Hypocretin in median raphe nucleus modulates footshock stimuli-induced REM sleep alteration.

Stress is one of major factors that cause sleep problems. Hypocretin represents a stress-related neuropeptide and is well known in maintaining physiological wakefulness. The hypocretinergic neurons originate in the lateral hypothalamic area (LHA) and transmit to several brain regions, including the median raphe nuclei (MRNs). The MRNs modulate both fear responses and sleep-wake activity; however, it remains unclear whether stress alters the levels of hypocretin to regulate MRNs and consequently disrupt sleep. In this paper, we employed the inescapable footshock stimuli (IFS) as a stressor and hypothesized that the IFS-induced sleep disruption is mediated by increased hypocretins in the MRNs. Our results demonstrate that the concentrations of hypocretin in the hypothalamus increased after IFS. Rapid eye movement (REM) sleep was reduced after footshock, and microinjection of non-selective hypocretin receptor antagonist TCS-1102 into the MRNs blocked the IFS-induced decrease of REM sleep. Furthermore, administration of hypocretins into the MRNs mimicked the IFS-induced REM sleep reduction. These results conclude that the increased levels of hypocretins in the MRNs mediate the IFS-induced REM sleep reduction.

Manipulation of Epileptiform Electrocorticograms (ECoGs) and Sleep in Rats and Mice by Acupuncture.

Ancient Chinese literature has documented that acupuncture possesses efficient therapeutic effects on epilepsy and insomnia. There is, however, little research to reveal the possible mechanisms behind these effects. To investigate the effect of acupuncture on epilepsy and sleep, several issues need to be addressed. The first is to identify the acupoints, which correspond between humans, rats, and mice. Furthermore, the depth of insertion of the acupuncture needle, the degree of needle twist in manual needle acupuncture, and the stimulation parameters for electroacupuncture (EA) need to be determined. To evaluate the effects of acupuncture on epilepsy and sleep, a feasible model of epilepsy in rodents is required. We administer pilocarpine into the left central nucleus of the amygdala (CeA) to simulate focal temporal lobe epilepsy (TLE) in rats. Intraperitoneal (IP) injection of pilocarpine induces generalized epilepsy and status epilepticus (SE) in rats. Five IP injections of pentylenetetrazol (PTZ) with a one-day interval between each injection successfully induces spontaneous generalized epilepsy in mice. Recordings of electrocorticograms (ECoGs), electromyograms (EMGs), brain temperature, and locomotor activity are used for sleep analysis in rats, while ECoGs, EMGs, and locomotor activity are employed for sleep analysis in mice. ECoG electrodes are implanted into the frontal, parietal, and contralateral occipital cortices, and a thermistor is implanted above the cerebral cortex by stereotactic surgery. EMG electrodes are implanted into the neck muscles, and an infrared detector determines locomotor activity. The criteria for categorizing vigilance stages, including wakefulness, rapid eye movement (REM) sleep, and non-REM (NREM) sleep are based on information from ECoGs, EMGs, brain temperature, and locomotor activity. Detailed classification criteria are stated in the text.

Retrospective study of the clinical effects of acupuncture on cervical neurological diseases in dogs.

This study was conducted to evaluate new acupuncture protocols for the clinical treatment of cervical spinal cord diseases in 19 dogs. Three treatment options containing Jing-jiaji (cervical jiaji) were developed to treat neck pain, hemiparesis, and tetraparesis depending on the severity. The interval between the neurological disease onset and treatment (duration of signs), time to improvement after treatment, and recovery time were compared in dogs by body weight, age, and dry needle acupuncture (AP) with or without electro-AP (EAP). The duration of signs was longer in dogs weighing greater than 10 kg than in those weighing less than 10 kg (p＜ 0.05). Improvement and recovery times did not vary by body weight. Additionally, improvement and recovery times did not vary by age. The improvement and recovery times were longer in the AP+EAP group than the AP group (p＜ 0.05). Acupuncture with Jing-jiaji was effective in cervical spinal cord diseases in different sized dogs and in middle-aged and senior dogs. This report standardized AP treatment containing Jing-jiaji for canine cervical problems and evaluated its effects. The newly standardized AP methodology offers clinical practitioners an effective way to improve the outcomes of cervical neurological diseases in dogs.

