminals distribute differentially on the labelled cells. Primary‐like inputs are largely restricted to distal dendrites and their spines. SP terminals provide more synaptic coverage than primary‐like or MP terminals; for both cell types the SP inputs are concentrated proximally on dendrites and cell bodies. The data suggest that elongate and large stellate cells function as second‐order projection neurons in the ascending taste system. The density, spatial distribution, and timing of activation of the various types of synapses could relate to the electrophysiological response properties of the projection neurons. © 1993 Wiley‐Liss, Inc.
Electron microscopic analysis of the rod pathway of the rat retina
Authors: Chun Myung‐Hoon , Han Seung‐Ho , Chung Jin‐Woong , Wässle Heinz
Published: January 2005

Two immunocytochemical markers were used to label the rod pathway of the rat retina. Rod bipolar cells were stained with antibodies against protein kinase C and AII‐amacrine cells with antibodies against parvalbumin. The synaptic circuitry of rod bipolars in the inner plexiform layer (IPL) was studied. Rod bipolar cells make approximately 15 ribbon synapses (dyads) in the IPL. Both postsynaptic members of the dyads are amacrine cells; one is usually the process of an AII‐amacrine cell and the other one frequently provides a reciprocal synapse. No direct output from rod bipolar cells into ganglion cells was found. AII‐amacrine cells make chemical output synapses with cone bipolar cells and ganglion cells in sublamina a of the IPL. They make gap junctions with cone bipolar cells and other AII‐amacrine cells in sublamina b of the IPL. The rod pathway of the rat retina is practically identical to that of the cat and of the rabbit retina. It is very likely that this circuitry is a general feature of mammalian retinal organization. © Wiley‐Liss, Inc.
Immunohistochemical localization of chicken gonadotropin‐releasing hormones I and II (cGnRH I and II) in turkey hen brain
Authors: Millam James R. , Faris Patricia L. , Youngren Orlan M. , El Halawani Mohamed E. , Hartman Boyd K.
Published: January 2005

The distribution of cells and fibers immunoreactive (ir) for either chicken gonadotropin‐releasing hormone I (cGnRH I; [Gln8]GnRH) or II ([His5, Trp7, Tyr8]GnRH) was determined in brains of turkey hens to reveal whether these peptides occur in separate neuronal systems. ir‐cGnRH I cells were located: along the medial aspect of the ventriculus lateralis, nucleus accumbens, and bed nucleus of the stria terminalis; ventral to the tractus septomesencephalicus and extending medially to the third ventricle, and caudally into the lateral hypothalamic area; and in a diffuse band extending from the nucleus preopticus medialis to the nucleus dorsomedialis anterior thalami. cGnRH I fibers were evident in these areas in addition to the hippocampus, nucleus subhabenularis medialis, nucleus ventromedialis hypothalami, and median eminence. Two groups of ir‐cGnRH II cells were observed: a magnocellular group lying between the substantia grisea centralis and the nucleus ruber; and a parvicellular group lying medial to the nucleus of the basal optic root and extending into the lateral hypothalamic area. ir‐cGnRH II fibers were prominent in limbic structures (cortex piriformis, lateral to nucleus taeniae, hippocampus); olfactory areas (tuberculum olfactorium, nucleus subhabenularis lateralis, nucleus septalis lateralis); areas that in other avian species have steroid‐concentrating cells or receptors (medial edge of lobus parolfactorius, nucleus septalis medialis, nucleus periventricularis magnocellularis, nucleus dorsomedialis posterior thalami); and areas containing ir‐GnRH I cells or fibers but not in median eminence. These results suggest that cGnRH I and II occur in separate neuronal systems and that cGnRH II does not directly promote pituitary gonadotropin secretion. © 1993 Wiley‐Liss, Inc.
The sites of origin of dopaminergic afferent fibers to the lateral habenular nucleus in the rat
Authors: Li Yun‐Qing , Takada Masahiko , Shinonaga Yasuhide , Mizuno Noboru
Published: January 2005

The lateral habenular nucleus of the rat contains a dense plexus of dopaminergic fibers, which are more marked in the medial part of the lateral habenular nucleus than in its lateral counterpart. Employing a combination of fluorescent retrograde axonal tracing with fluorogold and tyrosine hydroxylase immunofluorescence histochemistry, we investigated the distribution of cells of origin of the dopaminergic afferent fibers to the lateral habenular nucleus in the rat. The cells double‐labeled with both fluorogold injected into the lateral habenular nucleus and tyrosine hydroxylase antisera were seen in a variety of fore‐ and midbrain regions, including the bed nucleus of the stria terminalis, medial preoptic area, periventricular, ventromedial, and dorsomedial hypothalamic nuclei, ventral tegmental area, interfascicular nucleus, substantia nigra pars compacta, ventrolateral division of the midbrain periaqueductal gray, and dorsal raphe nucleus. The double‐labeled cells were located bilaterally with an ipsilateral predominance, and constituted approximately 10% of the total fluorogold‐positive cell population. We have further observed by anterograde axonal tracing with Phaseolus vulgaris–leucoagglutinin that projection fibers arising from the sites of origin of the dopaminergic afferent fibers to the lateral habenular nucleus terminate mainly in the medial part of the lateral habenular nucleus, and to a lesser extent in its lateral conterpart.

