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Malmierca MS, Niño-Aguillón BE, Nieto-Diego J, Porteros Á, Pérez-González D, Escera C. Pattern-sensitive neurons reveal encoding of complex auditory regularities in the rat inferior colliculus. Neuroimage 2019; 184:889-900. [DOI: 10.1016/j.neuroimage.2018.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 09/20/2018] [Accepted: 10/04/2018] [Indexed: 10/28/2022] Open
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Hippocampal Lateralization and Synaptic Plasticity in the Intact Rat: No Left-Right Asymmetry in Electrically Induced CA3-CA1 Long-Term Potentiation. Neuroscience 2018; 397:147-158. [PMID: 30513373 PMCID: PMC6347473 DOI: 10.1016/j.neuroscience.2018.11.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/23/2018] [Accepted: 11/28/2018] [Indexed: 12/24/2022]
Abstract
The hippocampus is not a unitary, homogeneous brain area. Anatomical and functional specialization is evident along the septotemporal axis of the structure, and between the left and right hemispheres. In the mouse brain, a left-right asymmetry has been discovered in the plasticity of CA3-CA1 projections originating in the left versus right hippocampus. Presynaptic afferents originating in the left hemisphere-including both uncrossed Schaffer collaterals, and crossed commissural projections to the contralateral CA1-form small, plastic synapses, whereas afferents originating in right CA3 contact larger, less plastic, synapses. Studies using optogenetic techniques to selectively activate fibers originating from one hemisphere in ex vivo slices have revealed that projections originating from left CA3 exhibit a far greater capacity for long-term potentiation (LTP) of synaptic strength than those originating on the right. However, corresponding data from rats are currently unavailable, leaving open the question of species differences in hippocampal symmetry. In the current study, we reanalyzed data from our previous in vivo LTP work to address this issue. We analyzed plasticity in independent Schaffer collateral and commissural projections to CA1 originating from left and right CA3 in male Lister-hooded rats. However, we found no differences in the magnitude and duration of LTP induced in either crossed or uncrossed pathways following high-frequency tetanization of left versus right CA3. This contrast with previous findings may stem from methodological differences between in vivo electrical and ex vivo optogenetic approaches, but may reflect a genuine species difference in the organization and laterality of the rodent CA3-CA1 system.
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Zieminska E, Toczylowska B, Diamandakis D, Hilgier W, Filipkowski RK, Polowy R, Orzel J, Gorka M, Lazarewicz JW. Glutamate, Glutamine and GABA Levels in Rat Brain Measured Using MRS, HPLC and NMR Methods in Study of Two Models of Autism. Front Mol Neurosci 2018; 11:418. [PMID: 30505268 PMCID: PMC6250849 DOI: 10.3389/fnmol.2018.00418] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 10/26/2018] [Indexed: 11/13/2022] Open
Abstract
The disorders of the glutamatergic neurotransmission have been associated with pathogenesis of autism. In this study we evaluated the impact of the in vivo and ex vivo test methodology on measurements of levels of neurotransmitter amino acids in hippocampus of rats for valproic acid- (VPA) and thalidomide- (THAL) induced models of autism. The main goal was to compare the changes in concentrations of glutamate (Glu), glutamine (Gln) and GABA between both autistic groups and the control, measured in vivo and ex vivo in homogenates. The rat pups underwent three in vivo tests: ultrasonic vocalization (USV), magnetic resonance spectroscopy (MRS) and unilateral microdialysis of the hippocampus. Analyses of homogenates of rat hippocampus were performed using high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy. For the statistical analysis, we performed univariate and multivariate tests. USV test, which is considered in rodents as an indicator of pathology similar to autism, showed decreased USV in VPA and THAL groups. In vivo MRS studies demonstrated increases of Glu content in male rat's hippocampus in VPA and THAL groups, while the microdialysis, which allows examination of the contents in the extracellular space, detected decreases in the basal level of Gln concentrations in VPA and THAL groups. Ex vivo HPLC studies showed that levels of Glu, Gln and GABA significantly increased in male rat's hippocampus in the VPA and THAL groups, while NMR studies showed increased levels of Gln and GABA in the VPA group. Collectively, these results are consistent with the hypothesis suggesting the role of the glutamatergic disturbances on the pathogenesis of autism. For all methods used, the values of measured changes were in the same direction. The orthogonal partial least square discriminant analysis confirmed that both animal models of autism tested here can be used to trace neurochemical changes in the brain.
