bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical and biochemical evidence for the putative inhibitory neurotransmitters histamine and GABA in lobster olfactory lobes
Authors: Orona Edward , Battelle Barbara‐Anne , Ache Barry W. 
Published: January 2005

AbstractAs an initial effort to investigate possible inhibitory interactions in the olfactory system of the spiny lobster, studies were conducted to identify and localize the putative inhibitory neurotransmitters histamine and GABA in the olfactory lobe. Biochemical studies demonstrated that olfactory lobe tissue was capable of synthesizing histamine from radioactive histidine and GABA from glutamic acid. Immunohistochemistry was used to localize histamine and GABA in brain sections, by using either avidin‐biotin conjugated peroxidase or fluorescein conjugated secondary antibody. Specific histamine‐like and GABA‐like immunoreactivity was found in soma clusters of olfactory interneurons, adjacent to the olfactory lobe. Small, putative glial cells displaying intense histamine‐like immunoreactivity were found interspersed among the glomeruli of the lobe. The accessory lobe exhibited moderate immunostaining for both histamine and GABA. Positive immunostaining for histamine and GABA was also found in the olfactory lobes, with a predominance of staining in the outer caps of the glomeruli, which are thought to be the regions where the primary afferent terminals contact the processes of second‐order olfactory neurons. These findings collectively implicate inhibition at the first synaptic level of the olfactory pathway in the spiny lobster.
Intrastriatal grafts derived from fetal striatal primordia: II. Reconstitution of cholinergic and dopaminergic systems
Authors: Liu Fu‐Chin , Graybiel Ann M. , Dunnett Stephen B. , Baughman Robert W. 
Published: January 2005

AbstractReconstitution of striatal cholinergic and dopaminergic systems was studied in intrastriatal grafts derived from embryonic day 15 rat striatal primordia and implanted into adult host rats in which unilateral ibotenic acid lesions had previously been made in the striatum. Histochemical, immunohistochemical, and ligand binding autoradiographic techniques were applied to analyze different constituents of these two systems and to study their locations relative to each other in grafts allowed to grow for 9–17 months following transplantation.For the cholinergic system, a modular organization was found in the striatal grafts with stains for choline acetyltransferase and acetylcholinesterase, respectively the synthetic and degradative enzymes for cholinergic neurons; by autoradiographic [3H] hemicholinium binding, specific for high affinity choline uptake sites associated with cholinergic terminals; and by autoradiographic [3H] pirenzepine binding, selective for M1 receptors. For the dopaminergic system, a comparable modular organization was found in the grafts by immunostaining for tyrosine hydroxylase, the catecholamine synthetic enzyme; by autoradiographic [3H] mazindol binding for dopamine uptake sites; and by [3H] SCH23390 binding for dopamine D1 receptors and [3H] sulpiride binding for dopamine D2 receptors. The results indicate that the distributions of the cholinergic and dopaminergic markers in striatal grafts are in close anatomical register.These markers for intracellular and membrane‐associated components of the cholinergic and dopaminergic systems were preferentially localized in the acetylcholesterase‐rich patches of the grafts in which cortical and thalamic fibers have also been found in striatal grafts, and in which output neurons projecting to the pallidum are located. This anatomical correlation suggests that the substrates for cholinergic‐dopaminergic interactions typical of the normal striatum may be reinstated in the grafts both in relation to efferent neurons establishing connections with the host brain that are typical of normal striatofugal connections, and in relation to major afferent fiber systems from the host brain originating in regions known to project densely to the normal striatum. Accordingly, the cholinergic and dopaminergic systems in such grafts may regulate the functional influence of the grafts on the behavior of host animals.
GABAergic neural elements in the rat basilar pons: Electron microscopic immunochemistry
Authors: Border B. G. , Mihailoff G. A. 
Published: January 2005

