Attention deficit/hyperactivity disorder (ADHD) is defined as a neurodevelopmental condition. The precise underlying mechanisms remain incompletely elucidated. A body of research suggests disruptions in both the cellular architecture and neuronal function within the brain regions of individuals with ADHD, coupled with disturbances in the biochemical parameters.
View Article and Find Full Text PDFNoradrenergic neurons in the locus coeruleus referred to as locus coeruleus neurons, provide the major supply of norepinephrine to the forebrain and play important roles in behavior through regulation of wakefulness and arousal. In a previous study using brain slice preparations, we reported that locus coeruleus neurons are subject to tonic inhibition mediated by γ-aminobutyric acid B receptors (GABABRs) and that the extent of tonic inhibition varies with ambient GABA levels. Since ambient GABA in the locus coeruleus was reported to fluctuate during the sleep-wakefulness cycle, here we tested whether GABABR-mediated tonic inhibition of locus coeruleus neurons could be a mechanism underlying changes in brain arousal.
View Article and Find Full Text PDFMediodorsal thalamic nucleus (MD) is a critical relay of nociception. This study recorded responses of MD neurons to noxious mechanical and thermal stimuli in isoflurane anesthetized rats. We found the threshold of noxious mechanical stimulation was 141 gw and that of noxious heat stimulation was 46 °C.
View Article and Find Full Text PDFIn a clinical setting, anxiety disorder is highly correlated with bipolar I disorder in humans. However, the comorbidity of anxiety behavior and bipolar disorder still remains unclear in an animal model. This study utilized an ouabain-induced animal mode to examine anxiety and mania in an open field test.
View Article and Find Full Text PDFThe present study examines whether housing style (e.g., single housing, same-strain-grouped housing, and different-strain-grouped housing) and rat strain (e.
View Article and Find Full Text PDFThe rostral agranular insular cortex (RAIC), an opioid-responsive site, is essential for modulating nociception in rats. Our previous studies have shown that morphine suppressed long latency laser heat-evoked nociceptive responses in the primary somatosensory cortex (SmI). By contrast, morphine significantly attenuated both short and long latency responses in the anterior cingulate cortex (ACC).
View Article and Find Full Text PDFPrimary somatosensory cortex (SI) is a key area in the processing of nociceptor inputs to our consciousness. To clarify the columnar and laminar organization of SI for pain processing, we compared spatiotemporal changes in neuronal activities of the primary sensorimotor cortex (SmI) of the rat in response to noxious laser heat stimulation applied to the mid-tail. Longitudinal and vertical array microelectrodes were chronically implanted in the cerebral cortex.
View Article and Find Full Text PDFNeural responses to sensory inputs caused by self-generated movements (reafference) and external passive stimulation (exafference) differ in various brain regions. The ability to differentiate such sensory information can lead to movement execution with better accuracy. However, how sensory responses are adjusted in regard to this distinguishability during motor learning is still poorly understood.
View Article and Find Full Text PDFGranger causality (GC) analysis has emerged as a powerful analytical method for estimating the causal relationship among various types of neural activity data. However, two problems remain not very clear and further researches are needed: (1) The GC measure is designed to be nonnegative in its original form, lacking of the trait for differentiating the effects of excitations and inhibitions between neurons. (2) How is the estimated causality related to the underlying synaptic weights? Based on the GC, we propose a computational algorithm under a best linear predictor assumption for analyzing neuronal networks by estimating the synaptic weights among them.
View Article and Find Full Text PDFAxon collateral projections to various lobules of the cerebellar cortex are thought to contribute to the coordination of neuronal activities among different parts of the cerebellum. Even though lobules I/II and IX/X of the cerebellar vermis are located at the opposite poles in the anterior-posterior axis, they have been shown to receive dense vestibular mossy fiber projections. For climbing fibers, there is also a mirror-image-like organisation in their axonal collaterals between the anterior and posterior cerebellar cortex.
View Article and Find Full Text PDFNeuronal oscillations have been shown to contribute to the function of the cerebral cortex by coordinating the neuronal activities of distant cortical regions via a temporal synchronization of neuronal discharge patterns. This can occur regardless whether these regions are linked by cortico-cortical pathways or not. Less is known concerning the role of neuronal oscillations in the cerebellum.
View Article and Find Full Text PDFAccurately sorting individual neurons is a technical challenge and plays an important role in identifying information flow among neurons. Spike sorting errors are almost unavoidable and can roughly be divided into two types: false positives (FPs) and false negatives (FNs). This study investigates how FPs and FNs affect results of the Granger causality (GC) analysis, a powerful method for detecting causal interactions between time series signals.
