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

Imagem de cálcio de dois fótons e campo amplo no colículo superior

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.

Autor em destaque: Revelando a codificação neural e os mecanismos de processamento visual no colículo superior 

Imagem de cálcio no colículo superior de camundongos

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  

Imagem de Cálcio de Campo Amplo de Neurônios Colículos Superiores de Camundongos

Para começar, injete 100 nanolitros de AAV expressando GCaMP6m a uma profundidade de 200 micrômetros no centro de cada lado do SC no camundongo mutante cujo córtex posterior não conseguiu se desenvolver. Após aproximadamente três semanas, implante uma cobertura de cinco milímetros de diâmetro deslizando sobre o SC. Depois de fixar a tampa deslizante, adquira imagens usando uma câmera CMOA depois de passar por um filtro de emissão a 10 hertz. As respostas de cálcio dos neurônios SC de um camundongo mutante do córtex parcial foram obtidas por microscopia de campo amplo.A imagem adquirida foi reduzida para um quarto do tamanho original, e respostas de cálcio evocadas visualmente são mostradas.

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 ...

Neurociência

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

Preparo de ventosa e plugs para obtenção de imagens de cálcio em camundongos

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

Injeção de Constructo Viral (AAV) no Colículo Superior de Camundongos para Imagem com Cálcio

Implantation of the Headplate in Mouse for Calcium Imaging 

Implante da Headplate em Camundongos para Imagem por Cálcio 

Implanting the Plug in the Mouse for Calcium Imaging

Implantando o plugue no mouse para imagens de cálcio

Two-Photon Calcium Imaging of Mouse Superior Colliculus Neurons

Imagem de cálcio de dois fótons de neurônios do colículo superior de camundongos