title: Unbalanced synaptic inputs underlying multi-peaked frequency selectivity in rat auditory cortex.
abstract: By measuring the frequency selectivity at different intensities in the primary auditory cortex of adult rats, we found that a small group of cortical neurons can exhibit relatively weak but robust selectivity at multiple frequencies that are different from the most preferred frequency. Both in vivo multi-unit recordings (26/93 recordings) and single-unit recordings (16/137 neurons) confirmed that the preferred frequencies are periodic and have an averaged bandwidth (BW) of 0.3-0.4 octaves, which leads to multi-peaked frequency selectivity. Interestingly, the averaged bandwidth of the ripple in the frequency response tuning curve was invariant with the sound intensity. An investigation of the synaptic currents in vivo also revealed similar multi-peaked frequency selectivity for both excitation and inhibition. While the excitatory and inhibitory inputs were relatively balanced for most frequencies, the ratio between excitation and inhibition at the peak and valley of each ripple was highly unbalanced. Since this multi-peaked frequency selectivity can be observed at the synaptic, single-cell, and population levels, our results reveal a potential mechanism underlying the multi-peaked pattern of frequency selectivity in the primary auditory cortex.
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Can
authors.initials: C
authors.lastname: Tao
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Guangwei
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Sumei
authors.initials: S
authors.lastname: Yan
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Yi
authors.identifier: 0000-0002-2623-8960
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Neurobiology, Chongqing Key Laboratory of Neurobiology, Third Military Medical University, 30 GaoTanyan Street, Chongqing, 400038, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004553:Electric Conductivity; D005260:Female; D008564:Membrane Potentials / Q000502:physiology; D008839:Microelectrodes; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*
keywords: frequency selectivity; in-vivo patchclamp; level invariance; primary auditory cortex