Name: Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons
Uploaded: 2023-04-21T15:00:00
Description: Watch this Scientific Journal Video about Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons at JoVE.com

wide-field calcium imaging of mouse superior colliculus neurons

Imagerie calcique à deux photons et à grand champ dans le colliculus supérieur

The superior colliculus (SC) is an important visual center in all vertebrates. In mammals, it receives direct inputs from the retina and the visual cortex1. While optical recording has been widely applied to the cortex2,3,4,5, its application in the SC is hindered by poor optical accesss6,7,8,9,10,11,12,13,14,15,16,17,18,19. The goal of this protocol is to provide details about two complementary methods for optical recording of the neural activity in the SC.
The SC is located beneath the cortex and transverse sinus, which limits optical access to the collicular neurons. One approach to overcome this limitation is to aspirate the overlaying cortex and expose the anterior-lateral SC7,9,10,13,14,19. However, because the SC receives cortical inputs, such an operation might affect how the SC neurons respond to visual stimuli. To overcome this limitation, we detail here an alternative protocol to image the superficial layer of the posterior-medial SC with a silicon plug, while leaving the cortex intact8,11. Specifically, to achieve single-cell resolution, we applied two-photon microscopy to image calcium responses in the posterior-medial SC of wild-type mice. In addition, to achieve broad coverage, we applied wide-field microscopy to image the entire SC of a mutant mouse whose posterior cortex has not developed20.
The two methods described in this protocol are complementary to each other. The two-photon calcium imaging without ablating the cortex is appropriate for recording neural activity at&#160;single-cell resolution with intact cortical inputs. The wide-field calcium imaging is appropriate for recording neural activity in the entire SC while sacrificing spatial resolution.

Pleins feux sur l’auteur : Dévoilement du codage neuronal et des mécanismes de traitement visuel dans le colliculus supérieur 

Imagerie calcique dans le colliculus supérieur de souris

My research focuses on neural coding and mechanisms for visual processing. We are trying to answer how various information is encoded in the brain, especially in the superior colliculus under the underlying neuro-mechanisms. To understand visual processing, scientists combine various approaches, including neuronal morphology, antegrade and retrograde tracing, IL sequencing, neuro modeling, machine learning, is understood well.The challenge is to remove the skull over the SSA, cutting and left in the bone in one larger piece, is likely to fail because the bone is attached to the dura. By combining two photo on a wide field calcium image, our recent work revealed the function architecture of motion direction in the mouse SC at both single cell resolution and a global scale. We found that neurons with similar preference form patches up to 500 micrometer under global to the upward on the nasal motion.With our protocol, we are addressing two research gaps. First, researchers can perform long-term cast imaging in mouse SC at a single cell resolution without breaking the cortex. Secondly, researchers can record the neuroactivity across the entire SC using widefield microscoping.Our protocol provides a measure to image the posterior medial SC at single cell resolution with a intact cortex in mice. Also, we use a biocompatible plug to expose the SC, which reduces infection for chronic imaging. Our results provide a way to study the neural coding of visual information across a large visual field.Combined with optogenetics, one can study half inputs from different brain regions modulating the neuroactivity in SC.

Watch this Scientific Journal Video about Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons at JoVE.com

Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons  

Imagerie calcique à grand champ des neurones du colliculus supérieur de souris

Pour commencer, injectez 100 nanolitres d’AAV exprimant GCaMP6m à une profondeur de 200 micromètres au centre de chaque côté du SC à la souris mutante dont le cortex postérieur n’a pas réussi à se développer. Après environ trois semaines, implantez une lamelle de cinq millimètres de diamètre sur le SC. Après avoir fixé la lamelle, acquérez des images à l’aide d’une caméra CMOA après avoir passé un filtre d’émission à 10 hertz. Les réponses calciques des neurones SC d’une souris mutante du cortex partiel ont été imagées à l’aide de la microscopie à grand champ.L’image acquise a été réduite à un quart de la taille d’origine, et les réponses calciques évoquées visuellement sont montrées.

Research

JoVE Journal

Neuroscience

Wide-Field Calcium Imaging of Mouse Superior Colliculus Neurons

Calcium Imaging in Mouse Superior Colliculus

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the ...

Recherche

Neurosciences

Preparation of a Suction Cup and Plugs for Calcium Imaging in Mouse

Préparation d’une ventouse et de bouchons pour l’imagerie calcique chez la souris

Viral Construct (AAV) Injection in Mouse Superior Colliculus for Calcium Imaging

Injection de construction virale (AAV) dans un colliculus supérieur de souris pour l’imagerie calcique

Implantation of the Headplate in Mouse for Calcium Imaging 

Implantation de la plaque frontale chez la souris pour l’imagerie calcique 

Implanting the Plug in the Mouse for Calcium Imaging

Implantation du bouchon dans la souris pour l’imagerie calcique

Two-Photon Calcium Imaging of Mouse Superior Colliculus Neurons

Imagerie calcique à deux photons des neurones du colliculus supérieur de souris