Neuroscience Letters

Alzheimer's disease (AD), a neurodegenerative disease affecting the elderly, frequently causes cognitive impairment and memory decline, and there are currently no effective therapeutic drugs available. Glutamate excitotoxicity is one of the pathogeneses of AD, and there is evidence that glutamic-oxaloacetic transaminase (GOT) can significantly reduce glutamate concentrations in the hippocampi of mice, but its role in APP/PS1 transgenic mice is unknown. We investigated the improvement of neurological function and related protein expression following subcutaneous injection of GOT in mice with AD...

Autism spectrum disorder (ASD) is a complex neurodevelopmental disease with an unclear underlying pathogenesis. Disruption of retinoic acid (RA)-retinoic acid receptor α (RARα) signaling and aberrant microglial activation were reported to be involved in the pathogenesis of ASD. However, the effect of RA-RARα signaling on microglial activation in ASD and the underlying mechanisms are unknown. Herein, we found inhibited RA-RARα signaling and increased microglial activation in valproic acid (VPA)-induced autism rats...

A complex interaction of inhibitory and facilitatory interneuronal processes may underlie development of cortical excitability in the human motor cortex. To determine whether distinct interneuronal processes mediated cortical excitability, threshold tracking transcranial magnetic stimulation was utilised to assess cortical excitability, with figure-of-eight coil oriented in posterior-anterior (PA), anterior-posterior (AP) and latero-medial (LM) directions. Motor evoked potential (MEP) responses were recorded over the contralateral abductor pollicis brevis...

Eugenol is widely used as an analgesic in the dental treatment. The underlying mechanisms may involve its modulation of various ion channels. Acid-sensing ion channels (ASICs) are pH sensors and expressed in trigeminal ganglion (TG) neurons. In the present study, we found that eugenol concentration-dependently inhibited ASIC currents in TG neurons with an IC50 of 98.8 ± 7.4 μM. Eugenol decreased the maximum response to acidic pH and did not alter pH0.5 in the concentration-response curve of acidic pH, suggesting a noncompetitive inhibition of ASICs by eugenol...

Insufficient sleep affects cognitive function, but the underlying mechanism and potential protective ways are yet to be fully understood. This study aimed to explore the influence of chronic sleep restriction (CSR) on the insulin-like growth factor-1 (IGF-1) signaling pathway, and whether down-regulating IGF-1 signaling pathway would modulate amyloid-β (Aβ) peptides metabolism and its cortical deposition after CSR. Methods 8-week IGF-1R+/- mice and wild-type (WT) C57BL/6 (C57) mice were divided into four groups: IGF-1R+/- CSR (MUSR), IGF-1R+/- control (MUCO), C57 CSR (C57SR) and C57 control (C57CO)...

Mirror activity is an involuntary activation of a muscle when the respective contralateral muscle is contracting. This phenomenon has been described primarily in children and in disease states, and, more recently, also in healthy adults. Different ways of assessing mirror activity have been described. In this work we propose a simple protocol for quantifying the amount of mirror activity during a brief isolated full force isometric contraction of a given muscle. The signal was analyzed by a custom-built algorithm that detects the beginning and the end of muscle contraction...

Rotenone, a naturally occurring toxin, has been used to induce sporadic Parkinson's disease (PD) in Drosophila melanogaster for decades. However, the age of flies varies considerably between studies in this model. To investigate the impact of age on the rotenone-induced PD model, we collected male flies at the age of 1, 5, 7, and 10 days post-eclosion, respectively. Then, flies were immediately exposed to a feeding medium supplemented with 250 μM rotenone for seven days. The motor ability of Drosophila was detected by negative geotaxis assay, and the number of dopamine (DA) neurons and tyrosine hydroxylase (TH) expression levels were evaluated...

Sodium intake effect of aldosterone has attracted much attention. In our recent study, aldosterone can play a nongenomic regulatory role on rapid sodium intake in the NTS (nucleus tractus solitarius) by activating G protein-coupled estrogen receptor (GPER), and it exhibited an obvious time-dependent and concentration-dependent regulation. However, the molecular mechanism how aldosterone regulated sodium intake rapidly, is unclear. To determine the molecular mechanism of rapid sodium intake regulation of aldosterone, rats with a stainless-steel cannula in the NTS were used (n=6 each subgroup), and were injected different concentrations of aldosterone / G1 (GPER agonist) / G15 (GPER antagonist) at different time points, then detected ERK1/2 protein expression...

Interhemispheric facilitation (IHF) describes potentiation of motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) over primary motor cortex (M1), when they are preceded (3-6 ms) by conditioning TMS below motor threshold (MT) delivered over the opposite M1. This effect is however obtained only when the conditioning stimulation is sufficiently circumscribed. In paired associative protocols, (500 ms) bursts of 140 Hz transcranial alternating current stimulation (tACS) interact with the state of neural circuits in the opposite hemisphere in a similar manner to sub-threshold TMS...

Otof, which encodes otoferlin, knockout mice are considered model mice for auditory neuropathy spectrum disorder, which is characterized by an absent auditory brainstem response (ABR) despite preserved distortion product otoacoustic emission (DPOAE). Although otoferlin-deficient mice lack neurotransmitter release at the inner hair cell (IHC) synapse, it remains unclear how the Otof mutation affects spiral ganglions. Thus, we used Otof-mutant mice carrying the Otoftm1a(KOMP)Wtsi allele (Otoftm1a ) and analyzed spiral ganglion neurons (SGNs) in Otoftm1a/tm1a mice by immunolabeling type Ⅰ SGNs (SGN-Ⅰ) and type II SGNs (SGN-II)...