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Affiliation(s)
- Elzbieta Zieminska
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Beata Toczylowska
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Dominik Diamandakis
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Wojciech Hilgier
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | | | - Rafal Polowy
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Jaroslaw Orzel
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.,Faculty of Electronics and Information Technology, Warsaw University of Technology, Warsaw, Poland
| | - Michal Gorka
- Faculty of Physics, University of Warsaw, Warsaw, Poland
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Khazen T, Shrivastava K, Jada R, Hatoum OA, Maroun M. Different mechanisms underlie stress-induced changes in plasticity and metaplasticity in the prefrontal cortex of juvenile and adult animals. Neurobiol Learn Mem 2018; 154:5-11. [DOI: 10.1016/j.nlm.2018.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 02/01/2018] [Accepted: 02/09/2018] [Indexed: 12/15/2022]
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55
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Mattingly MM, Donell BM, Rosen MJ. Late maturation of backward masking in auditory cortex. J Neurophysiol 2018; 120:1558-1571. [PMID: 29995598 DOI: 10.1152/jn.00114.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Speech perception relies on the accurate resolution of brief, successive sounds that change rapidly over time. Deficits in the perception of such sounds, indicated by a reduced ability to detect signals during auditory backward masking, strongly relate to language processing difficulties in children. Backward masking during normal development has a longer maturational trajectory than many other auditory percepts, implicating the involvement of central auditory neural mechanisms with protracted developmental time courses. Despite the importance of this percept, its neural correlates are not well described at any developmental stage. We therefore measured auditory cortical responses to masked signals in juvenile and adult Mongolian gerbils and quantified the detection ability of individual neurons and neural populations in a manner comparable with psychoacoustic measurements. Perceptually, auditory backward masking manifests as higher thresholds for detection of a short signal followed by a masker than for the same signal in silence. Cortical masking was driven by a combination of suppressed responses to the signal and a reduced dynamic range available for signal detection in the presence of the masker. Both coding elements contributed to greater masked threshold shifts in juveniles compared with adults, but signal-evoked firing suppression was more pronounced in juveniles. Neural threshold shifts were a better match to human psychophysical threshold shifts when quantified with a longer temporal window that included the response to the delayed masker, suggesting that temporally selective listening may contribute to age-related differences in backward masking. NEW & NOTEWORTHY In children, auditory detection of backward masked signals is immature well into adolescence, and detection deficits correlate with problems in speech processing. Our auditory cortical recordings reveal immature backward masking in adolescent animals that mirrors the prolonged development seen in children. This is driven by both signal-evoked suppression and dynamic range reduction. An extended window of analysis suggests that differences in temporally focused listening may contribute to late maturing thresholds for backward masked signals.
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Affiliation(s)
- Michelle M Mattingly
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
| | - Brittany M Donell
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
| | - Merri J Rosen
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio
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Arezoomandan R, Riahi E, Haghparast A. Minocycline increases firing rates of accumbal neurons and modifies the effects of morphine on neuronal activity. Addict Biol 2018; 23:1055-1066. [PMID: 28961365 DOI: 10.1111/adb.12557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 08/15/2017] [Accepted: 08/18/2017] [Indexed: 01/02/2023]
Abstract
Accumulating evidence indicated that minocycline, a glial cell modulator, is able to modify a variety of morphine effects. Here, we investigated minocycline effects on electrical activity of nucleus accumbens (NAc) neurons using single unit recording in urethane-anesthetized rats. In addition, we investigated whether minocycline can modify the effects of morphine on NAc neural activity during reinstatement of morphine-seeking behavior. Minocycline increased the NAc firing activity in intact animals. Electrophysiological recording in morphine-treated animals was performed, following the acquisition of morphine-induced conditioned place preference (5 mg/kg, s.c., 3 days) and a drug-free extinction period. In acutely minocycline- treated animals, the neurons were recorded for 40 minutes following a single injection of either minocycline (50 μg/5 μl, i.c.v.) or saline. Then a priming dose of morphine (1 mg/kg, s.c.) was injected while the recording was continued for an additional 40 minutes. Minocycline significantly increased the firing rates of neurons and significantly modified morphine inhibitory effects on NAc neurons. In subchronically minocycline-treated groups, the rats were given daily injections of minocycline (50 μg/5 μl, i.c.v) during the extinction period. Then, on the reinstatement day, NAc neurons were recorded for 10 minutes, the priming dose of morphine was administered and the recording was continued for 45 minutes. Our results showed the failure of minocycline to significantly modify the inhibitory effects of morphine. In conclusion, our findings indicated that minocycline modifies morphine-induced decreases in the firing rates of NAc neurons in the reinstatement phase.
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Affiliation(s)
- Reza Arezoomandan
- Addiction Department, School of Behavioral Sciences and Mental Health (Tehran Institute of Psychiatry); Iran University of Medical Sciences; Tehran Iran
| | - Esmail Riahi
- Physiology Department, School of Medicine; Tehran University of Medical Sciences; Tehran Iran
| | - Abbas Haghparast
- Neuroscience Research Center, School of Medicine; Shahid Beheshti University of Medical Sciences; Tehran Iran
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Opportunities and Challenges for Single-Unit Recordings from Enteric Neurons in Awake Animals. MICROMACHINES 2018; 9:mi9090428. [PMID: 30424361 PMCID: PMC6187697 DOI: 10.3390/mi9090428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/17/2018] [Accepted: 08/23/2018] [Indexed: 12/18/2022]
Abstract
Advanced electrode designs have made single-unit neural recordings commonplace in modern neuroscience research. However, single-unit resolution remains out of reach for the intrinsic neurons of the gastrointestinal system. Single-unit recordings of the enteric (gut) nervous system have been conducted in anesthetized animal models and excised tissue, but there is a large physiological gap between awake and anesthetized animals, particularly for the enteric nervous system. Here, we describe the opportunity for advancing enteric neuroscience offered by single-unit recording capabilities in awake animals. We highlight the primary challenges to microelectrodes in the gastrointestinal system including structural, physiological, and signal quality challenges, and we provide design criteria recommendations for enteric microelectrodes.
