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Wu PJ, Tseng HC, Chao CC, Liao YH, Yen CT, Lin WY, Hsieh ST, Sun WZ, Sun CK. Discontinuity third harmonic generation microscopy for label-free imaging and quantification of intraepidermal nerve fibers. Cell Rep Methods 2024; 4:100735. [PMID: 38503290 PMCID: PMC10985268 DOI: 10.1016/j.crmeth.2024.100735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 01/04/2024] [Accepted: 02/26/2024] [Indexed: 03/21/2024]
Abstract
Label-free imaging methodologies for nerve fibers rely on spatial signal continuity to identify fibers and fail to image free intraepidermal nerve endings (FINEs). Here, we present an imaging methodology-called discontinuity third harmonic generation (THG) microscopy (dTHGM)-that detects three-dimensional discontinuities in THG signals as the contrast. We describe the mechanism and design of dTHGM and apply it to reveal the bead-string characteristics of unmyelinated FINEs. We confirmed the label-free capability of dTHGM through a comparison study with the PGP9.5 immunohistochemical staining slides and a longitudinal spared nerve injury study. An intraepidermal nerve fiber (IENF) index based on a discontinuous-dot-connecting algorithm was developed to facilitate clinical applications of dTHGM. A preliminary clinical study confirmed that the IENF index was highly correlated with skin-biopsy-based IENF density (Pearson's correlation coefficient R = 0.98) and could achieve differential identification of small-fiber neuropathy (p = 0.0102) in patients with diabetic peripheral neuropathy.
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Affiliation(s)
- Pei-Jhe Wu
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Hsiao-Chieh Tseng
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei 100225, Taiwan
| | - Yi-Hua Liao
- Department of Dermatology, National Taiwan University Hospital, and National Taiwan University College of Medicine Taipei 100225, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Wen-Ying Lin
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan; Department of Anesthesiology, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei 100225, Taiwan
| | - Sung-Tsang Hsieh
- Department of Neurology, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei 100225, Taiwan.
| | - Wei-Zen Sun
- Department of Anesthesiology, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei 100225, Taiwan.
| | - Chi-Kuang Sun
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan; Graduate Institute of Biomedical Electronics and Bioinformatics and Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan.
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Wu WY, Cheng Y, Liang KC, Lee RX, Yen CT. Affective mirror and anti-mirror neurons relate to prosocial help in rats. iScience 2022; 26:105865. [PMID: 36632059 PMCID: PMC9826941 DOI: 10.1016/j.isci.2022.105865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/12/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Although empathic emotion is closely related to prosocial behavior, neuronal substrate that accounts for empathy-associated prosocial action remains poorly understood. We recorded neurons in the anterior cingulate cortex (ACC) and insular cortex (InC) in rats when they observed another rat in pain. We discovered neurons with anti-mirror properties in the ACC and InC, in addition to those with mirror properties. ACC neurons show higher coupling between activation of self-in-pain and others-in-pain, whereas the InC has a higher ratio of neurons with anti-mirror properties. During others-in-pain, ACC neurons activated more when actively nose-poking toward others and InC neurons activated more when freezing. To further illustrate prosocial function, we examined neuronal activities in the helping behavior test. Both ACC and InC neurons showed specific activation to rat rescuing which is contributed by mirror, but not anti-mirror neurons. Our work indicates the functional involvement of mirror neuron system in prosocial behaviors.
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Affiliation(s)
- Wen-Yi Wu
- Department of Psychology, Cornell University, Ithaca, NY 14850, USA
| | - Yawei Cheng
- Institute of Neuroscience, National Yang-Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Keng-Chen Liang
- Department of Psychology, National Taiwan University, Taipei 10617, Taiwan,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei 10617, Taiwan
| | - Ray X. Lee
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, MA 02139, USA,Program in Media Arts and Sciences, Massachusetts Institute of Technology, Cambridge, MA 02142, USA,Corresponding author
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, 1 Roosevelt Road Sec. 4, Taipei 10617, Taiwan,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei 10617, Taiwan,Corresponding author
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Borah BJ, Lee JC, Chi HH, Hsiao YT, Yen CT, Sun CK. Nyquist-exceeding high voxel rate acquisition in mesoscopic multiphoton microscopy for full-field submicron resolution resolvability. iScience 2021; 24:103041. [PMID: 34585109 PMCID: PMC8450254 DOI: 10.1016/j.isci.2021.103041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/15/2021] [Accepted: 08/23/2021] [Indexed: 12/04/2022] Open
Abstract
The Nyquist-Shannon criterion has never been realized in a laser-scanning mesoscopic multiphoton microscope (MPM) with a large field-of-view (FOV)-resolution ratio, especially when employing a high-frequency resonant-raster-scanning. With a high optical resolution nature, a current mesoscopic-MPM either neglects the criterion and degrades the digital resolution to twice the pixel size, or reduces the FOV and/or the raster-scanning speed to avoid aliasing. We introduce a Nyquist figure-of-merit (NFOM) parameter to characterize a laser-scanning MPM in terms of its optical-resolution retrieving ability. Based on NFOM, we define the maximum aliasing-free FOV, and subsequently, a cross-over excitation wavelength, below which the FOV becomes NFOM-constrained irrespective of an optimized optical design. We validate our idea in a custom-built mesoscopic-MPM with millimeter-scale FOV yielding an ultra-high FOV-resolution ratio of >3,000, while securing up-to a 1.6 mm Nyquist-satisfied aliasing-free FOV, a ∼400 nm lateral resolution, and a 70 M/s effective voxel-sampling rate, all at the same time. Nyquist figure-of-merit is introduced to characterize laser-scanning MPM digitization Maximum aliasing-free FOV and cross-over excitation wavelength are formulated High repetition-rate laser can enable high-speed large-FOV high-resolution MPM imaging Up-to 1.6 mm-wide non-aliased FOV and ∼400 nm digital resolution at 8 kHz line-rate
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Affiliation(s)
- Bhaskar Jyoti Borah
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Jye-Chang Lee
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Han-Hsiung Chi
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Yang-Ting Hsiao
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.,Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan
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4
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Yeh KY, Chiu HW, Tseng WT, Chen HC, Yen CT, Lu SS, Lin ML. A Dual-Mode Multifunctional Pulsed Radio-Frequency Stimulator for Trigeminal Neuralgia Relief and its Animal Model. IEEE Trans Biomed Circuits Syst 2021; 15:719-730. [PMID: 34260358 DOI: 10.1109/tbcas.2021.3097058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This work proposed a programmable pulsed radio-frequency (PRF) stimulator for trigeminal neuralgia (TN) relief on demand. The implantable stimulator is a miniaturized micro-system which integrates a wireless interface circuit, a sensor interface circuit, a PRF pattern generation circuit and a logic controller. The multifunctional stimulator capable of delivering current/voltage stimulation provides the choice of the biphasic sinusoidal, square and patterned waveform for PRF treatment researches. The external handheld device can wirelessly transmit the parameters of frequency, amplitude, pulse duration and repetition rate of the pulse train to the implanted stimulator. While stimulating, the temperature sensor can monitor the operating temperature. The feedback signal is transmitted in medical implanted communication system (MICS). The micro-system is fabricated in a 0.35 μm CMOS process with a chip size of 3.1 × 2.7 mm2. The fabricated chip was mounted on a 2.6 × 2.1 cm2 test board for studying the in vivo efficacy of pain relief by PRF. Animal studies of PRF stimulation and commonly-used medication for trigeminal neuralgia are also demonstrated and the presented results prove that PRF stimulation has greater effectiveness on trigeminal neuralgia relief comparing to the medication. The effectiveness period lasts at least 14 days. The results of neural recording show that the PRF stimulation of trigeminal ganglion (TG) attenuated neuron activities without being severely damaged. Pathology also revealed no lesion found on the stimulated area.
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Yeh HY, Lee JC, Chi HH, Chen CC, Liu Q, Yen CT. Longitudinal intravital imaging nerve degeneration and sprouting in the toes of spared nerve injured mice. J Comp Neurol 2021; 529:3247-3264. [PMID: 33880774 DOI: 10.1002/cne.25162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/26/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022]
Abstract
Neuropathic pain is pain caused by damage to the somatosensory nervous system. Both degenerating injured nerves and neighboring sprouting nerves can contribute to neuropathic pain. However, the mesoscale changes in cutaneous nerve fibers over time after the loss of the parent nerve has not been investigated in detail. In this study, we followed the changes in nerve fibers longitudinally in the toe tips of mice that had undergone spared nerve injury (SNI). Nav1.8-tdTomato, Thy1-GFP and MrgD-GFP mice were used to observe the small and large cutaneous nerve fibers. We found that peripheral nerve plexuses degenerated within 3 days of nerve injury, and free nerve endings in the epidermis degenerated within 2 days. The timing of degeneration paralleled the initiation of mechanical hypersensitivity. We also found that some of the Nav1.8-positive nerve plexuses and free nerve endings in the fifth toe survived, and sprouting occurred mostly from 7 to 28 days. The timing of the sprouting of nerve fibers in the fifth toe paralleled the maintenance phase of mechanical hypersensitivity. Our results support the hypotheses that both injured and intact nerve fibers participate in neuropathic pain, and that, specifically, nerve degeneration is related to the initiation of evoked pain and nerve sprouting is related to the maintenance of evoked pain.