FAM20C (family with sequence similarity 20-member C) is a protein kinase that phosphorylates secretory proteins, including the proteins that are essential to the formation and mineralization of calcified tissues. FAM20C loss-of-function mutations cause Raine syndrome in humans, characterized by generalized osteosclerosis, distinctive craniofacial dysmorphism, along with extensive intracranial calcification. Our previous studies revealed that inactivation of Fam20c in mice led to hypophosphatemic rickets. In this study, we examined the expression of Fam20c in the mouse brain and investigated brain calcification in Fam20c-deficient mice...

Transcranial direct current stimulation (tDCS) can modulate cortical excitability and relieve neuropathic pain (NP), but the role of several biomarkers in this process is not well understood. This study aimed to analyze the effects of tDCS on biochemical parameters in rats with neuropathic pain (NP) induced by chronic constriction injury (CCI) of the right sciatic nerve. Eighty-eight male 60-day-old Wistar rats were divided into nine groups: control (C), control-electrode off (CEoff), control-tDCS (C-tDCS), sham-lesion (SL), sham-lesion electrode off (SLEoff), sham-lesion (SL-tDCS), lesion (L), lesion electrode off (LEoff), and lesion-tDCS (L-tDCS)...

Pentobarbital-induced anesthesia is believed to be mediated by enhancement of the inhibitory action of γ-aminobutyric acid (GABA)ergic neurons in the central nervous system. However, it is unclear whether all components of anesthesia induced by pentobarbital, such as muscle relaxation, unconsciousness, and immobility in response to noxious stimuli, are mediated only through GABAergic neurons. Thus, we examined whether the indirect GABA and glycine receptor agonists gabaculine and sarcosine, respectively, the neuronal nicotinic acetylcholine receptor antagonist mecamylamine, or the N-methyl-d-aspartate receptor channel blocker MK-801 could enhance pentobarbital-induced components of anesthesia...

Although semantic control is known to play a critical role in selecting weakly associated representations for creative idea generation, direct evidence for this is still lacking. The current study aimed to reveal the role of brain regions, including the inferior frontal gyrus (IFG), medial frontal gyrus (MFG), and inferior parietal lobule (IPL), previously reported to be associated with creative idea generation. For this purpose, a functional MRI experiment with a newly developed category judgment task was conducted, which required participants to judge whether two words belonged to the same category...

Previous research has revealed a high degree of complexity of the conditioned response that appears after associating a context with the effects of the dopaminergic antagonist haloperidol. Specifically, when a drug-free test is performed in the presence of the context, conditioned catalepsy is observed. However, if the test is extended over time, the opposite effect occurs, namely, a conditioned increase in locomotor activity. In this paper, we present the results of an experiment with rats that received repeated administration of haloperidol or saline before or after exposure to the context...

The EYA1 gene is essential for normal inner ear development and affects the development and function of the inner ear in a dose-dependent manner. However, the mechanisms regulating EYA1 gene expression are not well understood. Recently, miRNAs have become recognized as important regulators of gene expression. In this study, we identified miR-124-3p through a microRNA (miRNA) target prediction website and found that miR-124-3p and its target site in the EYA1 3' untranslated region (3'UTR) are conserved in most vertebrates...

Paradoxical heat sensation (PHS) and the thermal grill illusion (TGI) are both related to the perception of warmth or heat from innocuous cold stimuli. Despite being described as similar perceptual phenomena, recent findings suggested that PHS is common in neuropathy and related to sensory loss, while TGI is more frequently observed in healthy individuals. To clarify the relationship between these two phenomena, we conducted a study in a cohort of healthy individuals to investigate the association between PHS and TGI...

Microglia, the resident immune cells of the brain, support normal brain function and the brain's response to disease and injury. The hippocampal dentate gyrus (DG) is an area of microglial study due to its central role in many behavioral and cognitive functions. Interestingly, microglia and related cells are distinct in female vs. male rodents, even in early life. Indeed, postnatal day (P)-dependent sex differences in number, density, and morphology of microglia have been reported in certain hippocampal subregions at specific ages...

Based on the mind-blindness hypothesis, a large number of studies have shown that individuals with autism-spectrum disorder (ASD) and autistic traits have empathy deficits. However, the recent double empathy theory contradicts the mind-blindness hypothesis and suggests that individuals with ASD and autistic traits do not necessarily lack empathy. Thus, the presence of empathy deficits in individuals with ASD and autistic traits is still controversial. We recruited 56 adolescents (28 high autistic traits, 28 low autistic traits, 14-17 years old) in this study to explore the relationship between empathy and autistic traits...

BACKGROUND AND PURPOSE: Previous studies have explored the clinical consequences of cortical microinfarction, mainly age-related cognitive decline. However, functional impairment of deep cortical microinfarction remains poorly understood. Based on anatomical knowledge and previous research, we infer that damage to the deep cortex may lead to cognitive deficits and communication impairment between the superficial cortex and thalamus. This study aimed to develop a new model of deep cortical microinfarction based on femtosecond laser ablation of a perforating artery...