Low-frequency electroacupuncture suppresses focal epilepsy and improves epilepsy-induced sleep disruptions.

BACKGROUND: The positive effects of acupuncture at Feng-Chi acupoints on treating epilepsy and insomnia have been well-documented in ancient Chinese literature. However, there is a lack of scientific evidence to elucidate the underlying mechanisms behind these effects. Our previous study demonstrated that high-frequency (100 Hz) electroacupuncture (EA) at Feng-Chi acupoints deteriorates both pilocarpine-induced focal epilepsy and sleep disruptions. This study investigated the effects of low-frequency (10 Hz) EA on epileptic activities and epilepsy-induced sleep disruptions. RESULTS: In rats, the Feng-Chi acupoint is located 3 mm away from the center of a line between the two ears. Rats received 30 min of 10 Hz EA stimuli per day before each day's dark period for three consecutive days. Our results indicated that administration of pilocarpine into the left CeA at the beginning of the dark period induced focal epilepsy and decreased both rapid eye movement (REM) sleep and non-REM (NREM) sleep during the consequent light period. Low-frequency (10 Hz) EA at Feng-Chi acupoints suppressed pilocarpine-induced epileptiform EEGs, and this effect was in turn blocked by naloxone (a broad-spectrum opioid receptor antagonist), but not by naloxonazine (a µ-receptor antagonist), naltrindole (a δ-receptor antagonist) and nor-binaltorphimine (a κ-receptor antagonist). Ten Hz EA enhanced NREM sleep during the dark period, and this enhancement was blocked by all of the opioid receptor antagonists. On the other hand, 10 Hz EA reversed pilocarpine-induced NREM suppression during the light period, and the EA's effect on the sleep disruption was only blocked by naloxonazine. CONCLUSIONS: These results indicate that low-frequency EA stimulation of Feng-Chi acupoints is beneficial in improving epilepsy and epilepsy-induced sleep disruptions, and that opioid receptors in the CeA mediate EA's therapeutic effects.

Functional and structural deficits of the dentate gyrus network coincide with emerging spontaneous seizures in an Scn1a mutant Dravet Syndrome model during development.

Dravet syndrome (DS) is characterized by severe infant-onset myoclonic epilepsy along with delayed psychomotor development and heightened premature mortality. A primary monogenic cause is mutation of the SCN1A gene, which encodes the voltage-gated sodium channel subunit Nav1.1. The nature and timing of changes caused by SCN1A mutation in the hippocampal dentate gyrus (DG) network, a core area for gating major excitatory input to hippocampus and a classic epileptogenic zone, are not well known. In particularly, it is still not clear whether the developmental deficit of this epileptogenic neural network temporally matches with the progress of seizure development. Here, we investigated the emerging functional and structural deficits of the DG network in a novel mouse model (Scn1a(E1099X/+)) that mimics the genetic deficit of human DS. Scn1a(E1099X/+) (Het) mice, similarly to human DS patients, exhibited early spontaneous seizures and were more susceptible to hyperthermia-induced seizures starting at postnatal week (PW) 3, with seizures peaking at PW4. During the same period, the Het DG exhibited a greater reduction of Nav1.1-expressing GABAergic neurons compared to other hippocampal areas. Het DG GABAergic neurons showed altered action potential kinetics, reduced excitability, and generated fewer spontaneous inhibitory inputs into DG granule cells. The effect of reduced inhibitory input to DG granule cells was exacerbated by heightened spontaneous excitatory transmission and elevated excitatory release probability in these cells. In addition to electrophysiological deficit, we observed emerging morphological abnormalities of DG granule cells. Het granule cells exhibited progressively reduced dendritic arborization and excessive spines, which coincided with imbalanced network activity and the developmental onset of spontaneous seizures. Taken together, our results establish the existence of significant structural and functional developmental deficits of the DG network and the temporal correlation between emergence of these deficits and the onset of seizures in Het animals. Most importantly, our results uncover the developmental deficits of neural connectivity in Het mice. Such structural abnormalities likely further exacerbate network instability and compromise higher-order cognitive processing later in development, and thus highlight the multifaceted impacts of Scn1a deficiency on neural development.

