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Biomedical subjects

N Mizuno

Publications and source records attributed to N Mizuno.

At least 127 records · Page 7Linked to original sources
PubMed1996

Pre- and postsynaptic localization of a metabotropic glutamate receptor, mGluR2, in the rat brain: an immunohistochemical study with a monoclonal antibody.

A monoclonal antibody against a metabotropic glutamate receptor, mGluR2, was produced by using a glutathione S-transferase (GST) fusion protein containing an N-terminal sequence of rat mGluR2. Intense mGluR2-like immunoreactivity (mGluR2-LI) was seen mainly in neuropil of the cerebral cortical regions, hippocampus, olfactory bulb, some diencephalic nuclei, dorsal cochlear nucleus and cerebellar cortex. In the cerebellar cortex, mGluR2-LI was seen only in Golgi cells. In Ammon's horn, mGluR2-LI was marked in the stratum lucidum of CA3 and the stratum lacunosum-moleculare of CA1-CA3, but not detected in the stratum pyramidale. The results indicate that mGluR2 is located not only presynaptically but also postsynaptically.

Animals↗
PubMed1996

Improved retrograde axonal transport and subsequent visualization of tetramethylrhodamine (TMR) -dextran amine by means of an acidic injection vehicle and antibodies against TMR.

We studied the ability of various dextran amines (DA) to retrogradely label cortical neurons to the full extent of their dendritic configurations. Corticothalamic neurons were labeled by pressure injection of DA into the ventrobasal thalamic nuclei of the rat brain. Of fluorescein-, Texas Red-, Cascade Blue- and tetramethylrhodamine (TMR)-DAs of MW 3000 and TMR-DA of MW 10,000, neurons were most efficiently labeled with TMR-DA of MW 3000. The use of acidic vehicles (pH 1-3) for dissolving TMR-DA enhanced the retrograde labeling, as compared with that of a neutral vehicle. The retrograde labeling with TMR-DA was more clearly demonstrated by using anti-TMR antibodies; the indirect immunofluorescence method with a rhodamine-conjugated secondary antibody and immunoperoxidase method with a peroxidase anti-peroxidase (PAP) complex revealed that the dendrites of many corticothalamic neurons were filled with TMR-DA. The Golgi-like retrograde labeling of TMR-DA visualized by the PAP immunoperoxidase method was comparable with that of biotinylated DA by the avidin-biotinylated peroxidase complex method. Similar Golgi-like dendritic staining was observed among corticospinal neurons after injection of TMR-DA into the corticospinal tract of the spinal cord. Most apical dendrites of corticospinal neurons extended into layer I, whereas those of corticothalamic neurons ended in layer IV or the deep part of layer III. The TMR-DA injection under acidic conditions and immunostaining with the anti-TMR antibodies are considered to be a useful method to visualize the dendrite configuration of cortical projection neurons.

Animals↗
PubMed1996

The sites of origin and termination of afferent and efferent components in the lingual and pharyngeal branches of the glossopharyngeal nerve in the Japanese monkey (Macaca fuscata).

Afferent and efferent components in the lingual and pharyngeal branches of the glossopharyngeal nerve (Li and Ph) of the Japanese monkey (Macaca fuscata) were examined. After injecting wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) unilaterally into the central cut end of the Li and Ph, or into the stylopharyngeal muscle, labeled neuronal cell bodies and terminal labeling were observed in the medulla oblongata, peripheral ganglia of the glossopharyngeal and vagus nerves, and cervical ganglia of the sympathetic trunk. The following conclusions were deduced from the results. The Li contains efferent fibers from the inferior salivatory nucleus, and superior cervical ganglion. The afferent fibers in the Li are composed mainly of peripheral processes of ganglion neurons in the superior and petrous ganglia of the glossopharyngeal nerve, and additionally of those of ganglion neurons in the jugular ganglion of the vagus nerve. The afferent fibers in the Li terminate mainly in the lateral division of the nucleus of the solitary tract, and additionally in the dorsal aspect of the lateral marginal region of the interpolar spinal trigeminal nucleus. The Ph is mainly composed of efferent fibers from the ambiguous nucleus and superior cervical ganglion; only a small number of afferent fibers from the sensory ganglia of the glossopharyngeal and vagus nerves are contained in the Ph. Stylopharyngeal motoneurons are distributed in the retrofacial part of the ambiguous nucleus.