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Affiliation(s)
- Han-Yuan Yeh
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Jye-Chang Lee
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Han-Hsiung Chi
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Qin Liu
- Department of Anesthesiology and the Center for the Study of Itch, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan
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Affiliation(s)
- Wen-Ying Lin
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
- National Taiwan University Cancer Center, National Taiwan University College of Medicine, Taipei, Taiwan, ROC
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Wei-Zen Sun
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
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7
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Affiliation(s)
- Tsung-Han Lee
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Shan-hui Hsu
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan, Republic of China
- Research and Development Center for Medical Devices, National Taiwan University, Taipei, Taiwan, Republic of China
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan, Republic of China
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8
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Lin WY, Chu WH, Chao THH, Sun WZ, Yen CT. Longitudinal FDG-PET scan study of brain changes in mice with cancer-induced bone pain and after morphine analgesia. Mol Pain 2019; 15:1744806919841194. [PMID: 30868934 PMCID: PMC6492350 DOI: 10.1177/1744806919841194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Morphine is the most commonly used drug for treating physical and psychological
suffering caused by advanced cancer. Although morphine is known to elicit
multiple supraspinal analgesic effects, its behavioral correlates with respect
to the whole-brain metabolic activity during cancer-induced bone pain have not
been elucidated. We injected 4T1 mouse breast cancer cells into the left femur
bone marrow cavity of BALB/c mice. All mice developed limb use deficits,
mechanical allodynia, and hypersensitivity to cold, which were effectively
suppressed with morphine. Serial 18F-fluorodeoxyglucose positron emission
tomography (FDG-PET) was performed for each mouse before cancer induction (0
day), after cancer-induced bone pain was established (14 days), and during
effective morphine treatment (16 days). The longitudinal FDG-PET imaging
analysis demonstrated that cancer-induced bone pain increased glucose uptake in
the insular cortex and hypothalamus and decreased the activity of the
retrosplenial cortex. Morphine reversed the activation of the insular cortex and
hypothalamus. Furthermore, morphine activated the amygdala and rostral
ventromedial medulla and suppressed the activity of anterior cingulate cortex.
Our findings of hypothalamic and insular cortical activation support the
hypothesis that cancer-induced bone pain has strong inflammatory and affective
components in freely moving animals. Morphine may provide descending inhibitory
and facilitatory actions in the treatment of cancer-induced bone pain in a
clinical setting.
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Affiliation(s)
- Wen-Ying Lin
- 1 Department of Life Science, National Taiwan University, Taipei.,2 Department of Anesthesiology, National Taiwan University Hospital, Taipei.,3 National Taiwan University Cancer Center, National Taiwan University College of Medicine, Taipei
| | - Wen-Hua Chu
- 1 Department of Life Science, National Taiwan University, Taipei
| | | | - Wen-Zen Sun
- 2 Department of Anesthesiology, National Taiwan University Hospital, Taipei
| | - Chen-Tung Yen
- 1 Department of Life Science, National Taiwan University, Taipei
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9
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Lin WY, Cheng YT, Huang YH, Lin FS, Sun WZ, Yen CT. Synergistic symptom-specific effects of ketorolac-tramadol and ketorolac-pregabalin in a rat model of peripheral neuropathy. J Chin Med Assoc 2019; 82:457-463. [PMID: 31180945 DOI: 10.1097/jcma.0000000000000115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND Although current neuropathic pain treatment guidelines do not recommend the use of nonsteroidal anti-inflammatory drugs (NSAIDs), whether NSAIDs can serve as a useful adjuvant to conventional multimodal therapy remains unclear. METHODS The spared nerve injury (SNI) rats rapidly developed profound and long-lasting spontaneous and evoked pain behaviors, including mechanical and cold allodynia of the ipsilateral hind paw. At day 5, we first characterized the nociceptive responses to ketorolac, tramadol, pregabalin, and their combinations. RESULTS We found that tramadol and pregabalin exerted dose-dependent analgesic effects on both spontaneous and evoked behaviors. However, ketorolac alone did not suppress any behaviors regardless of the dose. Ketorolac-tramadol and ketorolac-pregabalin produced variable degrees of additive suppression of spontaneous and evoked behavioral responses. Cold allodynia was profoundly diminished after ketorolac was added to ineffective pregabalin or tramadol. Mechanical allodynia was markedly attenuated by ketorolac-pregabalin but less so by ketorolac-tramadol mixtures. CONCLUSION Our data demonstrated that an NSAID alone failed to relieve spontaneous or evoked pain behaviors in the rat SNI model, but when combined with a weak opioid and α-2-δ-ligand produced a profound synergistic analgesic effect on cold allodynia and discrepant efficacy for mechanical allodynia and spontaneous pain.
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Affiliation(s)
- Wen-Ying Lin
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan, ROC
- National Taiwan University Cancer Center, National Taiwan University College of Medicine, Taipei, Taiwan, ROC
| | - Yu-Ting Cheng
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
| | - Yu-Hsin Huang
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
| | - Feng-Sheng Lin
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Wei-Zen Sun
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan, ROC
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Lin HC, Yen CT. Differential Expression of Phosphorylated ERK and c-Fos of Limbic Cortices Activities in Response to Tactile Allodynia of Neuropathic Rats. CHINESE J PHYSIOL 2019; 61:240-251. [PMID: 30139246 DOI: 10.4077/cjp.2018.bah617] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Neuropathic pain is due to lesion or dysfunction of the somatosensory system. Treating patients
with neuropathic pain is difficult because the underlying mechanisms are understood limitedly,
especially at the supraspinal level. In this study, we used two kinds of molecular markers to
investigate the neuronal activity changes in the anterior cingulate cortex, insular cortex (IC), and
medial prefrontal cortex (mPFC) of the neuropathic rats under tactile allodynia. We used spared
nerve injury of the sciatic nerve (SNI) as the neuropathic pain model. Two weeks after SNI surgery,
we applied repetitive allodynic stimulation to the conscious rats. After stimulation, the rats were
sacrificed, and the immunohistochemistry of phosphorylated extracellular signal-regulated kinase
(pERK) and c-Fos was performed. Quantification of immunoreactive cells was carried out by
stereological method. For pERK study, the expression of pERK was significantly increased in the
mPFC and IC of the SNI rats. For c-Fos study, only mPFC had elevated expression of c-Fos in the
SNI rats. The analgesic, gabapentin, reversed the mechanical hyper-sensitivity and the augmented
expression of limbic pERK and c-Fos in the SNI rats. Immunofluorescent staining revealed the
expression of pERK or c-Fos was restricted to neurons, not glia cells. Our results demonstrated that
tactile allodynia represented differential expression of pERK and c-Fos in the limbic cortices of the
neuropathic rats.
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Affiliation(s)
- Hsiao-Chun Lin
- Center for Neuromodulation Medical Electronics Systems, National Chiao Tung University,
Hsinchu 30010, Taiwan, Republic of China.,Biomedical Electronics Translational Research Center, National Chiao Tung University,
Hsinchu 30010, Taiwan, Republic of China
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan, Republic of China
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Saito N, Shima R, Yen CT, Yang RC, Ito E, Yoshioka T. Adhesive pyramidal thorn patches provide pain relief to athletes. Kaohsiung J Med Sci 2019; 35:230-237. [PMID: 30887714 DOI: 10.1002/kjm2.12044] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/09/2019] [Indexed: 12/14/2022] Open
Abstract
Pain in athletes is ideally treated without systemic medicine. Therefore, complementary and alternative medicine, including patch treatments, is often used. The physiologic mechanisms of pain relief produced by patch treatment, however, are not well elucidated. In the present study, we introduce a pyramidal thorn (PT) patch that we developed, demonstrate the effects of this PT patch for the treatment of various types of pain in 300 subjects, and suggest a physiologic mechanism for the pain relief effects. One treatment with the PT patch effectively relieved pain in almost half the subjects evaluated. Except for pain generated deeply under the skin, such as low-back pain, pain was eliminated within four treatments with the PT patch in almost all of the subjects. Interestingly, the pain-sensing region moved along the nerve fibers after each trial. Further, patches without PT also provided some pain relief. We considered that this effect was due to hair deflection on the skin; that is, adhesion of the PT patch activates Merkel cells directly as well as Merkel cell-neurite complexes around the hair follicles by deflecting the hair follicles, whereas adhesion of a patch without PT only activates the Merkel cell-neurite complexes. In any case, patch adhesion stimulates Aβ fibers to alleviate pain. Finally, we found that the pain threshold is increased by electric stimulation, suggesting that the gentle adhesion of a PT patch would be more effective. To our knowledge, this is the first study to demonstrate physiologically the validity of an adherent patch for pain relief.
