Assessing brain state and anesthesia level with two-photon calcium signals

Abstract

Brain states, such as wake, sleep, or different depths of anesthesia are usually assessed using electrophysiological techniques, such as the local field potential (LFP) or the electroencephalogram (EEG), which are ideal signals for detecting activity patterns such as asynchronous or oscillatory activities. However, it is technically challenging to have these types of measures during calcium imaging recordings such as two-photon or wide-field techniques. Here, using simultaneous two-photon and LFP measurements, we demonstrate that despite the slower dynamics of the calcium signal, there is a high correlation between the LFP and two-photon signals taken from the neuropil outside neuronal somata. Moreover, we find the calcium signal to be systematically delayed from the LFP signal, and we use a model to show that the delay between the two signals is due to the physical distance between the recording sites. These results suggest that calcium signals alone can be used to detect activity patterns such as slow oscillations and ultimately assess the brain state and level of anesthesia.

MicroRNA-9 promotes axon regeneration of mauthner-cell in zebrafish via her6/ calcium activity pathway

“…Calcium plays a pivotal role in orchestrating a myriad of intricate processes within the organism. It actively contributes to the transmission of neurotransmitters and serves as a key initiator of axonal regeneration[ 25 – 27 , 29 , 30 ]. The neuronal activity driven by calcium dynamics exerts a regulatory influence on axon regeneration, underscoring the significance of alterations in calcium levels as pivotal indicators throughout the process of axon regeneration [ 25 – 27 , 29 , 30 ].…”

“…It actively contributes to the transmission of neurotransmitters and serves as a key initiator of axonal regeneration[ 25 – 27 , 29 , 30 ]. The neuronal activity driven by calcium dynamics exerts a regulatory influence on axon regeneration, underscoring the significance of alterations in calcium levels as pivotal indicators throughout the process of axon regeneration [ 25 – 27 , 29 , 30 ]. Capitalizing on the unique transparency of zebrafish and their inherent capability for in vivo imaging, we employed the novel calcium probe, NEMOf, to capture calcium level dynamics during axon regeneration.…”

“…Characterization of changes in calcium levels in cells has been an important direction for detecting neuronal activity. GCaMP6f, GCaMP7f, and GCaMP8 have been commonly used as important probes for detecting calcium activity in neurons in recent years [ 25 – 27 ]. Combined with the advantages of zebrafish transparency, more and more studies have begun to use these probes for two-photon calcium imaging in zebrafish [ 21 , 28 – 30 ].…”

Dynamics and bifurcation structure of a mean-field model of adaptive exponential integrate-and-fire networks

“…The results show the firing rate of each population for three different values of the parameter b , which directly affects the range of the adaptation variable w . This adaptation variable is a slower variable playing an important role in modeling phenomena such as neuromodulation [Goldman et al, 2020, Tort-Colet et al, 2023]…”

Mapping brain state-dependent sensory responses across the mouse cortex

“…Firing rates were converted to calcium imaging signals through implementing a calcium monitor to the TVB model as in. 67 , 68 We simulated evoked responses in each brain state by applying an input current of 60 ms to the right barrel field cortex node. The onset of the stimulus was randomly delayed in each trial.…”