An Evaluation of Electroacupuncture at the Weizhong Acupoint (BL-40) as a Means of Relieving Pain Induced by Extracorporeal Shock Wave Lithotripsy.

Background. Extracorporeal shock wave lithotripsy (ESWL) is the preferred option for urolithiasis treatment. However, intensities of pain may be induced and the sedative anesthetic or analgesics were usually needed. The aim of this study was to develop an improved acupuncture-assisted anesthesia approach in pain relief. Methods. We conducted a single-blind, randomized controlled study in China Medical University Hospital. Patients treated by ESWL due to upper urolithiasis were randomly divided into control group, sham-EA group, and 100 Hz EA group. The high frequency electroacupuncture (EA) was applied at the Weizhong acupoint (100 Hz EA group) for 20 minutes prior to the ESWL. In the sham-EA group, the same procedures were performed as those of 100 Hz EA group but no electric current was given to stimulate the acupoints. In the control group, no action was taken before operation. The information including the numbers and dosage of analgesic requirements, pain score, vital signs, and the satisfaction of procedure was collected. Results. A total of 74 subjects were recruited and we found that the interval to the first request analgesic, the number/total dosage of additional analgesic, recovery time from anesthesia, and the satisfaction were all better in both the 100 Hz EA and the sham-EA group. The 100 Hz EA also showed better relief of painful sensations by delaying the onset of pain. Conclusions. The 100 Hz EA and the sham-EA can effectively relieve pain due to ESWL as well as reducing the dosage of opium analgesic used.

Amygdala opioid receptors mediate the electroacupuncture-induced deterioration of sleep disruptions in epilepsy rats.

BACKGROUND: Clinical and experimental evidence demonstrates that sleep and epilepsy reciprocally affect each other. Previous studies indicated that epilepsy alters sleep homeostasis; in contrast, sleep disturbance deteriorates epilepsy. If a therapy possesses both epilepsy suppression and sleep improvement, it would be the priority choice for seizure control. Effects of acupuncture of Feng-Chi (GB20) acupoints on epilepsy suppression and insomnia treatment have been documented in the ancient Chinese literature, Lingshu Jing (Classic of the Miraculous Pivot). Therefore, this study was designed to investigate the effect of electroacupuncture (EA) stimulation of bilateral Feng-Chi acupoints on sleep disruptions in rats with focal epilepsy. RESULTS: Our result indicates that administration of pilocarpine into the left central nucleus of amygdala (CeA) induced focal epilepsy and decreased both rapid eye movement (REM) sleep and non-REM (NREM) sleep. High-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints, in which a 30-min EA stimulation was performed before the dark period of the light:dark cycle in three consecutive days, further deteriorated pilocarpine-induced sleep disruptions. The EA-induced exacerbation of sleep disruption was blocked by microinjection of naloxone, µ- (naloxonazine), κ- (nor-binaltorphimine) or δ-receptor antagonists (natrindole) into the CeA, suggesting the involvement of amygdaloid opioid receptors. CONCLUSION: The present study suggests that high-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints exhibits no benefit in improving pilocarpine-induced sleep disruptions; in contrast, EA further deteriorated sleep disturbances. Opioid receptors in the CeA mediated EA-induced exacerbation of sleep disruptions in epileptic rats.

Activation of amygdala opioid receptors by electroacupuncture of Feng-Chi (GB20) acupoints exacerbates focal epilepsy.