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Affiliation(s)
- Norio Saito
- Research Institute for Elderly Health, Waseda University, Tokorozawa, Saitama, Japan.,Tokai Acupuncture Moxibustion Traditional Medicine Clinic, Numazu, Shizuoka, Japan
| | - Rei Shima
- Department of Biology, Waseda University, Tokyo, Japan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Rei-Cheng Yang
- Department of Pediatrics, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo, Japan.,Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Tohru Yoshioka
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
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12
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Lu PL, Tsai ML, Jaw FS, Yen CT. Distributions of different types of nociceptive neurons in thalamic mediodorsal nuclei of anesthetized rats. J Physiol Sci 2019; 69:387-397. [PMID: 30604289 PMCID: PMC10716950 DOI: 10.1007/s12576-018-00656-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 12/18/2018] [Indexed: 12/25/2022]
Abstract
Mediodorsal thalamic nucleus (MD) is a critical relay of nociception. This study recorded responses of MD neurons to noxious mechanical and thermal stimuli in isoflurane anesthetized rats. We found the threshold of noxious mechanical stimulation was 141 gw and that of noxious heat stimulation was 46 °C. A significantly higher percentage of noxious inhibitory neurons were found in the medial and central part of the MD, whereas a higher percentage of noxious excitatory neurons were found in the lateral part of the MD and adjacent intralaminar nuclei. The differential distribution of excitatory and inhibitory neurons implies functional differentiation between the medial and lateral part of the MD in nociception processing. Furthermore, by an analysis of the stimulus-response function (SRF), we found 80% of these excitatory neurons had a step-function or hat-shape-like SRF. This suggests that most of the MD neurons may serve as a system to distinguish innocuous versus noxious stimuli.
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Affiliation(s)
- Pen-Li Lu
- Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taibei, 10617, Taiwan
| | - Meng-Li Tsai
- Department of Biomechatronic Engineering, National Ilan University, 1, Sec. 1, Shen-Lung Road, I-Lan, 26047, Taiwan
| | - Fu-Shan Jaw
- Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taibei, 10617, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, 1 Roosevelt Road, Section 4, Taibei, 10617, Taiwan.
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13
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Chakraborty S, Lee SY, Lee JC, Yen CT, Sun CK. Saturated two-photon excitation fluorescence microscopy for the visualization of cerebral neural networks at millimeters deep depth. J Biophotonics 2019; 12:e201800136. [PMID: 30112801 DOI: 10.1002/jbio.201800136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 06/21/2018] [Accepted: 07/07/2018] [Indexed: 06/08/2023]
Abstract
Optical imaging is a key modality for observing biological specimen with higher spatial resolution. However, scattering and absorption of light in tissues are inherent barriers in maximizing imaging depth in biological tissues. To achieve this goal, use of light at near-infrared spectrum can improve the present situation. Here, the capability of saturated two-photon saturated excitation (TP-SAX) fluorescence microscopy to image at depths of >2.0 mm, with submicron resolution in transparent mouse brain imaging, is demonstrated. At such depths with scattering-enlarged point spread function (PSF), we find that TP-SAX is capable to provide spatial resolution improvement compared to its corresponding TPFM, which is on the other hand already providing a much improved resolution compared with single-photon confocal fluorescence microscopy. With the capability to further improve spatial resolution at such deep depth with scattering-enlarged PSF, TP-SAX can be used for exquisite visualization of delicate cerebral neural structure in the scattering regime with a submicron spatial resolution inside intact mouse brain.
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Affiliation(s)
- Sandeep Chakraborty
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Szu-Yu Lee
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
| | - Jye-Chang Lee
- Department of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Chen-Tung Yen
- Department of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Chi-Kuang Sun
- Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan
- Institute of Physics and Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
- Molecular Imaging Center and Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
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14
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Chao THH, Chen JH, Yen CT. Plasticity changes in forebrain activity and functional connectivity during neuropathic pain development in rats with sciatic spared nerve injury. Mol Brain 2018; 11:55. [PMID: 30285801 PMCID: PMC6167811 DOI: 10.1186/s13041-018-0398-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/20/2018] [Indexed: 01/08/2023] Open
Abstract
Neuropathic pain is a major worldwide health problem. Although central sensitization has been reported in well-established neuropathic conditions, information on the acute brain activation patterns in response to peripheral nerve injury is lacking. This study first mapped the brain activity in rats immediately following spared nerve injury (SNI) of the sciatic nerve. Using blood-oxygenation-level-dependent functional magnetic resonance imaging (BOLD-fMRI), we observed sustained activation in the bilateral insular cortices (ICs), primary somatosensory cortex (S1), and cingulate cortex. Second, this study sought to link this sustained activation pattern with brain sensitization. Using manganese-enhanced magnetic resonance imaging (MEMRI), we observed enhanced activity in the ipsilateral anterior IC (AIC) in free-moving SNI rats on Days 1 and 8 post-SNI. Furthermore, enhanced functional connectivity between the ipsilateral AIC, bilateral rostral AIC, and S1 was observed on Day 8 post-SNI. Chronic electrophysiological recording experiments were conducted to confirm the tonic neuronal activation in selected brain regions. Our data provide evidence of tonic activation-dependent brain sensitization during neuropathic pain development and offer evidence that the plasticity changes in the IC and S1 may contribute to neuropathic pain development.
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Affiliation(s)
- Tzu-Hao Harry Chao
- Department of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Jyh-Horng Chen
- Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd, Taipei, 10617, Taiwan.
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Hsu SH, Chang WC, Yen CT. Novel flexible nerve conduits made of water-based biodegradable polyurethane
for peripheral nerve regeneration. J Biomed Mater Res A 2017; 105:1383-1392. [DOI: 10.1002/jbm.a.36022] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/20/2017] [Accepted: 01/26/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Shan-hui Hsu
- Institute of Polymer Science and Engineering; National Taiwan University; Taipei Taiwan
| | - Wen-Chi Chang
- Institute of Polymer Science and Engineering; National Taiwan University; Taipei Taiwan
| | - Chen-Tung Yen
- Department of Life Science and Institute of Zoology; National Taiwan University; Taipei Taiwan
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Huang RY, Liao CC, Tsai SY, Yen CT, Lin CW, Chen TC, Lin WT, Chang CH, Wen YR. Rapid and Delayed Effects of Pulsed Radiofrequency on Neuropathic Pain: Electrophysiological, Molecular, and Behavioral Evidence Supporting Long-Term Depression. Pain Physician 2017; 20:E269-E283. [PMID: 28158164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
BACKGROUND Pulsed radiofrequency (PRF) has been widely employed for ameliorating clinical neuropathic pain. How PRF alters electrophysiological transmission and modulates biomolecular functions in neural tissues has yet to be clarified. We previously demonstrated that an early application of low-voltage bipolar PRF adjacent to the dorsal root ganglion (DRG) reduced acute neuropathic pain in animals. By contrast, the present study investigated how PRF alters postsynaptic sensitization to produce early and delayed effects on neuropathic pain. OBJECTIVES Our objective was to test the hypothesis that a 5-minute session of PRF could rapidly produce selective long-term depression (LTD) on C-fiber-mediated spinal sensitization and sustain the effect through the long-lasting inhibition of injury-induced ERK-MAPK activation. This may explain the prolonged analgesic effect of PRF on chronic neuropathic pain. STUDY DESIGN Experiments were conducted on both normal rats and neuropathic pain rats that received spinal nerve ligation (SNL) 8 days prior. SETTING An animal laboratory in a medical center of a university in Taiwan. METHODS We first compared changes in field potentials in the L5 superficial spinal dorsal horn (SDH) that were evoked by conditioning electrical stimuli in the sciatic nerve in male adult rats before (as the baseline) and after PRF stimulation for at least 2 hours. Bipolar PRF was applied adjacent to the L5 DRG at an intensity of 5 V for 5 minutes, whereas the control rats were treated with sham applications. The electrophysiological findings were tested for any correlation with induction of spinal phospho-ERK (p-ERK) in normal and neuropathic pain rats. We then investigated the delayed effect of PRF on SNL-maintained pain behaviors for 2 weeks as well as p-ERK in SDH among the control, SNL, and PRF groups. Finally, potential injury in the DRGs after PRF stimulation was evaluated through behavioral observations and ATF-3, a neuronal stress marker. RESULTS In the evoked field-potential study, the recordings mediated through A- and C-afferent fibers were identified as A-component and C-component, respectively. PRF significantly reduced the C-components over 2 hours in both the normal and SNL rats, but it did not affect the A-components. In the SNL rats, the C-component was significantly depressed in the PRF group compared with the sham group. PRF also inhibited acute p-ERK induced by mechanical nociception in both the control and SNL rats. For a longer period, PRF ameliorated SNL-maintained mechanical allodynia for 10 days and thermal analgesia for 14 days, and it significantly reduced late ERK activation within spinal neurons and astrocytes 14 days afterward. Moreover, PRF in the normal rats did not alter basal withdrawal thresholds or increase the expression and distribution of ATF-3 in the DRGs. LIMITATIONS Several issues should be considered before translating the animal results to clinical applications. CONCLUSIONS Low-voltage bipolar PRF produces LTD through selective suppression on the C-component, but not on the A-component. It also inhibits ERK activation within neurons and astrocytes in SDHs. The findings suggest that PRF alleviates long-lasting neuropathic pain by selectively and persistently modulating C-fiber-mediated spinal nociceptive hypersensitivity.Key words: Pulsed radiofrequency (PRF), dorsal root ganglion (DRG), neuropathic pain, ERK activation, evoked field potential, ATF-3, long-term depression (LTD), spinal nerve ligation (SNL).
