Anesthesiology
-
Experimental evidence shows postnatal exposure to anesthesia negatively affects brain development. The PDZ2 domain, mediating protein-protein interactions of the postsynaptic density-95 protein, serves as a molecular target for several inhaled anesthetics. The authors hypothesized that early postnatal disruption of postsynaptic density-95 PDZ2 domain interactions has persistent effects on dendritic spines and cognitive function. ⋯ Early disruption of PDZ2 domain-mediated protein-protein interactions mimics isoflurane in decreasing mushroom spine density and causing learning and memory deficits in mice. Prevention of the decrease in mushroom spine density with a nitric oxide donor supports a role for neuronal nitric oxide synthase pathway in mediating this cellular change associated with cognitive impairment.
-
It is a commonly held view that information flow between widely separated regions of the cerebral cortex is a necessary component in the generation of wakefulness (also termed "connected" consciousness). This study therefore hypothesized that loss of wakefulness caused by propofol anesthesia should be associated with loss of information flow, as estimated by the effective connectivity in the scalp electroencephalogram (EEG) signal. ⋯ Propofol-induced unresponsiveness is marked by a global decrease in information flow, greatest from the lateral frontal and prefrontal brain regions in a posterior and medial direction. Loss of information flow may be a useful measure of connected consciousness.