General anesthetics are commonly used in animal models to study how sensory
signals are represented in the brain. Here, we used two-photon (2P) calcium
activity imaging with cellular resolution to investigate how neuronal activity
in layer 2/3 of the mouse barrel cortex is modified under the influence of
different concentrations of chemically distinct general anesthetics. Our
results show that a high isoflurane dose induces synchrony in local neuronal
networks and these cortical activity patterns closely resemble those observed
in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also
induced similar activity patterns. While investigating the effects of deep
isoflurane anesthesia on whisker and auditory evoked responses in the barrel
cortex, we found that dedicated spatial regions for sensory signal processing
become disrupted. We propose that our isoflurane-2P imaging paradigm can serve
as an attractive model system to dissect cellular and molecular mechanisms
that induce the anesthetic state, and it might also provide important insight
into sleep-like brain states and consciousness