RT Journal Article
SR Electronic
T1 Glutamatergic Transmission Is Sustained at a Later Period of Development of Medial Nucleus of the Trapezoid Body–Lateral Superior Olive Synapses in Circling Mice
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 13003
OP 13007
DO 10.1523/JNEUROSCI.3002-08.2008
VO 28
IS 48
A1 Sung Hwa Hong
A1 Myeung Ju Kim
A1 Seung Cheol Ahn
YR 2008
UL http://www.jneurosci.org/content/28/48/13003.abstract
AB Synaptic transmission between the medial nucleus of the trapezoid body (MNTB) and the lateral superior olive (LSO) was investigated in circling mice, an animal model for inherited deafness, using the voltage-clamp technique. In postnatal day 9 (P9)∼P11 homozygous (cir/cir) circling mice, perfusion with 10 μm dl-APV and 10 μm CNQX reduced the 10 min average of postsynaptic currents (PSCs) to 8.8 ± 3.0% compared with controls (n = 6). In heterozygous (+/cir) mice in the same age range, the 10 min PSCs average was reduced to 87.5 ± 3.7% compared with controls (n = 7). In P0∼P2 homozygous (cir/cir) and heterozygous (+/cir) mice, the 10 min PSCs averages were 11.0 ± 2.6% (n = 9) and 84.1 ± 4.6% (n = 11), respectively. The effects of a glutamate antagonist mixture were almost the same in single fiber stimulation of P9∼P11 mice, reducing mean PSCs to 5.2 ± 3.1% (homozygous (cir/cir) mice, n = 8) and 78.3 ± 4.3% (heterozygous (+/cir) mice, n = 12). Immunohistochemical study revealed that glycine receptor (GlyR) immunoreactivity in heterozygous (+/cir) mice was more prominent than in homozygous (cir/cir) mice, while immunoreactivities of NR1 and NR2A-type NMDAR of P16 homozygous (cir/cir) mice were more prominent than in heterozygous (+/cir) mice of the same age. No significant difference was found in the immunoreactivity of NR2B-type NMDAR. These results indicate that glutamatergic transmission is sustained at a later period of developing MNTB–LSO synapses in homozygous (cir/cir) mice.