The relation between neuronal firing, local field potentials and hemodynamic activity in the human amygdala in response to aversive dynamic visual stimuli

Intracranial EEG in Episodic Memory Research: Possibilities, Limitations, Results

“…На сегодняшний день гораздо более надежным источником информации о роли осцилляций в этом диапазоне остаются методы иЭЭГ и МЭГ . При этом считается, что именно ЛПП-активность в высокочастотном гамма-диапазоне (>60 Гц) отражает изменения локальной электрофизиологической активности и коррелирует с гемодинамическим ответом (BOLD-сигналом; Fedele et al, 2020;Manning et al, 2009;Mukamel et al, 2005;. Наконец, поскольку формирование и стабилизация следа памяти -это развернутый во времени процесс, возможность регистрировать иЭЭГ-активность с помощью суточного ЭЭГ-мониторинга подходит для отслеживания этих процессов.…”

Aversive memory formation in humans is determined by an amygdala-hippocampus phase code

“…S3). We selected windows of broadband gamma activity (60-120 Hz) as a proxy of neuronal activity (23,24) around the hippocampal gamma peaks for both hippocampus and amygdala responses, and shifted these windows in time to compute the cross-correlogram for successful and unsuccessful encoding of aversive scenes. The shift in time is important because the observed phase opposition between PAC for two conditions (i.e., eR vs. eKF) implies a condition-dependent phase lead/lag between the high frequency activity in hippocampus relative to the theta phase cycle in amygdala (Fig.…”

“…The degree to which single neuron spiking phase-locks to human hippocampal theta oscillations is a predictor of memory strength ( 21, 22 ). Given that spiking has been shown to correlate with gamma power ( 23, 24 ), we hypothesized that a stronger modulation of hippocampal gamma band activity by amygdala theta oscillations would occur during encoding of aversive scenes leading to remembering. We thus tested the phase-amplitude coupling (PAC) associated with subsequently remembered vs .…”

“…Our second cohort comprised patients with microelectrode recordings, permitting testing the derived phase-dependent mechanism at the single neuron level. That is, with Cohort 1 we considered gamma activity as an index of spiking activity ( 23, 24 ) and with Cohort 2 ( n =6 patients, 7 electrodes) directly tested whether amygdala theta (3-12 Hz) organizes hippocampal neuronal firing by performing spike field coherence analysis (SFC) on simultaneous recordings of hippocampal single neurons and amygdala oscillatory activity ( Fig. 3B , fig S1 B).…”

“…This analysis measured transient connectivity (envelope cross-correlations) between amygdala and hippocampal broadband gamma activity. First, we band-pass filtered the time series from the amygdala and the hippocampus contacts between 60–120 Hz ( 23, 24 ) using a two-pass finite impulse response (FIR) filter with a filter order of 3 cycles of the lower bound. This range was chosen because it encompasses both amygdala and hippocampal gamma ranges.…”