Enhanced cortical and hippocampal neuronal excitability in mice deficient in the extracellular matrix glycoprotein tenascin-R.
Mice deficient in the extracellular matrix protein tenascin-R (TN-R-/- mice) show several indices of impaired perisomatic inhibition in hippocampal slices. The present study examined electroencephalograms (EEGs) and auditory-evoked potentials (AEPs) in freely moving TN-R-/- and wild-type control mice, focusing on the hippocampal CA1 field and cerebral cortex. TN-R-/- mice expressed normal high-frequency oscillations (ripples) in CA1 and only a slight reduction of peak theta frequency. In contrast, their hippocampal gamma oscillations were significantly enhanced in amplitude. Also, the amplitude of the cortical EEG of TN-R-/- mice was increased over a wide frequency range. The amplitude of cortical and, to a lesser degree hippocampal, AEPs was clearly enhanced in TN-R-/- mice. In addition, response habituation to repeated sound stimuli was significantly attenuated in TN-R-/- mice. These findings indicate that tenascin-R is involved in the regulation of certain inhibitory mechanisms in the intact brain.
Gurevicius
K
K
Department of Neuroscience and Neurology, University of Kuopio, 70211, Finland.
Gureviciene
I
I
Valjakka
A
A
Schachner
M
M
Tanila
H
H
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism*; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009474:Neurons / Q000378:metabolism*; D019063:Tenascin / Q000172:deficiency* / Q000235:genetics
D019063:Tenascin; C074638:tenascin R