The Role of the Mu Opioid Receptors of the Medial Prefrontal Cortex in the Modulation of Analgesia Induced by Acute Restraint Stress in Male Mice.

Mu opioid receptors (MORs) represent a vital mechanism related to the modulation of stress-induced analgesia (SIA). Previous studies have reported on the gamma-aminobutyric acid (GABA)ergic "disinhibition" mechanisms of MORs on the descending pain modulatory pathway of SIA induced in the midbrain. However, the role of the MORs expressed in the medial prefrontal cortex (mPFC), one of the main cortical areas participating in pain modulation, in SIA remains completely unknown.

Characterizing the dynamic learning process: Implications of a quantitative analysis.

Understanding the neural mechanisms involved in learning processes is crucial for unraveling the complexities of behavior and cognition. Sudden change from the untrained level to the fully-learned level is a pivotal feature of instrumental learning. However, the concept of change point and suitable methods to conveniently analyze the characteristics of sudden change in groups remain elusive, which might hinder a fuller understanding of the neural mechanism underlying dynamic leaning process.

Inhibition of cannabinoid degradation enhances hippocampal contextual fear memory and exhibits anxiolytic effects.

Recent studies have demonstrated the pivotal involvement of endocannabinoids in regulating learning and memory, but the conclusions obtained from different paradigms or contexts are somewhat controversial, and the underlying mechanisms remain largely elusive. Here, we show that JZL195, a dual inhibitor of fatty acid amide hydrolase and monoacylglycerol lipase, can enhance the performance of mice in a contextual fear conditioning task and increase the time spent in open arms in the elevated zero maze (EZM). Although the effect of JZL195 on fear memory could not be inhibited by antagonists of cannabinoid receptors, the effect on the EZM seems to be mediated by CB1R.

Antibacterial Activity and Mechanism of Madecassic Acid against .

Antibacterial resistance has become one of the most serious problems threating global health. To overcome this urgent problem, many scientists have paid great attention to developing new antibacterial drugs from natural products. Hence, for exploring new antibacterial drugs from Chinese medicine, a series of experiments were carried out for verifying and elucidating the antibacterial activity and mechanisms of madecassic acid (MA), which is an active triterpenoid compound isolated from the traditional Chinese medicine, .

Inhibition of the MAPK/c-Jun-EGR1 Pathway Decreases Photoreceptor Cell Death in the Mouse Model for Inherited Retinal Degeneration.

Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies that typically results in photoreceptor cell death and vision loss. Here, we explored the effect of early growth response-1 (EGR1) expression on photoreceptor cell death in () mice and its mechanism of action. To this end, single-cell RNA-seq (scRNA-seq) was used to identify differentially expressed genes in and congenic wild-type (WT) mice.

Differential Alterations in Striatal Direct and Indirect Pathways Mediate Two Autism-like Behaviors in Valproate-Exposed Mice.

Autism is characterized by two key diagnostic criteria including social deficits and repetitive behaviors. Although recent studies implicated ventral striatum in social deficits and dorsal striatum in repetitive behaviors, here we revealed coexisting and opposite morphologic and functional alterations in the dorsostriatal direct and indirect pathways, and such alterations in these two pathways were found to be responsible, respectively, for the two abovementioned different autism-like behaviors exhibited by male mice prenatally exposed to valproate. The alteration in direct pathway was characterized by a potentiated state of basal activity, with impairment in transient responsiveness of D1-MSNs during social exploration.

Autonomous Navigation of Unmanned Aircraft Using Space Target LOS Measurements and QLEKF.

An autonomous navigation method based on the fusion of INS (inertial navigation system) measurements with the line-of-sight (LOS) observations of space targets is presented for unmanned aircrafts. INS/GNSS (global navigation satellite system) integration is the conventional approach to achieving the long-term and high-precision navigation of unmanned aircrafts. However, the performance of INS/GNSS integrated navigation may be degraded gradually in a GNSS-denied environment.

The Contributions of Mu-Opioid Receptors on Glutamatergic and GABAergic Neurons to Analgesia Induced by Various Stress Intensities.

