Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 33
Filter
1.
J Altern Complement Med ; 26(12): 1182-1189, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32876468

ABSTRACT

Objectives: To investigate the efficacy of acupuncture in preventing cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) and explore its underlying mechanism. Design: A randomized, double-blinded, and placebo-controlled trial. Setting/Location: Subjects were recruited from Kyung Hee University Hospital at Gangdong, Seoul, Korea Subjects: A total of 50 patients admitted with acute SAH. Interventions: The study group received acupuncture treatments (n = 25), while the control group underwent mock transcutaneous electrical nerve stimulation and sham acupuncture (n = 25) six times/week for 2 weeks. Outcome measures: The primary outcome was the incidence of delayed ischemic neurologic deficit (DIND), and secondary measurements included angiographic vasospasm, vasospasm-related infarction, modified Rankin Scale score, and plasma nitric oxide (NO) and endothelin-1 (ET-1) levels. Results: The study group treated with acupuncture showed a lower incidence of DIND (9.1%) than the control group (20.8%); however, this difference in the incidence of DIND was not statistically significant. The study group demonstrated better clinical outcomes, especially in functional recovery. Significant alterations in plasma NO and ET-1 levels after the 2-week intervention were observed only in the study group. Conclusions: Their study shows that acupuncture treatment improved functional recovery after SAH and could potentially prevent cerebral vasospasm. These effects could be attributed to the recovery of endothelial dysfunction by acupuncture through modulating the plasma NO and ET-1 levels. The study protocol has been registered on www.clinicaltrials.gov (NCT02275949).


Subject(s)
Acupuncture Therapy , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/therapy , Vasospasm, Intracranial/etiology , Vasospasm, Intracranial/prevention & control , Adult , Aged , Double-Blind Method , Endothelin-1/blood , Female , Humans , Male , Middle Aged , Nitric Oxide/blood , Subarachnoid Hemorrhage/physiopathology , Treatment Outcome
2.
Medicine (Baltimore) ; 99(11): e19071, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32176032

ABSTRACT

BACKGROUND: It is important to manage inflammation after craniotomy. It may be prudent to reduce the excessive usage of antibiotics and to add supplementary treatments like acupuncture, which would be effective and safe. However, there are only a few studies available to date on the effects of acupuncture on anti-inflammatory response after craniotomy. The aim of this study was to explore the anti-inflammatory effects of acupuncture in patients after a craniotomy. METHODS: This study was a single-center, prospective, open-label, controlled trial. Forty-four subjects who underwent craniotomy for an unruptured aneurysm, facial spasm, or brain tumor were allocated to either an acupuncture group or a control group. Both groups received postoperative routine care in the Department of Neurosurgery. The subjects in the acupuncture group also received a total of 6 acupuncture treatments sessions within 8 days after craniotomy. Acupuncture treatments included acupuncture, electroacupuncture, and intradermal acupuncture. The serum interleukin (IL)-1ß and IL-6, tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and erythrocyte sedimentation rate levels were assessed four times within 7 days after surgery. The presence of fever, use of additional antibiotics, presence of infection including pneumonia or urinary tract infection, and safety were also reviewed. RESULTS: The IL-1ß levels of subjects who underwent aneurysmal clipping were significantly lower in the acupuncture group (P = .02). TNF-α levels of subjects who underwent aneurysmal clipping at the seventh postoperative day were also significantly lower in the acupuncture group (P = .03). Six cases of fever of unknown origin were observed in the control group, while none were seen in the acupuncture group, revealing that the incidence of fever was significantly lower in the acupuncture group (P = .02). No adverse events occurred during the trial. CONCLUSION: Acupuncture showed a possibility of alleviating inflammation by attenuating the levels of proinflammatory cytokines and significantly reduced the incidence of fever of unknown origin in patients after craniotomy. Acupuncture would be suitable as an adjunctive therapy to alleviate inflammation after craniotomy.


