Anesthesia Lowers Spatial Frequency Preference in the Primary Visual Cortex

This study examined the impact of general anesthesia on visual processing in the mouse primary visual cortex (V1). By directly comparing visual responses in the same layer 2/3 neurons between the awake and anesthetized states, we found that isoflurane anesthesia significantly shifts the preferred spatial frequency (SF) of neurons to lower values while leaving orientation tuning intact. This downward SF shift impaired the ability to encode fine visual details (high-SF) but not coarse information (low-SF). The shift was observed across all recorded cell types--including excitatory, somatostatin-expressing (SOM), and parvalbumin-expressing (PV) inhibitory neurons--though their respective magnitudes and underlying patterns were distinct. Furthermore, modulation of response gain and tuning sharpness was observed exclusively in SOM neurons. These results highlight the specific effects of anesthesia, which vary with visual feature and neuron type. These findings suggest that reduced sensory perception during anesthesia is linked to a degradation in spatial resolution at the cellular level.