1 To begin, set up a fear conditioning chamber2 enclosed in a sound-attenuating box. 3 Next, create two contexts:A and B.4 For context A, attach black stripes 5 on a white plastic board. 6 For context B, make the wall entirely black.
7 Use an overhead white light-emitting diode 8 to illuminate the experimental box. 9 Then, connect a scramble shocker to a grid floor 10 with stainless steel rods. 11 Now fix a speaker onto the box's ceiling.
12 Then, digitally modify and calibrate the amplitudes 13 of each stimulus. 14 Place the floor of the test chamber on a transducer 15 to detect vibrations. 16 Then place a CMOS camera on the chamber's ceiling 17 to track the subject's motion and record sound.
18 Set up the sound software to trigger tones or foot shocks 19 at scheduled time intervals. 20 Plan four days of fear conditioning, 21 with the first day assigned to habituation, 22 the next two days allocated to conditioning, 23 and the last day assigned to test or extinction sessions. 24 For the conditioning session, 25 present the unconditioned stimulus 26 immediately after terminating the conditioned stimulus.
27 After ending the fifth shock, 28 leave the subject in the context for one minute 29 before returning to its home cage. 30 To induce flight behaviors, on day one, 31 expose the subjects to five conditioned stimuli only 32 in context A.33 On days two and three, condition the subjects 34 with five conditioned and unconditioned 35 stimuli association trials in context B.36 On the last day, expose the animal to five trials 37 of only conditioned stimuli in context B.38 The group one mice displayed pronounced flight behaviors 39 on days three and four. 40 The total motion increased with increased conditioning.
41 Freezing during conditioned stimuli increased on day two 42 and remained constant in subsequent trials. 43 The animals demonstrated increased movements 44 at the onset of the condition stimuli 45 and were consistent throughout. 46 The group two mice showed flight behaviors 47 almost identical to group one on days two and three.
48 However, the animals did not show any flight behavior 49 during conditioned stimuli presentations in context A.50 The group one mice displayed significantly higher motion 51 and total number of jumps relative to group two. 52 However, the group two mice froze more.