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Affiliation(s)
- Ren-Yu Huang
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
| | - Chia-Chi Liao
- Central lab, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan
| | - Shih-Ying Tsai
- Department of Anesthesiology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Chen-Tung Yen
- Institute of Zoology, National Taipei University, Taipei, Taiwan
| | - Chii-Wann Lin
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
| | - Tsung-Chi Chen
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
| | - Wei-Tso Lin
- Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan
| | - Chi-Heng Chang
- Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan
| | - Yeong-Ray Wen
- Department of Anesthesiology, School of Medicine, China Medical University, Taichung, Taiwan; Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Pain Center, Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan; Acupuncture Research Center, China Medical University, Taichung, Taiwan
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Kuo CC, Lee JC, Chiou RJ, Tsai ML, Yen CT. Spatiotemporal Changes of Neuronal Responses in the Primary Somatosensory Cortex to Noxious Tail Stimulation in Awake and Pentobarbital-Anesthetized Rats. CHINESE J PHYSIOL 2016; 58:332-42. [PMID: 26387657 DOI: 10.4077/cjp.2015.bad291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Primary somatosensory cortex (SI) is a key area in the processing of nociceptor inputs to our consciousness. To clarify the columnar and laminar organization of SI for pain processing, we compared spatiotemporal changes in neuronal activities of the primary sensorimotor cortex (SmI) of the rat in response to noxious laser heat stimulation applied to the mid-tail. Longitudinal and vertical array microelectrodes were chronically implanted in the cerebral cortex. Evoked neuronal activities, including intracortical local field potentials (LFP) and ensemble single-unit activity (SU) around SmI were simultaneously recorded. The effect of pentobarbital on the neuronal responses was evaluated in comparison with the neuronal responses in conscious animals to explore the potential substrate of nociceptive processing in the conscious state. The results from the experiment with longitudinal microelectrode arrays indicated that noxious stimulation induced a neuronal response which was spread widely around the SmI of the conscious rat, and the range of neuronal responses was limited to the tail region of the SmI under anesthesia. The results from the experiment with vertical microelectrode arrays showed the universal neuronal responses through all cortical layers of the SmI in conscious rats, and sodium pentobarbital suppressed these neuronal responses in the supragranular layers significantly relative to the deeper layers and basal activity. These results imply that a wider range of cortical activation, both in the horizontal or vertical dimension, might be important for nociceptive processing in the conscious state.
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Affiliation(s)
- Chung-Chih Kuo
- Department of Physiology, School of Medicine, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan, Republic of China
| | - Jye-Chang Lee
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan, Republic of China
| | - Ruei-Jen Chiou
- Department of Anatomy and Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, Republic of China
| | - Meng-Li Tsai
- Department of Anatomy, School of Medicine, China Medical University, Taichung 40402, Taiwan, Republic of China
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan, Republic of China
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Lee RX, Huang JJ, Huang C, Tsai ML, Yen CT. Plasticity of cerebellar Purkinje cells in behavioral training of body balance control. Front Syst Neurosci 2015; 9:113. [PMID: 26300746 PMCID: PMC4524947 DOI: 10.3389/fnsys.2015.00113] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 07/20/2015] [Indexed: 11/13/2022] Open
Abstract
Neural responses to sensory inputs caused by self-generated movements (reafference) and external passive stimulation (exafference) differ in various brain regions. The ability to differentiate such sensory information can lead to movement execution with better accuracy. However, how sensory responses are adjusted in regard to this distinguishability during motor learning is still poorly understood. The cerebellum has been hypothesized to analyze the functional significance of sensory information during motor learning, and is thought to be a key region of reafference computation in the vestibular system. In this study, we investigated Purkinje cell (PC) spike trains as cerebellar cortical output when rats learned to balance on a suspended dowel. Rats progressively reduced the amplitude of body swing and made fewer foot slips during a 5-min balancing task. Both PC simple (SSs; 17 of 26) and complex spikes (CSs; 7 of 12) were found to code initially on the angle of the heads with respect to a fixed reference. Using periods with comparable degrees of movement, we found that such SS coding of information in most PCs (10 of 17) decreased rapidly during balance learning. In response to unexpected perturbations and under anesthesia, SS coding capability of these PCs recovered. By plotting SS and CS firing frequencies over 15-s time windows in double-logarithmic plots, a negative correlation between SS and CS was found in awake, but not anesthetized, rats. PCs with prominent SS coding attenuation during motor learning showed weaker SS-CS correlation. Hence, we demonstrate that neural plasticity for filtering out sensory reafference from active motion occurs in the cerebellar cortex in rats during balance learning. SS-CS interaction may contribute to this rapid plasticity as a form of receptive field plasticity in the cerebellar cortex between two receptive maps of sensory inputs from the external world and of efference copies from the will center for volitional movements.
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Affiliation(s)
- Ray X Lee
- Department of Life Science, National Taiwan University Taipei, Taiwan
| | - Jian-Jia Huang
- Graduate Institute of Electronics Engineering, National Taiwan University Taipei, Taiwan
| | - Chiming Huang
- School of Biological Sciences, University of Missouri-Kansas City Kansas City, MO, USA
| | - Meng-Li Tsai
- Department of Biomechatronic Engineering, National Ilan University Ilan, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University Taipei, Taiwan
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19
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20
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Lin HC, Huang YH, Chao THH, Lin WY, Sun WZ, Yen CT. Gabapentin reverses central hypersensitivity and suppresses medial prefrontal cortical glucose metabolism in rats with neuropathic pain. Mol Pain 2014; 10:63. [PMID: 25253440 PMCID: PMC4182821 DOI: 10.1186/1744-8069-10-63] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 09/10/2014] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Gabapentin (GBP) is known to suppress neuropathic hypersensitivity of primary afferents and the spinal cord dorsal horn. However, its supra-spinal action sites are unclear. We identify the brain regions where GBP changes the brain glucose metabolic rate at the effective dose that alleviates mechanical allodynia using 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning. RESULTS Comparing the PET imaging data before and after the GBP treatment, the spared nerve injury-induced increases of glucose metabolism in the thalamus and cerebellar vermis were reversed, and a significant decrease occurred in glucose metabolism in the medial prefrontal cortex (mPFC), including the anterior cingulate cortex. GBP treatment also reversed post-SNI connectivity increases between limbic cortices and thalamus. CONCLUSIONS Our results indicate that GBP analgesic effect may be mediated by reversing central hypersensitivity, and suppressing mPFC, a crucial part of the cortical representation of pain, in the brain.
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Affiliation(s)
- Hsiao-Chun Lin
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
| | - Yu-Hsin Huang
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Tzu-Hao Harry Chao
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
| | - Wen-Ying Lin
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Wei-Zen Sun
- />Department of Anesthesiology, National Taiwan University Hospital, Taipei, 10002 Taiwan
| | - Chen-Tung Yen
- />Department of Life Science, National Taiwan University, No 1, Section 4, Roosevelt Road, Taipei, 10617 Taiwan
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21
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Affiliation(s)
- Ting-Chen Tseng
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan, China
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan, China
| | - Shan-Hui Hsu
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei, Taiwan, China ; Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan, China
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22
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Lee RX, Huang JJ, Huang C, Tsai ML, Yen CT. Collateral projections from vestibular nuclear and inferior olivary neurons to lobules I/II and IX/X of the rat cerebellar vermis: a double retrograde labeling study. Eur J Neurosci 2014; 40:2811-21. [PMID: 24964034 DOI: 10.1111/ejn.12648] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/11/2014] [Accepted: 05/04/2014] [Indexed: 11/29/2022]
Abstract
Axon collateral projections to various lobules of the cerebellar cortex are thought to contribute to the coordination of neuronal activities among different parts of the cerebellum. Even though lobules I/II and IX/X of the cerebellar vermis are located at the opposite poles in the anterior-posterior axis, they have been shown to receive dense vestibular mossy fiber projections. For climbing fibers, there is also a mirror-image-like organisation in their axonal collaterals between the anterior and posterior cerebellar cortex. However, the detailed organisation of mossy and climbing fiber collateral afferents to lobules I/II and IX/X is still unclear. Here, we carried out a double-labeling study with two retrograde tracers (FluoroGold and MicroRuby) in lobules I/II and IX/X. We examined labeled cells in the vestibular nuclei and inferior olive. We found a low percentage of double-labeled neurons in the vestibular nuclei (2.1 ± 0.9% of tracer-labeled neurons in this brain region), and a higher percentage of double-labeled neurons in the inferior olive (6.5 ± 1.9%), especially in its four small nuclei (18.5 ± 8.0%; including the β nucleus, dorsal cap of Kooy, ventrolateral outgrowth, and dorsomedial cell column), which are relevant for vestibular function. These results provide strong anatomical evidence for coordinated information processing in lobules I/II and IX/X for vestibular control.