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58
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Zerbi V, Ielacqua GD, Markicevic M, Haberl MG, Ellisman MH, A-Bhaskaran A, Frick A, Rudin M, Wenderoth N. Dysfunctional Autism Risk Genes Cause Circuit-Specific Connectivity Deficits With Distinct Developmental Trajectories. Cereb Cortex 2018; 28:2495-2506. [PMID: 29901787 PMCID: PMC5998961 DOI: 10.1093/cercor/bhy046] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/16/2018] [Accepted: 02/12/2018] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorders (ASD) are a set of complex neurodevelopmental disorders for which there is currently no targeted therapeutic approach. It is thought that alterations of genes regulating migration and synapse formation during development affect neural circuit formation and result in aberrant connectivity within distinct circuits that underlie abnormal behaviors. However, it is unknown whether deviant developmental trajectories are circuit-specific for a given autism risk-gene. We used MRI to probe changes in functional and structural connectivity from childhood to adulthood in Fragile-X (Fmr1-/y) and contactin-associated (CNTNAP2-/-) knockout mice. Young Fmr1-/y mice (30 days postnatal) presented with a robust hypoconnectivity phenotype in corticocortico and corticostriatal circuits in areas associated with sensory information processing, which was maintained until adulthood. Conversely, only small differences in hippocampal and striatal areas were present during early postnatal development in CNTNAP2-/- mice, while major connectivity deficits in prefrontal and limbic pathways developed between adolescence and adulthood. These findings are supported by viral tracing and electron micrograph approaches and define 2 clearly distinct connectivity endophenotypes within the autism spectrum. We conclude that the genetic background of ASD strongly influences which circuits are most affected, the nature of the phenotype, and the developmental time course of the associated changes.
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Affiliation(s)
- Valerio Zerbi
- Neural Control of Movement Lab, HEST, ETH Zürich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Giovanna D Ielacqua
- Institute for Biomedical Engineering, University and ETH Zurich, Wolfgang-Pauli-Str. 27, Zurich, Switzerland
| | - Marija Markicevic
- Neural Control of Movement Lab, HEST, ETH Zürich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Matthias Georg Haberl
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA
| | - Arjun A-Bhaskaran
- INSERM, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, Bordeaux, France
- University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Bordeaux, France
| | - Andreas Frick
- INSERM, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, Bordeaux, France
- University of Bordeaux, Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, Bordeaux, France
| | - Markus Rudin
- Institute for Biomedical Engineering, University and ETH Zurich, Wolfgang-Pauli-Str. 27, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, Zurich, Switzerland
| | - Nicole Wenderoth
- Neural Control of Movement Lab, HEST, ETH Zürich, Winterthurerstrasse 190, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, Zurich, Switzerland
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59
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Li Q, Zhang X, Cheng N, Yang C, Zhang T. Notch1 knockdown disturbed neural oscillations in the hippocampus of C57BL mice. Prog Neuropsychopharmacol Biol Psychiatry 2018; 84:63-70. [PMID: 29410010 DOI: 10.1016/j.pnpbp.2018.01.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 01/17/2018] [Accepted: 01/29/2018] [Indexed: 12/30/2022]
Abstract
Neural oscillations and their interactions are associated with the coordination of neural groups, which provide a mechanism underlying information processing of brain functions. Notch1 receptor is involved in the neurological and psychiatric disorders, such as neurodevelopmental deficits, cerebral ischemia, Alzheimer's disease and depression. Here, we investigated the dynamics of neural oscillations in hippocampus of Notch1+/- mice in urethane-anesthetized state. Notch1 knockdown altered the distribution of power in the hippocampal DG areas, reduced theta (3-8 Hz) power and enhanced low gamma (LG, 30-50 Hz) and high gamma (HG, 50-100 Hz) power. Moreover, theta-gamma phase-amplitude coupling in the hippocampal DG area was markedly impaired in the Notch1+/- mice. The data further showed that the expression of NR2B was decreased, and the expressions of GABAARα1, GAD67 and parvalbumin were considerably increased after Notch1 knockdown. Taken together, our results suggest that Notch1 genetic deficiency significantly impaired the corss-frequency coupling of neural oscillations, and their interactions in the hippocampal DG region by means of disrupting the balance of excitatory and inhibitory receptors, which could be an underlying mechanism of cognitive impairment in neuropsychiatric disorders.
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Affiliation(s)
- Qun Li
- College of Life Sciences, Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 300071 Tianjin, PR China
| | - Xiaochen Zhang
- School of Medicine, State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071 Tianjin, PR China
| | - Ning Cheng
- College of Life Sciences, Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 300071 Tianjin, PR China
| | - Chunxiao Yang
- School of Medicine, State Key Laboratory of Medicinal Chemical Biology, Nankai University, 300071 Tianjin, PR China
| | - Tao Zhang
- College of Life Sciences, Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 300071 Tianjin, PR China.
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60
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Arslan G, Alici SK, Ayyildiz M, Agar E. Interaction between urethane and cannabinoid CB1 receptor agonist and antagonist in penicillin-induced epileptiform activity. Acta Neurobiol Exp (Wars) 2018; 77:128-136. [PMID: 28691717 DOI: 10.21307/ane-2017-045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous experimental studies have shown that various anesthetics alter the effects of cannabinoid agonists and antagonists on the cardiac response to different stimuli. Since no data have shown an interaction between urethane and cannabinoid signaling in epilepsy, we examined the suitability of urethane with regard to testing the effects of a cannabinoid CB1 receptor agonist and an antagonist on penicillin-induced epileptiform activity in rats. Permanent screw electrodes for electrocorticographic (ECoG) recordings, and a permanent cannula for administration of the substances to the brain ventricles, were placed into the cranium of rats. Epileptiform activity was induced by injection of penicillin through the cannula in conscious animal. The CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA; 7.5 μg) and the CB1 receptor antagonist [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3 carboxamide] (AM-251; 0.25 μg) were administered intracerebroventricularly 30 minutes after the penicillin application in urethane-anesthetized and conscious animals. Urethane completely eliminated spontaneous ictal events in ECoG recordings and reduced the frequency and total amount of epileptiform activity. It did not alter either the proconvulsant effects of AM-251 or the anticonvulsant effects of ACEA on penicillin-induced epileptiform activity. The electrophysiological evidence suggests that there is no possible interaction between urethane and cannabinoid CB1 receptors in this experimental model of epilepsy.
