  Several experiments provide evidence that specialized brain regions
functionally interact and reveal that the brain processes and integrates
information in a specific and structured manner. Networks can be applied to
model brain functional activities, providing means to characterize and quantify
this structured form of organization. Reports substantiate that different
physiological states or diseases that affect the central nervous system may be
associated with alterations in these networks, which might be reflected in
graphs of different architectures. However, the relationship between their
structure and the organism's distinct physiological conditions is poorly
comprehended. Therefore, experiments that estimate the functional neural
networks of subjects exposed to different controlled conditions are highly
relevant. Within this context, this research has sought to model large-scale
functional brain networks during an anesthetic induction process. The
experiment was based on intra-cranial recordings of the neural activities of an
old-world macaque of the species Macaca fuscata. Neural activity was recorded
during a Ketamine-Medetomidine anesthetic induction process, and networks were
estimated sequentially in five-second intervals. One and a half minutes after
administering the anesthetics, changes occurred in various network properties,
revealing a transition in the network architecture. During general anesthesia,
functional connectivity and network integration capabilities were reduced at
both local and global levels. Additionally, it has been verified that the brain
shifted to a highly specific and dynamic state. The results provide empirical
evidence and report the relationship between the induced state of anesthesia
and functional network properties, contributing to the elucidation of novel
aspects of the neural correlates of consciousness.
