scholarly journals The Basolateral Amygdala Mediates the Role of Rapid Eye Movement Sleep in Integrating Fear Memory Responses

Life ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Mayumi Machida ◽  
Brook L. W. Sweeten ◽  
Austin M. Adkins ◽  
Laurie L. Wellman ◽  
Larry D. Sanford
Keyword(s):  
Eye Movement ◽  
Basolateral Amygdala ◽  
Fear Memory ◽  
Oscillatory Activity ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Behavioral Stress ◽  
Immediate Recovery ◽  
And Control

The basolateral amygdala (BLA) mediates the effects of stress and fear on rapid eye movement sleep (REM) and on REM-related theta (θ) oscillatory activity in the electroencephalograph (EEG), which is implicated in fear memory consolidation. We used optogenetics to assess the potential role of BLA glutamate neurons (BLAGlu) in regulating behavioral, stress and sleep indices of fear memory, and their relationship to altered θ. An excitatory optogenetic construct targeting glutamatergic cells (AAV-CaMKIIα-hChR2-eYFP) was injected into the BLA of mice. Telemetry was used for real-time monitoring of EEG, activity, and body temperature to determine sleep states and stress-induced hyperthermia (SIH). For 3 h following shock training (ST: 20 footshocks, 0.5 mA, 0.5 s, 1 min interval), BLA was optogenetically stimulated only during REM (REM + L) or NREM (NREM + L). Mice were then re-exposed to the fear context at 24 h, 48 h, and 1 week after ST and assessed for behavior, SIH, sleep and θ activity. Control mice were infected with a construct without ChR2 (eYFP) and studied under the same conditions. REM + L significantly reduced freezing and facilitated immediate recovery of REM tested at 24 h and 48 h post-ST during contextual re-exposures, whereas NREM + L had no significant effect. REM + L significantly reduced post-ST REM-θ, but attenuated REM-θ reductions at 24 h compared to those found in NREM + L and control mice. Fear-conditioned SIH persisted regardless of treatment. The results demonstrate that BLAGlu activity during post-ST REM mediates the integration of behavioral and sleep indices of fear memory by processes that are associated with θ oscillations within the amygdalo-hippocampal pathway. They also demonstrate that fear memories can remain stressful (as indicated by SIH) even when fear conditioned behavior (freezing) and changes in sleep are attenuated.

GABAergic Neurons in the Dorsal–Intermediate Lateral Septum Regulate Sleep–Wakefulness and Anesthesia in Mice

2021 ◽  
Author(s):  
Di Wang ◽  
Qingchen Guo ◽  
Yu Zhou ◽  
Zheng Xu ◽  
Su-Wan Hu ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Eye Movement ◽  
Gabaergic Neurons ◽  
Lateral Septum ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Awake State ◽  
Isoflurane Anesthesia

Background The γ-aminobutyric acid–mediated (GABAergic) inhibitory system in the brain is critical for regulation of sleep–wake and general anesthesia. The lateral septum contains mainly GABAergic neurons, being cytoarchitectonically divided into the dorsal, intermediate, and ventral parts. This study hypothesized that GABAergic neurons of the lateral septum participate in the control of wakefulness and promote recovery from anesthesia. Methods By employing fiber photometry, chemogenetic and optogenetic neuronal manipulations, anterograde tracing, in vivo electrophysiology, and electroencephalogram/electromyography recordings in adult male mice, the authors measured the role of lateral septum GABAergic neurons to the control of sleep–wake transition and anesthesia emergence and the corresponding neuron circuits in arousal and emergence control. Results The GABAergic neurons of the lateral septum exhibited high activities during the awake state by in vivo fiber photometry recordings (awake vs. non–rapid eye movement sleep: 3.3 ± 1.4% vs. –1.3 ± 1.2%, P < 0.001, n = 7 mice/group; awake vs. anesthesia: 2.6 ± 1.2% vs. –1.3 ± 0.8%, P < 0.001, n = 7 mice/group). Using chemogenetic stimulation of lateral septum GABAergic neurons resulted in a 100.5% increase in wakefulness and a 51.2% reduction in non–rapid eye movement sleep. Optogenetic activation of these GABAergic neurons promoted wakefulness from sleep (median [25th, 75th percentiles]: 153.0 [115.9, 179.7] s to 4.0 [3.4, 4.6] s, P = 0.009, n = 5 mice/group) and accelerated emergence from isoflurane anesthesia (514.4 ± 122.2 s vs. 226.5 ± 53.3 s, P < 0.001, n = 8 mice/group). Furthermore, the authors demonstrated that the lateral septum GABAergic neurons send 70.7% (228 of 323 cells) of monosynaptic projections to the ventral tegmental area GABAergic neurons, preferentially inhibiting their activities and thus regulating wakefulness and isoflurane anesthesia depth. Conclusions The results uncover a fundamental role of the lateral septum GABAergic neurons and their circuit in maintaining awake state and promoting general anesthesia emergence time. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

