Reticular Activating System Research Articles

Visualization of fast calcium oscillations in the parafascicular nucleus

The parafascicular nucleus (Pf) is an ascending target of the pedunculopontine nucleus (PPN) and is part of the "non-specific" intralaminar thalamus. The PPN, part of the reticular activating system, is mainly involved in waking and rapid eye movement sleep. Gamma oscillations are evident in all Pf neurons and mediated by high threshold voltage-dependent N- and P/Q-type calcium channels. We tested the hypothesis that high-speed calcium imaging would reveal calcium-mediated oscillations in synchrony with patch clamp recorded oscillations during depolarizing current ramps. Patch-clamped 9 to 19-day-old rat Pf neurons (n = 148, dye filled n = 61, control n = 87) were filled with Fura 2, Bis Fura, or Oregon Green BAPTA-1. Calcium transients were generated during depolarizing current ramps and visualized with a high-speed, wide-field fluorescence imaging system. Cells manifested calcium transients with oscillations in both somatic and proximal dendrite fluorescence recordings. Fluorescent calcium transients were blocked with the nonspecific calcium channel blocker, cadmium, or the combination of ω-Agatoxin-IVA (AgA), a specific P/Q-type calcium channel blocker and ω-conotoxin-GVIA (CgTx), a specific N-type calcium channel blocker. We developed a viable methodology for studying high-speed oscillations without the use of multi-photon imaging systems.

Sleep Disordered Breathing in Children and Adolescents with Chiari Malformation Type I

Chiari malformation Type I (CM-I) has been associated with sleep disordered breathing (SDB). The aim of this study was to evaluate the prevalence of SDB in CM-I and its clinical correlates in a population of children and adolescents. Fifty-three consecutive children and adolescents affected by CM-I were enrolled (27 girls and 26 boys, mean age 10.3 ± 4.3, range: 3-18 years). All patients underwent neurological examination, MRI, and polysomnography (PSG). Otorhinolaryngologic clinical evaluation was performed in patients with polysomnographic evidence of sleep-related upper airway obstruction. Mean size of the herniation was 9.5 ± 5.4 mm. Fourteen patients had syringomyelia, 5 had hydrocephalus, 31 presented neurological signs, 14 had epileptic seizures, and 7 reported poor sleep. PSG revealed SDB in 13 subjects. Patients with SDB, compared to those without SDB, had a higher prevalence hydrocephalus (p = 0.002), syringomyelia (p = 0.001), and neurological symptoms (p = 0.028). No significant difference was observed in age, gender, prevalence of epilepsy, and size of the herniation. Obstructive SDB was associated with syringomyelia (p = 0.004), whereas central SDB was associated with hydrocephalus (p = 0.034). In our population of CM-I patients the prevalence of SDB was 24%, lower than that reported in literature. Moreover, our findings suggest that abnormalities in cerebrospinal fluid dynamics in CM-I, particularly syringomyelia and hydro-cephalus, are associated with SDB.

Trigeminal stimulation

Seizures are characterized by hypersynchronous neuronal discharges, and desynchronizing stimuli abort and sometimes prevent seizures. The most direct but invasive method has been the application of electrical cortical stimulation at seizure onset. This successful termination of seizures has formed the basis for translational research involving implantable seizure detection and neurostimulation devices. The pioneering work of Moruzzi and Magoun in 19491 demonstrated that stimulation of the ascending reticular activating system (ARAS) can have a desynchronizing effect on cortical rhythms. This system not only projects widely throughout cortex, but also receives collateral input from all sensory systems.

The Ascending Reticular Activating System from Pontine Reticular Formation to the Thalamus in the Human Brain

Introduction: Action of the ascending reticular activating system (ARAS) on the cerebral cortex is responsible for achievement of consciousness. In this study, we attempted to reconstruct the lower single component of the ARAS from the reticular formation (RF) to the thalamus in the normal human brain using diffusion tensor imaging (DTI).Methods: Twenty six normal healthy subjects were recruited for this study. A 1.5-T scanner was used for scanning of diffusion tensor images, and the lower single component of the ARAS was reconstructed using FMRIB software. We utilized two ROIs for reconstruction of the lower single component of the ARAS: the seed ROI – the RF of the pons at the level of the trigeminal nerve entry zone, the target ROI – the intralaminar nuclei of the thalamus at the level of the commissural plane.Results: The reconstructed ARAS originated from the pontine RF, ascended through the mesencephalic tegmentum just posterior to the red nucleus, and then terminated on the intralaminar nuclei of the thalamus. No significant differences in fractional anisotropy, mean diffusivity, and tract number were observed between hemispheres (p > 0.05).Conclusion: We reconstructed the lower single component of the ARAS from the RF to the thalamus in the human brain using DTI. The results of this study might be of value for the diagnosis and prognosis of patients with impaired consciousness.

