Biology subjects

Sonoda, K.

Publications and source records attributed to Sonoda, K..

3 recordsLinked to original sources

bioRxiv2024

Claudin-11 regulates immunological barrier formation and spermatogonial proliferation through stem cell factor

Tight junctions (TJs) between adjacent Sertoli cells are believed to form immunological barriers that protect spermatogenic cells expressing autoantigens from autoimmune responses. However, there is no direct evidence that Sertoli cell TJs (SCTJs) do indeed form immunological barriers. Here, we analyzed male mice lacking claudin-11 (Cldn11), which encodes a SCTJ component, and found autoantibodies against antigens of spermatocytes/spermatids in their sera. Defective spermatogenesis was not restored in Cldn11-deficient mice on a genetic background mimicking a severely impaired adaptive immune system. This suggests that defective spermatogenesis is not caused by autoimmune responses against spermatogenic cells. Further analyses showed that Cldn11 knockout impaired Sertoli cell polarization, localization of stem cell factor (SCF) (a key molecule for maintaining differentiating spermatogonia) to the basal compartment of seminiferous tubules, and also proliferation of differentiating spermatogonia. We propose that CLDN11 creates a microenvironment for SCF-mediated spermatogonial proliferation at the basal compartment via Sertoli cell polarization.

developmental biology↗

bioRxiv2021

Spontaneous modulations of high frequency cortical activity

ObjectiveWe clarified the clinical and mechanistic significance of physiological modulations of high-frequency broadband cortical activity associated with spontaneous saccadic eye movements during a resting state. MethodsWe studied 30 patients who underwent epilepsy surgery following extraoperative electrocorticography and electrooculography recordings. We determined whether high-gamma activity at 70-110 Hz preceding saccade onset would predict upcoming ocular behaviors. We assessed how accurately the model incorporating saccade-related high-gamma modulations would localize the primary visual cortex defined by electrical stimulation. ResultsThe whole-brain level dynamic atlas demonstrated transient high-gamma suppression in the striatal region before saccade onset and high-gamma augmentation subsequently involving the widespread posterior brain regions. More intense striatal high-gamma suppression predicted the upcoming saccade directed to the ipsilateral side and lasting longer in duration. The bagged-tree-ensemble model demonstrated that intense saccade-related high-gamma modulations localized the visual cortex with an accuracy of 95%. ConclusionsWe successfully animated the neural dynamics supporting saccadic suppression, a principal mechanism minimizing the perception of blurred vision during rapid eye movements. The primary visual cortex per se may prepare actively in advance for massive image motion expected during upcoming prolonged saccades. SignificanceMeasuring saccade-related electrocorticographic signals may help localize the visual cortex and avoid misperceiving physiological high-frequency activity as epileptogenic. Highlights- The whole-brain level dynamic atlas animated spontaneous high gamma modulations associated with saccadic eye movements. - Preceding high gamma activity in the striatal cortex predicted the direction and duration of the upcoming saccades. - Saccade-related high-gamma modulations localized the stimulation-defined visual cortex with an accuracy of 95%.

neuroscience↗

bioRxiv2018

Astrocytes in the mouse visual cortex reliably respond to visual stimulation

Astrocytes are known to contact with a great number of synapses and may integrate sensory inputs. In the ferret primary visual cortex, astrocytes respond to a visual stimulus with a delay of several seconds with respect to the surrounding neurons. However, in the mouse visual cortex, it remains unclear whether astrocytes respond to visual stimulations. In this study, using dual-color simultaneous in vivo two-photon Ca2+ imaging of neurons and astrocytes in the awake mouse visual cortex, we examined the visual responsiveness of astrocytes and their precise response timing relative to the surrounding neurons. Neurons reliably responded to visual stimulations, whereas astrocytes often showed neuromodulator-mediated global activities, which largely masked small periodic activities. Administration of the selective 1-adrenergic receptor antagonist prazosin substantially reduced such global astrocytic activities without affecting the neuronal visual responses. In the presence of prazosin, astrocytes showed weak but consistent visual responses mostly at their somata. Cross-correlation analysis estimated that the astrocytic visual responses were delayed by approximately 5 s relative to the surrounding neuronal responses. In conclusion, our research demonstrated that astrocytes in the primary visual cortex of awake mice responded to visual stimuli with a delay of several seconds relative to the surrounding neurons, which may indicate the existence of a common mechanism of neuron-astrocyte communication across species.\n\nHighlightsO_LIWe performed dual-color in vivo two-photon Ca2+ imaging of neurons and astrocytes.\nC_LIO_LI1-adrenoblocker prazosin substantially reduced global astrocytic activities.\nC_LIO_LIAstrocytes showed weak but reliable visual responses in the awake mouse visual cortex.\nC_LIO_LIAstrocytic visual responses were delayed by 5 s relative to the neuronal ones.\nC_LI

neuroscience↗