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Molecular profiling of CO2/pH-sensitive neurons in the locus coeruleus of bullfrogs reveals overlapping noradrenergic and glutamatergic cell identity.
Amaral-Silva L
,
Santin JM
.
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Locus coeruleus (LC) neurons regulate breathing by sensing CO2/pH. Neurons within the vertebrate LC are the main source of norepinephrine within the brain. However, they also use glutamate and GABA for fast neurotransmission. Although the amphibian LC is recognized as a site involved in central chemoreception for the control of breathing, the neurotransmitter phenotype of these neurons is unknown. To address this question, we combined electrophysiology and single-cell quantitative PCR to detect mRNA transcripts that define norepinephrinergic, glutamatergic, and GABAergic phenotypes in LC neurons activated by hypercapnic acidosis (HA) in American bullfrogs. Most LC neurons activated by HA had overlapping expression of noradrenergic and glutamatergic markers but did not show strong support for GABAergic transmission. Genes that encode the pH-sensitive K+ channel, TASK2, and acid-sensing cation channel, ASIC2, were most abundant, while Kir5.1 was present in 1/3 of LC neurons. The abundance of transcripts related to norepinephrine biosynthesis linearly correlated with those involved in pH sensing. These results suggest that noradrenergic neurons in the amphibian LC also use glutamate as a neurotransmitter and that CO2/pH sensitivity may be linkedto the noradrenergic cell identity.
Fig. 1. Locus coeruleus neurons of adult bullfrogs increased firing frequency in response to hypercapnia (5% CO2). Neurons in the region comprising the locus coeruleus (A) had firing frequency recorded in control conditions (B, C) and after being exposed to 5% CO2 (C, D). Hypercapnia increased firing frequency of all neurons used in this study (E, n = 19). Results were compared using paired t-test.
Fig. 2. mRNA abundance of neurotransmitter markers and candidate pH sensing ion channels. A) Individual neurons harvested after electrophysiological recordings had gene expression analyzed using RT qPCR (n = 19). B) mRNA transcript abundance for markers of noradrenergic (dopamine beta-hydroxylase; DBH), glutamatergic (vesicular glutamate transporter 2; vGluT2), and GABAergic (glutamate decarboxylase 1; GAD1) transmission. C) mRNA transcript abundance for markers of pH sensors, TASK2 (K+ channel), ASIC2 (cation channel), and Kir5.1 (K+ channel). Bars represent means ± SD. Results were compared using one-way ANOVA on rank (Kruskal-Wallis test) followed by Dunn's posthoc tests.
Fig. 3. Correlations between the noradrenergic marker (dopamine beta-hydroxylase; DBH) and pH sensors (n = 19). Expression of DBH was positively correlated to expression of the pH-sensing markers TASK2 (A) and ASIC2 (B) but not to Kir5.1 (C). A positive correlation was also observed between the abundance of TASK2 and ASIC2 (D).
Fig. 4. There was no correlation between the glutamatergic marker (vesicular glutamate transporter 2; VGluT2) and pH sensors (n = 19). The expression of vGluT2 was not related to the expression of the pH-sensing markers TASK2 (A), ASIC2 (B), or Kir5.1 (C). The expression of glutamatergic (VGluT2) and noradrenergic (dopamine beta hydroxylase; DBH) markers were also not related (D).
Figure S1 – Locus coeruleus neurons slightly decreased firing frequency on average when maintained in control conditions. Neurons in the region comprising the locus coeruleus had firing recorded in control conditions for 20 min (A). We observed a slight decrease in firing frequency over time (n=8). Results were compared using paired t-test.
Berridge,
The locus coeruleus-noradrenergic system: modulation of behavioral state and state-dependent cognitive processes.
2003, Pubmed
Berridge,
The locus coeruleus-noradrenergic system: modulation of behavioral state and state-dependent cognitive processes.
2003,
Pubmed
Biancardi,
Locus coeruleus noradrenergic neurons and CO2 drive to breathing.
2008,
Pubmed
Breton-Provencher,
Active control of arousal by a locus coeruleus GABAergic circuit.
2019,
Pubmed
D'Adamo,
Genetic inactivation of Kcnj16 identifies Kir5.1 as an important determinant of neuronal PCO2/pH sensitivity.