Subject(s)
Acupuncture Therapy/methods , Craniotomy/adverse effects , Inflammation/therapy , Postoperative Complications/therapy , C-Reactive Protein/analysis , Female , Humans , Inflammation/blood , Inflammation/etiology , Interleukin-1beta/blood , Interleukin-6/blood , Male , Middle Aged , Prospective Studies , Tumor Necrosis Factor-alpha/blood
3.
Nature ; 566(7744): 339-343, 2019 02.
Article in English | MEDLINE | ID: mdl-30760920

ABSTRACT

A psychotherapeutic regimen that uses alternating bilateral sensory stimulation (ABS) has been used to treat post-traumatic stress disorder. However, the neural basis that underlies the long-lasting effect of this treatment-described as eye movement desensitization and reprocessing-has not been identified. Here we describe a neuronal pathway driven by the superior colliculus (SC) that mediates persistent attenuation of fear. We successfully induced a lasting reduction in fear in mice by pairing visual ABS with conditioned stimuli during fear extinction. Among the types of visual stimulation tested, ABS provided the strongest fear-reducing effect and yielded sustained increases in the activities of the SC and mediodorsal thalamus (MD). Optogenetic manipulation revealed that the SC-MD circuit was necessary and sufficient to prevent the return of fear. ABS suppressed the activity of fear-encoding cells and stabilized inhibitory neurotransmission in the basolateral amygdala through a feedforward inhibitory circuit from the MD. Together, these results reveal the neural circuit that underlies an effective strategy for sustainably attenuating traumatic memories.


Subject(s)
Anxiety/psychology , Anxiety/therapy , Extinction, Psychological/physiology , Fear/physiology , Fear/psychology , Neural Pathways/physiology , Superior Colliculi/cytology , Superior Colliculi/physiology , Animals , Anxiety/physiopathology , Basolateral Nuclear Complex/cytology , Basolateral Nuclear Complex/physiology , Conditioning, Classical/physiology , Feedback, Physiological , Male , Mediodorsal Thalamic Nucleus/cytology , Mediodorsal Thalamic Nucleus/physiology , Mice , Neural Inhibition , Optogenetics , Photic Stimulation , Stress Disorders, Post-Traumatic , Time Factors
4.
Proc Natl Acad Sci U S A ; 115(43): 11078-11083, 2018 10 23.
Article in English | MEDLINE | ID: mdl-30297409

ABSTRACT

In the descending analgesia pathway, opioids are known to disinhibit the projections from the periaqueductal gray (PAG) to the rostral ventromedial medulla (RVM), leading to suppression of pain signals at the spinal cord level. The locus coeruleus (LC) has been proposed to engage in the descending pathway through noradrenergic inputs to the spinal cord. Nevertheless, how the LC is integrated in the descending analgesia circuit has remained unknown. Here, we show that the opioidergic analgesia pathway is bifurcated in structure and function at the PAG. A knockout as well as a PAG-specific knockdown of phospholipase C ß4 (PLCß4), a signaling molecule for G protein-coupled receptors, enhanced swim stress-induced and morphine-induced analgesia in mice. Immunostaining after simultaneous retrograde labeling from the RVM and the LC revealed two mutually exclusive neuronal populations at the PAG, each projecting either to the LC or the RVM, with PLCß4 expression only in the PAG-LC projecting cells that provide a direct synaptic input to LC-spinal cord (SC) projection neurons. The PAG-LC projection neurons in wild-type mice turned quiescent in response to opiates, but remained active in the PLCß4 mutant, suggesting a possibility that an increased adrenergic function induced by the persistent PAG-LC activity underlies the enhanced opioid analgesia in the mutant. Indeed, the enhanced analgesia in the mutant was reversed by blocking α2-noradrenergic receptors. These findings indicate that opioids suppress descending analgesia through the PAG-LC pathway, while enhancing it through the PAG-RVM pathway, i.e., two distinct pathways with opposing effects on opioid analgesia. These results point to a therapeutic target in pain control.


Subject(s)
Analgesia/methods , Mesencephalon/physiopathology , Pain Management/methods , Analgesics, Opioid/pharmacology , Animals , Male , Mesencephalon/drug effects , Mice , Mice, Inbred C57BL , Morphine/pharmacology , Neural Pathways/drug effects , Neural Pathways/physiology , Neurons/drug effects , Neurons/physiology , Pain/physiopathology , Spinal Cord/drug effects , Spinal Cord/physiology , Yin-Yang
6.
Neuron ; 95(2): 424-435.e6, 2017 Jul 19.
Article in English | MEDLINE | ID: mdl-28689981