scholarly journals Dream Recall upon Awakening from Non-Rapid Eye Movement Sleep in Older Adults: Electrophysiological Pattern and Qualitative Features

2020 ◽  
Vol 10 (6) ◽  
pp. 343 ◽  
Author(s):  
Serena Scarpelli ◽  
Aurora D’Atri ◽  
Chiara Bartolacci ◽  
Maurizio Gorgoni ◽  
Anastasia Mangiaruga ◽  
...  
Keyword(s):  
Eye Movement ◽  
Sleep Stage ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Dream Recall ◽  
Cortical Arousal ◽  
Beta Power ◽  
Dream Report

Several findings support the activation hypothesis, positing that cortical arousal promotes dream recall (DR). However, most studies have been carried out on young participants, while the electrophysiological (EEG) correlates of DR in older people are still mostly unknown. We aimed to test the activation hypothesis on 20 elders, focusing on the Non-Rapid Eye Movement (NREM) sleep stage. All the subjects underwent polysomnography, and a dream report was collected upon their awakening from NREM sleep. Nine subjects were recallers (RECs) and 11 were non-RECs (NRECs). The delta and beta EEG activity of the last 5 min and the total NREM sleep was calculated by Fast Fourier Transform. Statistical comparisons (RECs vs. NRECs) revealed no differences in the last 5 min of sleep. Significant differences were found in the total NREM sleep: the RECs showed lower delta power over the parietal areas than the NRECs. Consistently, statistical comparisons on the activation index (delta/beta power) revealed that RECs showed a higher level of arousal in the fronto-temporal and parieto-occipital regions than NRECs. Both visual vividness and dream length are positively related to the level of activation. Overall, our results are consistent with the view that dreaming and the storage of oneiric contents depend on the level of arousal during sleep, highlighting a crucial role of the temporo-parietal-occipital zone.

Basolateral amygdala regulates EEG theta-activity during rapid eye movement sleep

Neuroscience ◽  
2021 ◽  
Author(s):  
Mayumi Machida ◽  
Brook L.W. Sweeten ◽  
Austin M. Adkins ◽  
Laurie L. Wellman ◽  
Larry D. Sanford
Keyword(s):  
Eye Movement ◽  
Basolateral Amygdala ◽  
Theta Activity ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep

scholarly journals Brief Optogenetic Inhibition of the Basolateral Amygdala (BLA) in Mice Alters Effects of Stressful Experiences on Rapid Eye Movement Sleep (REM)

SLEEP ◽  
2017 ◽  
Author(s):  
Mayumi Machida ◽  
Laurie L. Wellman ◽  
Mairen E. Fitzpatrick ◽  
Olga Hallum ◽  
Amy M. Sutton ◽  
...  
Keyword(s):  
Eye Movement ◽  
Basolateral Amygdala ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Stressful Experiences
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