Yes, the trunk release is a positive trigger. Most units supply a negative output to use for that particular channel, so you'll almost certainly need to use a relay to invert the polarity to drive the circuit.
Grab a SPDT relay from any electronics store...
connect as followed...
terminal 86 to constant power
terminal 85 to the negative trunk release output of the brain
terminal 30 to the black/white wire connected to the trunk release button, usually found low in the driver'* kick panel area
terminal 87 also tied to constant power