Differential cell-type dependent brain state modulations of sensory representations in the non-lemniscal mouse inferior colliculus

Sensory responses of the neocortex are strongly influenced by brain state changes. However, it remains unclear whether and how the sensory responses of the midbrain are affected. Here we addressed this issue by using in vivo two-photon calcium imaging to monitor the spontaneous and sound-evoked activities in the mouse inferior colliculus (IC). We developed a method enabling us to image the first layer of non-lemniscal IC (IC shell L1) in awake behaving mice. Compared with the awake state, spectral tuning selectivity of excitatory neurons was decreased during isoflurane anesthesia. Calcium imaging in behaving animals revealed that activities of inhibitory neurons were highly correlated with locomotion. Compared with stationary periods, spectral tuning selectivity of excitatory neurons was increased during locomotion. Taken together, our studies reveal that neuronal activities in the IC shell L1 are brain state dependent, whereas the brain state modulates the excitatory and inhibitory neurons differentially.


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The sample size (number of neurons) of single animal was determined by the virus expression level (the number of virus-effected neurons and nuclear-filled neurons), window implantation quality (stability and clearance), and animal arousal state (active or not active). The sample size of animals were at least 4.
The neurons were selected (draw ROI) based on their spatial (reasonable size) and temporal characters (dynamic fluorescence changes). This procedure did not affect our conclusions. During following analysis, only the significantly tuned neurons were included for comparisons.
Replication was verified by recording neural activity of same animals across different days.
The used neuronal data that were allocated into excitatory neurons (Vglut2-Cre) or inhibitory neurons (VGAT-Cre) groups were based on pvalue test. Allocation was random.
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