Thus, we have found in the present study that the dopaminergic neurons sending their axons to the lateral habenular nucleus are widely distributed in the A9, A10, A14, and A15 dopaminergic cell groups. Such dopaminergic neurons may exert regulatory influences upon many limbic‐associated brain regions via the lateral habenular nucleus. © 1993 Wiley‐Liss, Inc.
Differential time course and spatial expression of Fos, Jun, and Krox‐24 proteins in spinal cord of rats undergoing subacute or chronic somatic inflammation
Authors: Lantéri‐Minet M. , de Pommery J. , Herdegen T. , Weil‐Fugazza J. , Bravo R. , Menétrey D.
Published: January 2005

We have used the evoked expression of both immediate early gene (IEG)‐encoded proteins (Krox‐24, c‐Fos, Fos B, Jun D, Jun B, c‐Jun), and dynorphin to monitor sensory processing in the spinal cords of rats undergoing subacute or chronic somatic inflammation (i.e., subcutaneous inflammation of the plantar foot and monoarthritis, respectively). Behavioral and immunocytochemical approaches were conducted in parallel up to 15 weeks postinjection in order to detect possible relationships between clinical evolution and spatiotemporal pattern of IEG‐encoded protein expression.

Each disease had specific characteristics both in terms of their clinical evolution and pattern of evoked protein expression. All IEG proteins were expressed in both cases. Most of the staining was observed in both the superficial layers of the dorsal horn and deep dorsal horn (laminae V–VII and X). Monoarthritis was distinguished by a high level of total protein expression. Staining was especially dense in the deep dorsal horn. More labelled cells were observed at 1–2 days and at 2 weeks postinjection, corresponding to the initiation and progressive phases of the disease, respectively. Subcutaneous inflammation was characterized by a moderate level of total IEG expression. More labelled cells were observed in the first day following injection. It is the relative degree of expression of each IEG‐encoded protein with regard to the others that characterized the progression of the diseases. Early stages of the diseases coincided with the expression of all Fos and Jun proteins, while late stages showed an increase in Jun D and Fos B involvement; Krox‐24 was induced mostly during the early phases and/or periods of paroxysm of the diseases. Persistent stimulation was characterized by a predominant expression in deep versus superficial layers of the dorsal horn. Evoked expression of c‐Jun in motoneurons was only observed in monoarthritis. The peak of dynorphin expression was late in regard to both the induction of inflammation and period of maximal IEG‐encoded protein expression.

The present work indicates that the neural processing that takes place during progression of these diseases can be monitored well at the spinal cord level by using the expression of an array of IEG‐encoded proteins. Study of long term evolutive diseases and especially those that evolve into chronicity can largely benefit from such an approach. © 1993 Wiley‐Liss, Inc.
Spatial organization of inner hair cell synapses and cochlear spiral ganglion neurons
Authors: Leake Patricia A. , Snyder Russell L. , Hradek Gary T.
Published: January 2005

The morphological organization of the central projections of the cat cochlear spiral ganglion into the cochlear nucleus was previously investigated by creating restricted lesions in the anteroventral cochlear nucleus (AVCN) to ablate selectively either the lateral or the medial aspect of isofrequency projection laminae. Such lesions resulted in highly selective retrograde degeneration of spiral ganglion cells. Ablation of the lateral part of the AVCN caused degeneration of cells within the scala tympani part of the ganglion, whereas medial ablations within the AVCN induced degeneration of the scala vestibuli aspect of the ganglion. The peripheral axons also degenerated and this fiber loss exhibited selective topographies that paralleled the cell loss within the spiral ganglion, although this phenomenon was more prominent in the proximal part of the osseous spiral lamina near the ganglion and less obvious more distally near the habenula perforata.

In this investigation, inner hair cells (IHCs) from these selective lesion cases were evaluated by electron microscopy of serial sections through the basal synaptic regions. Results demonstrated differential degeneration of afferent synapses, with greater (but not completely selective) loss of pillar synapses after lateral AVCN lesions and greater loss of modiolar synapses after medial lesions. Because auditory nerve fibers of different spontaneous discharge rates (SRs) have different spatial distributions on the IHC (Liberman, Science 216:1239, 1982), our results suggest that this SR‐based organization is maintained in a topographic organization across the vertical (scala tympani‐to‐scala vestibuli) dimension of the spiral ganglion cell cluster and carried into the ventral cochlear nuclei (VCN). Thus, in addition to the spiral frequency organization represented by the dorsal‐to‐ventral frequency map in the VCN, there is also an orderly organization of inputs from high‐ and low‐SR fibers across the lateral‐to‐medial dimension of the VCN such that the lateral isofrequency laminae receive a proportionately greater input from high‐SR fibers, whereas medial isofrequency laminae receive preferential input from low‐ and medium‐SR fibers. © 1993 Wiley‐Liss, Inc.
Histoautoradiographic detection of oxytocin‐ and vasopressin‐binding sites in the telencephalon of the rat
Authors: Krémarik Pascaline , Freund‐Mercier Marie‐José , Stoeckel Marie‐Elisabeth
Published: January 2005