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Affiliation(s)
- Gokhan Arslan
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Sabiha Kubra Alici
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Mustafa Ayyildiz
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey
| | - Erdal Agar
- Department of Physiology, Faculty of Medicine, University of Ondokuz Mayis, Samsun, Turkey;
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61
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Adrenergic Receptor Agonists’ Modulation of Dopaminergic and Non-dopaminergic Neurons in the Ventral Tegmental Area. Neuroscience 2018; 375:119-134. [DOI: 10.1016/j.neuroscience.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 01/02/2023]
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Bezdudnaya T, Hormigo KM, Marchenko V, Lane MA. Spontaneous respiratory plasticity following unilateral high cervical spinal cord injury in behaving rats. Exp Neurol 2018; 305:56-65. [PMID: 29596845 DOI: 10.1016/j.expneurol.2018.03.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 01/23/2018] [Accepted: 03/23/2018] [Indexed: 01/25/2023]
Abstract
Unilateral cervical C2 hemisection (C2Hx) is a classic model of spinal cord injury (SCI) for studying respiratory dysfunction and plasticity. However, most previous studies were performed under anesthesia, which significantly alters respiratory network. Therefore, the goal of this work was to assess spontaneous diaphragm recovery post-C2Hx in awake, freely behaving animals. Adult rats were chronically implanted with diaphragm EMG electrodes and recorded during 8 weeks post-C2Hx. Our results reveal that ipsilateral diaphragm activity partially recovers within days post-injury and reaches pre-injury amplitude in a few weeks. However, the full extent of spontaneous ipsilateral recovery is significantly attenuated by anesthesia (ketamine/xylazine, isoflurane, and urethane). This suggests that the observed recovery may be attributed in part to activation of NMDA receptors which are suppressed by anesthesia. Despite spontaneous recovery in awake animals, ipsilateral hemidiaphragm dysfunction still persists: i) Inspiratory bursts during basal (slow) breathing exhibit an altered pattern, ii) the amplitude of sighs - or augmented breaths - is significantly decreased, and iii) the injured hemidiaphragm exhibits spontaneous events of hyperexcitation. The results from this study offer an under-appreciated insight into spontaneous diaphragm activity and recovery following high cervical spinal cord injury in awake animals.
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Affiliation(s)
- Tatiana Bezdudnaya
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA 19129, USA.
| | - Kristiina M Hormigo
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA 19129, USA
| | - Vitaliy Marchenko
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA 19129, USA
| | - Michael A Lane
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, 2900 W Queen Lane, Philadelphia, PA 19129, USA
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63
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Mohapatra BR. Biocatalytic efficacy of immobilized cells of Chryseobacterium sp. Alg-SU10 for simultaneous hydrolysis of urethane and urea. BIOCATAL BIOTRANSFOR 2018. [DOI: 10.1080/10242422.2018.1445228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Bidyut R. Mohapatra
- Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Bridgetown, Barbados
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64
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Krentzel AA, Macedo-Lima M, Ikeda MZ, Remage-Healey L. A Membrane G-Protein-Coupled Estrogen Receptor Is Necessary but Not Sufficient for Sex Differences in Zebra Finch Auditory Coding. Endocrinology 2018; 159:1360-1376. [PMID: 29351614 PMCID: PMC5839738 DOI: 10.1210/en.2017-03102] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/11/2018] [Indexed: 12/24/2022]
Abstract
Estradiol acts as a neuromodulator in brain regions important for cognition and sensory processing. Estradiol also shapes brain sex differences but rarely have these concepts been considered simultaneously. In male and female songbirds, estradiol rapidly increases within the auditory forebrain during song exposure and enhances local auditory processing. We tested whether G-protein-coupled estrogen receptor 1 (GPER1), a membrane-bound estrogen receptor, is necessary and sufficient for neuroestrogen regulation of forebrain auditory processing in male and female zebra finches (Taeniopygia guttata). At baseline, we observed that females had elevated single-neuron responses to songs vs males. In males, narrow-spiking (NS) neurons were more responsive to conspecific songs than broad-spiking (BS) neurons, yet cell types were similarly auditory responsive in females. Following acute inactivation of GPER1, auditory responsiveness and coding were suppressed in male NS yet unchanged in female NS and in BS of both sexes. By contrast, GPER1 activation did not mimic previously established estradiol actions in either sex. Lastly, the expression of GPER1 and its coexpression with an inhibitory neuron marker were similarly abundant in males and females, confirming anatomical similarity in the auditory forebrain. In this study, we found: (1) a role for GPER1 in regulating sensory processing and (2) a sex difference in auditory processing of complex vocalizations in a cell type-specific manner. These results reveal sex specificity of a rapid estrogen signaling mechanism in which neuromodulation accounts and/or compensates for brain sex differences, dependent on cell type, in brain regions that are anatomically similar in both sexes.
