Reiko Ogawa-Meguro

Immunohistochemical localization of metabotropic glutamate receptors, mGluR2 and mGluR3, in rat cerebellar cortex

The distribution of the metabotropic glutamate receptors mGluR2 and mGluR3 was immunohistochemically examined in the rat cerebellar cortex at both light and electron microscope levels. An antibody was raised against a fusion protein containing a C-terminal portion of mGluR2. On immunoblot, the antibody reacted with both mGluR2 and mGluR3 in rat brain. mGluR2/3 immunoreactivity was expressed in cell bodies, dendrites, and axon terminals of Golgi cells, as well as in presumed glial processes. Golgi axon terminals with mGluR2/3 immunoreactivity were often encountered in the vicinity of glutamatergic mossy fiber terminals. The results suggest that transmitter glutamate may exert control influences upon Golgi cells not only through dendritic mGluR2/3, but also through axonal mGluR2/3.

Immunocytochemical localization of rat substance P receptor in the striatum.

A trp E fusion protein containing a C-terminal portion of the rat substance P receptor (SPR) was expressed in bacteria and used to produce an antibody. The antibody specifically reacted with SPR expressed in a mammalian cell line and rat striatum. Light and electron microscope analyses of the rat striatum revealed intense SPR-like immunoreactivity in neuronal somata and dendrites. These immunoreactive neurons constituted approximately 3% of the total population of striatal neurons; they were putative interneurons of large and medium-sized aspiny type.

Substance P-, vasoactive intestinal polypeptide-, and cholecystokinin-like immunoreactive fiber projections from the superior colliculus to the dorsal lateral geniculate nucleus in the rat

SummarySubstance P (SP)-, vasoactive intestinal polypeptide (VIP)-, and cholecystokinin (CCK)-like immunoreactive (LI) neurons were found in the superior colliculus (SC) of the rat, and examined to ascertain whether they sent projection fibers to the dorsal lateral geniculate nucleus (LGNd). Immunocytochemical staining with antisera against SP, VIP, and CCK showed that many immunoreactive neuronal cell bodies were located in the superficial layers of the SC, especially in the stratum griseum superficiale. The pattern of distribution of these immunoreactive neuronal cell bodies in the SC was similar to that of neuronal cell bodies which were retrogradely labeled with WGA-HRP (wheat germ agglutinin-horseradish peroxidase conjugate) injected ipsilaterally into the LGNd. On the other hand, SP-, VIP- and CCK-LI axons were seen most densely in the lateral part of the LGNd, especially in the small-celled LGNd zone adjacent to the optic tract, where anterograde labeling was also observed after injection of WGA-HRP ipsilaterally into the superficial layers of the SC. When a lesion was produced by kainic acid injection into the superficial layers of the SC, axons showing SP-, VIP-, or CCK-LI in the LGNd ipsilateral to the lesion were markedly depleted. The results indicate that SC-LGNd projection neurons contain SP, VIP, and/or CCK in the rat.

Direct projections from the globus pallidus to the midbrain and pons in the cat

Employing the anterograde and retrograde axonal tracing techniques with Phaseolus vulgaris leucoagglutinin and cholera toxin B subunit, we demonstrated direct projections from the globus pallidus (GP) to the midbrain and pons in the cat. Cells of origin of these projections were localized in the caudal 2/3 of the GP, and their major target sites included the peripeduncular region, nucleus of the brachium of the inferior colliculus, para-lateral lemniscal zone, nucleus sagulum, external and pericentral nuclei of the inferior colliculus, and cuneiform nucleus. A combination of retrograde axonal tracing and immunohistochemistry for choline acetyltransferase revealed that GP neurons giving rise to such descending projections were primarily non-cholinergic.

Direct projections of non-pyramidal neurons of Ammon's horn to the amygdala and the entorhinal cortex

When WGA-HRP (wheat germ agglutinin-horseradish peroxidase conjugate) was injected into the amygdala (lateral and basolateral amygdaloid nuclei) or entorhinal cortex of the cat, a number of nonpyramidal neurons in Ammons horn were retrogradely labeled. The results indicate that some non-pyramidal neurons in Ammons horn send projection fibers to the amygdala and entorhinal cortex.

Immunohistochemical localization of substance P receptor in the superior colliculus. A light and electron microscope study in the rat

The superficial layers of the superior colliculus (SC) have been known to contain many axons showing substance P-like immunoreactivity (SP-LI). We, therefore, immunohistochemically examined the distribution of SP receptor (SPR) in the superficial layers of the SC in the rat by using a specific antibody against SPR. The majority of SC neurons with SPR-LI were distributed in the zonal and the superficial gray layers, the rest of them were in the optic layer. Electron microscopy revealed that SPR-immunoreaction products in SC neurons were distributed not only in postsynaptic sites, but also in non-synaptic regions of perikaryal and dendritic profiles.

Pallidocortical projections to the tempolar polar gyrus in the cat

Marked projections from the globus pallidus (GP) to the temporal polar gyrus (TPG) of the cat were found by means of the PHA-L (Phaseolus vulgaris leucoagglutinin) and WGA-HRP (horseradish peroxidase conjugated to wheat germ agglutinin) methods. Pallidocortical fibers to the TPG originate mainly from the middle levels of the GP, and terminate all layers of the TPG cortex, especially in layers I, II and III. The GP neurons projecting to the TPG are large-multipolar or small-bipolar neurons. Almost all of these GP neurons show choline acetyltransferase-like immunoreactivity.