BACKGROUND: The effect of seizure suppression by acupuncture of Feng-Chi (GB20) acupoints has been documented in the ancient Chinese literature, Lingshu Jing (Classic of the Miraculous Pivot), however, there is a lack of scientific evidence to prove it. This current study was designed to elucidate the effect of electroacupuncture (EA) stimulation of bilateral Feng-Chi (GB20) acupoints on the epileptic activity by employing an animal model of focal epilepsy. METHODS: Administration of pilocarpine into the left central nucleus of amygdala (CeA) induced the focal epilepsy in rats. Rats received a 30-min 100 Hz EA stimulation of bilateral Feng-Chi acupoints per day, beginning at 30 minutes before the dark period and performing in three consecutive days. The broad-spectrum opioid receptor antagonist (naloxone), µ-receptor antagonist (naloxonazine), δ-receptor antagonist (naltrindole) and κ-receptor antagonist (nor-binaltorphimine) were administered directly into the CeA to elucidate the involvement of CeA opioid receptors in the EA effect. RESULTS: High-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints did not suppress the pilocarpine-induced epileptiform electroencephalograms (EEGs), whereas it further increased the duration of epileptiform EEGs. We also observed that epilepsy occurred while 100 Hz EA stimulation of Feng-Chi acupoints was delivered into naïve rats. EA-induced augmentation of epileptic activity was blocked by microinjection of naloxone, µ- (naloxonazine), κ- (nor-binaltorphimine) or δ-receptor antagonists (natrindole) into the CeA, suggesting that activation of opioid receptors in the CeA mediates EA-exacerbated epilepsy. CONCLUSIONS: The present study suggests that high-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints has no effect to protect against pilocarpine-induced focal epilepsy; in contrast, EA further exacerbated focal epilepsy induced by pilocarpine. Opioid receptors in the CeA mediated EA-induced exacerbation of focal epilepsy.

Electrical stimulation of left anterior thalamic nucleus with high-frequency and low-intensity currents reduces the rate of pilocarpine-induced epilepsy in rats.

PURPOSE: Bilateral electrical stimulation of anterior nuclei of thalamus (ANT) has shown promising effects on epileptic seizures. However, bilateral implantation increases the risk of surgical complications and side effects. This study was undertaken to access the effectiveness of a stimulation paradigm involving high frequency and low intensity currents to stimulate the left ANT in rats. METHODS: Male Sprague-Dawley rats were implanted with electroencephalogram (EEG) electrodes, and an additional concentric bipolar stimulation electrode into either the left or right ANT. The stimulus was a train of pulses (90 µs duration each) delivered with a frequency of 200 Hz and a current intensity of 50 µA. Thalamic stimuli were started 1 h before the first intraperitoneal pilocarpine injection (i.p., 300 mg/kg), and were applied for 5 h. RESULTS: EEG documented seizure activity and status epilepticus (SE) developed in 87.5% of rats treated with no ANT stimulation after a single dose of pilocarpine. Left ANT stimulation significantly increased the tolerance threshold for pilocarpine-induced EEG seizure activity; 20% of rats developed their EEG documented seizure activity after receiving the first dose, whereas 50%, 10% and 20% of rats did not develop seizure activity until they had received the 2nd, 3rd and 4th pilocarpine injection at 1-h intervals. Moreover, left thalamic stimulation reduced the occurrences of both EEG documented seizure activity and SE induced by single-dose pilocarpine to 25%. However, our result demonstrated that little effect on the occurrence rate of seizures and SE was found when rats received right ANT stimulation. CONCLUSIONS: These results suggest that continuously 5-h left ANT stimulation with high frequency and low intensity currents, beginning from 1h before the pilocarpine administration, may successfully reduce the occurrence rate of EEG documented seizure activity and SE development in rats.

Disrupted circadian rhythm in rats with nephrectomy-induced chronic kidney disease.