Towards an integrative theory of consciousness: Part 1 (Neurobiological and cognitive models)

The study of consciousness is poised today at interesting crossroads. There has been a surge of research into various neurobiological underpinnings of consciousness in the past decade. The present article looks at the theories regarding this complex phenomenon, especially the ones that neurobiology, cognitive neuroscience and cognitive psychology have to offer. We will first discuss the origin and etymology of word consciousness and its usage. Neurobiological correlates of consciousness are discussed with structures like the ascending reticular activating system, the amygdala, the cerebellum, the thalamus, the frontoparietal circuits, the prefrontal cortex and the precuneus. The cellular and microlevel theories of consciousness and cerebral activity at the neuronal level contributing to consciousness are highlighted, along with the various theories posited in this area. The role of neuronal assemblies and circuits along with firing patterns and their ramifications for the understanding of consciousness are discussed. A section on the role of anaesthesia and its links to consciousness is presented, along with details of split-brain studies in consciousness and altered states of awareness, including the vegetative states. The article finally discusses the progress cognitive psychology has made in identifying and theorising various perspectives of consciousness, perceptual awareness and conscious processing. Both recent and past researches are highlighted. The importance and salient features of each theory are discussed along with the pitfalls, if present. A need for integration of various theories to understand consciousness from a holistic perspective is stressed, to enable one to reach a theory that explains the ultimate neurobiology of consciousness.

Effects of leptin on pedunculopontine nucleus (PPN) neurons.

Leptin, a hormone that regulates appetite and energy expenditure, is increased in obese individuals, although these individuals often exhibit leptin resistance. Obesity is characterized by sleep/wake disturbances, such as excessive daytime sleepiness, increased REM sleep, increased nighttime arousals, and decreased percentage of total sleep time. Several studies have shown that short sleep duration is highly correlated with decreased leptin levels in both animal and human models. Arousal and rapid eye movement (REM) sleep are regulated by the cholinergic arm of the reticular activating system, the pedunculopontine nucleus (PPN). The goal of this project was to determine the role of leptin in the PPN, and thus in obesity-related sleep disorders. Whole-cell patch-clamp recordings were conducted on PPN neurons in 9- to 17-day-old rat brainstem slices. Leptin decreased action potential (AP) amplitude, AP frequency, and h-current (I(H)). These findings suggest that leptin causes a blockade of Na⁺ channels. Therefore, we conducted an experiment to test the effects of leptin on Na⁺ conductance. To determine the average voltage dependence of this conductance, results from each cell were equally weighted by expressing conductance as a fraction of the maximum conductance in each cell. I Na amplitude was decreased in a dose-dependent manner, suggesting a direct effect of leptin on these channels. The average decrease in Na⁺ conductance by leptin was ~40 %. We hypothesize that leptin normally decreases activity in the PPN by reducing I(H) and I(Na) currents, and that in states of leptin dysregulation (i.e., leptin resistance) this effect may be blunted, therefore causing increased arousal and REM sleep drive, and ultimately leading to sleep-related disorders.

Mutismo Acinético: revisión, propuesta de un protocolo neuropsicológico para el diagnóstico diferencial y su aplicación a un caso.

Title: Akinetic Mutism: a review, proposal of neuropsychological protocol to establish a differential diagnosis and its application to a case. Abstract: Akinetic mutism is considered as a disturbance of a persons motivational state, therefore the patient is unable to initiate verbal or mo- tor responses, although they continue to maintain sensorimotor and vigi- lant functions. The lesion can be vascular or it can be caused by infections, cerebral degeneration and toxicity. Lesions can influence the functions of two cerebral circuits: the Frontal medial cortex affecting to cingulated cor- tex, or it can damage the thalamic and mesencephalic regions related to the ascending reticular activating system. It is difficult to diagnose Akinetic Mutism since it can be confused with some types of aphasia and altered states of consciousness, which require different interventions. In order to complete a clinical protocol we rec- ommend a brief neuropsychological evaluation of functions such as atten- tion, praxis and language, all of which could be affected by the syndromes previously named. We expound a case of akinetic mutism evaluated with this protocol in order to show its specificity distinguishing akinetic mustism from other syndromes.