The endogenous opioid system plays a crucial role in stress-induced analgesia. Mu-opioid receptors (MORs), one of the major opioid receptors, are expressed widely in subpopulations of cells throughout the CNS. However, the potential roles of MORs expressed in glutamatergic (MOR) and γ-aminobutyric acidergic (MOR) neurons in stress-induced analgesia remain unclear.

Acute cannabinoids impair association learning via selectively enhancing synaptic transmission in striatonigral neurons.

Background: Cannabinoids and their derivatives attract strong interest due to the tremendous potential of their psychoactive effects for treating psychiatric disorders and symptoms. However, their clinical application is restricted by various side-effects such as impaired coordination, anxiety, and learning and memory disability. Adverse impact on dorsal striatum-dependent learning is an important side-effect of cannabinoids.

N-methyladenosine RNA modification of glutamatergic neurons is associated with contextual fear discrimination.

Fear memory overgeneralization is a hallmark of many stress-related disorders, especially posttraumatic stress disorder. The neurobiology of fear memory generalization and discrimination involves a series of interplays between molecular and cellular factors, the mechanisms of which remain largely unexplored. N-methyladenosine (mA) of RNA is a reversible and dynamically regulated posttranscriptional modification with especially high levels in mammalian brain.

RNA Biological Characteristics at the Peak of Cell Death in Different Hereditary Retinal Degeneration Mutants.

The present work investigated changes in the gene expression, molecular mechanisms, and pathogenesis of inherited retinal degeneration (RD) in three different disease models, to identify predictive biomarkers for their varied phenotypes and to provide a better scientific basis for their diagnosis, treatment, and prevention. Differentially expressed genes (DEGs) between retinal tissue from RD mouse models obtained during the photoreceptor cell death peak period ( at post-natal (PN) day 13, at PN23, at PN29) and retinal tissue from C3H wild-type mice were identified using Illumina high-throughput RNA-sequencing. Co-expression gene modules were identified using a combination of GO and KEGG enrichment analyses and gene co-expression network analysis.

Involvement of Midbrain Dopamine Neuron Activity in Negative Reinforcement Learning in Mice.

The activity of the midbrain dopamine system reflects the valence of environmental events and modulates various brain structures to modify an organism's behavior. A series of recent studies reported that the direct and indirect pathways in the striatum are critical for instrumental learning, but the dynamic changes in dopamine neuron activity that occur during negative reinforcement learning are still largely unclear. In the present study, by using a negative reinforcement learning paradigm employing foot shocks as aversive stimuli, bidirectional changes in substantia nigra pars compacta (SNc) dopamine neuron activity in the learning and habituation phases were observed.

Stress Controllability Modulates Basal Activity of Dopamine Neurons in the Substantia Nigra Compacta.

Prolonged stress induces neural maladaptations in the mesolimbic dopamine (DA) system and produces emotional and behavioral disorders. However, the effects of stress on activity of DA neurons are diverse and complex that hinge on the type, duration, intensity, and controllability of stressors. Here, controlling the duration, intensity, and type of the stressors to be identical, we observed the effects of stressor controllability on the activity of substantia nigra pars compacta (SNc) DA neurons in mice.

Single Exposure to Cocaine Impairs Reinforcement Learning by Potentiating the Activity of Neurons in the Direct Striatal Pathway in Mice.

Plasticity in the glutamatergic synapses on striatal medium spiny neurons (MSNs) is not only essential for behavioral adaptation but also extremely vulnerable to drugs of abuse. Modulation on these synapses by even a single exposure to an addictive drug may interfere with the plasticity required by behavioral learning and thus produce impairment. In the present work, we found that the negative reinforcement learning, escaping mild foot-shocks by correct nose-poking, was impaired by a single in vivo exposure to 20 mg/kg cocaine 24 h before the learning in mice.

Maternal folic acid supplementation prevents autistic behaviors in a rat model induced by prenatal exposure to valproic acid.

Maternal vitamin supplementation has been demonstrated to reduce the risks of a number of neurodevelopmental diseases in children. Autism spectrum disorder (ASD) is a group of neurodevelopment defects with high prevalence but without satisfactory therapy. The present work detected the effects of pregnancy supplementation with folic acid (FA) at different doses on rat models of ASD induced by prenatal exposure to valproic acid (VPA), an anti-epileptic increasing the risk of ASD when administered during pregnancy.

