Teiji Yamamoto

IDENTIFICATION OF THE NORMAL MICROGLIAL POPULATION IN HUMAN AND RODENT NERVOUS TISSUE USING LECTIN–HISTOCHEMISTRY

Identification of the normal microglial population in human and rodent nervous tissue using lectin–histochemistry

Shy-Drager syndrome and amyotrophic lateral sclerosis ☆: Cytoarchitectonic and morphometric studies of sacral autonomic neurons

In order to elucidate the morphological correlates of bladder-rectal dysfunctions in Shy-Drager syndrome, the sacral spinal cord was cytoarchitectonically studied and 3 groups of sacral motor neurons, the posterolateral motor neuron column (PL), inferior intermediolateral nucleus (IML) and cell group X of Onuf (Onuf), were morphometrically quantitated at the S3 level (5 cases), after which the results were compared with those from amyotrophic lateral sclerosis (5 cases) and an age-matched control group (4 cases). The sacral autonomic preganglionic nucleus of IML was localized chiefly in the S3-4 segments and was maximally developed in the caudal one-third of S3. The cell group X of Onuf was localized between the middle of S2 and the rostral one-third of S3 as a longitudinal slender column in the ventral horn. Between these two nuclei at the rostral S3 level, a connecting cellular bridge of neurons of intermediolateral cell type was identified. Morphometry disclosed a marked deprivation of IML, Onuf and somatic motor neurons in Shy-Drager syndrome and a severe loss of somatic motor neurons and a modest deprivation of IML neurons in ALS. These results imply that these two disorders distinguished by different clinical manifestations share a common loss of somatic motor and parasympathetic motor neurons at least in the sacral cord. There are, however, certain gradients in the severity of involvement in these heterogeneous cell groups.

Sacral spinal innervations of the rectal and vesical smooth muscles and the sphincteric striated muscles as demonstrated by the horseradish peroxidase method

To investigate the central organization of efferent neurons innervating the rectal and vesical smooth muscles and the sphincteric striated muscles in the cat, horseradish peroxidase (HRP) was injected into each of these structures and retrogradely labeled neurons were identified in the sacral spinal cord. Following HRP injections into these smooth muscle structures, labeled neurons were found in the intermediolateral and intermediolateral cell columns, the cell group X of Onuf and the nucleus myoleioticus medialis of the sacral cord. HRP injections into the external anal sphincter and bulbospongiosus muscles showed labeled neurons in the cell group X of Onuf and some in the nucleus myoleioticus medialis.

Retrograde Adriamycin Sensory Ganglionectomy: Novel Approach for the Treatment of Intractable Pain

Selective sensory ganglionectomy by means of retrograde suicide transport of adriamycin was performed on 3 patients with neuropathic pain in the areas of the trigeminal and intercostal nerves, producing significant pain relief, particularly from hyperalgesic pain. Adriamycin ganglionectomy is considered as a less invasive and highly selective pain treatment, which may possibly become an alternative for surgical ganglionectomy or rhizotomy.

Retrograde axoplasmic transport of Adriamycin An experimental form of motor neuron disease

Adriamycin (ADM) is a DNA-directed RNA inhibitor. In attempts to produce an experimental form of motor neuron disease, we injected the agent into rat sciatic nerve. Retrograde axoplasmic flow conveyed ADM into soma of the spinal motor neurons, as confirmed by fluorescence microscopy. Motor neuron degeneration, which included nuclear heterochromatinization and diffuse chromatolysis, was observed after 6 to 8 days. After 2 weeks, many neurons that gave rise to sciatic nerve efferents underwent dissolution. Retrograde axoplasmic flow and DNA-injurious substances could affect survival of motor neurons.

Intraneuronal laminin-like molecule in the central nervous system: demonstration of its unique differential distribution

Laminin, an extracellular matrix glycoprotein rich in basement membrane, is a multifunctional molecule of approximately 1000 kDa and is known to possess a potent neurotrophic activity. Laminin-like immunoreactivity (LLI) was for the first time demonstrated in mouse and rat CNS neurons by a sensitive immunohistochemical technique. Transblotting of SDS-PAGE of the supernatant of the mouse and rat brain homogenate identified distinct 180 kDa and weak 380 kDa bands immunoreactive to anti-laminin and these molecules differed from authentic laminin subunits. The intraneuronal distribution of LLI disclosed two distinct patterns; LLI-1 (diffuse perikaryal stain) and LLI-2 (coarse granular stain). By immunoelectron microscopy, LLI was localized to the ERs in LLI-1 neurons, whereas it appeared to be confined to lysosomes in LLI-2 neurons. LLI-1 neurons were found predominantly in hippocampal pyramidal, granule and neocortical layers 1-3, 6 neurons, in most of the striatal and thalamic neurons, and Purkinje cells. The majority of neurons in neocortical layers 4-5, medial septal and Meynert neurons, somatic motor neurons, and neurons of the deep cerebellar nuclei were classified as LLI-2 cells. No LLI was found in hypothalamic mammillary, habenular and vagal dorsal motor neurons (LLI-3). These observations may indicate intraneuronal production of laminin-related molecules in central neurons. We speculate that the laminin-related molecules (neurolaminin) play important roles in trophic or servo mechanisms in the CNS.

