title: Synaptic Basis for the Generation of Response Variation in Auditory Cortex.
abstract: Cortical neurons can exhibit significant variation in their responses to the same sensory stimuli, as reflected by the reliability and temporal precision of spikes. However the synaptic mechanism underlying response variation still remains unclear. Here, in vivo whole-cell patch-clamp recording of excitatory neurons revealed variation in the amplitudes as well as the temporal profiles of excitatory and inhibitory synaptic inputs evoked by the same sound stimuli in layer 4 of the rat primary auditory cortex. Synaptic inputs were reliably induced by repetitive stimulation, although with large variation in amplitude. The variation in the amplitude of excitation was much higher than that of inhibition. In addition, the temporal jitter of the synaptic onset latency was much smaller than the jitter of spike response. We further demonstrated that the amplitude variation of excitatory inputs can largely account for the spike variation, while the jitter in spike timing can be primarily attributed to the temporal variation of excitatory inputs. Furthermore, the spike reliability of excitatory but not inhibitory neurons is dependent on tone frequency. Our results thus revealed an inherent cortical synaptic contribution for the generation of variation in the spike responses of auditory cortical neurons.
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Can
authors.initials: C
authors.lastname: Tao
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Guangwei
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Sumei
authors.initials: S
authors.lastname: Yan
authors.affiliation: Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA.
authors.forename: Li I
authors.initials: LI
authors.lastname: Zhang
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Neurobiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan St., Chongqing, 400038, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology*; D013569:Synapses / Q000502:physiology*