AIMS: Our study investigated the role of circadian rhythm in the pathogenesis of sleep disturbance in patients with chronic kidney disease (CKD) based on an animal model. MAIN METHODS: Sixteen Sprague-Dawley (SD) rats (eight from 5/6 nephrectomized CKD group and eight from control group) were used for electroencephalography (EEG) and electromyography (EMG) recording. Eight rats (four from CKD and four from control group) were sacrificed at six Zeitgeber time (ZT) points and determined the mRNA expression of clock genes, rPer1, rPer2 and rBMAL1b in the hypothalamus. KEY FINDINGS: Our results demonstrated that both slow wave sleep (SWS) and rapid eye movement (REM) sleep were significantly increased in the ZT22-24 Zeitgeber time point of the dark period in the CKD rats when compared with those sleep architectures obtained from the control rats. The CKD-induced sleep disruptions were associated with significant upregulations of rPer1 (in ZT2, ZT6 and ZT14) and rPer2 mRNA expression (in ZT2 and ZT14) in the hypothalamus. SIGNIFICANCE: Our study elucidated that the increases of SWS and REM sleep during ZT22-24 of the dark period in the CKD rats might be due to the enhancement of rPer1 and rPer2 clock genes in the hypothalamus, suggesting that disrupted circadian rhythm plays a role in the pathogenesis of sleep disturbance in patients with CKD.

Kappa-opioid receptors in the caudal nucleus tractus solitarius mediate 100 hz electroacupuncture-induced sleep activities in rats.

Previous results demonstrated that 10 Hz electroacupuncture (EA) of Anmian acupoints in rats during the dark period enhances slow wave sleep (SWS), which involves the induction of cholinergic activity in the caudal nucleus tractus solitarius (NTS) and subsequent activation of opioidergic neurons and µ-receptors. Studies have shown that different kinds of endogenous opiate peptides and receptors may mediate the consequences of EA with different frequencies. Herein, we further elucidated that high-frequency (100 Hz)-EA of Anmian enhanced SWS during the dark period but exhibited no direct effect on rapid eye movement (REM) sleep. High-frequency EA-induced SWS enhancement was dose-dependently blocked by microinjection of naloxone or κ-receptor antagonist (nor-binaltorphimine) into the caudal NTS, but was affected neither by µ- (naloxonazine) nor δ-receptor antagonists (natatrindole), suggesting the role of NTS κ-receptors in the high-frequency EA-induced SWS enhancement. Current and previous results depict the opioid mechanisms of EA-induced sleep.

Effect of cannabidiol on sleep disruption induced by the repeated combination tests consisting of open field and elevated plus-maze in rats.

Patients with post-traumatic stress disorder (PTSD) frequently complain of having sleep disturbances, such as insomnia and rapid eye movement (REM) sleep abnormality. Cannabidiol (CBD), a psycho-inactive constituent of marijuana, reduces physiological non-REM (NREM) sleep and REM sleep in normal rats, in addition to generating its anxiolytic effect. However, the effects of CBD on anxiety-induced sleep disturbances remain unclear. Because anxiety progression is caused by persistent stress for a period of time, we employed the repeated combination tests (RCT) consisting of a 50-min open field (OF) and a subsequent 10-min elevated plus-maze (EPM) for four consecutive days to simulate the development of anxiety. Time spent in the centre arena of OF and during open arms of the EPM was substantially decreased in latter days of RCT, suggesting the habituation, which potentially lessens anxiety-mediated behavioural responses, was not observed in current tests. CBD microinjected into the central nucleus of amygdala (CeA) significantly enhanced time spent in centre arena of OF, increased time during the open arms and decreased frequency of entry to the enclosed arms of EPM, further confirming its anxiolytic effect. The decrease of NREM sleep during the first hour and the suppression of REM sleep during hours 4-10 after the RCT represent the similar clinical observations (e.g. insomnia and REM sleep interruption) in PTSD patients. CBD efficiently blocked anxiety-induced REM sleep suppression, but had little effect on the alteration of NREM sleep. Conclusively, CBD may block anxiety-induced REM sleep alteration via its anxiolytic effect, rather than via sleep regulation per se. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Biphasic effects of baicalin, an active constituent of Scutellaria baicalensis Georgi, in the spontaneous sleep-wake regulation.

