Dual brain cortical calcium imaging reveals social interaction-specific correlated activity in mice

Abstract

We employ cortical mesoscale GCaMP6s imaging of intracellular calcium levels to establish how brain activity is correlated when two mice engage in a staged social touch-like interaction. Using a rail system, two head-fixed mice begin at a distance where social touch is not possible (160 mm), after 90s they are brought so that macrovibrissae contact each other (6-12 mm snout to snout) for an additional 135s. During the period before, during, and after contact cortical mesoscale GCAMP6 signals were recorded from both mice simultaneously. When the mice were together we observed bouts of mutual whisking resulting in cross-mouse correlated barrel cortex activity. While correlations between whisker cortices were expected given mutual whisking, we also found significant synchronized brain-wide calcium signals at a frequency band of 0.01-0.1Hz when the mice were together. We present dual mouse brain imaging as new paradigm to assess social interactions in a more constrained manner. The effects of social interaction extend outside of regions associated with mutual touch and have global synchronizing effects on cortical activity.

Miniaturized head-mounted device for whole cortex mesoscale imaging in freely behaving mice

“…Even relatively simple behavioral assays in awake head-fixed animals require significant time for acclimatization and training 18,19 . To overcome some limitations of head-fixation, immersive virtual reality environments 20 , voluntarily head-fixation of mice in their home cages 21 , and a moveable head-restraint apparatus 22 have been used in mesoscale imaging studies. However, the lack of vestibular inputs and disruptions in eye-head movement coupling 23 ,and behavioral effects from increased stress 24 can significantly alter neural activity during head-fixation as compared to freely behaving animals 25 .…”

Chronic multiscale resolution of mouse brain networks using combined mesoscale cortical imaging and subcortical fiber photometry

“…Using these multiscale methods in neuroimaging will provide a richer and more thorough view of the brain activities underlying behavior. Combined with our head-fixed social interaction apparatus, 27 this method may provide richer insights into cortical and hypothalamic networks in social interaction. 28,29 To study the correlation between corticostriatal recording and behavior, we measured brain activity and behavior in head-fixed mice.…”

Comparison between transgenic and AAV-PHP.eB-mediated expression of GCaMP6s using in vivo wide-field functional imaging of brain activity

“…Clear dental cement, prepared by mixing 1 scoop of Metabond powder, 6 drops of C&B Metabond Quick Base, and one drop of C&B Universal catalyst (Parkell, Edgewood, New York) was used to glue a titanium head-fixing bar (22 × 3.25 × 2.8 mm) to the cerebellar plate, directly posterior to the lambda. 37 A layer of dental adhesive was applied directly on the skull, and a precut cover glass was placed gently on top of the mixture before it solidified. 15,37 For two of the AAV-PHP.eB mice, a stainless steel setscrew 15 was used for head-fixing instead of the titanium bar.…”

“…37 A layer of dental adhesive was applied directly on the skull, and a precut cover glass was placed gently on top of the mixture before it solidified. 15,37 For two of the AAV-PHP.eB mice, a stainless steel setscrew 15 was used for head-fixing instead of the titanium bar. Animals were monitored daily for 1 week postsurgery.…”