AbstractPrevious light microscopic immunoperoxidase studies of glutamic acid decarboxylase (GAD)‐immunoreactive neural elements in the rat basilar pontine nuclei revealed immunocytochemical reaction product in neuronal somata and axon terminals. In the present study, pre‐embedding immunoperoxidase labeling of GAD or gamma‐aminobutyric acid (GABA) and postembedding immunogold labeling of GABA allowed the ultrastructural visualization of these neural elements in the basilar pontine nuclei of colchicine‐treated animals. At the electron microscopic level, immunolabeled neuronal somata exhibited smoothly contoured nuclei, whereas some dendrites also contained reaction product after immunocytochemical treatment and were postsynaptic to both immunoreactive and nonimmunoreactive axon terminals. Synaptic boutons immunoreactive for GAD or GABA exhibited cross‐sectional areas that ranged from 0.1 to 3.8 μm2 and generally appeared round or elongated in most sections.The majority (95%) of immunolabeled boutons contained pleomorphic synaptic vesicles and formed symmetric synapses at their postsynaptic loci; however, boutons exhibiting round vesicles and boutons forming asymmetric synapses (5%) were also immunopositive. Small (<1.5 μm2) GAD‐ or GABA‐labeled axon terminals formed synaptic contact mainly with small dendritic profiles, dendritic spines, and neuronal somata, whereas large labeled boutons (>1.5 μm2) formed synapses with all sizes of dendritic profiles. Occasionally, a single immunolabeled bouton formed synaptic contact with two separate postsynaptic dendrites.It is suggested that the immunolabeled neuronal somata and dendrites observed in the rat basilar pontine nuclei represent a population of pontine local circuit neurons; however, it is known that GABAergic cell groups extrinsic to the pontine gray provide afferent projections to the basilar pons, and therefore at least some immunoreactive axon terminals present in the pontine nuclei are derived from these extrinsic sources. The ultrastructural observation of GABAergic neural elements in the rat basilar pontine nuclei confirms previous light microscopic findings and provides an anatomical substrate through which GABAergic neurons, whether arising from an intrinsic or extrinsic source, might exert an inhibitory influence on target cells within the pontine nuclei.
Morphology and physiology of cells in slice preparations of the posteroventral cochlear nucleus of mice
Authors: Oertel Donata , Wu Shu Hui , Garb Micah W. , Dizack Carol 
Published: January 2005

AbstractIn an effort to understand what integrative tasks are performed in the cochlear nuclei, the present study was undertaken to describe neuronal circuits in the posteroventral cochlear nucleus (PVCN) anatomically and physiologically. The cochlear nuclear complex receives auditory information from the cochlea through the auditory nerve. Within the cochlear nuclei, signals travel along several parallel and interconnected pathways. From the cochlear nuclei, transformed versions of the signals are passed to higher auditory centers in the brainstem. We have recorded electrophysiological responses from cells that were subsequently visualized with horseradish peroxidase (HRP). Responses to shocks to the auditory nerve root and to intracellularly injected current pulses were recorded and correlated with morphology. Two types of stellate cells and octopus cells were distinguished. T stellate cells project out of the cochlear nuclei through the T rapezoid body; D stellate cells do not. The axons of D stellate cells extend D orsalward to the dorsal cochlear nucleus (DCN) but have not been traced out of the nucleus. Both T and D stellate cells have terminal collaterals in the multipolar cell region of the PVCN and in the DCN. The endings of one T stellate cell formed a narrow band rostrocaudally in the fusiform cell layer of the DCN that resembled an isofrequency band. The endings of one D stellate cell lay closely apposed to multipolar cells in the deep layer of the DCN. The dendrites of T stellate cells are often aligned along the path of auditory nerve fibers and end in tufts, whereas those of D stellate cells extend radially in the plane of the lateral surface of the PVCN toward granule cell areas and branch sparingly. Octopus cells have dendrites oriented perpendicularly to the path of auditory nerve fibers. Their axons were cut medially in the slices; none had collateral branches.Both T and D stellate cells were monosynaptically excited to threshold by shocks to the nerve root, indicating that they could participate in local circuits that we measure physiologically. T stellate cells have action potentials that peak at about O m V and are followed by single undershoots. The D stellate cell that was best impaled fired overshooting action potentials that were followed by double undershoots. Octopus cells were monosynaptically excited to threshold by shocks to the auditory nerve.
Fate of grafted embryonic purkinje cells in the cerebellum of the adult “purkinje cell degeneration” mutant mouse. II. Development of synaptic responses: An in vitro study
Authors: Gardette R. , Crepel F. , Alvarado‐Mallart R. M. , Sotelo C. 
Published: January 2005

