Heterogeneity of subcellular localization and electrophoretic mobility of survival motor neuron (SMN) protein in mammalian neural cells and tissues

Spinal muscular atrophy is caused by defects in the survival motor neuron (SMN) gene. To better understand the patterns of expression of SMN in neuronal cells and tissues, we raised a polyclonal antibody (abSMN) against a synthetic oligopeptide from SMN exon 2. AbSMN immunostaining in neuroblastoma cells and mouse and human central nervous system (CNS) showed intense labeling of nuclear “gems,” along with prominent nucleolar immunoreactivity in mouse and human CNS tissues. Strong cytoplasmic labeling was observed in the perikarya and proximal dendrites of human spinal motor neurons but not in their axons. Immunoblot analysis revealed a 34-kDa species in the insoluble protein fractions from human SY5Y neuroblastoma cells, embryonic mouse spinal cord cultures, and human CNS tissue. By contrast, a 38-kDa species was detected in the cytosolic fraction of SY5Y cells. We conclude that SMN protein is expressed prominently in both the cytoplasm and nucleus in multiple types of neurons in brain and spinal cord, a finding consistent with a role for SMN as a determinant of neuronal viability.

A dendrodendritic reciprocal synapse provides a recurrent excitatory connection in the olfactory bulb

Neuronal synchronization in the olfactory bulb has been proposed to arise from a diffuse action of glutamate released from mitral cells (MC, olfactory bulb relay neurons). According to this hypothesis, glutamate spills over from dendrodendritic synapses formed between MC and granule cells (GC, olfactory bulb interneurons) to activate neighboring MC. The excitation of MC is balanced by a strong inhibition from GC. Here we show that MC excitation is caused by glutamate released from bulbar interneurons located in the GC layer. These reciprocal synapses depend on an unusual, 2-amino-5-phosphonovaleric acid-resistant, N-methyl-d-aspartate receptor. This type of feedback excitation onto relay neurons may strengthen the original sensory input signal and further extend the function of the dendritic microcircuit within the main olfactory bulb.

Observations sur les affections catarrhales en général, et paticulièrement sur celles connues sous les noms de rhumes de cerveau et de rhumes de poitrine /

Mode of access: Internet.

Observaciones sobre los efectos catarrales en general, y particularmente sobre los que se llaman reumas ó fluxiones de cerebro y de pecho /

Mode of access: Internet.

Rapports du physique et du moral de l'homme /

Mode of access: Internet.

Du degré de certitude de la médecine /

Incluye además del tít. de port.: Observations sur les hôpitaux; Journal de la maladie et de la mort de Mirabeau l'Aîné; Note sur le supplice de la guillotine; Rapport fait au conseil des cinq cents sur l'organisation des Écoles de médecine; Quelques principes et quelques vues sur les secours publiques.

El grado de certidumbre de la medicina /

Mode of access: Internet.

Compendio historico de las revoluciones y reforma de la medicina /

Mode of access: Internet.

Nouvelles recherches sur la structure de la peau /

Mode of access: Internet.

Rapports du physique et du moral de l'homme.

Retr. del aut.

Études médicales /

Mode of access: Internet.

Rapports du physique et du moral de l'homme /

El T. II contiene las tablas de la obra completa.

Famosi et antiqui problematis de telluris motu, vel quiete, hactenus optata solutio ... /

ITICCUUM1E012109.