The imbalance during pon farr could be transferred to others via a telepathic mating bond. It could also be transferred to other species during the same telepathic bond. (VOY: "Blood Fever") Certain microbes were also known to trigger pon farr prematurely. (ENT: "Bounty") Also during this period, the affected Vulcan's cortical levels rose and fell, as the brain's regulatory system appeared to shut down when serotonin levels became unbalanced. (VOY: "Blood Fever")