ABSTRACT

While the interaction of the cardinal rhythms of non-rapid-eye-movement (NREM) sleep-the thalamo-cortical spindles, hippocampal ripples, and the cortical slow oscillations-is thought to be critical for memory consolidation during sleep, the role spindles play in this interaction is elusive. Combining optogenetics with a closed-loop stimulation approach in mice, we show here that only thalamic spindles induced in-phase with cortical slow oscillation up-states, but not out-of-phase-induced spindles, improve consolidation of hippocampus-dependent memory during sleep. Whereas optogenetically stimulated spindles were as efficient as spontaneous spindles in nesting hippocampal ripples within their excitable troughs, stimulation in-phase with the slow oscillation up-state increased spindle co-occurrence and frontal spindle-ripple co-occurrence, eventually resulting in increased triple coupling of slow oscillation-spindle-ripple events. In-phase optogenetic suppression of thalamic spindles impaired hippocampus-dependent memory. Our results suggest a causal role for thalamic sleep spindles in hippocampus-dependent memory consolidation, conveyed through triple coupling of slow oscillations, spindles, and ripples.


Subject(s)
Hippocampus/physiology , Memory/physiology , Neocortex/physiology , Sleep/physiology , Thalamus/physiology , Animals , Electroencephalography/methods , Mice, Inbred C57BL , Mice, Transgenic , Optogenetics/methods
7.
Trials ; 18(1): 10, 2017 01 10.
Article in English | MEDLINE | ID: mdl-28069040

ABSTRACT

BACKGROUND: Despite recent advances in the medical and surgical fields, complications such as infection, pneumonia, or brain swelling may occur after a craniotomy. In some patients, perioperative antibiotic prophylaxis causes adverse effects such as itching, rash, or digestive conditions. Certain patients still develop infections severe enough to require a repeat operation despite antibiotic prophylaxis. Acupuncture has been used to treat inflammatory conditions, and many basic and clinical studies have provided evidence of its anti-inflammatory and immune regulatory effects. The aim of this study is to explore the effects of acupuncture on inflammation and immune function after craniotomy. METHODS: This trial will be a single-center, parallel-group clinical trial. Forty patients who underwent craniotomy for an unruptured aneurysm, facial spasm, or a brain tumor will be allocated to either the study or the control group. The study group will receive conventional management as well as acupuncture, electroacupuncture, and intradermal acupuncture, which will start within 48 h of the craniotomy. The patients will receive a total of six sessions within 8 days. The control group will only receive conventional management. The primary outcome measure will be the C-reactive protein levels, while the secondary outcomes will be the serum erythrocyte sedimentation rate and the tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 levels measured at four different time points: within 48 h prior to the craniotomy and on days 2, 4, and 7 after surgery. The presence of fever and infection, the use of additional antibiotics, the presence of infection, including pneumonia or urinary tract infection, and safety will also be investigated. DISCUSSION: In this trial, we will observe whether acupuncture has anti-inflammatory and immune regulatory effects after a craniotomy. If our study yields positive results and a placebo-controlled study also finds favorable results following our study, acupuncture could be recommended as an adjunctive therapy after a craniotomy. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02761096 . Registered on 27 April 2016.


Subject(s)
Acupuncture Therapy , Clinical Protocols , Craniotomy , Inflammation/prevention & control , Blood Sedimentation , C-Reactive Protein/analysis , Humans , Interleukin-6/blood , Outcome Assessment, Health Care , Sample Size , Tumor Necrosis Factor-alpha/blood
8.
Nat Commun ; 7: 13791, 2016 12 19.
Article in English | MEDLINE | ID: mdl-27991499

ABSTRACT

Neuronal firing patterns, which are crucial for determining the nature of encoded information, have been widely studied; however, the molecular identity and cellular mechanisms of spike-frequency adaptation are still not fully understood. Here we show that spike-frequency adaptation in thalamocortical (TC) neurons is mediated by the Ca2+-activated Cl- channel (CACC) anoctamin-2 (ANO2). Knockdown of ANO2 in TC neurons results in significantly reduced spike-frequency adaptation along with increased tonic spiking. Moreover, thalamus-specific knockdown of ANO2 increases visceral pain responses. These results indicate that ANO2 contributes to reductions in spike generation in highly activated TC neurons and thereby restricts persistent information transmission.


