The impact of multiple memory formation on dendritic complexity in the hippocampus and anterior cingulate cortex assessed at recent and remote time points

Tardive dystonia (TD) is a disabling disorder induced by neuroleptics. Internal globus pallidus (GPi) stimulation can dramatically improve TD. The present positron emission tomography and H215O study aimed to characterize the abnormalities of brain activation of TD and the impact of GPi stimulation on these abnormalities in five TD patients treated with GPi stimulation and eight controls. Changes of regional cerebral blood flow (rCBF) were determined: (i) at rest; (ii) when moving a joystick with the right hand in three freely chosen directions in on and off bilateral GPi stimulation. A significant increase of rCBF was found in TD patients in off-stimulation condition compared to controls: (1) during motor execution in the prefrontal, premotor lateral, and anterior cingulate cortex; (2) at rest, in the prefrontal and anterior cingulate cortex and the cerebellum. Internal globus pallidus stimulation led to a reduction of rCBF (1) during motor execution, in the primary motor and prefrontal cortex and the cerebellum; (2) at rest, in the primary motor and anterior cingulate cortex and supplementary motor area. The results are as follows: (1) TD is related to an excess of brain activity notably in the prefrontal and premotor areas; (2) GPi stimulation reduces the activation of motor, premotor, and prefrontal cortex as well as cerebellum.

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Neurons in the Nonhuman Primate Amygdala and Dorsal Anterior Cingulate Cortex Signal Aversive Memory Formation under Sedation

Anesthesiology ◽

10.1097/aln.0000000000003732 ◽

2021 ◽

Vol 134 (5) ◽

pp. 734-747

Author(s):

Nir Samuel ◽

Eilat Kahana ◽

Aryeh Taub ◽

Tamar Reitich-Stolero ◽

Rony Paz ◽

...

Keyword(s):

Firing Rate ◽

Anterior Cingulate Cortex ◽

Nonhuman Primates ◽

Cingulate Cortex ◽

Memory Formation ◽

Anterior Cingulate ◽

Response Ratio ◽

Dorsal Anterior Cingulate Cortex ◽

Median Response ◽

High Doses

Background Anesthetics aim to prevent memory of unpleasant experiences. The amygdala and dorsal anterior cingulate cortex participate in forging emotional and valence-driven memory formation. It was hypothesized that this circuitry maintains its role under sedation. Methods Two nonhuman primates underwent aversive tone–odor conditioning under sedative states induced by ketamine or midazolam (1 to 8 and 0.1 to 0.8 mg/kg, respectively). The primary outcome was behavioral and neural evidence suggesting memory formation. This study simultaneously measured conditioned inspiratory changes and changes in firing rate of single neurons in the amygdala and the dorsal anterior cingulate cortex in response to an expected aversive olfactory stimulus appearing during acquisition and tested their retention after recovery. Results Aversive memory formation occurred in 26 of 59 sessions under anesthetics (16 of 29 and 10 of 30, 5 of 30 and 21 of 29 for midazolam and ketamine at low and high doses, respectively). Single-neuron responses in the amygdala and dorsal anterior cingulate cortex were positively correlated between acquisition and retention (amygdala, n = 101, r = 0.51, P < 0.001; dorsal anterior cingulate cortex, n = 121, r = 0.32, P < 0.001). Neural responses during acquisition under anesthetics were stronger in sessions exhibiting memory formation than those that did not (amygdala median response ratio, 0.52 versus 0.33, n = 101, P = 0.021; dorsal anterior cingulate cortex median response ratio, 0.48 versus 0.32, n = 121, P = 0.012). The change in firing rate of amygdala neurons during acquisition was correlated with the size of stimuli-conditioned inspiratory response during retention (n = 101, r = 0.22 P = 0.026). Thus, amygdala and dorsal anterior cingulate cortex responses during acquisition under anesthetics predicted retention. Respiratory unconditioned responses to the aversive odor anesthetics did not differ from saline controls. Conclusions These results suggest that the amygdala–dorsal anterior cingulate cortex circuit maintains its role in acquisition and maintenance of aversive memories in nonhuman primates under sedation with ketamine and midazolam and that the stimulus valence is sufficient to drive memory formation. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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Changes in white matter in mice resulting from low-frequency brain stimulation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1802160115 ◽

2018 ◽

Vol 115 (27) ◽

pp. E6339-E6346 ◽

Cited By ~ 14

Author(s):

Denise M. Piscopo ◽

Aldis P. Weible ◽

Mary K. Rothbart ◽

Michael I. Posner ◽

Cristopher M. Niell

Keyword(s):