Afferent Pathways↗
PubMed1996

Localization of mu-opioid receptor-like immunoreactivity in the central components of the vagus nerve: a light and electron microscope study in the rat.

mu-Opioid receptor, the opioid receptor that shows the highest affinity for morphine, appears to induce a variety of side-effects, at least partly, directly through the mu-opioid receptor on neurons constituting the autonomic part of the vagus nerve. Thus, in the present study, location of mu-opioid receptor-like immunoreactivity in the central components of the autonomic part of the vagus nerve was examined in the rat. The intense immunoreactivity was observed light microscopically in the neuropil of the commissural subnucleus and the dorsal part of the medial subnucleus of the nucleus of the solitary tract, and in the neuropil of the rostral half of the ambiguus nucleus. The immunoreactivity was moderate in the neuropil of the rostral and lateral subnuclei and ventral part of the medial subnucleus of the nucleus of the solitary tract, and weak in the neuropil of the dorsal motor nucleus of the vagus nerve. In the nodose ganglion, many neurons of various sizes (17-48 microns in soma diameter) showed moderate immunoreactivity. After unilateral vagotomy at a level proximal to the nodose ganglion, the immunoreactivity in the ipsilateral ambiguus nucleus was apparently reduced within 48 h of the operation, and completely disappeared by the seventh day after the operation. In the nucleus of the solitary tract and dorsal motor nucleus of the vagus nerve, the reduction of immunoreactivity after the ganglionectomy was detectable on the fourth day after the operation, and became readily apparent by the seventh day after the operation; the immunoreactivity, none the less, still remained on the 10th day after the operation. Electron microscopically, the immunoreactivity in the ambiguus nucleus was seen mainly on dendritic profiles and additionally on somatic ones; no immunoreactivity was detected in axonal profiles. The immunoreactivity in the dorsal motor nucleus of the vagus nerve was observed only on dendritic profiles. The immunoreactivity in the nucleus of the solitary tract was seen on axonal and dendritic profiles, but not on somatic profiles. The immunoreactive axon terminals in the nucleus of the solitary tract were filled with spherical synaptic vesicles and made asymmetric synapses with dendritic profiles. The results indicate that the mu-opioid receptor in the central components of the autonomic part of the vagus nerve is located on dendrites and cell bodies of efferent neurons in the ambiguus, on dendrites of efferent neurons in the dorsal motor nucleus, and on axons which arise from nodose ganglion neurons and terminate in the nucleus of the solitary tract. The receptors on these structures may constitute the targets of enkephalin-containing and beta-endorphin-containing afferent axons arising from brainstem neurons. The receptors on the axon terminals of nodose ganglion neurons may be involved in regulation of the release of neurotransmitters and/or neuromodulators.

Animals↗
PubMed1996

Metabotropic glutamate receptors mGluR2 and mGluR5 are expressed in two non-overlapping populations of Golgi cells in the rat cerebellum.

The metabotropic glutamate receptor subtypes mGluR2 and mGluR5, which are thought to be coupled respectively to the inhibitory cyclic adenosine monophosphate (cAMP) cascade and the phosphatidylinositol hydrolysis/Ca2+ cascade, are known to be expressed on Golgi cells in the granular layer of the rat cerebellar cortex. In the present immunohistochemical study with a monoclonal antibody against mGluR2 and a polyclonal antibody for mGluR5, we examined whether or not mGluR2- and mGluR5-like immunoreactivities were both present in single Golgi cells in the rat cerebellar cortex. In double immunofluorescence histochemistry, no Golgi cells showed mGluR2- and mGluR5-like immunoreactivities simultaneously. Of the total number of Golgi cells immunoreactive for mGluR2 or mGluR5, about 90% were mGluR2-like immunoreactive, and about 10% were mGluR5-like immunoreactive. Golgi cells with mGluR2-like immunoreactivity were distributed evenly in the granular layer of all the cerebellar regions, while those with mGluR5-like immunoreactivity were distributed more frequently in the I, II, VII-X lobules of the vermis and the copula pyramidis of the hemisphere than in other cerebellar regions. The results indicate that Golgi cells containing mGluR2 are segregated from those possessing mGluR5. These two populations of Golgi cells, each equipped with a different metabolic glutamate receptor coupled to a different intracellular signal transduction system, may play different roles in the glutamatergic neuronal circuits in the cerebellar cortex.

Animals↗
PubMed1996

Application of the minimum jerk model to formation of the trajectory of the centre of mass during multijoint limb movements.