Subject(s)
Anoctamins/metabolism , Calcium/pharmacology , Sensory Receptor Cells/physiology , Thalamus/physiology , Adenoviridae , Animals , Anoctamins/genetics , Bestrophins/genetics , Bestrophins/metabolism , Female , Gene Expression Regulation/drug effects , Gene Knockdown Techniques , HEK293 Cells , Humans , Male , Mice , Mice, Inbred BALB C , NIH 3T3 Cells , Patch-Clamp Techniques , ortho-Aminobenzoates/pharmacology
9.
Mol Brain ; 9(1): 100, 2016 12 21.
Article in English | MEDLINE | ID: mdl-27998287

ABSTRACT

The transition from wakefulness to a nonrapid eye movement (NREM) sleep state at the onset of sleep involves a transition from low-voltage, high-frequency irregular electroencephalography (EEG) waveforms to large-amplitude, low-frequency EEG waveforms accompanying synchronized oscillatory activity in the thalamocortical circuit. The thalamocortical circuit consists of reciprocal connections between the thalamus and cortex. The cortex sends strong excitatory feedback to the thalamus, however the function of which is unclear. In this study, we investigated the role of the thalamic metabotropic glutamate receptor 1 (mGluR1)-phospholipase C ß4 (PLCß4) pathway in sleep control in PLCß4-deficient (PLCß4-/-) mice. The thalamic mGluR1-PLCß4 pathway contains synapses that receive corticothalamic inputs. In PLCß4-/- mice, the transition from wakefulness to the NREM sleep state was stimulated, and the NREM sleep state was stabilized, which resulted in increased NREM sleep. The power density of delta (δ) waves increased in parallel with the increased NREM sleep. These sleep phenotypes in PLCß4-/- mice were consistent in TC-restricted PLCß4 knockdown mice. Moreover, in vitro intrathalamic oscillations were greatly enhanced in the PLCß4-/- slices. The results of our study showed that thalamic mGluR1-PLCß4 pathway was critical in controlling sleep architecture.


Subject(s)
Phospholipase C beta/metabolism , Receptors, Metabotropic Glutamate/metabolism , Sleep/physiology , Thalamus/metabolism , Animals , Cerebral Cortex/physiology , Delta Rhythm/physiology , Mice, Inbred C57BL , Mice, Knockout , Phospholipase C beta/deficiency , Thalamus/physiology
10.
World J Biol Psychiatry ; 17(6): 439-48, 2016 09.
Article in English | MEDLINE | ID: mdl-26796250

ABSTRACT

OBJECTIVES: In patients with schizophrenia, γ-band (30-70 Hz) auditory steady-state electroencephalogram responses (ASSR) are reduced in power and phase locking. Here, we examined whether γ-ASSR deficits are also present in a mouse model of schizophrenia, whose behavioural changes have shown schizophrenia-like endophenotypes. METHODS: Electroencephalogram in frontal cortex and local field potential in primary auditory cortex were recorded in phospholipase C ß1 (PLC-ß1) null mice during auditory binaural click trains at different rates (20-50 Hz), and compared with wild-type littermates. RESULTS: In mutant mice, the ASSR power was reduced at all tested rates. The phase locking in frontal cortex was reduced in the ß band (20 Hz) but not in the γ band, whereas the phase locking in auditory cortex was reduced in the γ band. The cortico-cortical connectivity between frontal and auditory cortex was significantly reduced in mutant mice. CONCLUSIONS: The tested mouse model of schizophrenia showed impaired electrophysiological responses to auditory steady state stimulation, suggesting that it could be useful for preclinical studies of schizophrenia".


Subject(s)
Auditory Cortex/physiopathology , Evoked Potentials, Auditory , Frontal Lobe/physiopathology , Schizophrenia/physiopathology , Acoustic Stimulation , Animals , Disease Models, Animal , Electroencephalography , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout
11.
Trials ; 16: 68, 2015 Feb 28.
Article in English | MEDLINE | ID: mdl-25886483