Localization of oxytocin‐ and vasopressin‐binding sites has so far been studied in the rat brain by means of film autoradiographs. The disposal of iodinated ligands with high specificity has allowed us to develop histoautoradiography on emulsion‐coated sections and to reinvestigate on a microscopic scale the distribution of these sites in the telencephalon (septum, striatopallidal system, amygdala and hippocampus). This technique showed that oxytocin and vasopressin labelling presented distinct distributions and coincided with delimited zones, corresponding to anatomical subdivisions defined on cytoarchitectural and immunocytochemical bases. Vasopressin sites were seen in the dorsal and intermediate parts of the lateral septum and the juxtacapsular nucleus of the bed nucleus of the stria terminalis. Oxytocin sites were located in the ventral and intermediate parts of the lateral septum, the oval and the principal nuclei of the bed nucleus of the stria terminalis and the septofimbrial nucleus. In the striatopallidal system, vasopressin sites were found in the accumbens nucleus and the fundus striati, whereas oxytocin sites were in the accumbens nucleus, the head, and the posterolateral parts of the caudate‐putamen, the striatal cell bridges, and the olfactory tubercle. In the amygdala, vasopressin sites were not found, but oxytocin sites were located in the central, medial, and basomedial nuclei. In the hippocampus, vasopressin sites were located in the dentate gyrus (polymorph and molecular layers), and oxytocin sites, in the subiculum (molecular and pyramidal layers) and in the field CA1 of Ammon's horn (lacunosum moleculare and pyramidal layers). The localization of the binding sites at the microscopic level permitted us to reinvestigate whether or not correlation existed in a same area between innervation, electrophysiological effects, and presence of binding sites. © 1993 Wiley‐Liss, Inc.
Localization and differential expression of FMRFamide‐like immunoreactivity in the nematode Ascaris suum
Authors: Cowden Cynthia , Sithigorngul Paisarn , Brackley Philip , Guastella John , Stretton Antony O. W.
Published: January 2005

By immunocytochemical and immunohistochemical methods, FMRFamide‐like immunoreactivity (FLI) was localized to many neurons and processes in the Ascaris nervous system, including the head, tail, and lateral lines. Some of these cells were identified; they included sensory neurons, interneurons, and motor neurons. FLI was also present in the pharyngeal neurons and in their varicosities near the surface of the pharynx. By HPLC analysis of extract, only a subset of the FMRFamide‐like peptides (FLPs) expressed in Ascaris heads, and heads from which the pharynx had been removed, were expressed in the pharynx. Furthermore, FLPs appeared to be differentially expressed in female heads and tails and male heads and tails. Acetone and acid methanol differentially extracted subforms of FLI from Ascaris heads and from C. elegans. © 1993 Wiley‐Liss, Inc.
Golgi study of the telencephalon of the small‐spotted dogfish Scyliorhinus canicula L
Authors: Manso M. Jesús , Anadón Ramóan
Published: January 2005

The telencephalon of the small‐spotted dogfish, Scyliorhinus canicula L., was examined by Nissl and Golgi‐aldehyde techniques. On the basis of differences in perikaryal and dendritic morphology and size, several cell types were distinguished in pallial and subpallial regions, most of them reported here for the first time in elasmobranchs. In the pallium, the pallium dorsalis is the richest in cell types (eight types of neurons), whereas the neuron population of the pallium medialis is the most homogeneous. Dendrites of most neuron types in the pallium are smooth or sparsely thorny. Interestingly, the pallium dorsalis and pallium lateralis contain a type of primitive pyramidal cell characterized by the dense appearance of its thorny dendrites. In the subpallium, the area superficialis basalis contains a heterogeneous population (six types of neurons): large radial cells are the most characteristic cell type. Dendrites of these cell types are smooth or sparsely thorny. The cell populations of the nucleus N are roughly similar to those of the area superficialis basalis, but they lack the large radial cells characteristic of this area. The area centralis subpallialis and striatum consist of populations of small neurons. The regio septalis contains a rather homogeneous population of small cells. The populations in the nucleus entopeduncularis and the nucleus interstitialis of the basal forebrain bundle are the least varied and consist of large radial cells and bipolar cells similar to those of the area superficialis basalis. This investigation reveals important differences in cytoarchitecture that should be useful in the interpretation of immunocytochemical, tracing, and electrophysiological studies of the telencephalon of elasmobranchs. © 1993 Wiley‐Liss, Inc.
Increased serotoninergic innervation of the hamster's superior colliculus alters retinotectal projections
Authors: Rhoades Robert W. , Bennett‐Clarke Carol A. , Lane Richard D. , Leslie Michael J. , Mooney Richard D.
Published: January 2005

