title: Inverted optical intrinsic response accompanied by decreased cerebral blood flow are related to both neuronal inhibition and excitation.
abstract: Negative hemodynamic response has been widely reported in blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging studies, however its origin is still controversial. Optical intrinsic signal (OIS) imaging can be used to study brain activity by simultaneously recording hemodynamic signals at different wavelengths with high spatial resolution. In this study, we found transcorneal electrical stimulation (TcES) could elicit both positive OIS response (POR) and negative OIS response (NOR) in cats' visual cortex. We then investigated the property of this negative response to TcES and its relationship with cerebral blood flow (CBF) and neuronal activity. Results from laser speckle contrast imaging showed decreased CBF in the NOR region while increased CBF in the POR region. Both planar and laminar electrophysiological recordings in the middle (500-700 μm) cortical layers demonstrated that decreased and increased neuronal activities were coexisted in the NOR region. Furthermore, decreased neuronal activity was also detected in the deep cortical layers in the NOR region. This work provides evidence that the negative OIS together with the decreased CBF should be explained by mechanisms of both neuronal inhibition and excitation within middle cortical layers. Our results would be important for interpreting neurophysiological mechanisms underlying the negative BOLD signals.
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Zengguang
authors: Z
authors: Ma
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Pengjia
authors: P
authors: Cao
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Pengcheng
authors: P
authors: Sun
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Linna
authors: L
authors: Zhao
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Liming
authors: L
authors: Li
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Shanbao
authors: S
authors: Tong
authors: Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors: Yiliang
authors: Y
authors: Lu
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Yan
authors: Y
authors: Yan
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Yao
authors: Y
authors: Chen
authors: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors: Xinyu
authors: X
authors: Chai
mesh_terms: D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002415:Cats; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003315:Cornea / Q000502:physiology*; D004558:Electric Stimulation; D006439:Hemodynamics / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood*; D014793:Visual Cortex / Q000098:blood supply* / Q000502:physiology
chemical_list: D010100:Oxygen