2011,
Pubmed
Dias,
Antagonism of orexin receptor-1 in the retrotrapezoid nucleus inhibits the ventilatory response to hypercapnia predominantly in wakefulness.
2009,
Pubmed
Filippi,
vglut2 and gad expression reveal distinct patterns of dual GABAergic versus glutamatergic cotransmitter phenotypes of dopaminergic and noradrenergic neurons in the zebrafish brain.
2014,
Pubmed
Fonseca,
Orexin in the toad Rhinella schneideri: The location of orexinergic neurons and the role of orexin in ventilatory responses to hypercarbia and hypoxia.
2016,
Pubmed
Fonseca,
5-HT neurons of the medullary raphe contribute to respiratory control in toads.
2021,
Pubmed
Fournier,
Role of pontine neurons in central O(2) chemoreflex during development in bullfrogs (Lithobates catesbeiana).
2008,
Pubmed
Fremeau,
The expression of vesicular glutamate transporters defines two classes of excitatory synapse.
2001,
Pubmed
Fuzik,
Integration of electrophysiological recordings with single-cell RNA-seq data identifies neuronal subtypes.
2016,
Pubmed
Gestreau,
Task2 potassium channels set central respiratory CO2 and O2 sensitivity.
2010,
Pubmed
Goaillard,
Ion Channel Degeneracy, Variability, and Covariation in Neuron and Circuit Resilience.
2021,
Pubmed
Gonçalves,
Bicarbonate directly modulates activity of chemosensitive neurons in the retrotrapezoid nucleus.
2018,
Pubmed
González,
Ontogeny of catecholamine systems in the central nervous system of anuran amphibians: an immunohistochemical study with antibodies against tyrosine hydroxylase and dopamine.
1994,
Pubmed
,
Xenbase
González,
Noradrenaline in the brain of the South African clawed frog Xenopus laevis: a study with antibodies against noradrenaline and dopamine-beta-hydroxylase.
1993,
Pubmed
,
Xenbase
Gourine,
Brain H+ /CO2 sensing and control by glial cells.
2022,
Pubmed
Guyenet,
Neural Control of Breathing and CO2 Homeostasis.
2015,
Pubmed
Hammond,
The North American bullfrog draft genome provides insight into hormonal regulation of long noncoding RNA.
2017,
Pubmed
,
Xenbase
Hartman,
The use of dopamine -hydroxylase as a marker for the central noradrenergic nervous system in rat brain.
1972,
Pubmed
Hesselager,
pH Dependency and desensitization kinetics of heterologously expressed combinations of acid-sensing ion channel subunits.
2004,
Pubmed
Hodges,
Defects in breathing and thermoregulation in mice with near-complete absence of central serotonin neurons.
2008,
Pubmed
Howell,
Acid-base balance in cold-blooded vertebrates as a function of body temperature.
1970,
Pubmed
Hu,
Transformation to ischaemia tolerance of frog brain function corresponds to dynamic changes in mRNA co-expression across metabolic pathways.
2022,
Pubmed
Huda,
Acid-sensing ion channels contribute to chemosensitivity of breathing-related neurons of the nucleus of the solitary tract.
2012,
Pubmed
Imber,
A HCO(3)(-)-dependent mechanism involving soluble adenylyl cyclase for the activation of Ca²⁺ currents in locus coeruleus neurons.
2014,
Pubmed
Kobayashi,
Functional and high level expression of human dopamine beta-hydroxylase in transgenic mice.
1994,
Pubmed
Kodama,
Graded Coexpression of Ion Channel, Neurofilament, and Synaptic Genes in Fast-Spiking Vestibular Nucleus Neurons.
2020,
Pubmed
Kumar,
PHYSIOLOGY. Regulation of breathing by CO₂ requires the proton-activated receptor GPR4 in retrotrapezoid nucleus neurons.
2015,
Pubmed
Lee,
The regulation of glutamic acid decarboxylases in GABA neurotransmission in the brain.
2019,
Pubmed
Li,
Transient outwardly rectifying A currents are involved in the firing rate response to altered CO2 in chemosensitive locus coeruleus neurons from neonatal rats.
2013,
Pubmed
Li,
Structural basis for pH gating of the two-pore domain K+ channel TASK2.
2020,
Pubmed
Marder,
Cholinergic motor neurones in the stomatogastric system of the lobster.
