TY - JOUR
T1 - Time course and permeation of synaptic AMPA receptors in cochlear nuclear neurons correlate with input
AU - Gardner, Stephanie M.
AU - Trussell, Laurence O.
AU - Oertel, Donata
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 1999/10/15
Y1 - 1999/10/15
N2 - AMPA receptors mediate rapid glutamatergic synaptic transmission. In the mammalian cochlear nuclei, neurons receive excitatory input from either auditory nerve fibers, parallel fibers, or both fiber systems. The functional correlates of differences in the source of input were examined by recording AMPA receptor-mediated, miniature EPSCs (mEPSCs) in whole-cell voltage-clamp mode from identified neurons. Bushy, octopus, and T-stellate cells of the ventral cochlear nucleus (VCN) and tuberculoventral cells of the dorsal cochlear nucleus (DCN) receive most of their excitatory input from the auditory nerve; fusiform cells receive excitatory inputs from both the auditory nerve and parallel fibers; cartwheel cells receive excitatory input from parallel fibers alone, mEPSCs from bushy, octopus, T-stellate, and tuberculoventral cells had significantly faster decay time constants (0.35- 0.40 msec) than did those from fusiform and cartwheel cells (1.32-1.79 msec). Some fusiform cells had two populations of mEPSCs with distinct time courses. mEPSCs in cells with auditory nerve input alone were inhibited by philanthotoxin, a blocker of calcium-permeable AMPA receptors, whereas mEPSCs in cells with parallel fiber input were not. Thus AMPA receptors postsynaptic to the auditory nerve differ from those postsynaptic to parallel fibers both in channel-gating kinetics and in their permeability to calcium. These results confirm the conclusion that synaptic AMPA receptors are specialized according to the source of input (Hunter et al., 1993; Rubio and Wenthold, 1997; Wang et al., 1998).
AB - AMPA receptors mediate rapid glutamatergic synaptic transmission. In the mammalian cochlear nuclei, neurons receive excitatory input from either auditory nerve fibers, parallel fibers, or both fiber systems. The functional correlates of differences in the source of input were examined by recording AMPA receptor-mediated, miniature EPSCs (mEPSCs) in whole-cell voltage-clamp mode from identified neurons. Bushy, octopus, and T-stellate cells of the ventral cochlear nucleus (VCN) and tuberculoventral cells of the dorsal cochlear nucleus (DCN) receive most of their excitatory input from the auditory nerve; fusiform cells receive excitatory inputs from both the auditory nerve and parallel fibers; cartwheel cells receive excitatory input from parallel fibers alone, mEPSCs from bushy, octopus, T-stellate, and tuberculoventral cells had significantly faster decay time constants (0.35- 0.40 msec) than did those from fusiform and cartwheel cells (1.32-1.79 msec). Some fusiform cells had two populations of mEPSCs with distinct time courses. mEPSCs in cells with auditory nerve input alone were inhibited by philanthotoxin, a blocker of calcium-permeable AMPA receptors, whereas mEPSCs in cells with parallel fiber input were not. Thus AMPA receptors postsynaptic to the auditory nerve differ from those postsynaptic to parallel fibers both in channel-gating kinetics and in their permeability to calcium. These results confirm the conclusion that synaptic AMPA receptors are specialized according to the source of input (Hunter et al., 1993; Rubio and Wenthold, 1997; Wang et al., 1998).
KW - AMPA receptors
KW - Auditory nerve
KW - Auditory pathways
KW - Calcium permeability
KW - Cochlear nuclei
KW - GluR2 subunit
KW - MEPSCs
KW - Parallel fibers
KW - Philanthotoxin
KW - Polyamine
KW - Time course
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U2 - 10.1523/jneurosci.19-20-08721.1999
DO - 10.1523/jneurosci.19-20-08721.1999
M3 - Article
C2 - 10516291
AN - SCOPUS:0033570332
VL - 19
SP - 8721
EP - 8729
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 20
ER -