title: GABA-ergic interneurons involved in transcallosal inhibition of the visual cortices in vivo in mice.
abstract: In the current study we investigated the role of the corpus callosum, particularly the gamma-aminobutyric acid-ergic (GABAergic) projection neurons involved in interhemispheric inhibition (IHI). In order to explore IHI in primary visual cortices, we adopted a protocol whereby we performed a direct current lesion of the unilateral primary visual cortex with or without posterior callosotomy, and used two-photon Ca(2+)in vivo imaging on the opposite unaffected region to detect neural activities in mice. Following this procedure, the numbers of vesicular GABAergic transporters (VGATs) and GABAergic interneurons in the unaffected primary cortex were determined using immunofluorescence staining. Results indicated that following unilateral visual cortical lesioning without callosotomy, the neuronal Ca(2+) activities in the opposite side were significantly increased. However, the neuronal activities of the unaffected visual cortex in animals with unilateral cortical lesion with callosotomy were not significantly different. Additionally, there was no significant difference in the numbers of GABAergic interneurons in the unaffected region between each group, while the number of VGATs in the unaffected region was significantly decreased following unilateral visual cortical lesion without callosotomy, which was unchanged once with callosotomy. Finally, callosotomy alone without cortical lesioning produced no change in neuronal activities, the number of GABAergic interneurons or VGATs. Our results demonstrate that IHI between the homologous primary visual cortices occurs via the corpus callosum, and further indicate the important involvement of long-range GABAergic interneurons in transcallosal inhibition.
authors: Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors: Xiao-fei
authors: XF
authors: He
authors: Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China.
authors: Yue
authors: Y
authors: Lan
authors: Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors: Qun
authors: Q
authors: Zhang
authors: Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors: Feng-yin
authors: FY
authors: Liang
authors: Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors: Chuan-ming
authors: CM
authors: Luo
authors: Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China. Electronic address: guangchingx@163.com.
authors: Guang-qing
authors: GQ
authors: Xu
authors: Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors: Zhong
authors: Z
authors: Pei
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent / Q000378:metabolism; D003337:Corpus Callosum / Q000502:physiology* / Q000503:physiopathology; D005455:Fluorescent Antibody Technique; D007839:Functional Laterality / Q000502:physiology*; D059330:GABAergic Neurons / Q000502:physiology*; D007395:Interneurons / Q000502:physiology*; D008297:Male; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009433:Neural Inhibition / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology / Q000503:physiopathology; D014793:Visual Cortex / Q000502:physiology* / Q000503:physiopathology; D056969:Voltage-Sensitive Dye Imaging; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D005680:gamma-Aminobutyric Acid; D002118:Calcium
keywords: Corpus callosum; Direct current; Interhemispheric inhibition; Two-photon; Visual cortex