AIM OF THE STUDY: Baicalin is an active compound originating from the root of Scutellaria baicalensis Georgi, which has been used for anti-inflammation, anti-bacteria, anti-hypertension, anti-allergy and sedation since ancient China, though the neuronal mechanisms involved in the sedative effect is still unclear. Baicalin possesses the ability to decrease the expression of pro-inflammatory cytokines and nuclear factor (NF)-κB activity. Furthermore, baicalin has demonstrated an anxiolytic-like effect via activation of γ-aminobutyric acid-A (GABA(A)) receptors. Pro-inflammatory cytokines (e.g. interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α) and the GABAergic system promote sleep. This study was designed to determine whether the GABA(A) receptor activation and/or the suppression of pro-inflammatory cytokines mediate(s) baicalin-induced sleep alterations. MATERIALS AND METHODS: Baicalin was intracerebroventricularly (ICV) administered 20 min either prior to the beginning of the light period or before the onset of the dark period. Electroencephalogram (EEG) and gross body movement were acquired for sleep analysis. Pharmacological blockade of IL-1 and GABA(A) receptors were employed to elucidate the involvements of IL-1 and GABA(A) receptors in baicalin-induced sleep alterations. IL-1ß concentrations obtained after baicalin administration in several distinct brain regions were determined by ELISA. RESULTS: ICV administration of baicalin decreased slow wave sleep (SWS) during the first 2h of the light period. Rapid eye movement sleep (REMS) was not altered. The blockade of IL-1ß-induced SWS enhancement by baicalin suggests that the antagonism of IL-1 receptors is involved in baicalin-induced SWS decrement during the light period. However, IL-1ß concentrations during the light period were not altered after baicalin administration. In contrast, baicalin increased both SWS and REMS during hours 8-10 of the dark (active) period when baicalin was administered at the beginning of the dark period, and its effects were blocked by the GABA(A) receptor antagonist bicuculline. CONCLUSION: Baicalin exhibits biphasic effects on sleep-wake regulation; the decrease of SWS during the light period and increases of SWS and REMS during the dark period. Inhibition of IL-1 action and enhancement of GABA(A) receptor activity may mediate baicalin's effects during the light and dark period, respectively.

Endogenous opiates in the nucleus tractus solitarius mediate electroacupuncture-induced sleep activities in rats.

Electroacupuncture (EA) possesses various therapeutic effects, including alleviation of pain, reduction of inflammation and improvement of sleep disturbance. The mechanisms of EA on sleep improvement, however, remain to be determined. It has been stated in ancient Chinese literature that the Anmian (EX17) acupoint is one of the trigger points that alleviates insomnia. We previously demonstrated that EA stimulation of Anmian acupoints in rats during the dark period enhances non-rapid eye movement (NREM) sleep, which involves the induction of cholinergic activity in the nucleus tractus solitarius (NTS). In addition to cholinergic activation of the NTS, activation of the endogenous opioidergic system may also be a mechanism by which acupuncture affects sleep. Therefore, this study was designed to investigate the involvement of the NTS opioidergic system in EA-induced alterations in sleep. Our present results indicate that EA of Anmian acupoints increased NREM sleep, but not rapid eye movement sleep, during the dark period in rats. This enhancement in NREM sleep was dose-dependently blocked by microinjection of opioid receptor antagonist, naloxone, and the µ-opioid receptor antagonist, naloxonazine, into the NTS; administrations of δ-receptor antagonist, natrindole, and the κ-receptor antagonist, nor-binaltrophimine, however, did not affect EA-induced alterations in sleep. Furthermore, ß-endorphin was significantly increased in both the brainstem and hippocampus after the EA stimuli, an effect blocked by administration of the muscarinic antagonist scopolamine into the NTS. Our findings suggest that mechanisms of EA-induced NREM sleep enhancement may be mediated, in part, by cholinergic activation, stimulation of the opiodergic neurons to increase the concentrations of ß-endorphin and the involvement of the µ-opioid receptors.

The involvement of serotonin receptors in suanzaorentang-induced sleep alteration.