Smoothness of movement is an inherent characteristic of the motor repertoire of primates. According to the minimum hand jerk model, a major feature of motor coordination in two-joint upper limb movements by humans in the horizontal plane is the production of the smoothest possible movement of the end effector, the hand ('hand version'). In the present study, this model was extended to the formation of the trajectory of the centre of mass (CMt) of the whole arm system ('CMt version'), and its importance for the shaping of multijoint movements was tested against the classical 'hand version'. During point-to-point movements between many pairs of targets in the work space, the movements of the CMt showed lower changes of torque than in movements of the hand on a straight path. Furthermore, the CMt version of the minimum jerk model reproduced the curved hand trajectory that can be observed in actual human performance. Under the assumption that the smoothness criterion is induced by a high-level motor coordination, our results suggest that CMt-based planning can be an alternative strategy for joint coordination. It offers the advantage of the simplified scaling of joint torques which are suitable for execution of planned movements.

Computer Simulation↗
PubMed1996

Effect of polyol fatty acid esters on diclofenac permeation through rat skin.

The effects of a series of polyol fatty acid esters (sefsols) on diclofenac permeation through rat skin were investigated using in vitro and in vivo methods. Four monoesters and one diester of sefsol were selected as a vehicle components. The effects of each sefsol on in vitro diclofenac permeation were compared at a concentration of 5% sefsol in water. Monoesters of sefsol, except the glyceryl monoester, enhanced the percutaneous permeation of diclofenac. The highest enhancement was observed in propylene glycol monocaprylate. The plasma concentration of diclofenac was increased dramatically by the addition of 10% propylene glycol monocaprylate when applying the diclofenac sodium suspension to abdominal rat skin in vivo. These results suggest that the monoesters of polyol fatty acid are potential candidates to enhance the transdermal absorption of diclofenac sodium.

Administration, Cutaneous↗
PubMed1996

Isolation of a novel chick homolog of Serrate and its coexpression with C-Notch-1 in chick development.

Intercellular signaling mediated by the transmembrane proteins, Notch as receptor and its ligands, Delta and Serrate, plays essential roles in the developmental fate decision of many cell types in Drosophila. The Notch genes are highly conserved both in invertebrates and in vertebrates, suggesting that Notch pathway regulates cell fate decisions during vertebrates development. Notch, Delta and Serrate homologs in chicken have been cloned (Henrique et al., Nature 375: 787-790, 1995; Myat et al., Dev. Biol. 174: 233-247, 1996). We isolated a novel chick homolog of Drosophila Serrate, named C-Serrate-2, and examined its expression patterns during the early chick development using whole-mount in situ hybridization. C-Serrate-2 transcripts were detected in several tissues including the forebrain, the myotome and the apical ectodermal ridge (AER) of the limb bud of a 4-day-old chick embryo. In most of the regions where C-Serrate-2 was expressed, C-Notch-1 was also expressed. Our observations suggest that Serrate-2-Notch-1 signaling plays a role in a variety of morphogeneses during the chick development.

Amino Acid Sequence↗
PubMed1995

Presynaptic localization of a metabotropic glutamate receptor, mGluR7, in the primary afferent neurons: an immunohistochemical study in the rat.

An antibody which recognizes specifically a metabotropic glutamate receptor, mGluR7, was produced by using a trpE fusion protein containing a C-terminal sequence of rat mGluR7. Neuropil in laminae I and II of the dorsal horn of the rat, as well as many neuronal cell bodies in the dorsal root ganglion, showed mGluR7-like immunoreactivity; the immunoreactivity in neuropil was seen in axon terminals, which were filled with round synaptic vesicles and constituted axodendritic and axosomatic asymmetric synapses. The mGluR7-like immunoreactivity in laminae I and II in the dorsal horn was reduced after dorsal rhizotomy. The results indicate that some axon terminals of the primary afferent fibers to laminae I and II of the dorsal horn are provided with mGluR7.

Animals↗
PubMed1995

Presynaptic localization of mu-opioid receptor-like immunoreactivity in retinal axon terminals within the terminal nuclei of the accessory optic tract: a light and electron microscope study in the rat.

Neuropil within the terminal nuclei of the accessory optic tract of the rat showed intense to moderate mu-opioid receptor-like immunoreactivity (MOR-LI). After unilateral enucleation, MOR-LI within the terminal nuclei almost disappeared or was markedly reduced on the side contralateral to the operation. Electron microscopy revealed that MOR-LI axon terminals within the terminal nuclei were filled with round synaptic vesicles and in asymmetric synaptic contact mainly with dendritic profiles, and occasionally with somatic profiles.

Animals↗
PubMed1995

Distributions of the mRNAs for L-2-amino-4-phosphonobutyrate-sensitive metabotropic glutamate receptors, mGluR4 and mGluR7, in the rat brain.

