Angela Jacques1,2, Nicholas Chaaya1,2, Chiemi Hettiarachchi2, Marie-Louise Carmody1,2, Kate Beecher2,3, Arnauld Belmer2,3, Fatemeh Chehrehasa2,4, Selena Bartlett2,3, Andrew R Battle2,4,5, Luke R Johnson6,7,8. 1. School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia. 2. Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia. 3. School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia. 4. School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia. 5. The University of Queensland Diamantina Institute, Brisbane, Australia. 6. School of Psychology and Counselling, Queensland University of Technology, Brisbane, Australia. lukejohnsonphd@gmail.com. 7. Translational Research Institute, Institute of Health and Biomedical Innovation, Department of Psychology and Counselling, Queensland University of Technology, Brisbane, QLD, Australia. lukejohnsonphd@gmail.com. 8. Center for the Study of Traumatic Stress, Department of Psychiatry, USU School of Medicine, Bethesda, MD, USA. lukejohnsonphd@gmail.com.
Abstract
RATIONALE: The precise neural circuitry that encodes fear memory and its extinction within the brain are not yet fully understood. Fearful memories can be persistent, resistant to extinction, and associated with psychiatric disorders, especially post-traumatic stress disorder (PTSD). Here, we investigated the microtopography of neurons activated during the recall of an extinguished fear memory, as well as the influence of time on this microtopography. METHODS: We used the plasticity-related phosphorylated mitogen-activated protein kinase (pMAPK) to identify neurons activated in the recall of consolidated and extinguished auditory Pavlovian fear memories in rats. Quantitatively matched brain regions were used to investigate activity in the amygdala and prefrontal cortex. RESULTS: Recall of a consolidated, nonextinguished auditory fear memory resulted in a significantly greater number of activated neurons located in the dorsolateral subdivision of the lateral amygdala (LADL) when recalled 24 h after consolidation but not when recalled 7 days later. We found that the recall of an extinction memory was associated with pMAPK activation in the ventrolateral subdivision of the lateral amygdala (LAVL). Next, we showed that the pattern of pMAPK expression in the prelimbic cortex differed spatially following temporal variation in the recall of that memory. The deep and superficial layers of the pre-limbic cortex were engaged in recent recall of a fear memory, but only the superficial layers were recruited if the recall occurred 7 days later. CONCLUSIONS: Collectively, our findings demonstrate a functional microtopography of auditory fear memory during consolidation and extinction at the microanatomical level within the lateral amygdala and medial prefrontal cortex.
RATIONALE: The precise neural circuitry that encodes fear memory and its extinction within the brain are not yet fully understood. Fearful memories can be persistent, resistant to extinction, and associated with psychiatric disorders, especially post-traumatic stress disorder (PTSD). Here, we investigated the microtopography of neurons activated during the recall of an extinguished fear memory, as well as the influence of time on this microtopography. METHODS: We used the plasticity-related phosphorylated mitogen-activated protein kinase (pMAPK) to identify neurons activated in the recall of consolidated and extinguished auditory Pavlovian fear memories in rats. Quantitatively matched brain regions were used to investigate activity in the amygdala and prefrontal cortex. RESULTS: Recall of a consolidated, nonextinguished auditory fear memory resulted in a significantly greater number of activated neurons located in the dorsolateral subdivision of the lateral amygdala (LADL) when recalled 24 h after consolidation but not when recalled 7 days later. We found that the recall of an extinction memory was associated with pMAPK activation in the ventrolateral subdivision of the lateral amygdala (LAVL). Next, we showed that the pattern of pMAPK expression in the prelimbic cortex differed spatially following temporal variation in the recall of that memory. The deep and superficial layers of the pre-limbic cortex were engaged in recent recall of a fear memory, but only the superficial layers were recruited if the recall occurred 7 days later. CONCLUSIONS: Collectively, our findings demonstrate a functional microtopography of auditory fear memory during consolidation and extinction at the microanatomical level within the lateral amygdala and medial prefrontal cortex.
Authors: Marziah Hakim; Kate Beecher; Angela Jacques; Nicholas Chaaya; Arnauld Belmer; Andrew R Battle; Luke R Johnson; Selena E Bartlett; Fatemeh Chehrehasa Journal: Chem Senses Date: 2022-01-01 Impact factor: 4.985
Authors: Nicholas Chaaya; Joshua Wang; Angela Jacques; Kate Beecher; Michael Chaaya; Andrew Raymond Battle; Luke R Johnson; Fatemeh Chehrehasa; Arnauld Belmer; Selena E Bartlett Journal: Front Neural Circuits Date: 2021-07-06 Impact factor: 3.492