SUSPECTED NEUROTOXICITY DUE TOCLOSTRIDIUM PERFRINGENSTYPE B IN A TIGER (PANTHERA TIGRIS)

A 4-yr-old tiger (Panthera tigris) was referred with acute onset of severe abnormal consciousness. Neurological evaluation showed normal palpebral and corneal reflexes, normal pupil diameter with normal direct and consensual papillary light reflex, and absent menace response bilaterally. Diffuse forebrain lesion or focal lesion affecting the ascending reticular activating system was suspected. Complete blood examination and cerebrospinal fluid analysis were normal. Magnetic resonance imaging of the brain showed an empty sella as the only result. Clostridium perfringens 10(4) to 10(7) colony-forming units/g were detected in fecal flora samples. Multiplex polymerase chain reaction assay identified serotype B counts with production of epsilon toxin. This toxin specifically accumulates in the central nervous system, where it causes acute neurological signs in humans, domestic animals, and wildlife. In this communication, the acute onset of neurological signs without evidence of trauma, vascular, metabolic, or inflammatory diseases may be caused by neurotoxicity due to C. perfringens.

Projections from melanin-concentrating hormone (MCH) neurons to the dorsal raphe or the nuclear core of the locus coeruleus in the rat

Brainstem aminergic and cholinergic nuclei are essential components of reticular activating system which are under the control of hypothalamic sleep/arousal centers. In contrast to well-known role of hypocretin (Hcrt) as a potent wake-promoting substance, only recent reports stated that melanin-concentrating hormone (MCH) plays a role in the maintenance of rapid eye movement (REM) sleep. As the sequel to our report concerning the MCH/Hcrt projection to the brainstem cholinergic nuclei (Hong et al., 2011), in the present study we examined the differential projection from MCH/Hcrt neurons in medial and lateral subdivisions of the lateral hypothalamus (LH) to the dorsal raphe (DR) or the nuclear core of the locus coeruleus (LC) of the rat. Following the injection of Red Retrobeads into the LC core (n=6), the proportions of retrogradely labeled (retro-) MCH neurons over the total retro-cells were 4.4%±0.5% (medial subdivision) and 7.4%±0.6% (lateral one), whereas those of retro-Hcrt cells over the total retro-cells were 69.4%±3.6% (medial) and 64.4%±5.2% (lateral). Following midline-DR injections (n=6), the proportions of retro-MCH neurons over the total retro-cells were 14.3%±2.9% (medial) and 12.3%±1.6% (lateral), while those of retro-Hcrt cells over the total retro-cells were 46.5%±6.2% (medial) and 51.3%±9.5% (lateral). Following lateral wing-DR injections (n=3), the proportions of retro-MCH neurons over the total retro-cells were 15.5%±1.2% (medial) and 11.9%±3.1% (lateral), while those of retro-Hcrt cells over the total retro-cells were 48.5%±2.7% (medial) and 52.8%±2.3% (lateral). The statistical analysis showed that MCH neurons projecting to the LC core or DR were outnumbered by Hcrt cells (P<0.01) and that retro-MCH cells exhibited lateral predominance in LC injection cases (P<0.05). Based on our present as well as previous (Hong et al., 2011) observations, we suggested that MCH and Hcrt neurons in the LH provide preferential projections to the brainstem cholinergic and aminergic nuclei, respectively and that MCH projections to the nuclear core of the LC exhibit differential distribution within LH subdivisions.

Performance limitations of relay neurons.