View Article and Find Full Text PDFRationale: The influence of acute D2 agonist quinpirole on locomotor activity has been effectively characterized. However, few studies have addressed the dynamic changes in neuronal activity of the anterior cingulate cortex (ACC) and striatum (STR), two crucial regions for cognitive and motor functions, after quinpirole administration.
Objective: This study was conducted in order to acquire detailed information on the evoked activity of the neurons in the ACC and STR after acute quinpirole administration.
The transection of the inferior alveolar nerve (IANx) produces allodynia in the whisker pad (V2 division) of rats. Ectopic discharges from injured trigeminal ganglion (TG) neurons and thalamocortical reorganization are possible contributors to the sensitization of uninjured V2 primary and CNS neurons. To test which factor is more important, TG and ventroposterior medial nucleus (VPM) neurons were longitudinally followed before, during, and after IANx for up to 80 d.
View Article and Find Full Text PDFPain is a natural alarm that aids the body in avoiding potential danger and can also present as an important indicator in clinics. Infrared laser-evoked potentials can be used as an objective index to evaluate nociception. In animal studies, a short-pulse laser is crucial because it completes the stimulation before escape behavior.
View Article and Find Full Text PDFBackground: Alcohol is a widely abused substance and is responsible for significant morbidity and mortality worldwide. The precise mechanisms underlying ethanol (EtOH)'s actions in the central nervous system (CNS) remain elusive. In vitro studies suggest that GABAergic interneurons are important targets of EtOH action in the CNS.
View Article and Find Full Text PDFMice have gained more and more attention in recent years and been widely used in transgenic experiments. Although the number of researches on the heart rate variability (HRV) of mice has been gradually increasing, a consensus on the frequency ranges of autonomic modulation has not been established. Therefore, the main purpose of this study was to find a HRV "prototype" for conscious mice in the state of being motionless and breathing regularly (called "genuinely resting"), and to determine the frequency ranges corresponding to the autonomic modulation.
View Article and Find Full Text PDFChronic single-unit recording in subcortical brain regions is increasingly important in neurophysiological studies. However, methods for long-term, stable recording of multiple single-units in deep brain regions and in dura-surrounded ganglion have not yet been established. In the present study, we propose a bundled microwire array design which is capable of long-term recording of the trigeminal ganglion and deep-brain units.
View Article and Find Full Text PDFWe herein introduce an automated three-dimensional (3D) locomotion tracking and pose reconstruction system for rodents with superior robustness, rapidity, reliability, resolution, simplicity, and cost. An off-the-shelf composite infrared (IR) range camera was adopted to grab high-resolution depth images (640×480×2048 pixels at 20Hz) in our system for automated behavior analysis. For the inherent 3D structure of the depth images, we developed a compact algorithm to reconstruct the locomotion and body behavior with superior temporal and solid spatial resolution.
View Article and Find Full Text PDFBackground: Mice that have defects in their low-threshold T-type calcium channel (T-channel) genes show altered pain behaviors. The changes in the ratio of nociceptive neurons and the burst firing property of reticular thalamic (RT) and ventroposterior (VP) neurons in Cav3.2 knockout (KO) mice were studied to test the involvement of thalamic T-channel and burst firing activity in pain function.
View Article and Find Full Text PDFHeat-fusing is a common process for fabricating microwire tetrodes. However, it is time-consuming, and the high-temperature treatment can easily cause the insulation of the microwire to overheat leading to short circuits. We herein provide a simple, fast method to fabricate microwire tetrodes without the heat-fusion process.
View Article and Find Full Text PDFAttention-deficit/hyperactivity disorder (ADHD) is one of the most common childhood neuropsychiatric disorders. Based on neuroimaging studies, the striatum is reported to be abnormal in size, but it is still not clear how they change during developmental stages. Spontaneously hypertensive rats (SHRs) are the commonly used animal model for ADHD.
View Article and Find Full Text PDFCancer Chemother Pharmacol
September 2010
Purpose: Gastric cancer is one of the leading cancerous diseases worldwide. It is diagnosed often at the advanced stage for which chemotherapy is the main treatment option. The prognosis remains poor for metastatic, especially the diffuse type, gastric cancers.
View Article and Find Full Text PDFThe low-frequency (0.2-0.8 Hz) component of blood pressure (BP) variability (LF(BP)) is used as an index of the low-frequency variability of sympathetic nerve activity (SNA) (LF(SNA)) in rats.
View Article and Find Full Text PDFThe rostral ventrolateral medulla (RVLM) is critically important in the generation of sympathetic activity. The purpose of this study was to investigate whether discharges of RVLM neurons contribute to low-frequency (LF) sympathetic rhythms. Blood pressure (BP), renal sympathetic nerve activity (SNA), and neuronal activity in the RVLM were simultaneously recorded in seven anesthetized, paralyzed, and artificially ventilated rats.
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