AMPA receptors in hearing and hearing loss.
Ultrastructure and the nature of the tripartite synapse.
Dr. Rubio has studied the synaptic circuitries in the cochlear nucleus, the cerebellum and the hippocampus as well as the structure the organ of Corti in the cochlea. By taking a multidisciplinary approach, she developed expertise in functional assessment of hearing function, anatomy, ultrastructure, quantitative immunolabeling of a variety of proteins at the light and electron microscopic level and biochemistry. A long-term goal of Dr. Rubio’s research is focused on determining the molecular mechanisms that endow cochlear nerve fibers with temporal fidelity. These mechanisms are still largely unknown but are in place at central auditory nerve synapses and at the inner hair cell synapse in the cochlea.
Dr. Rubio’s current research focuses on determining the contribution of AMPA receptor subunit composition to sex-differences in hearing loss. AMPA receptor subunits (GluA 2, 3 and 4) located postsynaptically at the afferent dendrites of the spiral ganglion neurons are important molecular players that mediate fast synaptic transmission at the inner hair cell synapse in the cochlea. The contribution of each type of AMPA receptor subunits to overall glutamatergic receptor function and afferent transmission/sensitivity in the cochlea is poorly understood.
Dr. Rubio’s second research interest is to determine the role of glial cells in auditory function. In particular, the relationship (molecular and structural) of astrocyte process to central auditory nerve synapses in the normal hearing and in the hearing impaired. The role of astrocytes in the normal hearing and in the hearing impaired is understudied.
Representative Publications
GluA3 subunits are required for appropriate assembly of AMPAR GluA2 and GluA4 subunits on cochlear afferent synapses and for presynaptic ribbon modiolar-pillar morphology.
Rutherford MA, Bhattacharyya A, Xiao M, Cai HM, Pal I, Rubio ME.
Elife. 2023
Ultrastructural and functional changes at the tripartite synapse during epileptogenesis in a model of temporal lobe epilepsy.
Clarkson C., Smeal R., Gibbons M., White J.A., Rubio M.E., Wilcox K.S.
Experimental Neurology (2020)
Microcircuits of the Ventral Cochlear Nucleus.
Rubio M.E.
In: Oliver D., Cant N., Fay R., Popper A. (eds) The Mammalian Auditory Pathways. Springer Handbook of Auditory Research, vol 65, pp.41-71, Springer, Cham.(2018)
Molecular and structural changes in the cochlear nucleus in response to hearing loss.
Rubio M.E.
The Oxford Handbook of the Auditory System. Karl Kandler (ed.) Hearing loss effects in the auditory brainstem news and views, Oxford Press, New York. October (2018)
RAD52 is required for RNA-templated recombination repair in post-mitotic neurons.
Welty S., Teng Y., Liang Z., Zhao W., Sanders L., Greenamyre J.T., Rubio M.E., Thathiah A., Kodali R., Wetzel R., Levine A., Lan L.
Journal of Biological Chemistry (2017)
The number and distribution of AMPA receptor channels containing fast kinetic GluA3 and GluA4 subunits at auditory nerve synapses depend on the target cells.
Rubio M.E., Matsui K., Fukazawa Y., Kamasawa N., Harada H., Itakura M., Molnár E., Abe M., Sakimura K., Shigemoto R.
Brain Structure and Function (2017)
Impaired auditory processing and altered synaptic structure of the endbulb synapse in mice lacking GluA3 AMPA receptors.
García-Hernández S., Abe M., Sakimura K., Rubio M.E.
Hearing Research (2017)
Conductive hearing loss has long-lasting structural and molecular effects on pre- and post-synaptic structures of the auditory nerve in the cochlear nucleus.
Clarkson C., Antunes F.M., Rubio M.E.
Journal of Neuroscience (2016)
PubMed search for Rubio ME