This dataset contains skin conductance responses (SCR), electrocardyogram (ECG), respiration, electromygram (EMG), pupil size (PSR), and gaze coordinates measurements for 97 healthy subjects (49 females and 48 males aged 24.7 +/- 3.9) participating in a double-blind, placebo-controlled, randomized trial using a Pavlovian differential trace fear conditioning experiment with 2 sessions. The placebo group (n = 48) includes 24 females and 24 males, aged 24.09 +/- 4.06 years; the doxycycline (n = 49) group includes 25 females and 24 males, aged 24.43 +/- 3.75 years. CSs were isoluminant colored triangles presented on the screen center with grey background. US was a train of 83 square electric pulses with 0.2 ms duration with a duty cycle of 1.67%, delivered with a constant current stimulator on participants' dominant forearm through a pin-cathod/ring-anode configuration. SOA between the CS onset and US was 17 s. Participants underwent the conditioning task with CSs (CS+ 100% reinforced) and US delivery in session 1 with 4 blocks, and were tested in a retention/extinction task one week later in session 2 with 3 blocks, with CS and auditory startle probe (ST) delivered 15 s after CS onset via headphones (ca. 102 dB, 50 ms duration). No US was delivered during session 2. Participants in the doxycycline group received a single oral dosage of doxycycline à 200mg ~210 min before the start of fear conditioning in session 1, while the placebo group received a placebo (manitol). The ITI was jittered on each trial to be 30 +/- 2 s. During ITI, an attention task was performed with 14 sub-trials. The blocks in each session were recorded on the same day with self-paced breaks.