White Matter ◽

Corpus Callosum ◽

Anterior Cingulate Cortex ◽

Low Frequency ◽

Cingulate Cortex ◽

Subcortical White Matter ◽

Cellular Level ◽

Anterior Cingulate ◽

G Ratio ◽

The Impact

Recent reports have begun to elucidate mechanisms by which learning and experience produce white matter changes in the brain. We previously reported changes in white matter surrounding the anterior cingulate cortex in humans after 2–4 weeks of meditation training. We further found that low-frequency optogenetic stimulation of the anterior cingulate in mice increased time spent in the light in a light/dark box paradigm, suggesting decreased anxiety similar to what is observed following meditation training. Here, we investigated the impact of this stimulation at the cellular level. We found that laser stimulation in the range of 1–8 Hz results in changes to subcortical white matter projection fibers in the corpus callosum. Specifically, stimulation resulted in increased oligodendrocyte proliferation, accompanied by a decrease in the g-ratio within the corpus callosum underlying the anterior cingulate cortex. These results suggest that low-frequency stimulation can result in activity-dependent remodeling of myelin, giving rise to enhanced connectivity and altered behavior.

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The Impact of Accelerated HF-rTMS on the Subgenual Anterior Cingulate Cortex in Refractory Unipolar Major Depression: Insights From 18FDG PET Brain Imaging

Brain Stimulation ◽

10.1016/j.brs.2015.01.415 ◽

2015 ◽

Vol 8 (4) ◽

pp. 808-815 ◽

Cited By ~ 56

Author(s):

Chris Baeken ◽

Daniele Marinazzo ◽

Hendrik Everaert ◽

Guo-Rong Wu ◽

Christian Van Hove ◽

...

Keyword(s):

Major Depression ◽

Brain Imaging ◽

Anterior Cingulate Cortex ◽

Cingulate Cortex ◽

Anterior Cingulate ◽

Subgenual Anterior Cingulate Cortex ◽

18Fdg Pet ◽

The Impact ◽

Unipolar Major Depression

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Neuroticism predicts the impact of serotonin challenges on fear processing in subgenual anterior cingulate cortex

Scientific Reports ◽

10.1038/s41598-018-36350-y ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 6

Author(s):

Bettina Hornboll ◽

Julian Macoveanu ◽

Ayna Nejad ◽

James Rowe ◽

Rebecca Elliott ◽

...

Keyword(s):

Anterior Cingulate Cortex ◽

Cingulate Cortex ◽

Anterior Cingulate ◽

Subgenual Anterior Cingulate Cortex ◽

The Impact

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Anodal Transcranial Direct Current Stimulation of Anterior Cingulate Cortex Modulates Subcortical Brain Regions Resulting in Cognitive Enhancement

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2020.584136 ◽

2020 ◽

Vol 14 ◽

Author(s):

Ahsan Khan ◽

Xin Wang ◽

Chun Hang Eden Ti ◽

Chun-Yu Tse ◽

Kai-Yu Tong

Keyword(s):

Prefrontal Cortex ◽

Functional Connectivity ◽

Anterior Cingulate Cortex ◽

Resting State ◽

Cingulate Cortex ◽

Anterior Cingulate ◽

Resting State Functional Connectivity ◽

Subcortical Regions ◽

The Impact ◽

Experimental Group

Transcranial direct current stimulation (tDCS) has been widely utilized in research settings and modulates brain activity. The application of anodal tDCS on the prefrontal cortex has indicated improvement in cognitive functioning. The cingulate cortex, situated in the medial aspect of the prefrontal cortex, has been identified as a core region performing cognitive functions. Most of the previous studies investigating the impact of stimulation on the prefrontal cortex stimulated the dorsolateral prefrontal cortex (DLPFC), however, the impact of stimulation on cingulate has not been explored. The current study investigates the effect of stimulation on the resting-state functional connectivity of the anterior cingulate cortex with other regions of the brain and changes in behavioral results in a color-word Stroop task, which has repeatedly elicited activation in different regions of the cingulate. Twenty subjects were randomly assigned to the experimental and sham group, and their medial prefrontal area was stimulated using MRI compatible tDCS. Resting-state functional magnetic resonance imaging (rs-fMRI) and cognitive Stroop task were monitored before, during, and after the stimulation. Neuroimaging results indicated a significant decrease in resting-state functional connectivity in the experimental group during and after stimulation as compared to before stimulation in two clusters including right insular cortex, right central operculum cortex, right frontal operculum cortex and right planum polare with the left anterior cingulate cortex (L-ACC) selected as the seed. The behavioral results indicated a significant decrease in reaction time (RT) following stimulation in the experimental group compared to the sham group. Moreover, the change in functional connectivity in subcortical regions with L-ACC as the seed and change in RT was positively correlated. The results demonstrated that ACC has a close functional relationship with the subcortical regions, and stimulation of ACC can modulate these connections, which subsequently improves behavioral performance, thus, providing another potential target of stimulation for cognitive enhancement.Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04318522.

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