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Affiliation(s)
- Amanda A. Krentzel
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, Massachusetts 01002
- Correspondence: Amanda A. Krentzel, PhD, David Clark Laboratories, North Carolina State University, 100 Eugene Brooks Avenue, Raleigh, North Carolina 27607. E-mail:
| | - Matheus Macedo-Lima
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, Massachusetts 01002
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Foundation, Ministry of Education of Brazil, DF 70040-020 Brasília, Brazil
| | - Maaya Z. Ikeda
- Psychological and Brain Sciences, University of Massachusetts Amherst, Amherst, Massachusetts 01002
| | - Luke Remage-Healey
- Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, Massachusetts 01002
- Psychological and Brain Sciences, University of Massachusetts Amherst, Amherst, Massachusetts 01002
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, Massachusetts 01002
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65
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Cocaine-induced locomotor sensitization associates with slow oscillatory firing of neurons in the ventral tegmental area. Sci Rep 2018; 8:3274. [PMID: 29459754 PMCID: PMC5818474 DOI: 10.1038/s41598-018-21592-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/05/2018] [Indexed: 11/22/2022] Open
Abstract
The initiation of psychostimulant sensitization depends on the mesocorticolimbic dopamine (DA) system. Although many cellular adaptations has been reported to be associated with this addictive behavior, the overall influence of these adaptations on the network regulation of DA neurons has not been established. Here, we profile a network-driven slow oscillation (SO) in the firing activity of ventral tegmental area (VTA) putative DA and non-DA neurons and their correlation with locomotor sensitization induced by repeated administration of cocaine. One day after the last cocaine injection, the power of SO (Pso) significantly increased both in DA and non-DA neurons. Interestingly, the Pso in DA neurons was positively correlated, while Pso in non-DA neurons was negatively correlated with the level of locomotor sensitization. On the other hand, the firing rates of DA and non-DA neurons were both elevated, but none exhibited any correlation with the level of sensitization. Fourteen days after the last injection, the Pso of DA neurons dissipated but still positively correlated with the level of sensitization. In contrast, the Pso in non-DA neurons lost correlation with locomotor sensitization. These results suggest that cocaine-induced locomotor sensitization is associated with long-term network adaptation in DA system and that DA and non-DA neurons may corporately facilitate/hamper the initiation of locomotor sensitization.
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66
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Mohapatra BR. An Insight into the Prevalence and Enzymatic Abatement of Urethane in Fermented Beverages. Microb Biotechnol 2018. [DOI: 10.1007/978-981-10-7140-9_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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67
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Szczurowska E, Ahuja N, Jiruška P, Kelemen E, Stuchlík A. Impairment of neural coordination in hippocampal neuronal ensembles after a psychotomimetic dose of dizocilpine. Prog Neuropsychopharmacol Biol Psychiatry 2018; 81:275-283. [PMID: 28935586 DOI: 10.1016/j.pnpbp.2017.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 09/15/2017] [Accepted: 09/16/2017] [Indexed: 11/19/2022]
Abstract
The discoordination hypothesis of schizophrenia posits discoordination of neural activity as the central mechanism that underlies some psychotic symptoms (including 'hallmark' cognitive symptoms) of schizophrenia. To test this proposition, we studied the activity of hippocampal neurons in urethane anesthetized Long Evans rats after 0.15mg/kg dizocilpine (MK-801), an N-Methyl-d-aspartate (NMDA) glutamate receptor antagonist, which can cause psychotic symptoms in humans and cognitive control impairments in animals. We observed that MK-801 altered the temporal coordination, but not rate, of neuronal firing. Coactivation between neurons increased, driven primarily by increased coincident firing of cell pairs that did not originally fire together before MK-801 injection. Increased pairwise coactivation manifested as disorganized discharge on the level of neuronal ensembles, which in turn could lead to disorganization in information processing. Disorganization of neuronal activity after a psychotomimetic dose of MK-801 supports the discoordination hypothesis of psychosis.
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Affiliation(s)
- Ewa Szczurowska
- National Institute of Mental Health, Topolová 748, 250 67 Klecany, Czech Republic
| | - Nikhil Ahuja
- Department of Neurophysiology of Memory and Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Přemysl Jiruška
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Eduard Kelemen
- National Institute of Mental Health, Topolová 748, 250 67 Klecany, Czech Republic.
| | - Aleš Stuchlík
- Department of Neurophysiology of Memory and Institute of Physiology, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic.
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68
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Latif R, LI AA. Vasoreactivity of thoracic aorta in Nigella Sativa supplemented and/or exercise trained rats. Artery Res 2018. [DOI: 10.1016/j.artres.2017.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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69
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Functional networks and network perturbations in rodents. Neuroimage 2017; 163:419-436. [DOI: 10.1016/j.neuroimage.2017.09.038] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/15/2017] [Accepted: 09/19/2017] [Indexed: 11/16/2022] Open
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70
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Hildebrandt KJ, Sahani M, Linden JF. The Impact of Anesthetic State on Spike-Sorting Success in the Cortex: A Comparison of Ketamine and Urethane Anesthesia. Front Neural Circuits 2017; 11:95. [PMID: 29238293 PMCID: PMC5712555 DOI: 10.3389/fncir.2017.00095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/14/2017] [Indexed: 11/13/2022] Open
Abstract
Spike sorting is an essential first step in most analyses of extracellular in vivo electrophysiological recordings. Here we show that spike-sorting success depends critically on characteristics of coordinated population activity that can differ between anesthetic states. In tetrode recordings from mouse auditory cortex, spike sorting was significantly less successful under ketamine/medetomidine (ket/med) than urethane anesthesia. Surprisingly, this difficulty with sorting under ket/med anesthesia did not appear to result from either greater millisecond-scale burstiness of neural activity or increased coordination of activity among neighboring neurons. Rather, the key factor affecting sorting success appeared to be the amount of coordinated population activity at long time intervals and across large cortical distances. We propose that spike-sorting success is directly dependent on overall coordination of activity, and is most disrupted by large-scale fluctuations in cortical population activity. Reliability of single-unit recording may therefore differ not only between urethane-anesthetized and ket/med-anesthetized states as demonstrated here, but also between synchronized and desynchronized states, asleep and awake states, or inattentive and attentive states in unanesthetized animals.
