title: Intracortical Circuits in Thalamorecipient Layers of Auditory Cortex Refine after Visual Deprivation.
abstract: Sensory cortices do not work in isolation. The functional responses of neurons in primary sensory cortices can be affected by activity from other modalities. For example, short-term visual deprivations, or dark exposure (DE), leads to enhanced neuronal responses and frequency selectivity to sounds in layer 4 (L4) of primary auditory cortex (A1). Circuit changes within A1 likely underlie these changes. Prior studies revealed that DE enhanced thalamocortical transmission to L4 in A1. Because the frequency selectivity of L4 neurons is determined by both thalamocortical and intracortical inputs, changes in intralaminar circuits to L4 neurons might also contribute to improved sound responses. We thus investigated in mouse A1 whether intracortical circuits to L4 cells changed after DE. Using in vitro whole-cell patch recordings in thalamocortical slices from mouse auditory cortex, we show that DE can lead to refinement of interlaminar excitatory as well as inhibitory connections from L2/3 to L4 cells, manifested as a weakening of these connections. The circuit refinement is present along the tonotopic axis, indicating reduced integration along the tonotopic axis. Thus, cross-modal influences may alter the spectral and temporal processing of sensory stimuli in multiple cortical layers by refinement of thalamocortical and intracortical circuits.
authors.affiliation: Department of Biology, University of Maryland , College Park, MD 20742.
authors.forename: Xiangying
authors.initials: X
authors.lastname: Meng
authors.affiliation: Center for Biomedical Engineering and Technology, and Department of Physiology, University of Maryland School of Medicine , Baltimore, MD 21201.
authors.forename: Joseph P Y
authors.initials: JP
authors.lastname: Kao
authors.affiliation: Department of Biology, University of Maryland, College Park, MD 20742; Department of Neuroscience, Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218.
authors.forename: Hey-Kyoung
authors.identifier: 0000-0002-5554-983X
authors.initials: HK
authors.lastname: Lee
authors.affiliation: Department of Biology, University of Maryland , College Park, MD 20742.
authors.forename: Patrick O
authors.identifier: 0000-0002-7529-5435
authors.initials: PO
authors.lastname: Kanold
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000166:cytology / Q000502:physiology*; D003624:Darkness; D005260:Female; D008297:Male; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology; D018408:Patch-Clamp Techniques; D012683:Sensory Deprivation / Q000502:physiology*; D013788:Thalamus / Q000166:cytology / Q000502:physiology*; D046509:Tissue Culture Techniques; D014796:Visual Perception / Q000502:physiology*
keywords: Auditory cortex; crossmodal; dark exposure; intracortical; layer 4; mouse; plasticity; refinement; visual deprivation