Relay cells are prevalent throughout sensory systems and receive two types of inputs: driving and modulating. The driving input contains receptive field properties that must be transmitted while the modulating input alters the specifics of transmission. For example, the visual thalamus contains relay neurons that receive driving inputs from the retina that encode a visual image, and modulating inputs from reticular activating system and layer 6 of visual cortex that control what aspects of the image will be relayed back to visual cortex for perception. What gets relayed depends on several factors such as attentional demands and a subject's goals. In this paper, we analyze a biophysical based model of a relay cell and use systems theoretic tools to construct analytic bounds on how well the cell transmits a driving input as a function of the neuron's electrophysiological properties, the modulating input, and the driving signal parameters. We assume that the modulating input belongs to a class of sinusoidal signals and that the driving input is an irregular train of pulses with inter-pulse intervals obeying an exponential distribution. Our analysis applies to any order model as long as the neuron does not spike without a driving input pulse and exhibits a refractory period. Our bounds on relay reliability contain performance obtained through simulation of a second and third order model, and suggest, for instance, that if the frequency of the modulating input increases or the DC offset decreases, then relay increases. Our analysis also shows, for the first time, how the biophysical properties of the neuron (e.g. ion channel dynamics) define the oscillatory patterns needed in the modulating input for appropriately timed relay of sensory information. In our discussion, we describe how our bounds predict experimentally observed neural activity in the basal ganglia in (i) health, (ii) in Parkinson's disease (PD), and (iii) in PD during therapeutic deep brain stimulation. Our bounds also predict different rhythms that emerge in the lateral geniculate nucleus in the thalamus during different attentional states.

Mode and Behavior

This document collects a number of blog posts on the theme of behavioral mode. In this form the idea originates with Warren McCulloch, one of the grand old men of neuroscience and cybernetics. This conception would also give basic credence to the psychoanalytic conception of organ modes — oral, anal, and genital — though, ironically, McCulloch had little use for Freud — he entitled one of his papers “The Past of a Delusion” as an allusion to Freud’s The Future of an Illusion.McCulloch’s idea is simple: The most basic decision any vertebrate can make is to commit to some mode of behavior — such as exploring, eating, courting, fighting, playing, etc. Any more specific direction is elaborated from within one of these modes. What gives MuCulloch’s idea its force is his argument (and accompanying model) that modal commitment was mediated, not by the most sophisticated and evolutionarily advanced brain tissue, but by the most elementary and evolutionarily old brain tissue. This tissue, known as the reticular formation or the reticular activating system, is at the core of the brainstem. In effect, it has veto power over the cerebral cortex, but also, the power to activate the cortex.The seven posts in this document explore the implications of McCulloch’s conception of behavioral mode. In particular, these seven posts explore the implications of mode for our understanding of art and our construction of the self. They also lay the foundations for a pluralist view of the world.

Event-related potential patterns associated with hyperarousal in Gulf War illness syndrome groups

An exaggerated response to emotional stimuli is one of the several symptoms widely reported by veterans of the 1991 Persian Gulf War. Many have attributed these symptoms to post-war stress; others have attributed the symptoms to deployment-related exposures and associated damage to cholinergic, dopaminergic, and white matter systems. We collected event-related potential (ERP) data from 20 veterans meeting Haley criteria for Gulf War Syndromes 1–3 and from 8 matched Gulf War veteran controls, who were deployed but not symptomatic, while they performed an auditory three-condition oddball task with gunshot and lion roar sounds as the distractor stimuli. Reports of hyperarousal from the ill veterans were significantly greater than those from the control veterans; different ERP profiles emerged to account for their hyperarousability. Syndromes 2 and 3, who have previously shown brainstem abnormalities, show significantly stronger auditory P1 amplitudes, purported to indicate compromised cholinergic inhibitory gating in the reticular activating system. Syndromes 1 and 2, who have previously shown basal ganglia dysfunction, show significantly weaker P3a response to distractor stimuli, purported to indicate dysfunction of the dopaminergic contribution to their ability to inhibit distraction by irrelevant stimuli. All three syndrome groups showed an attenuated P3b to target stimuli, which could be secondary to both cholinergic and dopaminergic contributions or disruption of white matter integrity.

