Extinction recall of fear memories formed before stress is not affected despite higher theta activity in the amygdala
- National Centre for Biological Sciences, India
- Institute for Stem Cell Biology and Regenerative Medicine, India
- University of Edinburgh, United Kingdom
Figures
Figure 1
Normal expression of fear memories formed before stress.
(a) Experimental design. Rats were subjected to surgery for implanting recording electrodes, and then allowed to recover for 6–7 days. Next the rats were subjected to tone habituation followed by …
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Figure 1—source data 1
Data for animals across groups representing freezing response to CS and pretone during the different phases of behaviour (Figure 1b,e and f).
- https://doi.org/10.7554/eLife.35450.004
Figure 2 with 2 supplements
Stress-triggered persistent hyperactivity in the BLA but not the dmPFC.
(a) Representative micrographs and diagrams of recording electrode placements (red: CIS, black: Control) in the BLA (left) and dmPFC (right). (b) Summary of changes in tone-induced freezing behavior …
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Figure 2—source data 1
Data for animals representing freezing response to CS (Figure 2b) and AEP amplitude and theta power in dmPFC and BLA (Figure 2e,f)
- https://doi.org/10.7554/eLife.35450.008
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Figure 2—source data 2
Data for animals representing freezing response to CS (Figure 2—figure supplement 2b) and AEP amplitude and theta power in dmPFC and BLA (Figure 2—figure supplement 2c,d)
- https://doi.org/10.7554/eLife.35450.009
Figure 2—figure supplement 1
Representative traces and power spectra of tone evoked local field potentials (LFPs).
Auditory evoked potentials (AEPs) and power spectra evoked by the CS recorded from the (a) basolateral amygdala (BLA), and (b) the dorsal medial prefrontal cortex (dmPFC). The red line at the bottom …
Figure 2—figure supplement 2
Theta activity in the dmPFC, but not the BLA, mirrors the gradual decrease in freezing levels during the acquisition of fear extinction.
(a) Outline of experimental design depicted in Figure 1. The focus of analysis here is on behavioral and electrophysiological changes during fear recall and extinction learning on Day 11. (b) As …
Figure 3 with 1 supplement
Stress disrupts enhanced dmPFC-BLA theta synchrony and directional coupling during fear expression.
(a) Tone-evoked changes in theta-frequency coherence between the BLA and dmPFC in exemplars of control (top) and CIS (bottom) animals. Control animal exhibited higher synchrony during fear recall …
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Figure 3—source data 1
Data for animals representing theta coherence between dmPFC and BLA (Figure 3b) and dmPFC-BLA phase difference (Figure 3c)
- https://doi.org/10.7554/eLife.35450.012
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Figure 3—source data 2
Data for animals representing theta coherence between dmPFC and BLA (Figure 3—figure supplement 1b) and dmPFC-BLA phase difference (Figure 3—figure supplement 1c)
- https://doi.org/10.7554/eLife.35450.013
Figure 3—figure supplement 1
Stress also disrupts dmPFC-BLA theta synchrony and directional coupling during the acquisition of fear extinction.
(a) Analyses, similar to that shown in Figure 3, of theta coherence and directional coupling between dmPFC and BLA across trial blocks (1, 4, and 7, blue dotted circles) during the fear recall and …
Figure 4 with 1 supplement
Summary of results and proposed model for how the effects of chronic stress on extinction recall depend on whether the fear memory was formed before or after stress.
(a) In control animals, fear conditioning enhances freezing, which is subsequently reduced by extinction (black vertical arrows). This is accompanied by, first an increase and then a reduction, in …
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Figure 4—source data 1
Data for animals across groups representing freezing response to CS during the different phases of behaviour (Figure 4—figure supplement 1c,d)
- https://doi.org/10.7554/eLife.35450.016
Figure 4—figure supplement 1
Preliminary results on how pharmacological inactivation of the BLA has no impact on recall of fear memories formed before stress.
(a) Experimental design. Rats were subjected to surgery for implanting cannulae targeting the BLA, and then allowed to recover for 6–7 days. Next the rats were subjected to tone habituation followed …
Additional files
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Transparent reporting form
- https://doi.org/10.7554/eLife.35450.017