The distribution of mRNAs for metabotropic glutamate receptors, mGluR4 and mGluR7, which are highly sensitive for L-2-amino-4-phosphonobutyrate (L-AP4), was examined in the central nervous system of the rat by in situ hybridization. In general, the hybridization signals of mGluR7 mRNA were more widely distributed than those of mGluR4 mRNA, and differential expression of mGluR4 mRNA and mGluR7 mRNA was clearly indicated in some brain regions. Intense or moderate expression of mGluR4 mRNA was detected in the granule cells of the olfactory bulb and cerebellum, whereas no significant expression of mGluR7 mRNA was found in these cells. In other neurons or regions where mGluR7 mRNA was intensely or moderately expressed, no significant expression of mGluR4 mRNA was observed. Such were the mitral and tufted cells of the olfactory bulb; anterior olfactory nucleus; neocortical regions; cingulate cortex; retrosplenial cortex; piriform cortex; perirhinal cortex; CA1; CA3; granule cells of the dentate gyrus; superficial layers of the subicular cortex; deep layers of the entorhinal, parasubicular, and presubicular cortices; ventral part of the lateral septal nucleus; septohippocampal nucleus; triangular septal nucleus; nuclei of the diagonal band; bed nucleus of the stria terminalis; ventral pallidum; claustrum; amygdaloid nuclei other than the intercalated nuclei; preoptic region; hypothalamic nuclei other than the medial mammillary nucleus; ventral lateral geniculate nucleus; locus coeruleus; Purkinje cells; many nuclei of the lower brainstem other than the superior colliculus, periaqueductal gray, interpeduncular nucleus, pontine nuclei, and dorsal cochlear nucleus; and dorsal horn of the spinal cord. Both mGluR4 mRNA and mGluR7 mRNA were moderately or intensely expressed in the olfactory tubercle, superficial layers of the entorhinal cortex, CA4, septofimbrial nucleus, intercalated nuclei of the amygdala, medial mammillary nucleus, many thalamic nuclei, and pontine nuclei. Intense expression of both mGluR4 mRNA and mGluR7 mRNA was further detected in the trigeminal ganglion and dorsal root ganglia, whereas no significant expression of them was found in the pterygopalatine ganglion and superior cervical ganglion. The results indicate differential roles of the L-AP4-sensitive metabotropic glutamate receptors in the glutamatergic nervous system.

Animals↗
PubMed1995

Expression of c-fos protein in substance P receptor-like immunoreactive neurons in response to noxious stimuli on the urinary bladder: an observation in the lumbosacral cord segments of the rat.

Chemical irritation of the urinary bladder with formalin in the rat induced c-fos protein-like immunoreactivity in more than 80% of substance P receptor-like immunoreactive (SPR-LI) neurons of the dorsal commissural nucleus, sacral parasympathetic nucleus and lamina I in the 6th lumbar and 1st sacral cord segments. These neurons with SPR-LI may receive noxious information from the urinary bladder through the primary afferent fibers with substance P.

Animals↗
PubMed1995

Co-localization of mu-opioid receptor-like and substance P-like immunoreactivities in axon terminals within the superficial layers of the medullary and spinal dorsal horns of the rat.

The presence of mu-opioid receptor-like immunoreactivity (MOR-LI) on axon terminals was confirmed by light and electron microscopy within the superficial layers of the medullary and spinal dorsal horns of the rat. By means of double-immunofluorescence histochemistry, co-localization of MOR-LI and substance P (SP)-LI was occasionally observed in axon terminals within the superficial layers of the dorsal horns.

Animals↗
PubMed1995

Direct projections from the dorsolateral pontine tegmentum to pudendal motoneurons innervating the external urethral sphincter muscle in the rat.

Direct projections from the dorsolateral pontine tegmentum to pudendal motoneurons innervating the external urethral sphincter and the external and sphincter muscles were examined in the rat by the tract-tracing methods utilizing retrograde transport of cholera toxin B subunit and anterograde transport of biotinylated dextran amine. The dorsolateral pontine tegmental region, corresponding to the micturition reflex center of Barrington, was confirmed to send bilaterally, with an ipsilateral dominance, projection fibers to the spinal parasympathetic nucleus (inferior intermediolateral nucleus). The micturition reflex center of Barrington, however, did not seem to send many projection fibers to the ventral horn of the lumbosacral cord segments, whereas the region immediately ventral to the micturition reflex center of Barrington was found to send bilaterally, with a contralateral dominance, projection fibers to the dorsolateral group of pudendal motoneurons in both the male and female rats. In the female rat, the dorsolateral group of pudendal motoneurons are comprised primarily of motoneurons that innervate the external urethral sphincter muscle. The dorsomedial group of pudendal motoneurons, which contain motoneurons that innervate the external and sphincter and the bulbocavernosus muscles, did not seem to receive major projections from the dorsolateral pontine tegmental regions. It was also observed that the locus coeruleus sent some projection fibers bilaterally to the spinal parasympathetic nucleus but only a few to the ventral horn of the lumbosacral cord segments. Thus, the present results indicate that the dorsolateral group of pudendal motoneurons containing those innervating the external urethral sphincter muscle receive pontospinal projection fibers mainly from the dorsolateral pontine tegmental region immediately ventral to the micturition reflex center of Barrington.

