Long-Term Depression: A Learning-Related Type of Synaptic Plasticity in the Mammalian Central Nervous System

AbstractNeurological long-term sequelae are increasingly considered an important challenge in the recent COVID-19 pandemic. However, most evidence for neurological symptoms after SARS-CoV-2 infection and central nervous system invasion of the virus stems from individuals severely affected in the acute phase of the disease. Here, we report long-lasting cognitive impairment along with persistent cerebrospinal fluid anti-SARS-CoV-2 antibodies in a female patient with unremarkable standard examination 6 months after mild COVID-19, supporting the implementation of neuropsychological testing and specific cerebrospinal fluid investigation also in patients with a relatively mild acute disease phase.

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The Function of Selenium in Central Nervous System: Lessons from MsrB1 Knockout Mouse Models

Molecules ◽

10.3390/molecules26051372 ◽

2021 ◽

Vol 26 (5) ◽

pp. 1372

Author(s):

Tengrui Shi ◽

Jianxi Song ◽

Guanying You ◽

Yujie Yang ◽

Qiong Liu ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Synaptic Plasticity ◽

Mouse Model ◽

Mouse Models ◽

Knockout Mouse ◽

Methionine Sulfoxide ◽

Methionine Sulfoxide Reductase ◽

Knockout Mouse Model ◽

The Central Nervous System

MsrB1 used to be named selenoprotein R, for it was first identified as a selenocysteine containing protein by searching for the selenocysteine insert sequence (SECIS) in the human genome. Later, it was found that MsrB1 is homologous to PilB in Neisseria gonorrhoeae, which is a methionine sulfoxide reductase (Msr), specifically reducing L-methionine sulfoxide (L-Met-O) in proteins. In humans and mice, four members constitute the Msr family, which are MsrA, MsrB1, MsrB2, and MsrB3. MsrA can reduce free or protein-containing L-Met-O (S), whereas MsrBs can only function on the L-Met-O (R) epimer in proteins. Though there are isomerases existent that could transfer L-Met-O (S) to L-Met-O (R) and vice-versa, the loss of Msr individually results in different phenotypes in mice models. These observations indicate that the function of one Msr cannot be totally complemented by another. Among the mammalian Msrs, MsrB1 is the only selenocysteine-containing protein, and we recently found that loss of MsrB1 perturbs the synaptic plasticity in mice, along with the astrogliosis in their brains. In this review, we summarized the effects resulting from Msr deficiency and the bioactivity of selenium in the central nervous system, especially those that we learned from the MsrB1 knockout mouse model. We hope it will be helpful in better understanding how the trace element selenium participates in the reduction of L-Met-O and becomes involved in neurobiology.

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Monitoring of tricyclic antidepressant plasma levels and clinical response: a review of the literature. Part II

Psychiatry and Psychobiology ◽

10.1017/s0767399x00002911 ◽

1989 ◽

Vol 4 (2) ◽

pp. 81-90 ◽

Cited By ~ 2

Author(s):

I.R. De Oliveira ◽

P.A.S. Do Prado-Lima ◽

B. Samuel-Lajeunesse

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Elderly Patients ◽

Plasma Levels ◽

Tricyclic Antidepressant ◽

Review Of The Literature ◽

Central Nervous System Toxicity ◽

Routine Measurement ◽

System Toxicity

SummaryPart II of this paper contains some general considerations on tricyclic antidepressant (TCA) monitoring. Long-term assessment of TCA plasma levels is advised by the few existent studies, although each of these focusses on different aspects. Cardiovascular and central nervous system toxicity is reviewed as well as pharmacokinetics and the importance of protein binding. Some consideration is also given to their use in elderly patients. The authors conclude that although available data support its usefulness in many situations, routine measurement of TCA levels is not warranted.

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Self-buffering capacity of a human sulfatase for central nervous system delivery

Scientific Reports ◽

10.1038/s41598-021-86178-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Yi Wen ◽

Nazila Salamat-Miller ◽

Keethkumar Jain ◽

Katherine Taylor

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Buffering Capacity ◽

The Self ◽

High Concentration ◽

Formulation Design ◽

The Central Nervous System ◽

Therapeutic Enzymes ◽

Intrathecal Space

AbstractDirect delivery of therapeutic enzymes to the Central Nervous System requires stringent formulation design. Not only should the formulation design consider the delicate balance of existing ions, proteins, and osmolality in the cerebrospinal fluid, it must also provide long term efficacy and stability for the enzyme. One fundamental approach to this predicament is designing formulations with no buffering species. In this study, we report a high concentration, saline-based formulation for a human sulfatase for its delivery into the intrathecal space. A high concentration formulation (≤ 40 mg/mL) was developed through a series of systematic studies that demonstrated the feasibility of a self-buffered formulation for this molecule. The self-buffering capacity phenomenon was found to be a product of both the protein itself and potentially the residual phosphates associated with the protein. To date, the self-buffered formulation for this molecule has been stable for up to 4 years when stored at 5 ± 3 °C, with no changes either in the pH values or other quality attributes of the molecule. The high concentration self-buffered protein formulation was also observed to be stable when exposed to multiple freeze–thaw cycles and was robust during in-use and agitation studies.

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Multiplexed neurochemical transmission emulated using a dual-excitatory synaptic transistor

npj 2D Materials and Applications ◽

10.1038/s41699-021-00205-4 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Mingxue Ma ◽

Yao Ni ◽

Zirong Chi ◽

Wanqing Meng ◽

Haiyang Yu ◽

...

Keyword(s):

Neural Network ◽

Central Nervous System ◽

Nervous System ◽

Long Term Potentiation ◽

Short Term ◽

Term Potentiation ◽

Binary Neural Network ◽

Neuromorphic Systems ◽

Human Brains

AbstractThe ability to emulate multiplexed neurochemical transmission is an important step toward mimicking complex brain activities. Glutamate and dopamine are neurotransmitters that regulate thinking and impulse signals independently or synergistically. However, emulation of such simultaneous neurotransmission is still challenging. Here we report design and fabrication of synaptic transistor that emulates multiplexed neurochemical transmission of glutamate and dopamine. The device can perform glutamate-induced long-term potentiation, dopamine-induced short-term potentiation, or co-release-induced depression under particular stimulus patterns. More importantly, a balanced ternary system that uses our ambipolar synaptic device backtrack input ‘true’, ‘false’ and ‘unknown’ logic signals; this process is more similar to the information processing in human brains than a traditional binary neural network. This work provides new insight for neuromorphic systems to establish new principles to reproduce the complexity of a mammalian central nervous system from simple basic units.

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