Anterograde tracing with horseradish peroxidase (HRP) was used to compare the organization of retinotectal projections in normal adult hamsters and in animals that sustained subcutaneous injections of the neurotoxin 5,7‐dihydroxytryptamine (5,7‐DHT) on the day of birth. Neonatal injection of this neurotoxin decreases the density of the serotoninergic (5‐HT) innervation of the cerebral and cerebellar cortices, but increases the density of these fibers in the brainstem including the superior colliculus (SC). Analysis of tissue from the retinorecipient laminae of the SC by high‐pressure liquid chromatography indicated that these lesions increased the amount of 5‐HT in the adult SC by 47%. The increased serotoninergic innervation of SC was associated with a marked change in the distribution of the uncrossed retinotectal projection. In normal adult hamsters, fibers from the ipsilateral eye form dense clusters in the lowermost stratum griseum superficiale (SGS) and stratum opticum (SO). A small number of uncrossed fibers are also visible in the more caudal portions of these layers. In the animals that sustained neonatal 5,7‐DHT injections, uncrossed retinotectal fibers formed a nearly continuous band in rostral SO and lower SGS, and numerous labeled fibers were present in the caudal SC, primarily in the SO. Neonatal treatment with 5,7‐DHT also produced alterations in the crossed retinotectal pathway and in the crossed and uncrossed retinogeniculate projections. These results indicate that the 5‐HT input to the developing brainstem may strongly influence the development of retinofugal projections. © 1993 Wiley‐Liss, Inc.
Estrogen receptor‐immunoreactive forebrain neurons project to the ventrolateral hypothalamus in female guinea pigs
Authors: Delville Yvon , Blaustein Jeffrey D.
Published: January 2005

In rodents, the facilitation of sexual receptivity by estradiol and progesterone is suspected to be mediated by a network of neurons containing estrogen and progestin receptors. In female guinea pigs, this network would include estrogen receptor‐immunoreactive (ER‐ir) neurons located within the rostro‐ventral ventrolateral hypothalamus (r‐vVLH). This hypothesis predicts that a proportion of the neurons projecting to the r‐vVLH contains estrogen receptors. This prediction was tested through retrograde tracing combined with immunocytochemistry for estrogen receptors. Retrogradely labelled neurons were particularly abundant within the medial preoptic nucleus (MPN), bed nucleus of the stria terminalis (BST), anterior hypothalamus, amygdala, and lateral parabrachial nucleus. As predicted by the hypothesis, retrogradely labelled neurons were mostly observed in estrogen receptor‐rich areas. Retrogradely labelled neurons also containing estrogen receptor‐immunoreactivity (ER‐IR) were primarily found within the MPN, BST, and amygdala. However, a majority of retrogradely labelled neurons did not contain ER‐IR. As the preoptic area and the r‐vVLH are both responsive to estradiol in the facilitation of sexual receptivity by progesterone, these data are consistent with the hypothesis tested. However, our data also suggest that the network of neurons controlling sexual receptivity may include elements not directly sensitive to estradiol. Finally, the location of retrogradely labelled neurons is discussed with respect to the stimuli provided to the r‐vVLH in the context of sexual receptivity facilitated by estradiol and progesterone. © 1993 Wiley‐Liss, Inc.
Ultrastructure of serotonin‐immunoreactive terminals in the core and shell of the rat nucleus accumbens: Cellular substrates for interactions with catecholamine afferents
Authors: Van Bockstaele Elisabeth J. , Pickel Virginia M.
Published: January 2005

The nucleus accumbens is composed of a core region involved in motor functions and a shell region implicated in emotional and motivational processes. Both of these regions receive serotonin‐ and dopamine‐containing afferents. We examined whether the serotonin innervation or relation to catecholamine (mainly dopamine) axons in the nucleus accumbens shows common features or specializations corresponding to the noted functional differences in core and shell subregions. To address this question, we examined the ultrastructure of serotonin‐containing axons and their relation to catecholamine‐containing afferents in either the core or shell of the nucleus accumbens. Single coronal sections through the rat forebrain were processed for immunoperoxidase labeling of serotonin and immunogold silver labeling of tyrosine hydroxylase, the catecholamine‐synthesizing enzyme. Varicose processes showing peroxidase product for serotonin by light microscopy were confirmed to be axons and terminals by electron microscopy. In a quantitative analysis of serotonin‐immunoreactive terminals forming one or more contacts in single sections, some common features were observed. For the core (n = 120) and the shell (n = 82), 41% formed synaptic junctions with unlabeled dendrites, 75% were in apposition with unlabeled terminals, which often formed asymmetric junctions, and 20% were in apposition with axons or terminals containing tyrosine hydroxylase. Thus, in both the core and shell of the nucleus accumbens, serotonin terminals synapse on postsynaptic neurons and are likely to modulate or be modulated by presynaptic interactions with excitatory axons forming asymmetric junctions and by catecholaminergic afferents.