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Affiliation(s)
- Ray X Lee
- Department of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan
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Yao NW, Chen CCV, Yen CT, Chang C. Promoted Growth of Brain Tumor by the Transplantation of Neural Stem/Progenitor Cells Facilitated by CXCL12. Transl Oncol 2014; 7:S1936-5233(14)00042-4. [PMID: 24862537 PMCID: PMC4145393 DOI: 10.1016/j.tranon.2014.04.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/10/2014] [Accepted: 04/14/2014] [Indexed: 12/17/2022] Open
Abstract
The targeted migration of neural stem/progenitor cells (NSPCs) is a prerequisite for the use of stem cell therapy in the treatment of pathologies. This migration is regulated mainly by C-X-C motif chemokine 12 (CXCL12). Therefore, promotion of the migratory responses of grafted cells by upregulating CXCL12 signaling has been proposed as a strategy for improving the efficacy of such cell therapies. However, the effects of this strategy on brain tumors have not yet been examined in vivo. The aim of the present study was thus to elucidate the effects of grafted rat green fluorescent protein (GFP)-labeled NSPCs (GFP-NSPCs) with CXCL12 enhancement on a model of spontaneous rat brain tumor induced by N-ethyl-N-nitrosourea. T2-weighted magnetic resonance imaging was applied to determine the changes in tumor volume and morphology over time. Postmortem histology was performed to confirm the tumor pathology, expression levels of CXCL12 and C-X-C chemokine receptor type 4, and the fate of GFP-NSPCs. The results showed that the tumor volume and hypointense areas of T2-weighted images were both significantly increased in animals treated with combined NSPC transplantation and CXCL12 induction, but not in control animals or in those with tumors that received only one of the treatments. GFP-NSPCs appear to migrate toward tumors with CXCL12 enhancement and differentiate uniquely into a neuronal lineage. These findings suggest that CXCL12 is an effective chemoattractant that facilitates exogenous NSPC migration toward brain tumors and that CXCL12 and NSPC can act synergistically to promote tumor progression with severe hemorrhage.
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Affiliation(s)
- Nai-Wei Yao
- Department of Life Science, National Taiwan University, Taipei, Taiwan; Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan
| | - Chiao-Chi V Chen
- Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan.
| | - Chen Chang
- Institute of Biomedical Sciences, Academic Sinica, Taipei, Taiwan.
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Abstract
Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI.
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Affiliation(s)
| | - Jyh-Horng Chen
- Interdisciplinary MRI/MRS Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan
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Liu YT, Shao YW, Yen CT, Shaw FZ. Acid-induced hyperalgesia and anxio-depressive comorbidity in rats. Physiol Behav 2014; 131:105-10. [DOI: 10.1016/j.physbeh.2014.03.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 01/23/2014] [Accepted: 03/31/2014] [Indexed: 01/24/2023]
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Wu JJS, Chang WP, Shih HC, Yen CT, Shyu BC. Cingulate seizure-like activity reveals neuronal avalanche regulated by network excitability and thalamic inputs. BMC Neurosci 2014; 15:3. [PMID: 24387299 PMCID: PMC3893465 DOI: 10.1186/1471-2202-15-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 12/30/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cortical neurons display network-level dynamics with unique spatiotemporal patterns that construct the backbone of processing information signals and contribute to higher functions. Recent years have seen a wealth of research on the characteristics of neuronal networks that are sufficient conditions to activate or cease network functions. Local field potentials (LFPs) exhibit a scale-free and unique event size distribution (i.e., a neuronal avalanche) that has been proven in the cortex across species, including mice, rats, and humans, and may be used as an index of cortical excitability. In the present study, we induced seizure activity in the anterior cingulate cortex (ACC) with medial thalamic inputs and evaluated the impact of cortical excitability and thalamic inputs on network-level dynamics. We measured LFPs from multi-electrode recordings in mouse cortical slices and isoflurane-anesthetized rats. RESULTS The ACC activity exhibited a neuronal avalanche with regard to avalanche size distribution, and the slope of the power-law distribution of the neuronal avalanche reflected network excitability in vitro and in vivo. We found that the slope of the neuronal avalanche in seizure-like activity significantly correlated with cortical excitability induced by γ-aminobutyric acid system manipulation. The thalamic inputs desynchronized cingulate seizures and affected the level of cortical excitability, the modulation of which could be determined by the slope of the avalanche size. CONCLUSIONS We propose that the neuronal avalanche may be a tool for analyzing cortical activity through LFPs to determine alterations in network dynamics.
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Affiliation(s)
| | | | | | | | - Bai Chuang Shyu
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
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Chiou RJ, Kuo CC, Yen CT. Comparisons of terminal densities of cardiovascular function-related projections from the amygdala subnuclei. Auton Neurosci 2013; 181:21-30. [PMID: 24412638 DOI: 10.1016/j.autneu.2013.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 11/16/2013] [Accepted: 12/10/2013] [Indexed: 02/05/2023]
Abstract
The amygdala is important in higher-level control of cardiovascular functions. In this study, we compared cardiovascular-related projections among the subnuclei of the amygdala. Biotinylated dextran amine was injected into the central, medial, and basolateral nuclei of the amygdala, and the distributions and densities of anterograde-labeled terminal boutons were analyzed. We found that the medial, basolateral, and central nuclei all had projections into the cardiovascular-related areas of the hypothalamus. However, only the central nucleus had a significant direct projection into the medulla. By contrast, the medial nucleus had limited projections, and the basolateral nucleus had no terminals extending into the medulla. We concluded that the medial, central, and basolateral nuclei of the amygdala may influence cardiovascular-related nuclei through monosynaptic connections with cardiovascular-related nuclei in the hypothalamus and medulla.
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Affiliation(s)
- Ruei-Jen Chiou
- Department of Anatomy, School of Medicine, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 11031, Taiwan
| | - Chung-Chih Kuo
- Department of Physiology, School of Medicine, Tzu Chi University, 701 Chung-Yang Road, Section 3, Hualien 97004, Taiwan
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 10617, Taiwan.
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Yang PF, Chen YY, Chen DY, Hu JW, Chen JH, Yen CT. Comparison of fMRI BOLD response patterns by electrical stimulation of the ventroposterior complex and medial thalamus of the rat. PLoS One 2013; 8:e66821. [PMID: 23826146 PMCID: PMC3691267 DOI: 10.1371/journal.pone.0066821] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 05/10/2013] [Indexed: 12/13/2022] Open
Abstract
The objective of this study was to compare the functional connectivity of the lateral and medial thalamocortical pain pathways by investigating the blood oxygen level-dependent (BOLD) activation patterns in the forebrain elicited by direct electrical stimulation of the ventroposterior (VP) and medial (MT) thalamus. An MRI-compatible stimulation electrode was implanted in the VP or MT of α-chloralose-anesthetized rats. Electrical stimulation was applied to the VP or MT at various intensities (50 µA to 300 µA) and frequencies (1 Hz to 12 Hz). BOLD responses were analyzed in the ipsilateral forelimb region of the primary somatosensory cortex (iS1FL) after VP stimulation and in the ipsilateral cingulate cortex (iCC) after MT stimulation. When stimulating the VP, the strongest activation occurred at 3 Hz. The stimulation intensity threshold was 50 µA and the response rapidly peaked at 100 µA. When stimulating the MT, The optimal frequency for stimulation was 9 Hz or 12 Hz, the stimulation intensity threshold was 100 µA and we observed a graded increase in the BOLD response following the application of higher intensity stimuli. We also evaluated c-Fos expression following the application of a 200-µA stimulus. Ventroposterior thalamic stimulation elicited c-Fos-positivity in few cells in the iS1FL and caudate putamen (iCPu). Medial thalamic stimulation, however, produced numerous c-Fos-positive cells in the iCC and iCPu. The differential BOLD responses and c-Fos expressions elicited by VP and MT stimulation indicate differences in stimulus-response properties of the medial and lateral thalamic pain pathways.
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Affiliation(s)
- Pai-Feng Yang
- Interdisciplinary MRI/MRI Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - You-Yin Chen
- Department of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan
| | - Der-Yow Chen
- Department of Psychology, National Cheng Kung University, Tainan City, Taiwan
| | - James W. Hu
- Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Jyh-Horng Chen
- Interdisciplinary MRI/MRI Lab, Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- * E-mail: (JHC); (CTY)
| | - Chen-Tung Yen
- Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
- * E-mail: (JHC); (CTY)
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Hsu SH, Kuo WC, Chen YT, Yen CT, Chen YF, Chen KS, Huang WC, Cheng H. New nerve regeneration strategy combining laminin-coated chitosan conduits and stem cell therapy. Acta Biomater 2013; 9:6606-15. [PMID: 23376237 DOI: 10.1016/j.actbio.2013.01.025] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 01/07/2013] [Accepted: 01/23/2013] [Indexed: 11/24/2022]
Abstract
Nerve regeneration remains a difficult challenge due to the lack of safe and efficient matrix support. We designed a laminin (LN)-modified chitosan multi-walled nerve conduit combined with bone marrow stem cell (BMSC) grating to bridge a 10 mm long gap in the sciatic nerve of Sprague-Dawley rats. The repair outcome was monitored during 16 weeks after surgery. Successful grafting of LN onto the chitosan film, confirmed by immunolocalization, significantly improved cell adhesion. In vivo study showed that newly formed nerve cells covered the interior of the conduit to connect the nerve gap successfully in all groups. The rats implanted with the conduit combined with BMSCs showed the best results, in terms of nerve regrowth, muscle mass of gastrocnemius, function recovery and tract tracing. Neuroanatomical horseradish peroxidase tracer analysis of motor neurons in the lumbar spinal cord indicated that the amount and signal intensity were significantly improved. Furthermore, BMSCs suppressed neuronal cell death and promoted regeneration by suppressing the inflammatory and fibrotic response induced by chitosan after long-term implantation. In summary, this study suggests that LN-modified chitosan multi-walled nerve conduit combined with BMSCs is an efficient and safe conduit matrix for nerve regeneration.
