ON and OFF unipolar brush cells transform multisensory inputs to the auditory system

Neuron. 2015 Mar 4;85(5):1029-42. doi: 10.1016/j.neuron.2015.02.009.

Abstract

Unipolar brush cells (UBCs) of the dorsal cochlear nucleus (DCN) and vestibular cerebellar cortex receive glutamatergic mossy fiber input on an elaborate brush-like dendrite. Two subtypes of UBC have been established based on immunohistochemical markers and physiological profiles, but the relation of these subtypes to the response to mossy fiber input is not clear. We examined the synaptic physiology of auditory UBCs in mouse brain slices, identifying two response profiles, and correlated each with a specific UBC subtype. One subtype had a striking biphasic excitatory response mediated by AMPAR and mGluR1α. The second was mGluR1α negative and was dominated by a strongly inhibitory outward K(+) current. These two subtypes upregulated or downregulated spontaneous firing, respectively. By analogy to the retina, we propose that UBCs comprise ON and OFF cells with respect to their response to glutamatergic input and may therefore provide distinct parallel processing of multisensory input to their targets.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Auditory Pathways / cytology*
  • Auditory Pathways / physiology*
  • Brain Stem / cytology*
  • Brain Stem / physiology*
  • Cerebellum / cytology
  • Cerebellum / physiology
  • Interneurons / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Nerve Fibers / physiology*
  • Organ Culture Techniques