Marked differences in the morphology of serotonin axons were also seen in the core versus shell of the nucleus accumbens. By light microscopy, serotonin‐immunoreactive axons were thicker and more varicose than those found in the core. Ultrastructural analysis confirmed that, in contrast to the core, serotonin‐immunoreactive axons and terminals in the shell were larger in cross‐sectional diameter size (0.7 μm vs. 0.3 μm). Additionally, serotonin axon terminals in the shell contained more numerous immunoreactive large dense core vesicles and more frequently formed symmetric as opposed to asymmetric contacts with dendrites. The larger size and more numerous dense core vesicles in serotonin‐immunoreactive terminals in the shell support the concept that serotonin or co‐existing neurotransmitter may be more tonically released in the shell versus core of the nucleus accumbens. © 1993 Wiley‐Liss, Inc.
Distribution of substance P‐like immunoreactivity in the brain of the elasmobranch Scyliorhinus canicula
Authors: Rodriguez‐Moldes Isabel , Manso Maria Jesus , Becerra Manuela , Molist Pilar , Anadon Ramon
Published: January 2005

Immunohistochemical methods were used to study the distribution of substance P in the brain of the small‐spotted dogfish (Scyliorhinus canicula). Substance P‐like immunoreactive (SP‐IR) cell bodies and fibers were widely distributed. In the telencephalon, sparse populations ofSP‐IR neurons are present in the olfactory bulbs, pallium, and subpallium. In the subpallium numerous SP‐IR boutons form unusual coats (“pericellular appositions”) on SP‐immunonegative neurons. In the diencephalon numerous SP‐IR cerebrospinal fluid‐contacting neurons are present in the preoptic recess organ and organon vasculosum hypothalami. Numerous SP‐IR fibers also run in the hypothalamus, although no immunoreactivity was observed in the habenulo‐interpeduncular system. A terminal field of SP‐IR fibers is present in the median eminence. In the mesencephalic tegmentum, SP‐IR neurons were observed in the Edinger‐Westphal nucleus. SP‐IR fibers are present at high density in the basal tegmentum, forming a conspicuous tract. In the hindbrain, numerous SP‐IR fibers were observed in the isthmal region, the trigeminal descending root, the visceral sensory area and commissural nucleus, and the visceromotor column. SP‐IR fibers occur at high density in the substantia gelatinosa of the rostral spinal cord. © 1993 Wiley‐Liss, Inc.
Topography of cholinergic afferents from the nucleus basalis of meynert to representational areas of sensorimotor cortices in the rat
Authors: Baskerville Karen A. , Chang Howard T. , Herron Paul
Published: January 2005

We investigated (1) the topography of projection neurons in the nucleus basalis of Meynert (NBM) with efferents to restricted regions of the primary somatosensory (SI), the second somatosensory (SII), and the primary motor (MI) cortices in the rat; (2) the percentage of these NBM projection neurons that were cholinergic; and (3) the collateralization, if any, of single NBM neurons to different subdivisions within SI, to homotopic areas of SI and SII, and to homotopic areas of SI and MI. Retrograde single‐and double‐labeling techniques were used to study NBM projections to electrophysiologically identified subdivisions of SI and to homotopic representational areas of SI and SII, and of SI and MI. Choline acetyltransferase immunocytochemistry was done to identify cholinergic NBM neurons. Of the retrogradely labeled NBM neurons that projected to selective subdivisions of SI, SII, and MI, 89%, 87%, and 88%, respectively, were cholinergic. We found a rostral‐to‐caudal progression of retrogradely labeled NBM neurons following a medial‐to‐lateral sequence of injections into subdivisions of SI. Overlapping groups of single‐labeled NBM neurons were observed after injections of different tracers into adjacent subdivisions within SI or homotopic areas of SI and SII, and of SI and MI. We conclude that NBM innervation to SI, SII, and MI is mostly cholinergic in the rat, that each cortical area receives cholinergic afferents from neurons widely distributed within the NBM, and that each NBM neuron projects to a restricted cortical area without significant collateralization to adjacent subdivisions within SI or to homotopic areas of SI and SII, or SI and MI. © 1993 Wiley‐Liss, Inc.
Localization of cholecystokinin binding sites in the adult and developing Brazilian opossum brain
Authors: Kuehl‐Kovarik M. Cathleen , Ross Lynne R. , Elmquist Joel K. , Jacobson Carol D.
Published: January 2005