Abnormal reinforcement learning in a mice model of autism induced by prenatal exposure to valproic acid.

Individuals with autism spectrum disorder (ASD) display dysfunction in learning from environmental stimulus that have positive or negative emotional values, posing obstacles to their everyday life. Unfortunately, mechanisms of the dysfunction are still unclear. Although early intervention for ASD victims based on reinforcement learning are commonly used, the mechanisms and characteristics of the improvement are also unknown.

The Endocannabinoid System Contributes to Memory Deficits Induced by Rapid-eye-movement Sleep Deprivation in Adolescent Mice.

Sleep loss or insomnia is among the contributing factors of cognitive deficit, the underlying mechanisms of which remain largely elusive. The endocannabinoid (eCB) system plays a role in sleep, while it is unknown if it is involved in the regulation of memory retrieval by sleep deprivation. In addition, it still controversial how rapid-eye-movement sleep deprivation (REMSD) affects the spatial memory of adolescent mice.

Loss of control over mild aversive events produces significant helplessness in mice.

Most of the pathophysiology of depression are still unknown because of its numerous disease states of distinct etiology and pathogenesis. Stressful rodent models have been used to test a number of hypotheses regarding the etiology of depression. The learned helplessness rodent model demonstrates that having no control at all over aversive events produces helplessness and depression, but the role of loss of control over aversive events in helplessness is still not reliably modelled or deeply investigated.

Hippocampal µ-opioid receptors on GABAergic neurons mediate stress-induced impairment of memory retrieval.

Stressful life events induce abnormalities in emotional and cognitive behaviour. The endogenous opioid system plays an essential role in stress adaptation and coping strategies. In particular, the µ-opioid receptor (μR), one of the major opioid receptors, strongly influences memory processing in that alterations in μR signalling are associated with various neuropsychiatric disorders.

5-HT1A autoreceptor in dorsal raphe nucleus mediates sensitization of conditioned place preference to cocaine in mice experienced with chronic pain.

Chronic stress, including chronic neuropathic pain, cannot only induce depressive disorders but also enhance sensitization to addictive drugs. Ample evidence support the implication of the 5-hydroxytryptamine (5-HT) system in the enhanced sensitization to cocaine. However, mechanisms underpinning such an enhancement are still unclear.

Acute Stress Facilitates LTD Induction at Glutamatergic Synapses in the Hippocampal CA1 Region by Activating μ-Opioid Receptors on GABAergic Neurons.

Acute stress impairs recall memory through the facilitation of long-term depression (LTD) of hippocampal synaptic transmission. The endogenous opioid system (EOS) plays essential roles in stress-related emotional and physiological responses. Specifically, behavioral studies have shown that the impairment of memory retrieval induced by stressful events involves the activation of opioid receptors.

Cannabinoids-induced peripheral analgesia depends on activation of BK channels.

The endogenous cannabinoid system is involved in the physiological inhibitory control of pain and is of particular interest for the development of therapeutic approaches for pain management. Selective activation of the peripheral CB1 cannabinoid receptor has been shown to suppress the heightened firing of primary afferents, which is the peripheral mechanism underlying neuropathic pain after nerve injury. However, the mechanism underlying this effect of CB1 receptor remains unclear.

Improvement of therapeutic effects of mesenchymal stem cells in myocardial infarction through genetic suppression of microRNA-142.

Transplanted mesenchymal stem cells (MSCs) have been shown to contribute to myocardial repair after myocardial infarction (MI), primarily through production and secretion some growth factors and cytokines related to cell survival and regeneration. Further improvement of the therapeutic potential of MSCs appears to be an attractive strategy for MI treatment. CXC chemokine receptor (CXCR) 7 is the receptor for stromal cell-derived factor-1 (SDF-1), an important chemokine that is essential for tissue repair and angiogenesis.

Review on clinical update of essential tremor.

Essential tremor (ET) is considered a benign disease without any pathological changes. Nevertheless, this point of view has recently been challenged. In recent years, studies have shown that ET occurs with other non-motor symptoms, such as cognitive deficits, depression, anxiety, balance disorder, hearing impairment, olfactory dysfunction and sleep problems.