ABSTRACT

BACKGROUND: Subarachnoid hemorrhage (SAH) is a neurological disease with a high mortality rate. Several serious complications frequently arise after successful surgery for this condition. Cerebral vasospasm, one such complication, occurs in 50 to 70% of SAH patients. These patients suffer neurological symptoms known as delayed ischemic neurological deficit (DIND); however, the effect of treatment of vasospasm is limited. The major pathogenesis of cerebral vasospasm is the reduction of nitric oxide (NO) and activation of vasoconstrictors. Acupuncture is known to increase the production and activity of vascular endothelial cell-derived NO and improve endothelium-dependent vasodilatation. A preliminary retrospective case study to investigate the ability of acupuncture to prevent the occurrence of cerebral vasospasm has been conducted. However, no randomized, controlled clinical trials have been carried out to evaluate the efficacy of acupuncture for cerebral vasospasm. METHODS/DESIGN: This trial will be a single-center, randomized, placebo-controlled, parallel group, patient-assessor-blinded clinical trial. A total of 80 patients with SAH will be randomized into two groups: a study group given acupuncture, electroacupuncture, and intradermal acupuncture, and a control group given mock transcutaneous electrical nerve stimulation and sham intradermal acupuncture. Intervention will start within 96 h after SAH, and a total of 12 sessions will be performed during a 2-week period. The primary outcome measure will be the occurrence of DIND, and the secondary outcomes will be vasospasm as measured by cerebral angiography, transcranial Doppler, clinical symptoms, vasospasm-related infarcts, NO and endothelin-1 plasma levels, mortality, and modified Rankin Scale scores. DISCUSSION: This trial will examine the efficacy and safety of acupuncture for cerebral vasospasm after SAH. The placebo effect will be excluded and the mechanism of action of the treatments will be evaluated through blood testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT02275949 , Registration date: 26 October 2014.


Subject(s)
Acupuncture Therapy , Clinical Protocols , Subarachnoid Hemorrhage/complications , Vasospasm, Intracranial/therapy , Acupuncture Therapy/adverse effects , Data Interpretation, Statistical , Humans , Nitric Oxide/physiology , Outcome Assessment, Health Care , Sample Size
12.
Eur J Neurosci ; 39(11): 1810-23, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24819022

ABSTRACT

A large forebrain circuit, including the thalamus, amygdala and frontal cortical regions, is responsible for the establishment and extinction of fear-related memories. Understanding interactions among these three regions is critical to deciphering the basic mechanisms of fear. With the advancement of molecular and optogenetics techniques, the mouse has become the main species used to study fear-related behaviours. However, the basic connectivity pattern of the forebrain circuits involved in processing fear has not been described in this species. In this study we mapped the connectivity between three key nodes of the circuit, i.e. the basolateral nucleus of the amygdala (BLA), the mediodorsal nucleus of the thalamus (MD) and the medial prefrontal cortex, which were shown to have closed triangular connectivity in rats. In contrast to rat, we found no evidence for this closed loop in mouse. There was no major input from the BLA to the MD and little overlap between medial prefrontal regions connected with both the BLA and MD. The common nodes in the frontal cortex, which displayed reciprocal connection with both the BLA and MD were the agranular insular cortex and the border zone of the cingulate and secondary motor cortex. In addition, the BLA can indirectly affect the MD via the orbital cortex. We attribute the difference between our results and earlier rat studies to methodological problems rather than to genuine species difference. Our data demonstrate that the BLA and MD communicate via cortical sectors, the roles in fear-related behaviour of which have not been extensively studied. In general, our study provides the morphological framework for studies of murine fear-related behaviours.


Subject(s)
Amygdala/physiology , Fear , Frontal Lobe/physiology , Nerve Net/cytology , Thalamus/physiology , Amygdala/cytology , Animals , Frontal Lobe/cytology , Male , Mice , Mice, Inbred C57BL , Nerve Net/physiology , Neural Pathways/cytology , Neural Pathways/physiology , Thalamus/cytology
13.
Pflugers Arch ; 466(4): 719-34, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24519464

ABSTRACT

Absence epilepsy accompanies the paroxysmal oscillations in the thalamocortical circuit referred as spike and wave discharges (SWDs). Low-threshold burst firing mediated by T-type Ca(2+) channels highly expressed in both inhibitory thalamic reticular nuclei (TRN) and excitatory thalamocortical (TC) neurons has been correlated with the generation of SWDs. A generally accepted view has been that rhythmic burst firing mediated by T-type channels in both TRN and TC neurons are equally critical in the generation of thalamocortical oscillations during sleep rhythms and SWDs. This review examined recent studies on the T-type channels in absence epilepsy which leads to an idea that even though both TRN and TC nuclei are required for thalamocortical oscillations, the contributions of T-type channels to TRN and TC neurons are not equal in the genesis of sleep spindles and SWDs. Accumulating evidence revealed a crucial role of TC T-type channels in SWD generation. However, the role of TRN T-type channels in SWD generation remains controversial. Therefore, a deeper understanding of the functional consequences of modulating each T-type channel subtype could guide the development of therapeutic tools for absence seizures while minimizing side effects on physiological thalamocortical oscillations.