Cholecystokinin (CCK) is now recognized as one of the most abundant peptides in the mammalian central nervous system. We have previously used immunohistochemistry to localize CCK in the adult and developing Brazilian opossum brain. However, little is known about the distribution of CCK binding sites in the developing mammalian brain. Therefore, to further our knowledge of the sites of action for CCK during development, we initiated a series of studies to localize CCK binding sites in the adult and developing Brazilian opossum. This species was chosen because pups are born in a fetus‐like state. Receptor autoradiography was performed on coronally sectioned brains of 1 to 60 day postnatal (PN) animals and adults with 125I‐Bolton Hunter‐CCK‐8 as the radioligand. Binding is evident in the 1PN opossum brainstem and is observed in the developing forebrain by 5PN. Region‐specific binding increases during development, and binding in the 35PN brain resembles the adult pattern. Binding is evident prior to the detection of CCK‐like immunoreactivity in many areas. The facial motor nucleus is identifiable and exhibits high levels of binding in Brazilian opossum pups of 10 to 35 days of age. However, binding is undetectable in the facial motor nucleus of 45 and 60PN pups. In general, the binding patterns for CCK in the adult opossum resemble those of other mammals and likely mediate similar physiological functions. However, some cholecystokininergic pathways appear to be unique to neonatal mammals. © 1993 Wiley‐Liss, Inc.
Monosynaptic innervation of trigeminal motor neurones involved in mastication by neurones of the parvicellular reticular formation
Authors: Mogoseanu D. , Smith A. D. , Bolam J. P.
Published: January 2005

In order to determine whether neurones in the parvicellular reticular formation are in direct synaptic contact with motor neurones innervating masticatory muscles, a combined retrograde and anterograde transport study was carriedd out in the rat at both light and electron microscopic levels. The animals received injections of the retrograde tracers wheat germ agglutinin conjugated to horseradish peroxidase or cholera toxin B conjugated to horseradish peroxidase into the masticatory muscles and of the anterograde tracer biocytin into the ipsilateral parvicellular reticular formation. The trigeminal motor nucleus was then examined for both anterograde and retrograde labelling in the light and electron microscopes.

Retrogradely labelled motor neurones were identified in the trigeminal motor nucleus. They were large and their locations within the nucleus depended on the muscle injected. In addition, terminals anterogradely labelled with the biocytin that was injected in the parvicellular reticular formation were identified throughout the motor nucleus. At the electron microscopic level, the retrogradely labelled cells were found to receive input both from distinct types of unlabelled terminals and from terminals that were anterogradely labelled from the parvicellular reticular formation. The labelled terminals comprised one of the four classes of afferent terminals, being 1–2 μm in diameter and densely packed with spherical vesicles. They formed mostly asymmetrical but also symmetrical synapses with the labelled perikarya and dendrites. Anterogradely labelled terminals were also observed to form both symmetrical and asymmetrical synaptic contacts with unlabelled structures in the motor nucleus.

It is concluded that neurones in the parvicellular reticular formation form direct synaptic contact with motor neurones of masticatory muscles. This pathway may represent the anatmical substrate by which the reticular formation exerts at least part of its influence on mastication. Since the parvicellular reticular formation receives input from the substantia nigra pars reticulata, it is possible that this pathway represents a system whereby the basal ganglia directly influence orofacial movement. © 1993 Wiley‐Liss, Inc.
Neocortex and hippocampus contain distinct distributions of calcium‐calmodulin protein kinase II and GAP43 mRNA
Authors: Jacobs Kimberle M. , Neve Rachael L. , Donoghue John P.
Published: January 2005

Calcium‐calmodulin protein kinase II and GAP43 are two molecules which have been linked to synaptic plasticity. Localization of mRNA for these molecules identifies the neuronal populations which have the potential to utilize these mechanisms. General descriptions for calcium‐calmodulin protein kinase II or GAP43 mRNA have been previously reported. In light of recent evidence that suggests that at some sites these two molecules may interact, we sought to determine the cortical distribution in detail, and to examine the extent of overlap between neuronal populations containing each mRNA. To this end we have used in situ hybridization techniques to study the distribution of calcium‐calmodulin protein kinase II and GAP43 mRNA in adjacent sections of adult rat forebrain. Overall, the distribution patterns were distinct but partially overlapping. For both calcium‐calmodulin protein kinase II and GAP43, mRNA levels were highest in hippocampus, allo‐ and neocortex, compared to moderate to low levels in striatum and thalamic nuclei. Within the heavily labeled regions certain populations expressed both calcium‐calmodulin protein kinase II and GAP43 mRNA at high levels, while other populations were selective for calcium‐calmodulin protein kinase II. In the hippocampus, the stratum pyramidale of CAI‐3 expressed high levels of both calcium‐calmodulin protein kinase II and GAP43 mRNA. Granule cells of the fascia dentata and the stratum radiatum of CA3 both contained moderate to high levels of calcium‐calmodulin protein kinase II mRNA, but near background levels of GAP43 mRNA label. Within the neocortex, deep layers were distinguished from superficial layers by their lack of calcium‐calmodulin protein kinase II mRNA expression within the neuropil, and the presence of GAP43 mRNA in neurons located in layer V and the deepest part of layer VI. Thus, layer V and deep layer VI neurons showed high levels of label for both GAP43 and calcium‐calmodulin protein kinase II mRNA, while neurons of superficial layers contained only calcium‐calmodulin protein kinase II mRNA. These markers differentiate neuronal populations which can also be distinguished on the basis of their ability to undergo specific forms of synaptic plasticity. These different forms of plasticity may be due in part to the laminar‐specific patterns of GAP43 and calcium‐calmodulin protein kinase II mRNA that we have described. © 1993 Wiley‐Liss, Inc.
Cytoarchitecture of spinal‐projecting neurons in the brain of the larval sea lamprey
Authors: Swain Gary P. , Snedeker Joseph A. , Ayers Joseph , Selzer Michael E.
Published: January 2005