AbstractSolid pieces of cerebellar primordia from 12‐day‐old C57Bl embryos were implanted in the cerebellar vermis of 3–4‐month‐old “Purkinje cell degeneration” mutant mice. Ten to 22 days after grafting, mutant mice were sacrificed, and synaptic responses of grafted Purkinje cells were studied by intracellular recordings performed in 400 μm thick sagittal slices in vitro.As early as 10 days after transplantation, grafted Purkinje cells have already completed their migration from the implant into the host molecular layer. Accordingly, inhibitory as well as excitatory responses were already elicited in these cells by electrical stimulation of the host subcortical white matter. Furthermore, a transient stage of multiple innervation of Purkinje cells by climbing fibers exists between 10 and 15 days after grafting, as revealed by the stepwise variation in amplitude of the climbing fiber‐mediated excitatory postsynaptic potentials recorded before 15 days after grafting. Thirteen days after transplantation, typical all‐or‐none climbing fiber‐mediated responses, parallel fiber‐mediated excitatory postsynaptic potentials, and inhibitory postsynaptic potentials were also already present. Finally, normal adult‐type synaptic responses were observed in all tested cells 15 to 17 days after grafting.Together with the companion paper (Sotelo et al., 1990), these results demonstrate that grafted Purkinje cells are able to impose on host afferents a pattern of synaptogenesis which closely follows that occuring during normal development, in particular, the transient stage of multiple innervation of Purkinje cells by climbing fibers.
Organization of the auditory pathway in the thoracic ganglia of noctuid moths
Authors: Boyan George , Williams Lez , Fullard James 
Published: January 2005

AbstractWe describe the neuroarchitecture of the noctuid thoracic nerve cord and use this framework to interpret the organization of the auditory pathway responsible for escape behaviour in noctuid moths.Noctuid moths possess only two auditory receptors (A1, A2), in each ear. The axon of the A1 cell projects initially to a glomerulus located ventrally and medially in the metathoracic ganglion, where it bifurcates. One branch ascends in the ventral intermediate tract to the brain, the other descends in the ventral intermediate tract into abdominal neuromeres of the metathoracic ganglion. Both axons arborize in the median ventral and ring tracts in each neuromere. The central projections of the A2 cell remain largely within the metathoracic ganglion. The axon bifurcates at the midline and directs arborizations dorsally to the dorsal intermediate and median dorsal tracts, and ventrally into the ring tract where the arborizations overlap those of the A1 afferent. The afferent projections remain ipsilateral to the ear of origin.We describe a posterior auditory association area in the metathoracic ganglion in which the major arborizations of several identified interneurones overlap those of the A1 afferent and make monosynaptic connections with it. These interneurones all respond tonically to sound stimuli. We have also identified the projections of the A1 afferent, interneurones, and motor neurones in the segmentally equivalent anterior auditory association area of the mesothoracic ganglion. An interneurone with major arborizations in the same tracts as the A1 afferent, and receiving monosynaptic input from it, is described. The arborizations of higher order interneurones lie mainly in dorsal tracts along with those of flight motor neurones. All interneurones in this anterior centre respond phasically or phasic/tonically to sound stimuli.The relevance of this anatomical organization for predator avoidance behaviour is considered and the organization of auditory pathways in tympanate insects compared.
Organization of the primary projections of the lateral line nerves in the lamprey lampetra japonica
Authors: Koyama Hiromichi , Kishida Reiji , Goris Richard C. , Kusunoki Toyokazu 
Published: January 2005