Subject(s)
Action Potentials/physiology , Calcium Channels, T-Type/physiology , Epilepsy, Absence/physiopathology , Thalamus/physiopathology , Animals , Electroencephalography/trends , Epilepsy, Absence/diagnosis , Epilepsy, Absence/genetics , Humans , Mutation/physiology
14.
Proc Natl Acad Sci U S A ; 110(50): 20266-71, 2013 Dec 10.
Article in English | MEDLINE | ID: mdl-24282303

ABSTRACT

T-type Ca(2+) channels in thalamocortical (TC) neurons have long been considered to play a critical role in the genesis of sleep spindles, one of several TC oscillations. A classical model for TC oscillations states that reciprocal interaction between synaptically connected GABAergic thalamic reticular nucleus (TRN) neurons and glutamatergic TC neurons generates oscillations through T-type channel-mediated low-threshold burst firings of neurons in the two nuclei. These oscillations are then transmitted from TC neurons to cortical neurons, contributing to the network of TC oscillations. Unexpectedly, however, we found that both WT and KO mice for CaV3.1, the gene for T-type Ca(2+) channels in TC neurons, exhibit typical waxing-and-waning sleep spindle waves at a similar occurrence and with similar amplitudes and episode durations during non-rapid eye movement sleep. Single-unit recording in parallel with electroencephalography in vivo confirmed a complete lack of burst firing in the mutant TC neurons. Of particular interest, the tonic spike frequency in TC neurons was significantly increased during spindle periods compared with nonspindle periods in both genotypes. In contrast, no significant change in burst firing frequency between spindle and nonspindle periods was noted in the WT mice. Furthermore, spindle-like oscillations were readily generated within intrathalamic circuits composed solely of TRN and TC neurons in vitro in both the KO mutant and WT mice. Our findings call into question the essential role of low-threshold burst firings in TC neurons and suggest that tonic firing is important for the generation and propagation of spindle oscillations in the TC circuit.


Subject(s)
Brain Waves/physiology , Models, Neurological , Neurons/metabolism , Periodicity , Sleep/physiology , Thalamus/metabolism , Animals , Calcium Channels, T-Type/genetics , Electroencephalography , Mice , Mice, Knockout
15.
Proc Natl Acad Sci U S A ; 109(38): 15497-501, 2012 Sep 18.
Article in English | MEDLINE | ID: mdl-22949656

ABSTRACT

Major cognitive and emotional faculties are dominantly lateralized in the human cerebral cortex. The mechanism of this lateralization has remained elusive owing to the inaccessibility of human brains to many experimental manipulations. In this study we demonstrate the hemispheric lateralization of observational fear learning in mice. Using unilateral inactivation as well as electrical stimulation of the anterior cingulate cortex (ACC), we show that observational fear learning is controlled by the right but not the left ACC. In contrast to the cortex, inactivation of either left or right thalamic nuclei, both of which are in reciprocal connection to ACC, induced similar impairment of this behavior. The data suggest that lateralization of negative emotions is an evolutionarily conserved trait and mainly involves cortical operations. Lateralization of the observational fear learning behavior in a rodent model will allow detailed analysis of cortical asymmetry in cognitive functions.


