Past- tense. Fully correct for immediate response. The inability for the electrical impulse sent to the brain to perform (root word: synapse) the action called upon. Sensory Overload in a manner, and not exactly desirable. 'Snapped', may be common usage, but for authenticity and desciptiveness, 'SYNAPPED' is the correct spelling, and the autonomic reaction that ensues.
As in,'' When she first heard about it, she was just fine for a moment, and then she just ... 'synapped'! Now she's on the 6:00 News!...And,you can't even understand her!"