Transcriptomes and Neurotransmitter Profiles of Classes of Gustatory and Somatosensory Neurons in the Geniculate Ganglion

Nat Commun. 2017 Oct 2;8(1):760. doi: 10.1038/s41467-017-01095-1.

Abstract

Taste buds are innervated by neurons whose cell bodies reside in cranial sensory ganglia. Studies on the functional properties and connectivity of these neurons are hindered by the lack of markers to define their molecular identities and classes. The mouse geniculate ganglion contains chemosensory neurons innervating lingual and palatal taste buds and somatosensory neurons innervating the pinna. Here, we report single cell RNA sequencing of geniculate ganglion neurons. Using unbiased transcriptome analyses, we show a pronounced separation between two major clusters which, by anterograde labeling, correspond to gustatory and somatosensory neurons. Among the gustatory neurons, three subclusters are present, each with its own complement of transcription factors and neurotransmitter response profiles. The smallest subcluster expresses both gustatory- and mechanosensory-related genes, suggesting a novel type of sensory neuron. We identify several markers to help dissect the functional distinctions among gustatory neurons and address questions regarding target interactions and taste coding.Characterization of gustatory neural pathways has suffered due to a lack of molecular markers. Here, the authors report single cell RNA sequencing and unbiased transcriptome analyses to reveal major distinctions between gustatory and somatosensory neurons and subclusters of gustatory neurons with unique molecular and functional profiles.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Ear Auricle / innervation
  • Geniculate Ganglion / cytology
  • Geniculate Ganglion / metabolism*
  • Homeodomain Proteins / genetics
  • Mice
  • Nerve Tissue Proteins / genetics
  • Neurotransmitter Agents / metabolism*
  • Receptors, Purinergic P2X2 / genetics
  • Receptors, Purinergic P2X3 / genetics
  • Sensory Receptor Cells / metabolism*
  • Sequence Analysis, RNA
  • Single-Cell Analysis
  • Sodium-Potassium-Exchanging ATPase / genetics
  • Synaptosomal-Associated Protein 25 / genetics
  • Taste
  • Taste Buds
  • Tongue / innervation
  • Touch
  • Transcription Factors / genetics
  • Transcriptome*

Substances

  • Homeodomain Proteins
  • NBPhox protein
  • Nerve Tissue Proteins
  • Neurotransmitter Agents
  • P2rx2 protein, mouse
  • P2rx3 protein, mouse
  • Prrxl1 protein, mouse
  • Receptors, Purinergic P2X2
  • Receptors, Purinergic P2X3
  • Snap25 protein, mouse
  • Synaptosomal-Associated Protein 25
  • Transcription Factors
  • Fxyd2 protein, mouse
  • Sodium-Potassium-Exchanging ATPase