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Wu MT, Huang PY, Yen CT, Chen CC, Lee MJ. A novel SCN9A mutation responsible for primary erythromelalgia and is resistant to the treatment of sodium channel blockers. PLoS One 2013; 8:e55212. [PMID: 23383113 PMCID: PMC3561374 DOI: 10.1371/journal.pone.0055212] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/19/2012] [Indexed: 01/14/2023] Open
Abstract
Primary erythromelalgia (PE) is an autosomal dominant neurological disorder characterized by severe burning pain and erythema in the extremities upon heat stimuli or exercise. Mutations in human SCN9A gene, encoding the α-subunit of the voltage-gated sodium channel, Na(v)1.7, were found to be responsible for PE. Three missense mutations of SCN9A gene have recently been identified in Taiwanese patients including a familial (I136V) and two sporadic mutations (I848T, V1316A). V1316A is a novel mutation and has not been characterized yet. Topologically, I136V is located in DI/S1 segment and both I848T and V1316A are located in S4-S5 linker region of DII and DIII domains, respectively. To characterize the elelctrophysiological manifestations, the channel conductance with whole-cell patch clamp was recorded on the over-expressed Chinese hamster overy cells. As compared with wild type, the mutant channels showed a significant hyperpolarizing shift in voltage dependent activation and a depolarizing shift in steady-state fast inactivation. The recovery time from channel inactivation is faster in the mutant than in the wild type channels. Since warmth can trigger and exacerbate symptoms, we then examine the influence of tempearture on the sodium channel conduction. At 35°C, I136V and V1316A mutant channels exhibit a further hyperpolarizing shift at activation as compared with wild type channel, even though wild type channel also produced a significant hyperpolarizing shift compared to that of 25°C. High temperature caused a significant depolarizing shift in steady-state fast inactivation in all three mutant channels. These findings may confer to the hyperexcitability of sensory neurons, especially at high temperature. In order to identifying an effective treatment, we tested the IC₅₀ values of selective sodium channel blockers, lidocaine and mexiletine. The IC₅₀ for mexiletine is lower for I848T mutant channel as compared to that of the wild type and other two mutants which is comparable to the clinical observations.
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Affiliation(s)
- Min-Tzu Wu
- Graduate Institute of Zoology, College of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Po-Yuan Huang
- Graduate Institute of Zoology, College of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Chen-Tung Yen
- Graduate Institute of Zoology, College of Life Sciences, National Taiwan University, Taipei, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ming-Jen Lee
- Department of Neurology, National Taiwan University Hospital, Tapei, Taiwan
- Medical Genetics, National Taiwan University Hospital, Tapei, Taiwan
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Hsu SH, Lin CH, Yen CT, Wang PH, Dai LG, Jiang CF. A Comparison Study for the Efficacy of Novel Micropatterned Nerve Conduits versus Commercial Ones in Regeneration of Transected Rat Sciatic Nerve. ACTA ACUST UNITED AC 2012. [DOI: 10.1166/jnsne.2012.1026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Lu PL, Hsu SS, Tsai ML, Jaw FS, Wang AB, Yen CT. Temporal and spatial temperature distribution in the glabrous skin of rats induced by short-pulse CO2 laser. J Biomed Opt 2012; 17:117002. [PMID: 23117813 DOI: 10.1117/1.jbo.17.11.117002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Pain is a natural alarm that aids the body in avoiding potential danger and can also present as an important indicator in clinics. Infrared laser-evoked potentials can be used as an objective index to evaluate nociception. In animal studies, a short-pulse laser is crucial because it completes the stimulation before escape behavior. The objective of the present study was to obtain the temporal and spatial temperature distributions in the skin caused by the irradiation of a short-pulse laser. A fast speed infrared camera was used to measure the surface temperature caused by a CO2 laser of different durations (25 and 35 ms) and power. The measured results were subsequently implemented with a three-layer finite element model to predict the subsurface temperature. We found that stratum corneum was crucial in the modeling of fast temperature response, and escape behaviors correlated with predictions of temperature at subsurface. Results indicated that the onset latency and duration of activated nociceptors must be carefully considered when interpreting physiological responses evoked by infrared irradiation.
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Affiliation(s)
- Pen-Li Lu
- National Taiwan University, Institute of Biomedical Engineering, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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Chu YF, Yen CT, Lee LJ. Neonatal whisker clipping alters behavior, neuronal structure and neural activity in adult rats. Behav Brain Res 2012; 238:124-33. [PMID: 23098795 DOI: 10.1016/j.bbr.2012.10.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 10/09/2012] [Accepted: 10/13/2012] [Indexed: 12/31/2022]
Abstract
Early experience plays critical roles during the development of sensory systems. For example, neonatal surgical manipulations of the whiskers in rodents lead to altered neural activity and behaviors later in life. However, while surgical procedures damage the sensory pathway; it is hard to examine the impact of whisker deprivation on adult animals. To address this issue, we performed a neonatal whisker clipping (WC0-3) paradigm, a non-invasive procedure, from the day of birth (P0) to postnatal day (P) 3, and examined behavioral performances in their adult age. With fully regrown whiskers, the WC0-3 rats exhibited shorter crossable distance than controls in a gap-crossing task, suggesting a defect in their whisker-specific tactile function. In their somatosensory cortex, the layer IV spiny stellate neurons had reduced dendritic complexity and spine density. After exploration in a novel environment, the expression of an activity-dependent immediate early gene, c-fos, increased dramatically in the somatosensory cortex. However, in WC0-3 rats, the number of c-Fos positive cells was less than those in control rats, indicating a fault in transducing sensory-related neural activity between cortical layers in WC0-3 rats. Together, our results demonstrate the roles of early tactile experience on the establishment of layer-specific excitatory connection in the barrel cortex. Early sensory insufficiency would leave long-lasting functional deficits in the sensory system.
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Affiliation(s)
- Yu-Fei Chu
- Graduate Institute of Zoology, National Taiwan University, Taipei, Taiwan
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Huang JJ, Yen CT, Tsai ML, Valenzuela CF, Huang C. Acute ethanol exposure increases firing and induces oscillations in cerebellar Golgi cells of freely moving rats. Alcohol Clin Exp Res 2012; 36:2110-6. [PMID: 22563923 DOI: 10.1111/j.1530-0277.2012.01818.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 03/02/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Alcohol is a widely abused substance and is responsible for significant morbidity and mortality worldwide. The precise mechanisms underlying ethanol (EtOH)'s actions in the central nervous system (CNS) remain elusive. In vitro studies suggest that GABAergic interneurons are important targets of EtOH action in the CNS. Although EtOH generally acts to inhibit CNS neurons, it appears to cause an increase in GABAergic interneuron excitability. However, it has yet to be demonstrated that EtOH produces this effect in the brain of behaving animals. Here, we demonstrate for the first time that acute EtOH exposure excites a subtype of GABAergic interneuron (cerebellar Golgi cell [GoC]) in a freely moving animal. METHODS Electrophysiological recordings were made from microwire arrays implanted in the anterior cerebellum of freely moving rats. RESULTS Cerebellar GoCs display a slow, irregular, spontaneous action potential firing pattern under control conditions. EtOH caused dramatic and consistent increases in the rate and regularity of GoC discharges, including a redistribution of the power in the GoC spike train, such that power became concentrated in the 26.7 ± 7.3 Hz region. CONCLUSIONS Taken together with our previous findings, these data suggest that a major mechanism of EtOH actions on cerebellar function is an EtOH-induced de-afferentation at the input stage of the cerebellar cortex in the form of granule cell inhibition, and that this inhibition is caused by an increase in GoC firing. It is likely that GoCs may play a significant role both in the gating of information transmission to granule cells and in the modulation of the overall excitability of the cerebellum by tonically controlling granule cell activity.
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Affiliation(s)
- Jian-Jia Huang
- Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan
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Wu JJS, Shih HC, Yen CT, Shyu BC. Network dynamics in nociceptive pathways assessed by the neuronal avalanche model. Mol Pain 2012; 8:33. [PMID: 22537828 PMCID: PMC3478175 DOI: 10.1186/1744-8069-8-33] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/26/2012] [Indexed: 01/04/2023] Open
Abstract
Background Traditional electroencephalography provides a critical assessment of pain responses. The perception of pain, however, may involve a series of signal transmission pathways in higher cortical function. Recent studies have shown that a mathematical method, the neuronal avalanche model, may be applied to evaluate higher-order network dynamics. The neuronal avalanche is a cascade of neuronal activity, the size distribution of which can be approximated by a power law relationship manifested by the slope of a straight line (i.e., the α value). We investigated whether the neuronal avalanche could be a useful index for nociceptive assessment. Findings Neuronal activity was recorded with a 4 × 8 multichannel electrode array in the primary somatosensory cortex (S1) and anterior cingulate cortex (ACC). Under light anesthesia, peripheral pinch stimulation increased the slope of the α value in both the ACC and S1, whereas brush stimulation increased the α value only in the S1. The increase in α values was blocked in both regions under deep anesthesia. The increase in α values in the ACC induced by peripheral pinch stimulation was blocked by medial thalamic lesion, but the increase in α values in the S1 induced by brush and pinch stimulation was not affected. Conclusions The neuronal avalanche model shows a critical state in the cortical network for noxious-related signal processing. The α value may provide an index of brain network activity that distinguishes the responses to somatic stimuli from the control state. These network dynamics may be valuable for the evaluation of acute nociceptive processes and may be applied to chronic pathological pain conditions.