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Affiliation(s)
- K Jannis Hildebrandt
- Cluster of Excellence Hearing4all, University of Oldenburg, Oldenburg, Germany.,Department of Neuroscience, University of Oldenburg, Oldenburg, Germany
| | - Maneesh Sahani
- Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom
| | - Jennifer F Linden
- Ear Institute, University College London, London, United Kingdom.,Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
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71
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Tanaka M, Wang X, Mikoshiba K, Hirase H, Shinohara Y. Rearing-environment-dependent hippocampal local field potential differences in wild-type and inositol trisphosphate receptor type 2 knockout mice. J Physiol 2017; 595:6557-6568. [PMID: 28758690 DOI: 10.1113/jp274573] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/25/2017] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS Mice reared in an enriched environment are demonstrated to have larger hippocampal gamma oscillations than those reared in isolation, thereby confirming previous observations in rats. To test whether astrocytic Ca2+ surges are involved in this experience-dependent LFP pattern modulation, we used inositol trisphosphate receptor type 2 (IP3 R2)-knockout (KO) mice, in which IP3 /Ca2+ signalling in astrocytes is largely diminished. We found that this experience-dependent gamma power alteration persists in the KO mice. Interestingly, hippocampal ripple events, the synchronized events critical for memory consolidation, are reduced in magnitude and frequency by both isolated rearing and IP3 R2 deficiency. ABSTRACT Rearing in an enriched environment (ENR) is known to enhance cognitive and memory abilities in rodents, whereas social isolation (ISO) induces depression-like behaviour. The hippocampus has been documented to undergo morphological and functional changes depending on these rearing environments. For example, rearing condition during juvenility alters CA1 stratum radiatum gamma oscillation power in rats. In the present study, hippocampal CA1 local field potentials (LFP) were recorded from bilateral CA1 in urethane-anaesthetized mice that were reared in either an ENR or ISO condition. Similar to previous findings in rats, gamma oscillation power during theta states was higher in the ENR group. Ripple events that occur during non-theta periods in the CA1 stratum pyramidale also had longer intervals in ISO mice. Because astrocytic Ca2+ elevations play a key role in synaptic plasticity, we next tested whether these changes in LFP are also expressed in inositol trisphosphate receptor type 2 (IP3 R2)-knockout (KO) mice, in which astrocytic Ca2+ elevations are largely diminished. We found that the gamma power was also higher in IP3 R2-KO-ENR mice compared to IP3 R2-KO-ISO mice, suggesting that the rearing-environment-dependent gamma power alteration does not necessarily require the astrocytic IP3 /Ca2+ pathway. By contrast, ripple events showed genotype-dependent changes, as well as rearing condition-dependent changes: ISO housing and IP3 R2 deficiency both lead to longer inter-ripple intervals. Moreover, we found that ripple magnitude in the right CA1 tended to be smaller in IP3 R2-KO. Because IP3 R2-KO mice have been reported to have depression phenotypes, our results suggest that ripple events and the mood of animals may be broadly correlated.
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Affiliation(s)
| | | | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama, Japan
| | - Hajime Hirase
- Laboratory for Neuron-Glia Circuitry.,Brain and Body System Science Institute, Saitama University, Saitama, Japan
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72
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Ma J, Ma Y, Dong B, Bandet MV, Shuaib A, Winship IR. Prevention of the collapse of pial collaterals by remote ischemic perconditioning during acute ischemic stroke. J Cereb Blood Flow Metab 2017; 37:3001-3014. [PMID: 27909265 PMCID: PMC5536804 DOI: 10.1177/0271678x16680636] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/23/2016] [Accepted: 10/30/2016] [Indexed: 02/05/2023]
Abstract
Collateral circulation is a key variable determining prognosis and response to recanalization therapy during acute ischemic stroke. Remote ischemic perconditioning (RIPerC) involves inducing peripheral ischemia (typically in the limbs) during stroke and may reduce perfusion deficits and brain damage due to cerebral ischemia. In this study, we directly investigated pial collateral flow augmentation due to RIPerC during distal middle cerebral artery occlusion (MCAo) in rats. Blood flow through pial collaterals between the anterior cerebral artery (ACA) and the MCA was assessed in male Sprague Dawley rats using in vivo laser speckle contrast imaging (LSCI) and two photon laser scanning microscopy (TPLSM) during distal MCAo. LSCI and TPLSM revealed that RIPerC augmented collateral flow into distal MCA segments. Notably, while control rats exhibited an initial dilation followed by a progressive narrowing of pial arterioles 60 to 150-min post-MCAo (constricting to 80-90% of post-MCAo peak diameter), this constriction was prevented or reversed by RIPerC (such that vessel diameters increased to 105-110% of post-MCAo, pre-RIPerC diameter). RIPerC significantly reduced early ischemic damage measured 6 h after stroke onset. Thus, prevention of collateral collapse via RIPerC is neuroprotective and may facilitate other protective or recanalization therapies by improving blood flow in penumbral tissue.
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Affiliation(s)
- Junqiang Ma
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- The First Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yonglie Ma
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Bin Dong
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Mischa V Bandet
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Ashfaq Shuaib
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB, Canada
| | - Ian R Winship
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
- Ian R Winship, 12-127 Clinical Sciences Building, Edmonton, AB T6G 2R3, Canada.
