Article Figures & Data
Figures
- Figure 1.
Phox2b-immunoreactive (-ir) cells and NK1R expression in the parafacial region of neonatal rat medulla. A, Distribution Phox2b-ir cells. Each dot represents a single Phox2b-ir nucleus plotted on the 50-μm-thick coronal section. Phox2b-ir cells in the facial and retrofacial nuclei were not plotted. Panels were arranged in a direction corresponding to the most caudal (upper left) to most rostral (lower right) sections. Values denote distance from the level of the caudal end of facial nucleus (VIIc) (Ruangkittisakul et al., 2006). B, Phox2b immunoreactivity and NK1R expression in the most rostral medulla, corresponding to i or j in A. NK1R expression (left), Phox2b immunoreactivity (middle) and merge of both (right). Dotted line in middle panel denotes a rostral cluster of Phox2b-immunoreactive cells which also express NK1R (right column). FN, Facial nucleus; RFN, retrofacial nucleus; CST, corticospinal tract.
- Figure 2.
A Phox2b-immunoreactive Pre-I neuron in parafacial region. The neuron was recorded at the level of 400 μm rostral to the caudal end of facial nucleus. A, Membrane potential trajectory and C4 inspiratory activity. B, Membrane potential change in response to hypercapnia in the presence of 0.5 μm TTX. CO2 concentration was changed from 2% to 8%. Square current pulse (500 ms, 0.1 Hz, 20 pA) was applied to monitor change of input resistance. Negative deflections of the baseline membrane potential are proportional to input resistance. Note that application of 8% CO2 induced membrane depolarization and increase of input resistance. C, Camera lucida drawing of the neuron. D, Phox2b immunoreactivity of this neuron. The neuron labeled with Lucifer yellow (green) in the electrode solution showed Phox2b immunoreactivity (red). FN, facial nucleus.
- Figure 3.
A Phox2b-immunoreactive tonic firing neuron in the parafacial region. The neuron was recorded at the level of 150 μm rostral to the caudal end of facial nucleus. A, Averaged membrane potential (19 cycles) triggered by the C4 activity. Note modulation of the membrane potential showing slight depolarization during the preinspiratory phase. B, Membrane potential change in response to hypercapnia in the presence of 0.5 μm TTX. CO2 concentration was changed from 2% to 8%. Square current pulse (500 ms, 0.1 Hz, 20 pA) was applied to monitor the change of input resistance. Negative deflections of the baseline membrane potential are proportional to input resistance. Note that application of 8% CO2 induced membrane depolarization and increase of input resistance. C, Camera lucida drawing of the neuron. D, Phox2b immunoreactivity of this neuron. The neuron labeled with Lucifer yellow (green) showed Phox2b immunoreactivity (magenta). FN, Facial nucleus; RFN, retrofacial nucleus.
- Figure 4.
Distribution of recorded neurons in the parafacial region. Location of neurons are plotted on 50 μm coronal sections. Values denote distance from level of the caudal end of facial nucleus (VIIc). Circles, Preinspiratory neurons; squares, tonic firing neurons; solid, Phox2b immunoreactive and CO2 sensitive; cross, Phox2b immunoreactive and CO2 insensitive; open, Phox2b negative and CO2 insensitive; FN, facial nucleus; RFN, retrofacial nucleus; CST, corticospinal tract.
Additional Files
Supplemental Data
Files in this Data Supplement:
- supplemental material - Supplemental Materials
- supplemental material - Supplemental Figures