Forebrain ischemia induced by temporary bilateral common carotid occlusion in normotensive rats

Ischemic brain lesions were induced in adult Wistar and Fischer rats by temporary occlusion of the bilateral common carotid artery. The severity of ischemic lesions depended on the duration of carotid occlusion. While 2 h occlusion resulted in 15 deaths among 40 rats and the development of ischemic lesions in 16 of 25 asymptomatic survivors, none died after 0.5 h occlusion and yet 13 of 30 apparently asymptomatic rats had ischemic lesions when examined on day 7. Histological examination combined with immunohistochemistry of autologous albumin for assessing the integrity of the blood-brain barrier (BBB) revealed two distinct lesions: (1) ischemic neural damage with extensive tissue permeation of serum albumin, (2) death of individual neurons sparing other neural elements in the absence of the BBB breakdown. Ischemic neural damage with BBB breakdown was common in animals dying within 48 h after reflow. The lesions without BBB breakdown, on the other hand, were found solely in asymptomatic animals in which groups of severely degenerated neurons were preferentially located in the CA 1 region of the hippocampus, the caudoputamen and deeper layers of the neocortex. The sequential measurements of regional cerebral blood flow (rCBF) in the bilateral hippocampus by the hydrogen clearance method disclosed a steady decrease in rCBF after the occlusion, 51% of the pre-occlusion state at 10 min, 35% at 25 min and 32% at 40 min. The simplicity of procedure could make this model suitable for the study of the pathogenesis of ischemic neuronal damage in a critically low perfusion state.

Wallerian degeneration induces Ia-antigen expression in the rat brain

Strong expression of class II major histocompatibility (MHC II, Ia) antigens was observed in areas of Wallerian degeneration following either a cryoinjury to the cerebral and cerebellar cortex or unilateral eye enucleation in adult Wistar and Lewis rats. The Wallerian degeneration was disclosed by the Fink-Heimer method but not by routine histological examination. The Ia antigens were localized exclusively to the cells labeled with OX-42 antibody and mistletoe-1 lectin (ML-1) and possessing the morphological identity of microglia. Development of Ia-expressing microglia at the sites of Wallerian degeneration was accompanied by neither tissue permeation of serum components as assessed by immunohistochemistry for autologous albumin nor tissue migration of hematogenous inflammatory cells.

Identification of the superior salivatory nucleus in the cat as studied by the HRP method.

Using horseradish peroxidase (HRP) bathing of either the intermediofacial nerve or the chorda tympani, the localization of the superior salivatory nucleus that gives rise to parasympathetic fibers to the submandibular and sublingual glands was identified in the cat. The superior salivatory nucleus demonstrated by this study does not exist in the pons but does exist in the dorsal part of the reticular formation of the rostral medulla oblongata. Neurons of this nucleus were generally medium-sized and multipolar, with densely stained Nissl substance.

Targeting of adoptively transferred experimental allergic encephalitis lesion at the sites of wallerian degeneration.

SummaryTo clarify the implication of the major histocompatibility complex class II (Ia) antigen induction in microglia following Wallerian degeneration in the central nervous system (CNS), experimental allergic encephalitis (EAE) was adoptively transferred to Lewis rats in which Ia antigens had been induced in microglia at the sites of Wallerian degeneration. In addition to randomly distributed typical EAE lesions, the recipient rats developed distinct inflammatory lesions in accord with the distribution of Ia-positive microglia; i.e., in the ipsilateral thalamus after cortical cryoinjury, and in the ipsilateral optic nerve, the contralateral optic tract and superior colliculus after unilateral eye ball enucleation. Thus, the EAE locus may be targeted by this approach. The inflammatory response was inducible by transfer of myelin basic protein-stimulated lymphocytes but not by transfer of phytohemagglutinin-stimulated or non-stimulated lymphocytes. When examined using monoclonal antibody surface markers; OX-6 for Ia antigen, W3/13 for pan T lymphocyte and OX-8 for cytotoxic/suppresser T lymphocyte, the types of lymphocytes in these lesions did not differ from those in ordinary EAE lesions in the spinal cord. The potential role of non-immunologically induced Ia-positive cell clusters that serve as a target for autoimmune CNS diseases was discussed.