Neuroanatomic Connectivity of the Human Ascending Arousal System Critical to Consciousness and Its Disorders

The ascending reticular activating system (ARAS) mediates arousal, an essential component of human consciousness. Lesions of the ARAS cause coma, the most severe disorder of consciousness. Because of current methodological limitations, including of postmortem tissue analysis, the neuroanatomic connectivity of the human ARAS is poorly understood. We applied the advanced imaging technique of high angular resolution diffusion imaging (HARDI) to elucidate the structural connectivity of the ARAS in 3 adult human brains, 2 of which were imaged postmortem. High angular resolution diffusion imaging tractography identified the ARAS connectivity previously described in animals and also revealed novel human pathways connecting the brainstem to the thalamus, the hypothalamus, and the basal forebrain. Each pathway contained different distributions of fiber tracts from known neurotransmitter-specific ARAS nuclei in the brainstem. The histologically guided tractography findings reported here provide initial evidence for human-specific pathways of the ARAS. The unique composition of neurotransmitter-specific fiber tracts within each ARAS pathway suggests structural specializations that subserve the different functional characteristics of human arousal. This ARAS connectivity analysis provides proof of principle that HARDI tractography may affect the study of human consciousness and its disorders, including in neuropathologic studies of patients dying in coma and the persistent vegetative state.

Reticular activating system in depression and epilepsy

Reticular activating system in depression and epilepsy

Gamma Band Activity in the Reticular Activating System

This review considers recent evidence showing that cells in three regions of the reticular activating system (RAS) exhibit gamma band activity, and describes the mechanisms behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanisms behind this ceiling effect have been recently elucidated. We describe recent findings showing that every cell in the PPN have high-threshold, voltage-dependent P/Q-type calcium channels that are essential, while N-type calcium channels are permissive, to gamma band activity. Every cell in the Pf also showed that P/Q-type and N-type calcium channels are responsible for this activity. On the other hand, every SubCD cell exhibited sodium-dependent subthreshold oscillations. A novel mechanism for sleep–wake control based on well-known transmitter interactions, electrical coupling, and gamma band activity is described. The data presented here on inherent gamma band activity demonstrates the global nature of sleep–wake oscillation that is orchestrated by brainstem–thalamic mechanism, and questions the undue importance given to the hypothalamus for regulation of sleep–wakefulness. The discovery of gamma band activity in the RAS follows recent reports of such activity in other subcortical regions like the hippocampus and cerebellum. We hypothesize that, rather than participating in the temporal binding of sensory events as seen in the cortex, gamma band activity manifested in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking and paradoxical sleep. Most of our thoughts and actions are driven by pre-conscious processes. We speculate that continuous sensory input will induce gamma band activity in the RAS that could participate in the processes of pre-conscious awareness, and provide the essential stream of information for the formulation of many of our actions.

The Preconscious Mind and Gamma Band Activity in the Reticular Activating System

Gamma waves are high frequency neural oscillations in the range of 30–100 Hz, on average ∼40 Hz. These waves have been implicated in creating the unity of conscious perception, or binding, and are related to awareness, problem solving, and rapid eye movement (REM) sleep. Based on our level of awareness, Sigmund Freud and his followers have divided the mind into three different parts, the preconscious mind, the subconscious mind, and the conscious mind. The preconscious mind includes those things of which we are aware, but to which we are not paying attention. If we choose to pay attention, we bring them to the conscious mind (Civin and Lombardi, 1990). In this issue of Frontiers in Sleep and Chronobiology, Urbano et al. (2012) suggest that gamma band activity in the reticular activating system (RAS) mediates preconscious awareness, and that it is the maintained high frequency activity across various nuclei that keeps the “stream of consciousness,” as William James called it, flowing across our preconscious mind (James, 2007). This mechanism allows us to survive in a complex world, being aware of the traffic and pedestrians around us as we commute to work. When a stimulus introduces potential danger, for example, an oncoming bus, we instantly bring it into conscious control in order to respond.

Laser-induced evoked potentials in the brain after nonperceptible optical stimulation at the neiguan acupoint: a preliminary report.

We report on small but reproducible human cerebral evoked potentials after bilateral nonperceptible laser needle (658 nm, 40 mW, 500 μm, 1 Hz) irradiation of the Neiguan acupoint (PC6). The results which are unique in scientific literature were obtained in a 26-year-old female healthy volunteer within a joint study between the Medical University of Graz, the Karl-Franzens University of Graz, and the Graz University of Technology. The findings of the 32-channel evoked potential analysis indicate that exposure to laser needle stimulation with a frequency of 1 Hz can modulate the ascending reticular activating system. Further studies are absolutely necessary to confirm or refute the preliminary findings.

