Characterization of auditory synaptic inputs to gerbil perirhinal cortex

Front Neural Circuits. 2015 Aug 14:9:40. doi: 10.3389/fncir.2015.00040. eCollection 2015.


The representation of acoustic cues involves regions downstream from the auditory cortex (ACx). One such area, the perirhinal cortex (PRh), processes sensory signals containing mnemonic information. Therefore, our goal was to assess whether PRh receives auditory inputs from the auditory thalamus (MG) and ACx in an auditory thalamocortical brain slice preparation and characterize these afferent-driven synaptic properties. When the MG or ACx was electrically stimulated, synaptic responses were recorded from the PRh neurons. Blockade of type A gamma-aminobutyric acid (GABA-A) receptors dramatically increased the amplitude of evoked excitatory potentials. Stimulation of the MG or ACx also evoked calcium transients in most PRh neurons. Separately, when fluoro ruby was injected in ACx in vivo, anterogradely labeled axons and terminals were observed in the PRh. Collectively, these data show that the PRh integrates auditory information from the MG and ACx and that auditory driven inhibition dominates the postsynaptic responses in a non-sensory cortical region downstream from the ACx.

Keywords: auditory cortex; calcium; intrinsic; medial geniculate; synaptic.

Publication types

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

MeSH terms

  • Animals
  • Auditory Cortex / cytology*
  • Auditory Cortex / physiology*
  • Auditory Pathways / drug effects
  • Auditory Pathways / physiology*
  • Bicuculline / analogs & derivatives
  • Bicuculline / pharmacology
  • Calcium / metabolism
  • Dextrans / metabolism
  • Electric Stimulation
  • Excitatory Amino Acid Antagonists / pharmacology
  • Excitatory Postsynaptic Potentials / drug effects
  • GABA-A Receptor Antagonists / pharmacology
  • Gerbillinae
  • In Vitro Techniques
  • Inhibitory Postsynaptic Potentials / drug effects
  • Neurons / drug effects
  • Neurons / physiology*
  • Patch-Clamp Techniques
  • Potassium Channel Blockers / pharmacology
  • Quinoxalines / pharmacology
  • Rhodamines / metabolism
  • Statistics, Nonparametric
  • Synapses / drug effects
  • Synapses / physiology*
  • Thalamus / physiology


  • Dextrans
  • Excitatory Amino Acid Antagonists
  • Fluoro-Ruby
  • GABA-A Receptor Antagonists
  • Potassium Channel Blockers
  • Quinoxalines
  • Rhodamines
  • FG 9041
  • bicuculline methobromide
  • Calcium
  • Bicuculline