Developmental changes in membrane excitability and morphology of neurons in the nucleus angularis of the chicken

Synaptic Physiology in the Cochlear Nucleus Angularis of the Chick

“…The 10 -90% rise times and exponential decay time constants of the EPSP were much slower than those of the underlying synaptic currents, and we showed that the decay time constant was directly correlated to the membrane time constants in NA neurons (Fukui and Ohmori 2003;Soares et al 2002). Due to their shorter membrane time constants, the EPSP decay times reported for NM neuron (with a half-decay of Ͻ1 ms) (Zhang and Trussell 1994a) are faster than even the fastest we report here for NA (ϳ4 ms).…”

“…Thus while all these neuron all receive fast underlying synaptic currents, the membrane time constant is the governing factor for how these EPSPs decay. The broad range of EPSP decay time constants we show across different NA neurons combined with differential expression of voltage-dependent currents (Fukui and Ohmori 2003;Soares et al 2002) could furthermore lead to differential integration of auditory inputs within NA. NA neurons with the slower EPSPs are precluded from encoding the precise temporal information present in the auditory nerve inputs, thus contributing to the segregation of acoustic information in the two nuclei.…”

Synaptic Physiology in the Cochlear Nucleus Angularis of the Chick

“…The 10 -90% rise times and exponential decay time constants of the EPSP were much slower than those of the underlying synaptic currents, and we showed that the decay time constant was directly correlated to the membrane time constants in NA neurons (Fukui and Ohmori 2003;Soares et al 2002). Due to their shorter membrane time constants, the EPSP decay times reported for NM neuron (with a half-decay of Ͻ1 ms) (Zhang and Trussell 1994a) are faster than even the fastest we report here for NA (ϳ4 ms).…”

“…Thus while all these neuron all receive fast underlying synaptic currents, the membrane time constant is the governing factor for how these EPSPs decay. The broad range of EPSP decay time constants we show across different NA neurons combined with differential expression of voltage-dependent currents (Fukui and Ohmori 2003;Soares et al 2002) could furthermore lead to differential integration of auditory inputs within NA. NA neurons with the slower EPSPs are precluded from encoding the precise temporal information present in the auditory nerve inputs, thus contributing to the segregation of acoustic information in the two nuclei.…”

Target-specific regulation of presynaptic release properties at auditory nerve terminals in the avian cochlear nucleus

“…3B). Similar analysis of the MK801 decay times in NM was performed, assigning location according to previously described tonotopic division along the mediolateral and rostrocaudal axes (Fukui and Ohmori 2003;Rubel and Parks 1975). NM recording spanned a similar range along this axis and also showed a nonsignificant trend in decay times (R 2 ϭ 0.195, P ϭ 0.13; Fig.…”

Beyond timing in the auditory brainstem: intensity coding in the avian cochlear nucleus angularis

“…Single-spiking neurons respond with only one action potential to injections of depolarizing current, and are characterized by a lowthreshold voltage-gated, dendrotoxin-sensitive potassium conductance that is activated at rest, and consequently have a low input resistance and fast membrane time constant. In NA, single-spiking neurons correspond to stubby neurons, and thus these neurons have response properties similar to those found in NM and NL (Fukui and Ohmori, 2003;Soares et al, 2002). These biophysical similarities between single-spiking NA neurons and the timing pathway neurons suggest the stubby neurons may mediate transmission of temporal information.…”

Synaptic Physiology in the Cochlear Nucleus Angularis of the Chick

“…The 10 -90% rise times and exponential decay time constants of the EPSP were much slower than those of the underlying synaptic currents, and we showed that the decay time constant was directly correlated to the membrane time constants in NA neurons (Fukui and Ohmori 2003;Soares et al 2002). Due to their shorter membrane time constants, the EPSP decay times reported for NM neuron (with a half-decay of Ͻ1 ms) (Zhang and Trussell 1994a) are faster than even the fastest we report here for NA (ϳ4 ms).…”

