Amygdala-hippocampal dynamics during salient information processing.
Jie ZhengKristopher L AndersonStephanie L LealAvgusta ShestyukGultekin GulsenLilit MnatsakanyanSumeet VaderaFrank P K HsuMichael A YassaRobert T KnightJack J LinPublished in: Nature communications (2017)
Recognizing motivationally salient information is critical to guiding behaviour. The amygdala and hippocampus are thought to support this operation, but the circuit-level mechanism of this interaction is unclear. We used direct recordings in the amygdala and hippocampus from human epilepsy patients to examine oscillatory activity during processing of fearful faces compared with neutral landscapes. We report high gamma (70-180 Hz) activation for fearful faces with earlier stimulus evoked onset in the amygdala compared with the hippocampus. Attending to fearful faces compared with neutral landscape stimuli enhances low-frequency coupling between the amygdala and the hippocampus. The interaction between the amygdala and hippocampus is largely unidirectional, with theta/alpha oscillations in the amygdala modulating hippocampal gamma activity. Granger prediction, phase slope index and phase lag analysis corroborate this directional coupling. These results demonstrate that processing emotionally salient events in humans engages an amygdala-hippocampal network, with the amygdala influencing hippocampal dynamics during fear processing.
Keyphrases
- prefrontal cortex
- temporal lobe epilepsy
- functional connectivity
- resting state
- cerebral ischemia
- end stage renal disease
- signaling pathway
- newly diagnosed
- ejection fraction
- blood brain barrier
- healthcare
- ionic liquid
- working memory
- room temperature
- brain injury
- high frequency
- tertiary care
- transcranial magnetic stimulation