scholarly journals Proteomic Profiling of Astrocytic O-GlcNAc Transferase-Related Proteins in the Medial Prefrontal Cortex

2021 ◽  
Vol 14 ◽  
Author(s):  
Jun Fan ◽  
Qiu-Ling Zhong ◽  
Ran Mo ◽  
Cheng-Lin Lu ◽  
Jing Ren ◽  
...  

The medial prefrontal cortex (mPFC), a key part of the brain networks that are closely related to the regulation of behavior, acts as a key regulator in emotion, social cognition, and decision making. Astrocytes are the majority cell type of glial cells, which play a significant role in a number of processes and establish a suitable environment for the functioning of neurons, including the brain energy metabolism. Astrocyte’s dysfunction in the mPFC has been implicated in various neuropsychiatric disorders. Glucose is a major energy source in the brain. In glucose metabolism, part of glucose is used to convert UDP-GlcNAc as a donor molecule for O-GlcNAcylation, which is controlled by a group of enzymes, O-GlcNAc transferase enzyme (OGT), and O-GlcNAcase (OGA). However, the role of O-GlcNAcylation in astrocytes is almost completely unknown. Our research showed that astrocytic OGT could influence the expression of proteins in the mPFC. Most of these altered proteins participate in metabolic processes, transferase activity, and biosynthetic processes. GFAP, an astrocyte maker, was increased after OGT deletion. These results provide a framework for further study on the role of astrocytic OGT/O-GlcNAcylation in the mPFC.

2007 ◽  
Vol 19 (2) ◽  
pp. 351-362 ◽  
Author(s):  
Philippe-Olivier Harvey ◽  
Philippe Fossati ◽  
Martin Lepage

It is unclear whether the involvement of the medial prefrontal cortex (mPFC) during encoding is restricted to the evaluative processing of to-be-encoded stimuli or if it is instead actively engaged during memory formation. The difficulty of assessing the contribution of the mPFC to encoding based on previous neuroimaging studies partly arises from the use of several types of stimuli, such as emotional or social ones. These different types of stimulus content could differently modulate mPFC activity during memory formation and thus partly explain the variable contribution of this region to encoding. Using emotional/neutral and social/nonsocial pictures, we conducted an event-related functional magnetic resonance imaging study using a subsequent memory paradigm as the main analytical strategy. We observed that the brain activity in the dorsal and orbital mPFC is significantly and specifically predictive of the successful encoding of social compared with nonsocial pictures. In contrast, the activity in the amygdala specifically predicts the successful encoding of emotional compared with neutral pictures. The modulation of the mPFC by social information in a memory encoding context could be associated with the initiation of self-referential processes whose contribution is to enhance memory formation.


2021 ◽  
pp. 1-14
Author(s):  
Qingwei Huo ◽  
Sidra Tabassum ◽  
Ming Chen ◽  
Mengyao Sun ◽  
Yueming Deng ◽  
...  

Background: Neuropathological features of Alzheimer’s disease are characterized by the deposition of amyloid-β (Aβ) plaques and impairments in synaptic activity and memory. However, we know little about the physiological role of amyloid-β protein precursor (AβPP) from which Aβ derives. Objective: Evaluate APP deficiency induced alterations in neuronal electrical activity and mitochondrial protein expression. Methods: Utilizing electrophysiological, biochemical, pharmacological, and behavioral tests, we revealed aberrant local field potential (LFP), extracellular neuronal firing and levels of mitochondrial proteins. Result: We show that APP knockout (APP -/- ) leads to increased gamma oscillations in the medial prefrontal cortex (mPFC) at 1-2 months old, which can be restored by baclofen (Bac), a γ-aminobutyric acid type B receptor (GABABR) agonist. A higher dose and longer exposure time is required for Bac to suppress neuronal firing in APP -/-  mice than in wild type animals, indicating enhanced GABABR mediated activity in the mPFC of APP -/-  mice. In line with increased GABABR function, the glutamine synthetase inhibitor, L-methionine sulfonate, significantly increases GABABR levels in the mPFC of APP -/-  mice and this is associated with a significantly lower incidence of death. The results suggest that APP -/-  mice developed stronger GABABR mediated inhibition. Using HEK 293 as an expression system, we uncover that AβPP functions to suppress GABABR expression. Furthermore, APP -/-  mice show abnormal expression of several mitochondrial proteins. Conclusion: APP deficiency leads to both abnormal network activity involving defected GABABR and mitochondrial dysfunction, suggesting critical role of AβPP in synaptic and network function.


2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Masaki Isoda

As a frontal node in the primate social brain, the medial prefrontal cortex (MPFC) plays a critical role in coordinating one's own behavior with respect to that of others. Current literature demonstrates that single neurons in the MPFC encode behavior-related variables such as intentions, actions, and rewards, specifically for self and other, and that the MPFC comes into play when reflecting upon oneself and others. The social moderator account of MPFC function can explain maladaptive social cognition in people with autism spectrum disorder, which tips the balance in favor of self-centered perspectives rather than taking into consideration the perspective of others. Several strands of evidence suggest a hypothesis that the MPFC represents different other mental models, depending on the context at hand, to better predict others’ emotions and behaviors. This hypothesis also accounts for aberrant MPFC activity in autistic individuals while they are mentalizing others. Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2016 ◽  
Vol 113 (52) ◽  
pp. E8492-E8501 ◽  
Author(s):  
Roland G. Benoit ◽  
Daniel J. Davies ◽  
Michael C. Anderson

Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.


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