Modified Fear Conditioning for Inducing Flight Behaviors in Mice

We are investigating the neural correlation for various dementia behaviors in fear learning and extinction. The present protocol could aid in the development of a new treatment for anxiety disorder and post-traumatic stress disorder. Our protocol uses two sound pressure levels of conditioning stimuli to assess freezing, darting, and flight, so our technique can assess various differential behaviors better than classical fear conditioning.

Our laboratory focuses on neural correlates for fear learning and extinction. The neural mechanisms of various differential behaviors to threats could support the development of new treatment for anxiety disorder and PTSD. To begin, set up a fear conditioning chamber enclosed in a sound attenuating box.

Next, create two contexts, A and B.For context A, attach black stripes on a white plastic board. For context B, make the wall entirely black. Use an overhead white light emitting diode to illuminate the experimental box.

Then connect a scramble shocker to a grid floor with stainless steel rods. Now fix a speaker onto the box's ceiling. Then digitally modify and calibrate the amplitudes of each stimulus.

Place the floor of the test chamber on a transducer to detect vibrations. Then place a CMOS camera on the chamber's ceiling to track the subject's motion and record sound. Set up the sound software to trigger tones or foot shocks at scheduled time intervals.

Plan four days of fear conditioning with the first day assigned to habituation. The next two days allocated to conditioning, and the last day assigned to test or extinction sessions. For the conditioning session, present the unconditioned stimulus immediately after terminating the conditioned stimulus.

After ending the fifth shock, leave the subject in the context for one minute before returning to its home cage. To induce flight behaviors, on day one, expose the subjects to five conditions stimuli only in context A.On days two and three, condition the subjects with five conditioned and unconditioned stimuli association trials in context B.On the last day expose the animal to five trials of only conditioned stimuli in context B.The Group 1 mice displayed pronounced flight behaviors on days three and four. The total motion increased with increased conditioning.

Freezing during conditioned stimuli, increased on day two and remained constant in subsequent trials. The animals demonstrated increased movements at the onset of the condition stimuli and were consistent throughout. The Group 2 mice showed flight behaviors almost identical to Group 1 on days two and three.

However, the animals did not show any flight behavior during condition stimuli presentations in context A.The Group 1 mice displayed significantly higher motion and total number of jumps relative to Group 2. However, the Group 2 mice froze more.