Anal Canal↗
PubMed1995

Premotor neurons for trigeminal motor nucleus neurons innervating the jaw-closing and jaw-opening muscles: differential distribution in the lower brainstem of the rat.

The distribution of premotor neurons for trigeminal motor nucleus neurons innervating the jaw-closing and jaw-opening muscles was examined in the lower brainstem of the rat by using retrograde and anterograde labeling techniques. First, Fluorogold, a fluorescent retrograde tracer, was injected into the dorsolateral or ventromedial division of the trigeminal motor nucleus, each of which contains motoneurons innervating the jaw-closing or jaw-opening muscles, respectively. Second, Phaseolus vulgaris-leucoagglutinin, an anterograde tracer, was injected into each of the lower brainstem sites, where clusters of retrogradely labeled premotor neurons had been seen in the first set of experiments. Third, after injection of the anterograde tracer into a lower brainstem site, followed by injection of the retrograde tracer cholera toxin B subunit into a masticatory muscle, termination of anterogradely labeled axons onto retrogradely labeled motoneurons was confirmed with the aid of a confocal laser-scanning microscope. It was found that the premotor neurons distributed in the mesencephalic trigeminal nucleus, medial part of the parabrachial region, supratrigeminal region, and dorsal parts of the principal sensory, oral spinal and interpolar spinal trigeminal nuclei project preferentially to the dorsolateral division of the trigeminal motor nucleus, whereas those in the lateral part of the parabrachial region, intermediate parts of the principal sensory, oral spinal and interpolar spinal trigeminal nuclei, and alpha part of the gigantocellular reticular nucleus project preferentially to the ventromedial division of the trigeminal motor nucleus. The dorsal and lateral parts of the medullary reticular formation and the medullary raphe nuclei contain premotor neurons of both types. Group k motoneurons, a cluster of trigeminal motoneurons that innervate the tensor tympani muscle, receive projection fibers predominantly from the dorsolateral part of the oral pontine reticular formation.

Animals↗
PubMed1995

The modified method of two-step differential extraction of sperm and vaginal epithelial cell DNA from vaginal fluid mixed with semen.

This investigation was undertaken as an efficient method for isolating sperm DNA from a mixed fluid sample which contains vaginal epithelial cells in a greater amount. The modified method of the two-step differential extraction procedure was found to be suitable for separating sperm DNA and vaginal epithelial cell DNA from the mixed stains. As the first step of digestion, vaginal epithelial cells in the mixed stains were lysed with Proteinase K and SDS, and sperm heads remaining in the lysed solution were collected by centrifugation. As the second step digestion, the sperm heads were lysed with the buffer containing Proteinase K, SDS and DTT as reducing agent. DNA fractions extracted from the two lysed solutions were enriched, one with sperm DNA and the other with vaginal epithelial cell DNA. MCT118(D1S80), ApoB VNTR and HLADQ alpha types of sperm DNA were detected and were confirmed by matching with corresponding male blood DNA. In the case of vaginal secretion mixed with semen of two males, the mixture of MCT118 types of the two males was detected in sperm DNA fraction.

Base Sequence↗
PubMed1995

Immunocytochemical localization of mu-opioid receptor in the rat caudate-putamen.

A guinea pig antibody against a C-terminal peptide of rat mu-opioid receptor (MOR) was produced to examine the distribution of MOR in the rat caudate-putamen (CP). The anti-peptide antibody recognized a protein of M(r) 69,000 in Triton X-100 extract of rat brain and in the membrane fraction of MOR-expressing culture cells. Intense MOR-like immunoreactivity (LI) was observed in island-like areas of the CP. Some MOR-LI was located on the cell bodies and dendrites of CP neurons. Double immunofluorescence study revealed that the intensely MOR-immunoreactive areas showed weak calbindin-LI, surrounded by intensely calbindin-positive regions. The results indicate that MOR-LI is enriched in the 'patches' of the neostriatal mosaic compartmentation.

Animals↗