Brainstem lesions in permanent vegetative state

Vegetative state has mainly been associated with widespread damage of cortex, white matter and/or thalamus, whereas brainstem findings are usually absent or include focal, slight and non-haemorrhagic lesions. Functional integrity of the brainstem is considered to be necessary for preservation of sleep/wake cycle (arousal and wakefulness), particularly midline structures of the upper pons and midbrain. Awareness, instead, mainly relies on the integrity of the cerebral cortex, white matter, basal ganglia and thalamus. We present here the neuroanatomical study of a case of post-traumatic permanent vegetative state which is characterized by a quite complex damage also at the level of the brainstem. After a car accident a young woman was referred to Neurosurgical Unit in coma and paraplegia due to head injury and C2 fracture. Spontaneous sleep/wake cycle recovered in the following months. Magnetic resonance, performed one month after the trauma, showed injuries of midbrain, thalamus and left frontal lobe. The patient died more than 15 years after the trauma. Macroscopic examination showed generalized hypotrophy of cerebral hemispheres, cerebellum and brainstem. Partial degeneration of the basal ganglia and severe volumetric reduction of the hemispheric white matter were observed. Wide and bilateral thalamic necrosis and degeneration was found. Transverse sections of the brainstem showed degeneration of the descending and ascending systems of motor and sensitive fibres, and neuronal loss in the inferior olivary complex, pontine nuclei, red nucleus and substantia nigra. In the midbrain, areas of necrosis with reactive astrogliosis extended from the mesencephalic aqueduct towards the interpeduncular fossa, affecting the periaqueductal grey matter, and the dorsal and median raphe nuclei. On the basis of the neuroanatomic description of the damaged areas, we discuss the role of the midbrain reticular activating system and possible plasticity responses in the mechanisms of arousal/wakefulness.

Laser acupuncture - innovative basic research: visual and laser-induced evoked potentials

Laser acupuncture is a therapeutic medical method. Innovative basic research is necessary within this fascinating area of research. This publication focuses on visual evoked potentials (VEP) elucidated by non-invasive and partially non-perceptible laser stimulation. Materials (Subjects) and Methods: The first part of this study presents systematic VEP-monitoring in connection with laser acupuncture and manual needle acupuncture in 40 healthy volunteers. The second part deals with bilateral non-perceptible laser needle (658 nm, 40 mW, 500 µm, 1 Hz) irradiation of the Neiguan acupoint (PC6) in a 26-year-old female healthy volunteer using a new 32-channel evoked potential analysis technique. We were not able to find significant changes in latency or amplitudes of VEPs during laser acupuncture within the first part of the study. However in the second part we report about human cerebral evoked potentials after non-perceptible laser stimulation. The findings indicate that exposure to laser needle stimulation with a frequency of 1 Hz can modulate the ascending reticular activating system. Further studies are necessary to confirm or refute the very interesting findings.

Differential Localization of Pain-Related Neural Responses During Acupuncture Stimulation Using Blood Oxygen Level Dependent (BOLD) fMRI in a Canine Model

The objective of this study was to differentiate the neuronal responses, which was related or unrelated, to pain associated with acupuncture stimulation, and to localize the brain regions with response to stimulation that is unrelated to pain by using Blood Oxygen Level Dependent (BOLD) functional MRI (fMRI). BOLD fMRI was performed in six normal healthy beagle dogs, during placebo and verum acupuncture stimulations, at the right side of BL60 (KunLun) acupoint before and after local anesthesia of the acupoint. The order of the four sessions was placebo; verum acupuncture stimulation; before local anesthesia; and followed by the same stimulation after local anesthesia. One-sample t-test analysis was performed to localize the activated or deactivated areas, during both pre-anesthesia and post-anesthesia. In order to compare the pre-anesthesia to post-anesthetic responses, and placebo to verum acupuncture stimulation, within-subject analysis was performed. The post-anesthetic verum acupuncture stimulation resulted in increased activations in the left somatic afferent area I and II, right visual and auditory association area, and the descending reticular activating system of the brainstem. In addition, differential areas during post-anesthesia compared to that of the pre-anesthesia were in the left olfactory peduncle and descending reticular activating system of the brainstem. These results indicate that the areas of specific neural pathway are considered to be unrelated to the pain response during acupuncture stimulation.