The descending spinal projecting system of the lamprey is of interest because it includes axons that activate swimming pattern generatorsand because regeneration of this system is involved in the behavioral recovery of lampreys following spinal transection. However, little is known about the true size of this projection and of the distribution of its terminations along the spinal cord. Brain neurons with spinal projections were studied in larval sea lampreys by using wholemount preparations labeled retrogradely with horseradish peroxidase (HRP) from spinal injections at 10%, 15%, 25%, 50%, 70%, and 75% of body length from the anterior end. Neurons projecting to different levels of the spinal cord were mapped. A large number of descending axons terminated within nine segments caudal to the last gill. The spinal projection system was divided into 10 bilateral groups based on cytoarchitectural landmarks. All of the lateral nuclear groups had contralateral spinal projections. In addition to the 12 pairs of Müller cells, the pair of Mauthner cells, and the pair of auxiliary Mauthner cells described by previous authors, the study revealed four pairs of smaller neurons that were individually identifiable. © 1993 Wiley‐Liss, Inc.
Synaptic relationships involving local axon collaterals of pyramidal neurons in the cat motor cortex
Authors: Keller Asaf , Asanuma Hiroshi
Published: January 2005

The intracortical synaptic relationships of pyramidal neurons in the cat motor cortex were studied by intracellular recording and labeling techniques. Neurons that responded with monosynaptic excitatory postsynaptic potentials (EPSPs) to microstimulation in the somatosensory cortex were identified by intracellular recordings. Long‐term potentiation (LTP) was evoked in all of these neurons (n = 15), following tetanic stimulation (50 Hz, 5 s) of their afferents from the somatosensory cortex. Three of these cells (cells A‐C) were identified as pyramidal neurons, following intracellular injections of Neurobiotin. The intracortical axon collaterals of these labeled cells arborized extensively, forming terminal clusters both in clse proximity to the parent soma and along their long, horizontal branches. Terminal clusters in both the proximal and in the distal termination zones of each of the cells were studied by electron microscopy. In their proximal arborization zones, the axon collaterals of the labeled pyramidal neurons synapsed preferentially with dendritic spines belonging to other pyramidal cells. In contrast, in their distal terminal clusters, the axon collateals of each of the cells formed synapses in different proportions with different postsynaptic targets. The distal axon collaterals of cell A formed 86% of their synapses with pyramidal neurons; those of cell B formed 64% of their synapses with pyramidal cells, the remaining synapses with the dendritic shafts and somata of nonpyramidal neurons, and those of cell C provided most of their output (68%) to nonpyramidal, presumably inhibitory neurons. These findings suggest a high selectivity of intrinsic axon collaterals to form specific patterns of synapses. The patterns of synaptic interactions formed by these intrinsic axon collaterals may be a substrate for shaping and modulating representation maps in the motor cortex. © 1993 Wiley‐Liss, Inc.
Cholinergic innervation of olfactory glomeruli in the rat: An ultrastructural immunocytochemical study
Authors: Jeune Hélène Le , Jourdan François
Published: January 2005

The ultrastructural organization of cholinergic afferents to the rat olfactory bulb (OBI) was studied with the aid of choline acetyltransferase (ChAT) immunocytochemistry in electron microscopy. Particular attention has been paid to a subset of glomeruli characterized by a remarkably high density of cholinergic afferents. Numerous cholinergic terminals making symmetric or asymmetric synaptic contacts were observed in the periglomerular area. ChAT‐labelled terminals have a diameter ranging from 0.3 to 1.5 μm and contain numerous clear agranular vesicles. Axo‐somatic and axo‐dendritic contacts were both observed in contact with several types of target neurons. Three types of cholinoceptive, noncholinergic neurons could be identified: periglomerular cells, superficial short‐axon cells, and external tufted cells. Our results provide an anatomical substrate for the hypotheses concerning the complex effects of acetylcholine in the processing of sensory information in the olfactory bulb. © 1993 Wiley‐Liss, Inc.
Immunolocalization of different forms of neural cell adhesion molecule (NCAM) in rat taste buds
Authors: Nelson Gina M. , Finger Thomas E.
Published: January 2005

Taste buds consist of approximately 100 taste cells, including three morphological types of short receptor cells which synapse on the peripheral gustatory nerves. Some of the receptor cells produce neural cell adhesion molecule (NCAM), which may play a role in formation of specific connections in this system. Antibodies directed against different forms of NCAM were utilized in an attempt to define not only the distribution, but also the type of NCAM within taste buds.