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Affiliation(s)
- José Jiun-Shian Wu
- Institute of Biomedical Science, Academia Sinica, Taipei, Republic of China
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Abstract
We used 18F-fluorodeoxyglucose small-animal positron-emission tomography to determine whether different styles of coping with stress are associated with different patterns of neuronal activity in the hypothalamus. Adult rats were subjected to immobilization (IMO)-stress or to a non-immobilized condition for 30 min, in random order on separate days, each of which was followed by brain-scanning. Some rats in the immobilized condition were allowed to actively cope with the stress by chewing a wooden stick during IMO, while the other immobilized rats were given nothing to chew on. Voxel-based statistical analysis of the brain imaging data shows that chewing counteracted the stress-induced increased glucose uptake in the hypothalamus to the level of the non-immobilized condition. Region-of-interest analysis of the glucose uptake values further showed that chewing significantly suppressed stress-induced increased glucose uptake in the paraventricular hypothalamic nucleus and the anterior hypothalamic area but not in the lateral hypothalamus. Together with the finding that the mean plasma corticosterone concentration at the termination of the IMO was also significantly suppressed when rats had an opportunity to chew a wooden stick, our results showed that active coping by chewing inhibited the activation of the hypothalamic-pituitary-adrenal axis to reduce the endocrine stress response.
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Affiliation(s)
- Yumie Ono
- Department of Physiology and Neuroscience, Kanagawa Dental College, Yokosuka, Kanagawa, Japan
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Tseng WT, Yen CT, Tsai ML. A bundled microwire array for long-term chronic single-unit recording in deep brain regions of behaving rats. J Neurosci Methods 2011; 201:368-76. [PMID: 21889539 DOI: 10.1016/j.jneumeth.2011.08.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 08/17/2011] [Accepted: 08/18/2011] [Indexed: 11/29/2022]
Affiliation(s)
- Wan-Ting Tseng
- Institute of Zoology and Department of Life Science, National Taiwan University, Taipei, Taiwan
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Ono Y, Lin HC, Chen HH, Yang PF, Lai WS, Chen JH, Onozuka M, Tzen KY, Yen CT. Active coping prevents stress-increased glucose metabolism in the rat hypothalamus. Neurosci Res 2011. [DOI: 10.1016/j.neures.2011.07.1608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Ou-Yang TH, Tsai ML, Yen CT, Lin TT. An infrared range camera-based approach for three-dimensional locomotion tracking and pose reconstruction in a rodent. J Neurosci Methods 2011; 201:116-23. [PMID: 21835202 DOI: 10.1016/j.jneumeth.2011.07.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 07/20/2011] [Accepted: 07/21/2011] [Indexed: 11/18/2022]
Abstract
We herein introduce an automated three-dimensional (3D) locomotion tracking and pose reconstruction system for rodents with superior robustness, rapidity, reliability, resolution, simplicity, and cost. An off-the-shelf composite infrared (IR) range camera was adopted to grab high-resolution depth images (640×480×2048 pixels at 20Hz) in our system for automated behavior analysis. For the inherent 3D structure of the depth images, we developed a compact algorithm to reconstruct the locomotion and body behavior with superior temporal and solid spatial resolution. Since the range camera operates in the IR spectrum, interference from the visible light spectrum did not affect the tracking performance. The accuracy of our system was 98.1±3.2%. We also validated the system, which yielded strong correlation with automated and manual tracking. Meanwhile, the system replicates a detailed dynamic rat model in virtual space, which demonstrates the movements of the extremities of the body and locomotion in detail on varied terrain.
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Affiliation(s)
- Tai-Hsien Ou-Yang
- Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei, Taiwan
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Min MY, Yang HW, Yen CT, Chen CC, Chen CC, Cheng SJ. ERK, synaptic plasticity and acid-induced muscle pain. Commun Integr Biol 2011; 4:394-6. [PMID: 21966555 DOI: 10.4161/cib.4.4.15694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 04/04/2011] [Indexed: 11/19/2022] Open
Abstract
Chronic pain is characterized by post-injury pain hypersensitivity. Current evidence suggests that it might result from altered neuronal excitability and/or synaptic functions in pain-related pathways and brain areas, an effect known as central sensitization. Increased activity of extracellular signal-regulated kinase (ERK) has been well-demonstrated in the dorsal horn of the spinal cord in chronic pain animal models. Recently, increased ERK activity has also been identified in two supraspinal areas, the central amygdala and the paraventricular thalamic nucleus anterior. Our recent work on the capsular central amygdala has shown that this increased ERK activity can enhance synaptic transmission, which might account for central sensitization and behavior hypersensitivity in animals receiving noxious stimuli.
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Affiliation(s)
- Ming-Yuan Min
- Institute of Zoology and College of Life Science; National Taiwan University; Taipei
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Liao YF, Tsai ML, Chen CC, Yen CT. Involvement of the Cav3.2 T-type calcium channel in thalamic neuron discharge patterns. Mol Pain 2011; 7:43. [PMID: 21639922 PMCID: PMC3127773 DOI: 10.1186/1744-8069-7-43] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Accepted: 06/04/2011] [Indexed: 11/30/2022] Open
Abstract
Background Mice that have defects in their low-threshold T-type calcium channel (T-channel) genes show altered pain behaviors. The changes in the ratio of nociceptive neurons and the burst firing property of reticular thalamic (RT) and ventroposterior (VP) neurons in Cav3.2 knockout (KO) mice were studied to test the involvement of thalamic T-channel and burst firing activity in pain function. Results Under pentobarbital or urethane anesthesia, the patterns of tonic and burst firings were recorded in functionally characterized RT and VPL neurons of Cav3.2 KO mice. Many RT neurons were nociceptive (64% under pentobarbital anesthesia and 50% under urethane anesthesia). Compared to their wild-type (WT) controls, fewer nociceptive RT neurons were found in Cav3.2 KO mice. Both nociceptive and tactile RT neurons showed fewer bursts in Cav3.2 KO mice. Within a burst, RT neurons of Cav3.2 KO mice had a lower spike frequency and less-prominent accelerando-decelerando change. In contrast, VP neurons of Cav3.2 KO mice showed a higher ratio of bursts and a higher discharge rate within a burst than those of the WT control. In addition, the long-lasting tonic firing episodes in RT neurons of the Cav3.2 KO had less stereotypic regularity than their counterparts in WT mice. Conclusions RT might be important in nociception of the mouse. In addition, we showed an important role of Cav3.2 subtype of T-channel in RT burst firing pattern. The decreased occurrence and slowing of the bursts in RT neurons might cause the increased VP bursts. These changes would be factors contributing to alternation of pain behavior in the Cav3.2 KO mice.
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Affiliation(s)
- Yi-Fang Liao
- Institute of Zoology, National Taiwan University, Roosevelt Road, Taipei, Taiwan
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Kapoor A, Hsu WM, Wang BJ, Wu GH, Lin TY, Lee SJ, Yen CT, Liang SM, Liao YF. Caveolin-1 regulates γ-secretase-mediated AβPP processing by modulating spatial distribution of γ-secretase in membrane. J Alzheimers Dis 2011; 22:423-42. [PMID: 20847442 DOI: 10.3233/jad-2010-100531] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Amyloidogenic processing of amyloid-β precursor protein (AβPP) is associated with cholesterol- and sphingolipid-rich lipid rafts. Caveolin-1, a raft-residing protein, has been implicated in the pathogenesis of Alzheimer's disease. To determine the role of caveolin-1 in governing γ-secretase-mediated AβPP proteolysis, cellular γ-secretase activity was assessed in response to alteration in caveolin-1 expression. We demonstrated that suppression of caveolin-1 expression by RNA interference resulted in a significant increase in γ-secretase-mediated proteolysis of AβPP, generation of amyloid-β, and cleavage of Notch. Overexpression of caveolin-1 attenuated γ-secretase-mediated proteolysis of AβPP and Notch, substantiating the negative regulation of γ-secretase by caveolin-1. Furthermore, we found that cells deficient in caveolin-1 exhibited significantly increased co-localization of γ-secretase with clathrin-coated non-caveolar endocytic vesicles, demonstrating that the partitioning of γ-secretase between caveolar and non-caveolar membranes can be modulated by caveolin-1. Our data also showed that JNK activation is essential for caveolin-1-mediated regulation of γ-secretase. Together, our results strongly suggest that caveolin-1 is an important regulator of γ-secretase activity.