Sedative-hypnotic medications, including benzodiazepines and non-benzodiazepines, are usually prescribed for the insomniac patients; however, the addiction, dependence and adverse effects of those medications have drawn much attention. In contrast, suanzaorentang, a traditional Chinese herb remedy, has been efficiently used for insomnia relief in China, although its mechanism remains unclear. This study was designed to further elucidate the underlying mechanism of suanzaorentang on sleep regulation. One ingredient of suanzaorentang, zizyphi spinosi semen, exhibits binding affinity for serotonin (5-hydroxytryptamine, 5-HT) receptors, 5-HT(1A) and 5-HT(2), and for GABA receptors. Our previous results have implicated that GABA(A) receptors, but not GABA(B), mediate suanzaorentang-induced sleep alteration. In current study we further elucidated the involvement of serotonin. We found that high dose of suanzaorentang (4 g/kg/2 ml) significantly increased non-rapid eye movement sleep (NREMS) when comparing to that obtained after administering starch placebo, although placebo at dose of 4 g/kg also enhanced NREMS comparing with that obtained from baseline recording. Rapid eye movement sleep (REMS) was not altered. Administration of either 5-HT(1A) antagonist (NAN-190), 5-HT(2) antagonist (ketanserin) or 5-HT(3 )antagonist (3-(4-Allylpiperazin-1-yl)-2-quinoxalinecarbonitrile) blocked suanzaorentang-induced NREMS increase. These results implicate the hypnotic effect of suanzaorentang and its effects may be mediated through serotonergic activation, in addition to GABAergic system.

Gamma-aminobutyric acid (GABA) receptor mediates suanzaorentang, a traditional Chinese herb remedy, -induced sleep alteration.

The sedative-hypnotic medications, including benzodiazepines and non-benzodiazepines, are the most common treatments for insomnia. However, concerns regarding patterns of inappropriate use, dependence and adverse effects have led to caution in prescribing those sedative-hypnotic medications. On the other hand, a traditional Chinese herb remedy, suanzaorentang, has been efficiently and widely used in clinic for insomnia relief without severe side effects in Asia. Although suanzaorentang has been reported to improve sleep disruption in insomniac patients, its mechanism is still unclear. The present study was designed to elucidate the effects of oral administration of suanzaorentang on physiological sleep-wake architectures and its underlying mechanism in rats. We found that oral administration of suanzaorentang at the beginning of the dark onset dose-dependently increased non-rapid eye movement sleep (NREMS) during the dark period, but had no significant effect on rapid eye movement sleep (REMS). Our results also indicated that intracerebroventricular (ICV) administration of gamma-aminobutyric acid (GABA) receptor type A antagonist, bicuculline, significantly blocked suanzaorentang-induced enhancement in NREMS during the dark period, but GABA(B) receptor antagonist, 2-hydroxysaclofen had no effect. These results implicated that this traditional Chinese herb remedy, suanzaorentang increases spontaneous sleep activity and its effects may be mediated through the GABA(A) receptors, but not GABA(B) receptors.

Pallidotomy effect on the cortical excitability in patients with severe Parkinson's disease.

Surgical lesions in the medial pallidum have been shown to ameliorate motor deficits in patients with Parkinson's disease (PD). It is believed that interruption of the pallidothalamocortical projections to the motor cortex is required for the satisfactory results. In this report, we adopt cortico-cortical inhibition as the tool to assess the pallidotomy effect on cortical excitability in PD. Interstimulus interval between 1 and 15 msec were investigated. The average peak-to-peak amplitude was measured and calculated at each delay. A total of 8 patients (M:F = 4:4) 54.9 years of age (SD = 9.6) and 10 controls were recruited for the study. In the controls, the inhibitory phenomenon was observed from the 1-msec to the 4-msec delay points and the maximal inhibition was at the 3-msec delay point (33.69% +/- 6.50% of the control response). Mild facilitation was noticed since the 5-msec delay point and thereafter. In patients before operation, a similar trend of inhibition was also observed in the initial 4 msec with the maximal inhibition also at the 3-msec delay point (64.66 +/- 6.77% of the control response). In the postoperative group, the short interstimulus interval inhibition can no longer be observed and the conditioned response was 95.06 +/- 23.68% of the control at the 3-msec delay point. The suppression was gone at and after the 7-msec delay point. Results of repeated-measures analysis of variance show a significant difference among the controls and PD patients before and 3 months after pallidotomy (F = 3.40, P = 0.05). Post hoc examination revealed a significant difference between the controls and PD patients 3 months after pallidotomy at the 3-msec delay point (P = 0.004). However, no correlation was observed between the 3-msec inhibition and the Unified Parkinson's Disease Rating Scale Motor score or the dyskinesia score. The results suggest that pallidotomy can modulate the cortical inhibitory circuitry in patients with PD.

