Benito de Celis Alonso1, Silke Kreitz2, Silvia Hidalgo Tobn3, Carlos Herrera1, Florian Spiegel2, Sebastian Spiegel2, Marina Sergeyeva2, Andreas Hess2
1Faculty of Medicine, BUAP, Benemrita Universidad Autnoma de Puebla, Puebla, PUE, Mexico; 2Pharmacology and Toxicology, FAU Erlagen-Nuremberg, Erlangen, Bayern, Germany; 3UAM Universidad Autnoma de Mxico, Mexico
Resting-state imaging analyzes the low frequency fluctuations of the BOLD signal (0.01-0.1 Hz) when brain is at rest. It is accepted that these fluctuations reflect neuronal activity (1,2) and also a certain degree of structural (3) and functional connectivity (4). It is known that resting states are reproducible in other order of mammalians (5) and that they are not affected by sleep (6) or even sedation (7). Results for rodents are obtained regularly under anesthesia and apparently the narcotic has no effect on resting-states (8,9) even if other authors establish that there should be anesthetic confounds (10, 11). No study tackles the effect on resting-states of total experimental time under anesthesia. In this study, we compared resting states in two scenarios, one before and after an fMRI experiment and other when no fMRI experiment was performed between resting state measurements. Our results show that there is a decay in both cases of correlation strength that depends on the total time animals have been under anesthesia, This decay does not seem to imply a change in the nature of the correlations.
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