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Affiliation(s)
- Arun Kapoor
- Laboratory of Molecular Neurobiology, Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
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Yang PF, Chen DY, Hu JW, Chen JH, Yen CT. Functional tracing of medial nociceptive pathways using activity-dependent manganese-enhanced MRI. Pain 2011; 152:194-203. [DOI: 10.1016/j.pain.2010.10.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 10/09/2010] [Accepted: 10/20/2010] [Indexed: 11/30/2022]
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Hsu JW, Lee LC, Chen RF, Yen CT, Chen YS, Tsai ML. Striatal volume changes in a rat model of childhood attention-deficit/hyperactivity disorder. Psychiatry Res 2010; 179:338-41. [PMID: 20493538 DOI: 10.1016/j.psychres.2009.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 08/20/2009] [Accepted: 08/21/2009] [Indexed: 01/26/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is one of the most common childhood neuropsychiatric disorders. Based on neuroimaging studies, the striatum is reported to be abnormal in size, but it is still not clear how they change during developmental stages. Spontaneously hypertensive rats (SHRs) are the commonly used animal model for ADHD. We investigated volume differences of the striatum at various ages before puberty in SHRs versus a control strain, Wistar-Kyoto rats (WKYs). Volumes of the bilateral striatum were measured using micrographs of Nissl-stained serial sections in both strains of rats at the ages of 4, 5, 6, 7, 8, 9, and 10weeks (n=4, each strain at each age). The results demonstrated that the age of a significant striatal volume difference between SHRs and WKYs was 5weeks; however, there was no significant difference for the corresponding total brain volume at each matched age. It suggested that the timing for striatal abnormalities in ADHD occurs during an early stage of childhood.
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Affiliation(s)
- Ju-Wei Hsu
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan
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Liao CC, Chen RF, Lai WS, Lin RCS, Yen CT. Distribution of large terminal inputs from the primary and secondary somatosensory cortices to the dorsal thalamus in the rodent. J Comp Neurol 2010; 518:2592-611. [PMID: 20503429 DOI: 10.1002/cne.22354] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The present study was undertaken to determine the precise projection pattern from the primary (S1) and secondary (S2) somatosensory cortices to the posterior nuclear proper (POm) and ventroposterior thalamic nuclei (VP). The POm was previously shown to receive large boutons arising exclusively from layer V of the S1 barrel region. This descending input was proposed to play a key role, namely, as a driver, in shaping the receptive property of POm neurons. To determine whether other body parts and the S2 also contribute such unique inputs to the dorsal thalamus, anterograde neuroanatomical tracers were focally deposited in the S1 and S2 forepaw and whisker regions of rats and C57BL6-Tg (GFPm)/Thy1 transgenic mice. Our major findings were that, 1) irrespective of body representations, both the S1 and the S2 provided corticothalamic large terminals to the POm with comparable morphological characteristics and 2) descending large terminals were also noted in particular subzones within the VP, including boundary and caudal areas. We concluded, based on these findings, that the rodent VP has three partitions: the rostral VP innervated by small corticothalamic terminals, the caudal VP with both corticothalamic small and large terminals, and a surrounding shell region, which also contained large terminals. Furthermore, assuming that the large terminal has a driver's role, we propose that particular subzones in the VP may play a role as a multiple-order thalamic relay so that they can simultaneously coordinate with first- and higher-order relays in the thalamocortical circuitry for processing somatosensory information.
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Affiliation(s)
- Chia-Chi Liao
- Central Laboratory, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei 111, Taiwan
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Tsai ML, Tseng WT, Yen CT, Chen RF. The correlation of mean sympathetic activity with low-frequency blood pressure and sympathetic variability. Clin Exp Hypertens 2010; 31:615-24. [PMID: 19886859 DOI: 10.3109/10641960902929461] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The low-frequency (0.2-0.8 Hz) component of blood pressure (BP) variability (LF(BP)) is used as an index of the low-frequency variability of sympathetic nerve activity (SNA) (LF(SNA)) in rats. It is unclear whether the LF(BP) can be used as an index of the mean SNA (mSNA). We investigated the correlation of the LF(BP) with different levels of the mSNA in this study to evaluate if it is a feasible tool for detecting differences in mSNA under physiological conditions. Correlation of the LF(SNA) with different mSNA levels was also investigated. The BP and renal SNA of rats were recorded in a nonanesthetized state. Values of the mSNA obtained from 531 recording epochs in six rats were graded into 30 levels with a bin resolution of 0.05 normalized units. A linear regression analysis showed that the correlation between the mSNA and LF(SNA) was higher than that between the mSNA and LF(BP). The mSNA was well correlated with the LF(SNA) over a wider mSNA range, while it was correlated with the LF(BP) only in a restricted range. These results demonstrated a restricted condition under which measuring the LF(BP) can be a definitive index of the mSNA, and further suggest the possibility of using the weighted LF(BP) as an index of the mSNA via intermediation by the LF(SNA) for a wider mSNA range.
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Affiliation(s)
- Meng-Li Tsai
- Department of Biomechatronic Engineering, National Ilan University, Ilan, Taiwan
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48
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Tseng WT, Chen RF, Tsai ML, Yen CT. Correlation of discharges of rostral ventrolateral medullary neurons with the low-frequency sympathetic rhythm in rats. Neurosci Lett 2009; 454:22-7. [PMID: 19429047 DOI: 10.1016/j.neulet.2009.02.057] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 02/17/2009] [Accepted: 02/23/2009] [Indexed: 10/21/2022]
Abstract
The rostral ventrolateral medulla (RVLM) is critically important in the generation of sympathetic activity. The purpose of this study was to investigate whether discharges of RVLM neurons contribute to low-frequency (LF) sympathetic rhythms. Blood pressure (BP), renal sympathetic nerve activity (SNA), and neuronal activity in the RVLM were simultaneously recorded in seven anesthetized, paralyzed, and artificially ventilated rats. Fifty-one RVLM neurons were recorded and classified into three differential functional groups according to their activities related to baroreceptor input. Those in the category of spike firing inhibited by a BP increase (BP(I)) and which excited sympathetic discharges was the most abundant (24%). Coherence analysis was used to examine the relationship of the firing frequency of RVLM neurons with the LF (0.2-0.8Hz) rhythm of SNA. Forty-one percent of RVLM neurons showed a significant correlation to LF rhythms, and BP(I) neurons with sympathoexcitatory properties were the major contributors. In another 4 baroreceptor-denervated rats, 36 RVLM neurons were recorded. In these rats, RVLM neuronal activities no longer changed with BP fluctuations. Nevertheless, more than 40% of RVLM neurons were sympathoexcitatory, and 36% of RVLM neurons were still correlated with the LF SNA rhythm. Our results suggest that there are RVLM neurons involved in generating the LF rhythm in SNA and that the baroreflex can induce the participation of more neurons in LF rhythm generation.
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Affiliation(s)
- Wan-Ting Tseng
- Institute of Zoology and Department of Life Science, National Taiwan University, 1 Roosevelt Road, Section 4, Taipei 106, Taiwan
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Abstract
Spikes are classified according to their finite differences in various orders. The fundamental idea that makes it work is that finite differences can extract and isolate features from spikes. This method showed better sorting quality and involved less labor than the methods of principal component analysis, original reduced feature set, and wavelet-based spike classifiers.
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Affiliation(s)
- Chien-Chang Yen
- Department of Mathematics, Fu-Jen Catholic University, Taipei, Taiwan
| | - Wei-Chang Shann
- Department of Mathematics, National Central University, Chung-Li, Taiwan
| | - Chen-Tung Yen
- Institute of Zoology and Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Meng-Li Tsai
- Department of Biomechatronic Engineering, National Ilan University, 1 Shen Lung Rd., Sec. 1, Ilan, 260 Taiwan
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Kuo CC, Chiou RJ, Liang KC, Yen CT. Differential involvement of the anterior cingulate and primary sensorimotor cortices in sensory and affective functions of pain. J Neurophysiol 2008; 101:1201-10. [PMID: 19091928 DOI: 10.1152/jn.90347.2008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study examined the role of neurons in different pain-related functions of the anterior cingulate cortex (ACC) and primary sensorimotor cortex (SmI) by assessing their abilities to code different levels of noxious heat and activity changes evoked by classical fear conditioning involving electric shocks. Multiple single-unit activity was recorded with microwires implanted in the SmI and ACC of each rat. In the first set of experiments, the middle segment of the tail in each rat was irradiated with laser-heat pulses of various intensities. Neuronal responses in both the SmI and ACC increased with the intensity of the laser heat, although there was a significantly higher percentage of intensity-related units in the SmI. Furthermore, the stimulus-response curve of SmI ensemble activity had a steeper slope than that of the ACC. In the second set of experiments, rats were trained and tested on a conditioned fear-potentiated startle task in which a light was paired with an electric shock and, later, the startle response was elicited by a burst of noise in the presence or absence of light. A higher percentage of ACC units changed their neuronal responses to the conditioned stimulus after the light-shock pairing and the average activity change was also significantly stronger. Our results suggest that SmI neurons are better at coding laser-heat intensity than ACC neurons, whereas more ACC neurons are involved in conditioned fear associated with an electric shock than SmI neurons. These data provide evidence for differential contributions of the SmI and ACC to sensory and affective dimensions of pain.
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Affiliation(s)
- Chung-Chih Kuo
- Institute of Zoology, National Taiwan University, Taipei, Taiwan
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