Subject(s)
Cerebral Cortex/physiology , Fear , Thalamus/physiology , Animals , Anxiety , Behavior, Animal , Brain Mapping/methods , Electric Stimulation , Male , Maze Learning , Mice , Mice, Inbred C57BL , Microscopy, Fluorescence/methods , Models, Biological , Movement , Social Behavior
16.
J Neurosci ; 32(35): 12228-36, 2012 Aug 29.
Article in English | MEDLINE | ID: mdl-22933804

ABSTRACT

The thalamic output during different behavioral states is strictly controlled by the firing modes of thalamocortical neurons. During sleep, their hyperpolarized membrane potential allows activation of the T-type calcium channels, promoting rhythmic high-frequency burst firing that reduces sensory information transfer. In contrast, in the waking state thalamic neurons mostly exhibit action potentials at low frequency (i.e., tonic firing), enabling the reliable transfer of incoming sensory inputs to cortex. Because of their nearly complete inactivation at the depolarized potentials that are experienced during the wake state, T-channels are not believed to modulate tonic action potential discharges. Here, we demonstrate using mice brain slices that activation of T-channels in thalamocortical neurons maintained in the depolarized/wake-like state is critical for the reliable expression of tonic firing, securing their excitability over changes in membrane potential that occur in the depolarized state. Our results establish a novel mechanism for the integration of sensory information by thalamocortical neurons and point to an unexpected role for T-channels in the early stage of information processing.


Subject(s)
Action Potentials/physiology , Calcium Channels, T-Type/physiology , Neocortex/physiology , Neurons/physiology , Thalamus/physiology , Animals , Female , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Neurological , Neocortex/cytology , Thalamus/cytology , Wakefulness/physiology
17.
PLoS One ; 7(1): e30699, 2012.
Article in English | MEDLINE | ID: mdl-22292022

ABSTRACT

Thalamocortical (TC) neurons are known to relay incoming sensory information to the cortex via firing in tonic or burst mode. However, it is still unclear how respective firing modes of a single thalamic relay neuron contribute to pain perception under consciousness. Some studies report that bursting could increase pain in hyperalgesic conditions while others suggest the contrary. However, since previous studies were done under either neuropathic pain conditions or often under anesthesia, the mechanism of thalamic pain modulation under awake conditions is not well understood. We therefore characterized the thalamic firing patterns of behaving mice in response to nociceptive pain induced by inflammation. Our results demonstrated that nociceptive pain responses were positively correlated with tonic firing and negatively correlated with burst firing of individual TC neurons. Furthermore, burst properties such as intra-burst-interval (IntraBI) also turned out to be reliably correlated with the changes of nociceptive pain responses. In addition, brain stimulation experiments revealed that only bursts with specific bursting patterns could significantly abolish behavioral nociceptive responses. The results indicate that specific patterns of bursting activity in thalamocortical relay neurons play a critical role in controlling long-lasting inflammatory pain in awake and behaving mice.


Subject(s)
Chronic Pain/chemically induced , Chronic Pain/physiopathology , Formaldehyde/toxicity , Neurons/drug effects , Neurons/physiology , Thalamus/drug effects , Animals , Behavior, Animal/drug effects , Behavior, Animal/physiology , Cell Communication/drug effects , Electrophysiological Phenomena/drug effects , Male , Mice , Mice, Inbred C57BL , Models, Biological , Nociception/drug effects , Nociception/physiology , Synaptic Transmission/drug effects , Synaptic Transmission/physiology , Thalamus/cytology , Thalamus/physiology
18.
Nat Neurosci ; 15(2): 308-14, 2011 Dec 25.
Article in English | MEDLINE | ID: mdl-22197828

ABSTRACT

The mediodorsal thalamic nucleus has been implicated in the control of memory processes. However, the underlying neural mechanism remains unclear. Here we provide evidence for bidirectional modulation of fear extinction by the mediodorsal thalamic nucleus. Mice with a knockout or mediodorsal thalamic nucleus-specific knockdown of phospholipase C ß4 exhibited impaired fear extinction. Mutant mediodorsal thalamic nucleus neurons in slices showed enhanced burst firing accompanied by increased T-type Ca(2+) currents; blocking of T channels in vivo rescued the fear extinction. Tetrode recordings in freely moving mice revealed that, during extinction, the single-spike (tonic) frequency of mediodorsal thalamic nucleus neurons increased in wild-type mice, but was static in mutant mice. Furthermore, tonic-evoking microstimulations of the mediodorsal thalamic nucleus, contemporaneous with the extinction tones, rescued fear extinction in mutant mice and facilitated it in wild-type mice. In contrast, burst-evoking microstimulation suppressed extinction in wild-type mice, mimicking the mutation. These results suggest that the firing mode of the mediodorsal thalamic nucleus is critical for the modulation of fear extinction.


