Little has been revealed about silica pathways, which apparently was a technology in the construction of Cylon "brains." Commander Adama compares silica pathways to a brain of sorts. He quickly mentions the technology as he challenges Leoben Conoy of being a new form of Cylon while the two are walking deep inside Ragnar Anchorage (Miniseries).
Apparently, Cylons are affected by the radiation generated by Ragnar's planetary storm. The radiation effects are not immediate on even Cylon agents, occurring within the space of hours after initial exposure. Humans appear to experience no symptoms to exposure.
During or after the Cylon War, it is probable that the Colonial Fleet picked this location for the Anchorage as a last refuge "pit stop" for Colonial ships who fought off the mechanical Cylons in the war. It is unknown how quickly (or slowly) mechanical Cylons are affected by the Ragnar radiation.
Based on observations of the two Cylon agents in the Miniseries after their extended stays within the station, symptoms seem to include elements of headache, nausea, and some level of fever or other heat-producing symptom. A Cylon agent sweats with extended exposure (Miniseries).
Whatever silica pathways may be, medical scanning technology cannot distinguish between them and human brain tissue. Otherwise, a brain scan would visually show the differences between Cylon and human brains, foregoing the need for Gaius Baltar's Cylon detector.
Notes
- Since humans are based on carbon compounds, viewers may think that synthetic Cylons would be easily detectable since human bodies should have far fewer silicate compounds than that of a Cylon agent. But, given Gaius Baltar's duplicity in serving himself versus the good of the surviving Colonials, it is possible that this detection option is one he has chosen to ignore. Or, the use of silicates may still be key to Cylon "brain" design, but could use the same proportions of silicate traces found in the human body, with neglible differences.