1976,
Pubmed
Martinez,
The differential contribution of pacemaker neurons to synaptic transmission in the pyloric network of the Jonah crab, Cancer borealis.
2019,
Pubmed
Milsom,
Control of Breathing in Ectothermic Vertebrates.
2022,
Pubmed
Mir,
Locus Coeruleus Acid-Sensing Ion Channels Modulate Sleep-Wakefulness and State Transition from NREM to REM Sleep in the Rat.
2021,
Pubmed
Moechars,
Vesicular glutamate transporter VGLUT2 expression levels control quantal size and neuropathic pain.
2006,
Pubmed
Moriyama,
Glutamatergic chemical transmission: look! Here, there, and anywhere.
2004,
Pubmed
Mulkey,
Respiratory control by ventral surface chemoreceptor neurons in rats.
2004,
Pubmed
Noronha-de-Souza,
Locus coeruleus is a central chemoreceptive site in toads.
2006,
Pubmed
Pellizzari,
Neuron populations use variable combinations of short-term feedback mechanisms to stabilize firing rate.
2023,
Pubmed
Pinal,
Uniqueness and redundancy in GABA production.
1998,
Pubmed
Pineda,
Carbon dioxide regulates the tonic activity of locus coeruleus neurons by modulating a proton- and polyamine-sensitive inward rectifier potassium current.
1997,
Pubmed
Putnam,
Cellular mechanisms involved in CO(2) and acid signaling in chemosensitive neurons.
2004,
Pubmed
Ransdell,
Rapid homeostatic plasticity of intrinsic excitability in a central pattern generator network stabilizes functional neural network output.
2012,
Pubmed
Reeves,
An imidazole alphastat hypothesis for vertebrate acid-base regulation: tissue carbon dioxide content and body temperature in bullfrogs.
1972,
Pubmed
Santin,
Respiratory signaling of locus coeruleus neurons during hypercapnic acidosis in the bullfrog, Lithobates catesbeianus.
2013,
Pubmed
Santin,
How important is the CO2 chemoreflex for the control of breathing? Environmental and evolutionary considerations.
2018,
Pubmed
Santin,
Activation state of the hyperpolarization-activated current modulates temperature-sensitivity of firing in locus coeruleus neurons from bullfrogs.
2015,
Pubmed
Santin,
Environmentally induced return to juvenile-like chemosensitivity in the respiratory control system of adult bullfrog, Lithobates catesbeianus.
2016,
Pubmed
Santin,
Membrane Voltage Is a Direct Feedback Signal That Influences Correlated Ion Channel Expression in Neurons.
2019,
Pubmed
Santin,
Temperature influences neuronal activity and CO2/pH sensitivity of locus coeruleus neurons in the bullfrog, Lithobates catesbeianus.
2013,
Pubmed
Schulz,
Variable channel expression in identified single and electrically coupled neurons in different animals.
2006,
Pubmed
Schulz,
Quantitative expression profiling of identified neurons reveals cell-specific constraints on highly variable levels of gene expression.
2007,
Pubmed
Stinner,
Effect of temperature on pH and electrolyte concentration in air-breathing ectotherms.
2000,
Pubmed
Tapia,
Neurotransmitter identity and electrophysiological phenotype are genetically coupled in midbrain dopaminergic neurons.
2018,
Pubmed
Temporal,
Neuromodulation independently determines correlated channel expression and conductance levels in motor neurons of the stomatogastric ganglion.
2012,
Pubmed
Temporal,
Activity-dependent feedback regulates correlated ion channel mRNA levels in single identified motor neurons.
2014,
Pubmed
Vallejo,
Noradrenergic modulation determines respiratory network activity during temperature changes in the in vitro brainstem of bullfrogs.
2018,
Pubmed
van de Wiel,
Connexin26 mediates CO2-dependent regulation of breathing via glial cells of the medulla oblongata.
2020,
Pubmed
Veerla,
Analysis of promoter regions of co-expressed genes identified by microarray analysis.
2006,
Pubmed
Wang,
Locus Coeruleus in Non-Mammalian Vertebrates.
2022,
Pubmed
Yang,
Locus coeruleus anchors a trisynaptic circuit controlling fear-induced suppression of feeding.
2021,
Pubmed