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73
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Massey CA, Richerson GB. Isoflurane, ketamine-xylazine, and urethane markedly alter breathing even at subtherapeutic doses. J Neurophysiol 2017; 118:2389-2401. [PMID: 28747467 DOI: 10.1152/jn.00350.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/19/2017] [Accepted: 07/20/2017] [Indexed: 11/22/2022] Open
Abstract
Anesthetics are widely used for animal research on respiratory control in vivo, but their effect on breathing and CO2 chemoreception has not been well characterized in mice, a species now often used for these studies. We previously demonstrated that 1% isoflurane markedly reduces the hypercapnic ventilatory response (HCVR) in adult mice in vivo and masks serotonin [5-hydroxytryptamine (5-HT)] neuron chemosensitivity in vitro. Here we investigated effects of 0.5% isoflurane on breathing in adult mice and also found a large reduction in the HCVR even at this subanesthetic concentration. We then tested the effects on breathing of ketamine-xylazine and urethane, anesthetics widely used in research on breathing. We found that these agents altered baseline breathing and blunted the HCVR at doses within the range typically used experimentally. At lower doses ventilation was decreased, but mice appropriately matched their ventilation to metabolic demands due to a parallel decrease in O2 consumption. Neither ketamine nor urethane decreased chemosensitivity of 5-HT neurons. These results indicate that baseline breathing and/or CO2 chemoreception in mice are decreased by anesthetics widely viewed as not affecting respiratory control, and even at subtherapeutic doses. These effects of anesthetics on breathing may alter the interpretation of studies of respiratory physiology in vivo.NEW & NOTEWORTHY Anesthetics are frequently used in animal research, but their effects on physiological functions in mice have not been well defined. Here we investigated the effects of commonly used anesthetics on breathing in mice. We found that all tested anesthetics significantly reduced the hypercapnic ventilatory response (HCVR), even at subtherapeutic doses. In addition, ketamine-xylazine and urethane anesthesia altered baseline breathing. These data indicate that breathing and the HCVR in mice are highly sensitive to anesthetic modulation.
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Affiliation(s)
- Cory A Massey
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa.,Department of Neurology, University of Iowa, Iowa City, Iowa
| | - George B Richerson
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa; .,Department of Neurology, University of Iowa, Iowa City, Iowa.,Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa; and.,Veterans Affairs Medical Center, Iowa City, Iowa
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74
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Loutit AJ, Maddess T, Redmond SJ, Morley JW, Stuart GJ, Potas JR. Characterisation and functional mapping of surface potentials in the rat dorsal column nuclei. J Physiol 2017; 595:4507-4524. [PMID: 28333372 DOI: 10.1113/jp273759] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/10/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The brainstem dorsal column nuclei (DCN) process sensory information arising from the body before it reaches the brain and becomes conscious. Despite significant investigations into sensory coding in peripheral nerves and the somatosensory cortex, little is known about how sensory information arising from the periphery is represented in the DCN. Following stimulation of hind-limb nerves, we mapped and characterised the evoked electrical signatures across the DCN surface. We show that evoked responses recorded from the DCN surface are highly reproducible and are unique to nerves carrying specific sensory information. ABSTRACT The brainstem dorsal column nuclei (DCN) play a role in early processing of somatosensory information arising from a variety of functionally distinct peripheral structures, before being transmitted to the cortex via the thalamus. To improve our understanding of how sensory information is represented by the DCN, we characterised and mapped low- (<200 Hz) and high-frequency (550-3300 Hz) components of nerve-evoked DCN surface potentials. DCN surface potentials were evoked by electrical stimulation of the left and right nerves innervating cutaneous structures (sural nerve), or a mix of cutaneous and deep structures (peroneal nerve), in 8-week-old urethane-anaesthetised male Wistar rats. Peroneal nerve-evoked DCN responses demonstrated low-frequency events with significantly longer durations, more high-frequency events and larger magnitudes compared to responses evoked from sural nerve stimulation. Hotspots of low- and high-frequency DCN activity were found ipsilateral to stimulated nerves but were not symmetrically organised. In conclusion, we find that sensory inputs from peripheral nerves evoke unique and characteristic DCN activity patterns that are highly reproducible both within and across animals.
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Affiliation(s)
- Alastair J Loutit
- The Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, 2601, Australia.,School of Medical Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Ted Maddess
- The Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Stephen J Redmond
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - John W Morley
- School of Medicine, Western Sydney University, Sydney, New South Wales, 2560, Australia.,School of Medical Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Greg J Stuart
- The Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - Jason R Potas
- The Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australian Capital Territory, 2601, Australia.,School of Medical Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.,ANU Medical School, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
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75
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Paasonen J, Salo RA, Ihalainen J, Leikas JV, Savolainen K, Lehtonen M, Forsberg MM, Gröhn O. Dose-response effect of acute phencyclidine on functional connectivity and dopamine levels, and their association with schizophrenia-like symptom classes in rat. Neuropharmacology 2017; 119:15-25. [DOI: 10.1016/j.neuropharm.2017.03.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 01/31/2017] [Accepted: 03/20/2017] [Indexed: 10/19/2022]
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76
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Phillips EAK, Schreiner CE, Hasenstaub AR. Diverse effects of stimulus history in waking mouse auditory cortex. J Neurophysiol 2017; 118:1376-1393. [PMID: 28566458 DOI: 10.1152/jn.00094.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/10/2017] [Accepted: 05/29/2017] [Indexed: 11/22/2022] Open
Abstract
Responses to auditory stimuli are often strongly influenced by recent stimulus history. For example, in a paradigm called forward suppression, brief sounds can suppress the perception of, and the neural responses to, a subsequent sound, with the magnitude of this suppression depending on both the spectral and temporal distances between the sounds. As a step towards understanding the mechanisms that generate these adaptive representations in awake animals, we quantitatively characterize responses to two-tone sequences in the auditory cortex of waking mice. We find that cortical responses in a forward suppression paradigm are more diverse in waking mice than previously appreciated, that these responses vary between cells with different firing characteristics and waveform shapes, but that the variability in these responses is not substantially related to cortical depth or columnar location. Moreover, responses to the first tone in the sequence are often not linearly related to the suppression of the second tone response, suggesting that spike-frequency adaptation of cortical cells is not a large contributor to forward suppression or its variability. Instead, we use a simple multilayered model to show that cell-to-cell differences in the balance of intracortical inhibition and excitation will naturally produce such a diversity of forward interactions. We propose that diverse inhibitory connectivity allows the cortex to encode spectro-temporally fluctuating stimuli in multiple parallel ways.NEW & NOTEWORTHY Behavioral and neural responses to auditory stimuli are profoundly influenced by recent sounds, yet how this occurs is not known. Here, the authors show in the auditory cortex of awake mice that the quality of history-dependent effects is diverse and related to cell type, response latency, firing rates, and receptive field bandwidth. In a cortical model, differences in excitatory-inhibitory balance can produce this diversity, providing the cortex with multiple ways of representing temporally complex information.