“…Thus while all these neuron all receive fast underlying synaptic currents, the membrane time constant is the governing factor for how these EPSPs decay. The broad range of EPSP decay time constants we show across different NA neurons combined with differential expression of voltage-dependent currents (Fukui and Ohmori 2003;Soares et al 2002) could furthermore lead to differential integration of auditory inputs within NA. NA neurons with the slower EPSPs are precluded from encoding the precise temporal information present in the auditory nerve inputs, thus contributing to the segregation of acoustic information in the two nuclei.…”

Target-specific regulation of presynaptic release properties at auditory nerve terminals in the avian cochlear nucleus

“…3B). Similar analysis of the MK801 decay times in NM was performed, assigning location according to previously described tonotopic division along the mediolateral and rostrocaudal axes (Fukui and Ohmori 2003;Rubel and Parks 1975). NM recording spanned a similar range along this axis and also showed a nonsignificant trend in decay times (R 2 ϭ 0.195, P ϭ 0.13; Fig.…”

Beyond timing in the auditory brainstem: intensity coding in the avian cochlear nucleus angularis

“…Single-spiking neurons respond with only one action potential to injections of depolarizing current, and are characterized by a lowthreshold voltage-gated, dendrotoxin-sensitive potassium conductance that is activated at rest, and consequently have a low input resistance and fast membrane time constant. In NA, single-spiking neurons correspond to stubby neurons, and thus these neurons have response properties similar to those found in NM and NL (Fukui and Ohmori, 2003;Soares et al, 2002). These biophysical similarities between single-spiking NA neurons and the timing pathway neurons suggest the stubby neurons may mediate transmission of temporal information.…”

Synaptic Physiology in the Cochlear Nucleus Angularis of the Chick

“…The 10 -90% rise times and exponential decay time constants of the EPSP were much slower than those of the underlying synaptic currents, and we showed that the decay time constant was directly correlated to the membrane time constants in NA neurons (Fukui and Ohmori 2003;Soares et al 2002). Due to their shorter membrane time constants, the EPSP decay times reported for NM neuron (with a half-decay of Ͻ1 ms) (Zhang and Trussell 1994a) are faster than even the fastest we report here for NA (ϳ4 ms).…”

“…Thus while all these neuron all receive fast underlying synaptic currents, the membrane time constant is the governing factor for how these EPSPs decay. The broad range of EPSP decay time constants we show across different NA neurons combined with differential expression of voltage-dependent currents (Fukui and Ohmori 2003;Soares et al 2002) could furthermore lead to differential integration of auditory inputs within NA. NA neurons with the slower EPSPs are precluded from encoding the precise temporal information present in the auditory nerve inputs, thus contributing to the segregation of acoustic information in the two nuclei.…”

Target-specific regulation of presynaptic release properties at auditory nerve terminals in the avian cochlear nucleus

“…3B). Similar analysis of the MK801 decay times in NM was performed, assigning location according to previously described tonotopic division along the mediolateral and rostrocaudal axes (Fukui and Ohmori 2003;Rubel and Parks 1975). NM recording spanned a similar range along this axis and also showed a nonsignificant trend in decay times (R 2 ϭ 0.195, P ϭ 0.13; Fig.…”

Beyond timing in the auditory brainstem: intensity coding in the avian cochlear nucleus angularis

“…Single-spiking neurons respond with only one action potential to injections of depolarizing current, and are characterized by a lowthreshold voltage-gated, dendrotoxin-sensitive potassium conductance that is activated at rest, and consequently have a low input resistance and fast membrane time constant. In NA, single-spiking neurons correspond to stubby neurons, and thus these neurons have response properties similar to those found in NM and NL (Fukui and Ohmori, 2003;Soares et al, 2002). These biophysical similarities between single-spiking NA neurons and the timing pathway neurons suggest the stubby neurons may mediate transmission of temporal information.…”