Within each taste bud approximately 10% of the taste cells exhibit abundant immunoreactivity for 180 kD (ld) or 140 kD (sd) forms of NCAM (i.e., those with an intracellular domain) along virtually the entire surface of the cell. Ultrastructural analysis reveals that these abundantly immunoreactive taste cells are of the intermediate morphological type, although not all of the intermediate taste cells within any bud are immunoreactive. In addition, the ultrastructural studies show that punctate (ld/sd) NCAM‐immunoreactivity occurs on the membranes of taste cells and nerve fibers throughout each taste bud. The embryonic form of NCAM (E‐NCAM), rich in polysialic acid residues, is present only in association with nerve fibers and other unidentified elongate, thin profiles of a few taste buds.

The nerve plexus beneath the gustatory epithelium is also rich in NCAM‐immunoreactivity. These fibers occasionally reveal immunoreactivity indicative of only the 120 kD (ssd) form of NCAM, typical of glial cells. © 1993 Wiley‐Liss, Inc.
Presence and biological activity of a GnRH‐like factor in the nervous system of Helisoma trivoluis
Authors: Goldberg Jeffrey I. , Garofalo Rafe , Price Christopher J. , Chang John P.
Published: January 2005

Gonadotropin‐releasing hormone (GnRH) constitutes a family of neuropeptides found throughout the vertebrates. Although a GnRH‐like peptide has also been isolated from yeast (α‐mating factor), the presence of GnRH has not been clearly demonstrated in inverterate phyla. In this study, we tested the hypothesis that GnRH‐like peptides are present and functional in the central nervous system (CNS) of the gastropod mollusc, Helisoma trivoluis. The presence of a GnRH‐like peptide was examined by three methods: (1) in immunofluorescence studies with four different antibodies generated against several GnRH peptides, select neurons and putative neurosecretory cells were specifically and consistently labelled throughout the CNS; (2) reverse‐phase high performance liquid chromatography (HPLC) and radioimmunoassay (RIA) analysis revealed a GnRH‐like factor which co‐migrates with mammalian (m)GnRH; and (3) in bioactivity experiments, extracts of Helisoma trivolvis CNS mimicked GnRH in stimulating gonadotropin release from dispersed goldfish pituitary cells in static culture.

Two functional assays were carried out to examine the potential biological roles of GnRH‐like peptides in Helisoma. (1) Intracellular recordings of left‐parietal and visceral ganglion neurons revealed diverse electrophysiological responses to mGnRH. These effects were attenuated by a mGnRH antagonist. (2) Addition of mGnRH arrested neurite outgrowth in a subpopulation of dissociated embryonic Helisoma neurons in culture. Taken together, these results strongly suggest that a mGnRH‐like peptide is an important neuropeptide in Helisoma. A hypothesis is presented that GnRH‐like peptides may be ancient factors that are conserved both structurally and functionally in the evolution of animals. © 1993 Wiley‐Liss, Inc.
Pigment‐dispersing hormone‐immunoreactive neurons in the nervous system of wild‐type Drosophila melanogaster and of several mutants with altered circadian rhythmicity
Authors: Helfrich‐Förster Charlotte , Homberg Uwe
Published: January 2005

Antisera against the crustacean pigment‐dispersing hormone (β‐PDH) were used in immunocytochemical preparations to investigate the anatomy of PDH‐immunoreactive neurons in the nervous system of wild‐type Drosophila melanogaster and in that of several brain mutants of this species, some of which express altered circadian rhythmicity. In the wild‐type and in all rhythmic mutants (small optic lobes, sine oculis, small optic lobes;sine oculis), eight cell bodies at the anterior base of the medulla (PDFMe neurons) exhibit intense PDH‐like immunoreactivity. Four of the eight somata are large and four are smaller. The four large PDFMe neurons have wide tangential arborizations in the medulla and send axons via the posterior optic tract to the contralateral medulla. Fibers from the four small PDFMe neurons ramify in the median protocerebrum dorsal to the calyces of the mushroom bodies. Their terminals are adjacent to other PDH‐immunoreactive somata (PDFCa neurons) which send axons via the median bundle into the tritocerebrum. The results suggest a possible involvement of the PDFMe neurons in the circadian pacemaking system of Drosophila. The location and size of the PDFMe neurons are identical with those of neurons containing the period protein which is essential for circadian rhythmicity. Changes in the arborizations of the PDFMe neurons in small optic lobes; sine oculis mutants are suited to explain the splitting in the locomotor rhythm of these flies. In the arrhythmic mutant, disconnected, the PDFMe neurons are absent. The arrhythmic mutant per°, however, shows normal PDH immunoreactivity and therefore, does not prevent the expression of PDH‐like peptides in these neurons.© 1993 Wiley‐Liss, Inc.