Effects of electroacupuncture at 'Anmian (Extra)' acupoints on sleep activities in rats: the implication of the caud al nucleus tractus solitarius.

Electroacupuncture (EAc) possesses a broad therapeutic effect, including improvement of sleep disturbances. The mechanism of sleep improvement with EAc, however, is still unclear. The present study investigated the effects of EAc stimulation of 'Anmian (extra)' acupoints on sleep organization and the implication of an active structure, the caudal nucleus tractus solitarius (NTS). Rats were implanted with electroencephalogram (EEG) recording electrodes, and 32-gauge acupuncture needles were bilaterally inserted into 'Anmian (extra)' acupoints in the rats, followed by electrical stimulation for 20 min. Twenty-three-hour continuous EEGs were then recorded. Results showed that rapid eye movement sleep (REMS) was enhanced during the dark period when a single EAc stimulation was given 25 min prior to the onset of the dark period. REMS and slow-wave sleep (SWS) increased during the dark period after administration of EAc stimuli on 2 consecutive days. Electrical stimulation of non-acupoints produced no change in the sleep pattern. Pharmacological blockade of muscarinic cholinergic receptors by systemic administration of scopolamine dose-dependently attenuated EAc-induced changes in REMS and SWS. Furthermore, electrical lesions in the bilateral caudal NTS produced significant blockade of EAc-induced sleep enhancement. However, in rats without EAc, scopolamine increased SWS during the dark period, but caudal NTS lesions did not alter sleep. In addition, neither EAc nor scopolamine with EAc manipulation produced any change in the slow-wave activity (SWA) during SWS; however, the SWA during SWS was significantly reduced after caudal NTS lesion with EAc. These results suggest that the caudal NTS may be involved in the regulation of EAc-induced sleep alterations.

The central serotonergic system mediates the analgesic effect of electroacupuncture on ZUSANLI (ST36) acupoints.

Evidence in the past decade indicates that the mechanisms of anti-nociception of electroacupuncture (EAc) involve actions of neuropeptides (i.e., enkephalin and endorphin) and monoamines (i.e., serotonin and norepinephrine) in the central nervous system. Our present results using a subcutaneous injection of formalin to test pain sensation in mice provide further understanding of the involvement of serotonin in the actions of EAc-induced analgesia. Our observations show that (1) EAc at three different frequencies (2, 10 and 100 Hz) elicited an anti-nociceptive effect as determined by behavioral observations of reduced hindpaw licking; (2) exogenously intracerebroventricular administration of 5-hydroxytryptamine (5-HT) exhibited an analgesic effect, which partially mimicked the analgesic actions of EAc; (3) the anti-nociception of EAc at different frequencies was attenuated after reduced biosynthesis of serotonin by the administration of the tryptophan hydroxylase inhibitor, P-chlorophenylalanine, and (4) the 5-HT(1A) and 5-HT(3) receptor antagonists, pindobind-5-HT(1A) and LY-278584, respectively, blocked three different frequencies of EAc-induced analgesic effects, but the anti-nociceptive effect of 100 Hz EAc was potentiated by the 5-HT(2) receptor antagonist, ketanserin. These observations suggest that 5-HT(1A) and 5-HT(3) receptors partially mediate the analgesic effects of EAc, but that the 5-HT(2) receptor is conversely involved in the nociceptive response.