Autori: Paulo Vianney Rodrigues, Ovidiu Iancu, Eric Washburn, John P. Welsh

Editorial: The Tucker-Davis Symposium on Advances and Perspectives in Auditory Neurophysiology, 2008.

Rezumat:

Electrical synapses are mediated by channels known as gap junctions, which are formed by
oligomerization of connexin 36 (CX36) proteins in neurons. Recently, we developed a lentivector that
carries a dominant negative form of the CX36 which blocks the generation of electrical synapses.
Experimental evidence collected in intracellular recordings in vitro support the hypothesis that the role
of electrical synapses is to synchronize neuronal networks at specific frequency bands to process
sensory information. We directly tested this hypothesis by infecting a large neuronal population with
the lentivirus carrying the mutated CX36 and recording auditory evoked potentials induced by 10 Khz
pure tones played at 70 db in the auditory cortex of awake rats. We also recorded the LFP activity of
uninfected rats and rats infected with an innocuous lentivector carrying the gene of the Green
Fluorescent Protein. We then performed spectral analysis of these three LFP data sets. Our
preliminary results indicate that the LFP spectrograms of these three experimental groups are overall
similar. However, the power spectral density of the LFP shows that there is a 10 fold decrease in the
power across a wide frequency range in the LFP of rats injected with the mutated CX36. Our
preliminary results also indicate that there is a decrease in coherence at alpha, beta, and gamma
frequency bands in these rats. To our knowledge, this is the first experimental evidence suggesting
that electrical synapses underlie a temporal code for the processing of sensorial information in awake
rats.

Cuvinte cheie: neural auditory processing

URL: http://www.apan.jhu.edu/