Temporal changes in c-Fos activation patterns induced by conditioned fear
Autor: | József Haller, Éva Mikics, Aron Tulogdi, Mate Toth, Laszlo Biro, Rita Nagy, Mano Aliczki, Barbara Klausz, Petra Soros |
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Rok vydání: | 2012 |
Předmět: |
Male
Conditioning Classical Hippocampus Amygdala Periaqueductal gray c-Fos Stress Disorders Post-Traumatic Monoaminergic medicine Animals Rats Wistar Prefrontal cortex Neurons Fear processing in the brain biology General Neuroscience Brain Fear Extinction (psychology) Immunohistochemistry Rats Disease Models Animal medicine.anatomical_structure biology.protein Psychology Proto-Oncogene Proteins c-fos Neuroscience |
Zdroj: | Brain Research Bulletin. 88:359-370 |
ISSN: | 0361-9230 |
Popis: | Mechanisms underlying shock-induced conditioned fear - a paradigm frequently used to model posttraumatic stress disorder, PTSD - are usually studied shortly after shocks. Some of the brain regions relevant to conditioned fear were activated in all the c-Fos studies published so far, but the overlap between the activated regions was small across studies. We hypothesized that discrepant findings were due to dynamic neural changes that followed shocks, and a more consistent picture would emerge if consequences were studied after a longer interval. Therefore, we exposed rats to a single session of footshocks and studied their behavioral and neural responses one and 28 days later. The neuronal activation marker c-Fos was studied in 24 brain regions relevant for conditioned fear, e.g. in subdivisions of the prefrontal cortex, hippocampus, amygdala, hypothalamic defensive system, brainstem monoaminergic nuclei and periaqueductal gray. The intensity of conditioned fear (as shown by the duration of contextual freezing) was similar at the two time-points, but the associated neuronal changes were qualitatively different. Surprisingly, however, Multiple Regression Analyses suggested that conditioned fear-induced changes in neuronal activation patterns predicted the duration of freezing with high accuracy at both time points. We suggest that exposure to electric shocks is followed by a period of plasticity where the mechanisms that sustain conditioned fear undergo qualitative changes. Neuronal changes observed 28 days but not 1 day after shocks were consistent with those observed in human studies performed in PTSD patients. |
Databáze: | OpenAIRE |
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