AbstractThe lateral line sensory system of Lampetra japonica is innervated by the anterior and posterior lateral line nerves. The anterior lateral line nerve innervates all electroreceptors throughout the body and mechanoreceptors of the head. The posterior lateral line nerve innervates trunk mechanoreceptors. The anterior lateral line nerve consists of two ganglia (anterior lateral line and intracapsular) and four major peripheral branches (superficial ophthalmic, buccal, hyomandibular, and recurrent nerves). The posterior lateral line nerve has one posterior lateral line ganglion and one peripheral branch. The location and central projection patterns of the primary sensory neurons of these branches of the lateral line nerves were studied with the aid of horseradish peroxidase labeling.The ganglion cells of the buccal nerve were found in the rostral half, and those of the hyomandibular nerve were found in the caudal half of the medial part of the anterior lateral line ganglion. The lateral part of the anterior lateral line ganglion contains ganglion cells of the recurrent nerve and the superficial ophthalmic nerve. The rostral half of the intracapsular ganglion contains ganglion cells of the recurrent, hyomandibular, and buccal nerves. The ganglion cells of the posterior lateral line nerve were found in the posterior lateral line ganglion. The buccal nerve afferents terminated mainly in the lateral part of the ipsilateral mechanoreceptive medial nucleus. The peripheral part of the electroreceptive dorsal nucleus also received several afferents. The hyomandibular afferents terminated ipsilaterally in the central part of the medial nucleus and in the dorsolateral part of the dorsal nucleus. Some afferents of the hyomandibular nerve ascended and descended in the descending nucleus of the trigeminal nerve near its dorsal margin. The ventral nucleus, the primary nucleus of the VIIIth nerve, received a few fibers of the buccal and hyomandibular nerves. In the recurrent nerve, the fibers of the lateral part of the anterior lateral line ganglion terminated throughout the entire dorsal nucleus, and the fibers of the intracapsular ganglion projected to the dorsolateral part of the nucleus. The afferents of the posterior lateral line nerve terminated in the medial part of the ipsilateral medial nucleus and in the lateral part of the contralateral medial nucleus. In the cerebellar area, afferents of the anterior lateral line nerve were located laterally to those of the posterior lateral line nerve. Several fibers terminated in some branchiomotor nuclei, the cerebellar crest, and the dorsal gray near the obex level. No efferent cell bodies were found in the place where efferent neurons of the VIIIth nerve have been previously reported.
Anatomical investigation of projections from thalamus to posterior parietal cortex in the rhesus monkey: A WGA‐HRP and fluorescent tracer study
Authors: Schmahmann Jeremy D. , Pandya Deepak N. 
Published: January 2005

AbstractThe parietothalamic projections have been shown to be heterogeneous and appear to be a reflection of the detailed architectonic parcellation of the parietal lobe. In the present study WGA‐HRP injections were placed in the different subdivisions of the posterior parietal cortex of the rhesus monkey to determine whether a similarly complex pattern also exists in the thalamocortical pathway. Additionally, in an attempt to determine whether there is an intranuclear specificity of projections from individual thalamic nuclei to different subdivisions of the parietal lobe, multiple retrograde fluorescent tracers were injected into the rostral to caudal sectors of the parietal lobe of the same animal. Different subdivisions of the parietal lobe appear to receive different sets of thalamic input. Thus the superior parietal lobule (SPL) projections are derived from more lateral regions in the thalamus, arising predominantly from the lateral posterior (LP) and pulvinar oralis (PO) nuclei, with additional contributions from the pulvinar lateralis (PL) and pulvinar medialis (PM) nuclei. The inferior parietal lobule (IPL), by contrast, receives its projections from more medial thalamic regions, its main thalamic input originating from PM, and aided by LP, PL, and PO. Both the SPL and IPL also receive projections from the mediodorsal (MD), ventroposterior, ventrolateral, intralaminar, and limbic nuclei, albeit from different components within these nuclei.A topographical arrangement also exists in the thalamic projections to the rostral versus the caudal subdivisions of both the SPL and the IPL. Thus, in the SPL, the ventral posterolateral nucleus, pars oralis (VPLo), ventral lateral nucleus, pars oralis (VLo), and ventral lateral nucleus, pars medialis (VLm) project to rostral, whereas the PM and limbic nuclei, anteroventral (AV), and anteromedial (AM), project to area PGm on the medial convexity of the SPL. With respect to projections to the IPL, the ventral posteromedial (VPM) and PO nuclei project to rostral regions, whereas the limbic nuclei lateral dorsal (LD), AM and AV project only to the caudalmost area, Opt. A rostrocaudal difference is reflected also within certain nuclei (LP, PO, and PM) that project to the SPL or IPL. Thus rostral parietal subdivisions receive projections from ventral regions within these thalamic nuclei, whereas caudal parietal afferents arise from the dorsal parts of these nuclei. Intervening cortical levels receive projections from intermediate positions within the nuclei.It therefore seems that the increasing architectonic and functional complexity as one moves from rostral to caudal in the SPL and IPL appear to be reflected in the thalamic afferents. More rostral areas relate to modality‐specific thalamic nuclei, whereas more caudal regions concerned with complex functions derive their input from multimodal and limbic nuclei.
Fibre organization of the monkey's optic tract: I. Segregation of functionally distinct optic axons
Authors: Reese B. E. , Cowey A. 
Published: January 2005