Subject(s)
Action Potentials/physiology , Conditioning, Psychological/physiology , Extinction, Psychological/physiology , Fear , Neurons/physiology , Thalamus/cytology , Acoustic Stimulation/adverse effects , Action Potentials/genetics , Animals , Anxiety/genetics , Anxiety/psychology , Behavior, Animal , Calcium Channels/metabolism , Dose-Response Relationship, Drug , Drug Delivery Systems , Electric Stimulation , Electroencephalography , In Vitro Techniques , Mice , Mice, Inbred C57BL , Mice, Transgenic , Motor Activity/genetics , Patch-Clamp Techniques , Phospholipase C beta/deficiency , Phospholipase C beta/metabolism , Phosphopyruvate Hydratase/metabolism , RNA, Small Interfering/pharmacology , Signal Transduction/genetics
19.
J Neurosci ; 31(11): 4063-73, 2011 Mar 16.
Article in English | MEDLINE | ID: mdl-21411648

ABSTRACT

Hypoxic damage to the prefrontal cortex (PFC) has been implicated in the frontal lobe dysfunction found in various neuropsychiatric disorders. The underlying subcortical mechanisms, however, have not been well explored. In this study, we induced a PFC-specific hypoxia-like damage by cobalt-wire implantation to demonstrate that the role of the mediodorsal thalamus (MD) is critical for the development of frontal lobe dysfunction, including frontal lobe-specific seizures and abnormal hyperactivity. Before the onset of these abnormalities, the cross talk between the MD and PFC nuclei at theta frequencies was enhanced. During the theta frequency interactions, burst spikes, known to depend on T-type Ca(2+) channels, were increased in MD neurons. In vivo knockout or knockdown of the T-type Ca(2+) channel gene (Ca(V)3.1) in the MD substantially reduced the theta frequency MD-PFC cross talk, frontal lobe-specific seizures, and locomotor hyperactivity in this model. These results suggest a two-step model of prefrontal dysfunction in which the response to a hypoxic lesion in the PFC results in abnormal thalamocortical feedback driven by thalamic T-type Ca(2+) channels, which, in turn, leads to the onset of neurological and behavioral abnormalities. This study provides valuable insights into preventing the development of neuropsychiatric disorders arising from irreversible PFC damage.


Subject(s)
Calcium Channels, T-Type/metabolism , Frontal Lobe/injuries , Frontal Lobe/physiopathology , Neurons/metabolism , Thalamus/metabolism , Analysis of Variance , Animals , Blotting, Western , Conditioning, Classical/physiology , Electrophysiology , Fear , Female , Foreign Bodies , Frontal Lobe/metabolism , Immunohistochemistry , Magnetic Resonance Imaging , Male , Mice , Motor Activity/physiology
20.
J Neurosci ; 31(4): 1213-8, 2011 Jan 26.
Article in English | MEDLINE | ID: mdl-21273406

ABSTRACT

Ryanodine receptors (RyRs) are highly conductive intracellular Ca(2+) release channels which are widely expressed in the CNS. They rapidly increase the intracellular Ca(2+) concentrations in neuronal cells in response to Ca(2+) influx through voltage-gated Ca(2+) channels. A previous study reported that RyRs were expressed in thalamocortical (TC) neurons, but their physiological function has remained elusive. Here, we show that the activation of RyRs in TC neurons in mice decreases their tonic firing rate while blocking them induces the opposite response. Furthermore, activation of RyRs in ventroposteriomedial/ventroposteriolateral nuclei reduces the behavioral responses to inflammatory pain and blocking them increases the responses. This study highlights the importance of the intracellular Ca(2+) release via RyRs in controlling the excitability of TC neurons and in inflammatory pain signal processing in the thalamus.


Subject(s)
Neurons/physiology , Pain/physiopathology , Ryanodine Receptor Calcium Release Channel/physiology , Thalamus/physiopathology , Action Potentials , Animals , Calcium Channel Agonists/pharmacology , Calcium Channel Blockers/pharmacology , Inflammation/physiopathology , Male , Mice , Pain Measurement , Thalamic Nuclei/physiopathology
SELECTION OF CITATIONS
SEARCH DETAIL