Name: Preparation of a Suction Cup and Plugs for Calcium Imaging in Mouse
Uploaded: 2023-04-21T15:00:00
Description: Watch this Scientific Journal Video about Preparation of a Suction Cup and Plugs for Calcium Imaging in Mouse at JoVE.com

preparation of a suction cup and plugs for calcium imaging in mouse

Imaging a due fotoni e calcio ad ampio campo nel collicolo superiore

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.

Autore in primo piano: Svelare la codifica neurale e i meccanismi di elaborazione visiva nel collicolo superiore 

Imaging del calcio nel collicolo superiore del topo

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 Preparation of a Suction Cup and Plugs for Calcium Imaging in Mouse at JoVE.com

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

Preparazione di una ventosa e tappi per l'imaging del calcio nel topo

Inizia il processo di creazione di una ventosa depositando una goccia di PBS in un piatto acrilico. Utilizzare un ago piatto calibro 21 per riempire la punta dell'ago con PBS per capillarità. Coprire la punta dell'ago con un adesivo siliconico traslucido e fissarlo per circa 10 minuti.Tagliare l'adesivo siliconico con le forbici fino a ottenere un disco di due millimetri di diametro. Per preparare i tappi, prendi uno spessore di plastica di 0,75 millimetri e ritaglia un quadrato di un centimetro al centro. Pulisci lo spessore e i due blocchi acrilici con alcol e puliscili con carta per lenti.Posizionare lo spessore su un blocco acrilico e depositare l'adesivo siliconico al centro per riempire il 90% dell'apertura. Aggiungi un altro blocco acrilico. Applicare circa un chilogrammo di forza e attendere 20 minuti.Sotto un microscopio operatorio, tagliare l'adesivo siliconico con un bisturi in prismi triangolari da 1,5 millimetri. Rimuovere la polvere dai prismi triangolari con del nastro di plastica appiccicoso e posizionarli su un vetrino. Posizionare il vetrino coprioggetto con i prismi triangolari sotto un trattamento corona e accenderlo.Avvicinare il trattamento corona al vetrino coprioggetto finché non compare un fulmine e tenerlo in quella posizione per alcuni minuti fino a quando i prismi e il vetrino coprioggetto non sono fissati. Dopo aver messo i tappi in una capsula di Petri, incubare a 70 gradi Celsius per una notte.

Research

JoVE Journal

Neuroscience

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

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 ...