AbstractThe fibre organization of the monkey's optic tract was examined by implanting pellets of horseradish peroxidase into different locations within the tract, or into the superior colliculus and pretectum. Retinae were examined for the distribution, size, and morphological types of retrogradely labelled ganglion cells; optic tracts were examined for the distribution of anterogradely and retrogradely labelled axonal profiles; and lateral geniculate nuclei were examined for the distribution of anterogradely labelled processes within distinct geniculate laminae.Localized implants in the optic tract produced retrograde labelling of ganglion cells across wide regions of the retinal surface. The maximum density of labelled cells was always substantially less than the total ganglion cell density known to be present at those retinal loci. Distinct retinal ganglion cell types were labelled from differing regions within the optic tract: implants into the deep (dorsal) portion of the tract, far removed from the outer, pial, surface, retrogradely labelled predominantly Pβ retinal ganglion cells, whereas implants into the superficial (ventral), subpial, part of the tract retrogradely labelled primarily the other retinal ganglion cell types, i.e., the Pα, Pγ, and Pϵ cells. Within any given class of axon, there is a mapping of the centroperipheral retinal axis across the deep‐to‐superficial dimension of the tract, but this retinotopy is extremely coarse. Anterograde labelling of axonal terminations within the lateral geniculate nucleus showed a corresponding specificity for distinct geniculate laminae, the deep implants labelling the parvocellular laminae, superficial implants labelling the magnocellular laminae. Implants into the visual centres of the midbrain produced retrograde axonal labelling rostral to the lateral geniculate nucleus only in the superficial part of the optic tract.These results demonstrate that the monkey's optic tract is not a simple topographic mapping of retinal eccenticity. Rather, the primary organizational principle is that of a segregation of functionally distinct optic axon classes. As fibre order in the mammalian optic tract is also a chronological index of axonal arrival during development, the present results provide specific predictions about the temporal order of ganglion call genesis and axonal addition within the visual pathway. They also provide an anatomical basis for the functionally selective visual impairments that may arise following local damage to the optic tract in humans.
Choline acetyltransferase‐like immunoreactivity in the superior colliculus of the cat and its relation to the pattern of acetylcholinesterase staining
Authors: Illing R.‐B. 
Published: January 2005

AbstractCholine acetyltransferase, the biosynthetic enzyme for acetylcholine, is thought to be a marker for cholinergic neurons. This report presents an analysis of the pattern of choline acetyltransferase‐like immunoreactivity in the superior colliculus of the cat, A dense network of highly varicose immunoreactive fibers pervaded the superficial gray and optical layer. The density of the fiber network in the superficial layers was heterogeneous, forming a mosaic pattern with a period of about 400 μm. The antigen was also located in numerous small perikarya embedded in this network. This neuronal population reached a density of 2,000 cells/mm3 of the superficial gray layer and suggested the presence of a substantial cholinergic system originating in the superior colliculus. A detailed comparison was made between the pattern of choline acetyltransferase‐like immunoreactivity and the distribution of acetylcholinesterase activity. By comparisons of adjacent sections, both staining patterns were found to be similar in all collicular layers. In particular, the compartmental distribution of immunoreactivity in the intermediate collicular layers seemed to mimic the pattern of acetylcholinesterase staining. A double‐staining technique demonstrated a near‐perfect correlation between the two patterns. In conclusion, there was no indication of heightened acetylcholinesterase activity without an associated elevation in choline acetyltransferase‐like immunoreactivity throughout the superior colliculus. In this part of the brain, the presence of the putative cholinergic terminals could fully account for the distribution of acetylcholinesterase activity.