Limits...
Auditory synapses to song premotor neurons are gated off during vocalization in zebra finches.

Hamaguchi K, Tschida KA, Yoon I, Donald BR, Mooney R - Elife (2014)

Bottom Line: A potential site for this interaction is the song premotor nucleus HVC, which receives auditory input and contains neurons (HVCX cells) that innervate an anterior forebrain pathway (AFP) important to feedback-dependent vocal plasticity.Using intracellular recordings in singing zebra finches, we found that DAF failed to perturb singing-related synaptic activity of HVCX cells, although many of these cells responded to auditory stimuli in non-singing states.These findings support a model in which the AFP accesses feedback independent of HVC.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Duke University Medical Center, Durham, United States.

ABSTRACT
Songbirds use auditory feedback to learn and maintain their songs, but how feedback interacts with vocal motor circuitry remains unclear. A potential site for this interaction is the song premotor nucleus HVC, which receives auditory input and contains neurons (HVCX cells) that innervate an anterior forebrain pathway (AFP) important to feedback-dependent vocal plasticity. Although the singing-related output of HVCX cells is unaltered by distorted auditory feedback (DAF), deafening gradually weakens synapses on HVCX cells, raising the possibility that they integrate feedback only at subthreshold levels during singing. Using intracellular recordings in singing zebra finches, we found that DAF failed to perturb singing-related synaptic activity of HVCX cells, although many of these cells responded to auditory stimuli in non-singing states. Moreover, in vivo multiphoton imaging revealed that deafening-induced changes to HVCX synapses require intact AFP output. These findings support a model in which the AFP accesses feedback independent of HVC. DOI: http://dx.doi.org/10.7554/eLife.01833.001.

Show MeSH
The design of the integrated intracellular microdrive used in these experiments.(A) Schematic diagram of sharp intracellular microdrive, based on a Microdrive design developed by Michale Fee. (B) A male zebra finch with a microdrive implanted over HVC.DOI:http://dx.doi.org/10.7554/eLife.01833.004
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3927426&req=5

fig1s1: The design of the integrated intracellular microdrive used in these experiments.(A) Schematic diagram of sharp intracellular microdrive, based on a Microdrive design developed by Michale Fee. (B) A male zebra finch with a microdrive implanted over HVC.DOI:http://dx.doi.org/10.7554/eLife.01833.004

Mentions: To determine whether synaptic inputs onto HVCX cells convey auditory feedback signals during singing, we made intracellular sharp electrode recordings from HVC neurons in unrestrained, young adult (∼95 days post hatch [dph]) male zebra finches using a modified version of recording techniques developed recently (Lee et al., 2006; Long et al., 2010) (Figure 1—figure supplement 1). We recorded from a total of 72 HVCX neurons in 11 birds as they engaged in spontaneous bouts of singing produced in social isolation (i.e., undirected song) and/or listened to playback of the bird’s own song (BOS). HVCX cells were identified either by antidromic stimulation methods (Figure 1A,B), DC current-evoked firing patterns (Mooney, 2000), or characteristic singing-related hyperpolarization (Long et al., 2010). As previously reported (Long et al., 2010), all HVCX cells we recorded without current injection showed spontaneous, regular action potential activity when the bird was not vocalizing (8.2 ± 5.8 Hz, mean ±SD), entered a hyperpolarized state within several hundred milliseconds before song onset (baseline −58.5 ± 7.1 mV, during singing −62.3 ± 7.3 mV), and all except two exhibited one or more action potential bursts during the utterance of the stereotyped sequence of syllables constituting the song motif (Figure 1D, Video 1). Each cell’s pattern of subthreshold membrane potential activity (Vm) and action potential bursts were highly stereotyped from one motif to the next and from bout to bout (Figure 1D).10.7554/eLife.01833.003Figure 1.Sharp intracellular recordings from sensorimotor neurons in singing birds.


Auditory synapses to song premotor neurons are gated off during vocalization in zebra finches.

Hamaguchi K, Tschida KA, Yoon I, Donald BR, Mooney R - Elife (2014)

The design of the integrated intracellular microdrive used in these experiments.(A) Schematic diagram of sharp intracellular microdrive, based on a Microdrive design developed by Michale Fee. (B) A male zebra finch with a microdrive implanted over HVC.DOI:http://dx.doi.org/10.7554/eLife.01833.004
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927426&req=5

fig1s1: The design of the integrated intracellular microdrive used in these experiments.(A) Schematic diagram of sharp intracellular microdrive, based on a Microdrive design developed by Michale Fee. (B) A male zebra finch with a microdrive implanted over HVC.DOI:http://dx.doi.org/10.7554/eLife.01833.004
Mentions: To determine whether synaptic inputs onto HVCX cells convey auditory feedback signals during singing, we made intracellular sharp electrode recordings from HVC neurons in unrestrained, young adult (∼95 days post hatch [dph]) male zebra finches using a modified version of recording techniques developed recently (Lee et al., 2006; Long et al., 2010) (Figure 1—figure supplement 1). We recorded from a total of 72 HVCX neurons in 11 birds as they engaged in spontaneous bouts of singing produced in social isolation (i.e., undirected song) and/or listened to playback of the bird’s own song (BOS). HVCX cells were identified either by antidromic stimulation methods (Figure 1A,B), DC current-evoked firing patterns (Mooney, 2000), or characteristic singing-related hyperpolarization (Long et al., 2010). As previously reported (Long et al., 2010), all HVCX cells we recorded without current injection showed spontaneous, regular action potential activity when the bird was not vocalizing (8.2 ± 5.8 Hz, mean ±SD), entered a hyperpolarized state within several hundred milliseconds before song onset (baseline −58.5 ± 7.1 mV, during singing −62.3 ± 7.3 mV), and all except two exhibited one or more action potential bursts during the utterance of the stereotyped sequence of syllables constituting the song motif (Figure 1D, Video 1). Each cell’s pattern of subthreshold membrane potential activity (Vm) and action potential bursts were highly stereotyped from one motif to the next and from bout to bout (Figure 1D).10.7554/eLife.01833.003Figure 1.Sharp intracellular recordings from sensorimotor neurons in singing birds.

Bottom Line: A potential site for this interaction is the song premotor nucleus HVC, which receives auditory input and contains neurons (HVCX cells) that innervate an anterior forebrain pathway (AFP) important to feedback-dependent vocal plasticity.Using intracellular recordings in singing zebra finches, we found that DAF failed to perturb singing-related synaptic activity of HVCX cells, although many of these cells responded to auditory stimuli in non-singing states.These findings support a model in which the AFP accesses feedback independent of HVC.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology, Duke University Medical Center, Durham, United States.

ABSTRACT
Songbirds use auditory feedback to learn and maintain their songs, but how feedback interacts with vocal motor circuitry remains unclear. A potential site for this interaction is the song premotor nucleus HVC, which receives auditory input and contains neurons (HVCX cells) that innervate an anterior forebrain pathway (AFP) important to feedback-dependent vocal plasticity. Although the singing-related output of HVCX cells is unaltered by distorted auditory feedback (DAF), deafening gradually weakens synapses on HVCX cells, raising the possibility that they integrate feedback only at subthreshold levels during singing. Using intracellular recordings in singing zebra finches, we found that DAF failed to perturb singing-related synaptic activity of HVCX cells, although many of these cells responded to auditory stimuli in non-singing states. Moreover, in vivo multiphoton imaging revealed that deafening-induced changes to HVCX synapses require intact AFP output. These findings support a model in which the AFP accesses feedback independent of HVC. DOI: http://dx.doi.org/10.7554/eLife.01833.001.

Show MeSH