ICAM5 and post-traumatic stress disorder: In this context, we explain the observed relation between ICAM-5 production and PTSD development2 by hypothesizing that ICAM-5 production was a pre-existing condition due to inflammatory/immunogenic challenge on the background of which the massive glutamate input induced a synaptic “locking” of the activated network, manifested behaviorally as persistent re-experiencing of the traumatic event.