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Affiliation(s)
- Elizabeth A K Phillips
- Coleman Memorial Laboratory, University of California, San Francisco, California.,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
| | - Christoph E Schreiner
- Coleman Memorial Laboratory, University of California, San Francisco, California.,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
| | - Andrea R Hasenstaub
- Coleman Memorial Laboratory, University of California, San Francisco, California; .,Neuroscience Graduate Program, University of California, San Francisco, California.,Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.,Center for Integrative Neuroscience, University of California, San Francisco, California; and.,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California
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77
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Effect of diazepam and yohimbine on neuronal activity in sham and hemiparkinsonian rats. Neuroscience 2017; 351:71-83. [DOI: 10.1016/j.neuroscience.2017.03.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/20/2017] [Accepted: 03/25/2017] [Indexed: 11/21/2022]
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78
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Bytautiene J, Baranauskas G. Rat superior colliculus neurons respond to large visual stimuli flashed outside the classical receptive field. PLoS One 2017; 12:e0174409. [PMID: 28379979 PMCID: PMC5381878 DOI: 10.1371/journal.pone.0174409] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 03/08/2017] [Indexed: 11/18/2022] Open
Abstract
Spatial integration of visual stimuli is a crucial step in visual information processing yet it is often unclear where this integration takes place in the visual system. In the superficial layers of the superior colliculus that form an early stage in visual information processing, neurons are known to have relatively small visual receptive fields, suggesting limited spatial integration. Here it is shown that at least for rats this conclusion may be wrong. Extracellular recordings in urethane-anaesthetized young adult rats (1.5–2 months old) showed that large stimuli of over 10° could evoke detectable responses well outside the borders of ‘classical’ receptive fields determined by employing 2° – 3.5° stimuli. The presence of responses to large stimuli well outside these ‘classical’ receptive fields could not be explained neither by partial overlap between the visual stimulus and the receptive field, nor by reflections or light dispersion from the stimulation site. However, very low frequency (<0.1 Hz) residual responses to small stimuli presented outside the receptive field may explain the obtained results if we assume that the frequency of action potentials during a response to a stimulus outside RF is proportional to the stimulus area. Thus, responses to large stimuli outside RF may be predicted by scaling according to the stimulus area of the responses to small stimuli. These data demonstrate that neurons in the superficial layers of the superior colliculus are capable of integrating visual stimuli over much larger area than it can be deduced from the classical receptive field.
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Affiliation(s)
- Juntaute Bytautiene
- Neurophysiology laboratory, Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Gytis Baranauskas
- Neurophysiology laboratory, Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
- * E-mail:
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79
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Kim JE, Kim IS, Kim K, Lim S, Kwon H, Kang CS, Ahn S, Yu KK, Lee YH. Development of a bio-magnetic measurement system and sensor configuration analysis for rats. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:044704. [PMID: 28456227 DOI: 10.1063/1.4979071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Magnetoencephalography (MEG) based on superconducting quantum interference devices enables the measurement of very weak magnetic fields (10-1000 fT) generated from the human or animal brain. In this article, we introduce a small MEG system that we developed specifically for use with rats. Our system has the following characteristics: (1) variable distance between the pick-up coil and outer Dewar bottom (∼5 mm), (2) small pick-up coil (4 mm) for high spatial resolution, (3) good field sensitivity (45∼ 80fT/cm/Hz), (4) the sensor interval satisfies the Nyquist spatial sampling theorem, and (5) small source localization error for the region to be investigated. To reduce source localization error, it is necessary to establish an optimal sensor layout. To this end, we simulated confidence volumes at each point on a grid on the surface of a virtual rat head. In this simulation, we used locally fitted spheres as model rat heads. This enabled us to consider more realistic volume currents. We constrained the model such that the dipoles could have only four possible orientations: the x- and y-axes from the original coordinates, and two tangentially layered dipoles (local x- and y-axes) in the locally fitted spheres. We considered the confidence volumes according to the sensor layout and dipole orientation and positions. We then conducted a preliminary test with a 4-channel MEG system prior to manufacturing the multi-channel system. Using the 4-channel MEG system, we measured rat magnetocardiograms. We obtained well defined P-, QRS-, and T-waves in rats with a maximum value of 15 pT/cm. Finally, we measured auditory evoked fields and steady state auditory evoked fields with maximum values 400 fT/cm and 250 fT/cm, respectively.
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Affiliation(s)
- Ji-Eun Kim
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - In-Seon Kim
- Center for Mass and Related Quantities, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Kiwoong Kim
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Sanghyun Lim
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Hyukchan Kwon
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Chan Seok Kang
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - San Ahn
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Kwon Kyu Yu
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
| | - Yong-Ho Lee
- Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), Daejeon, South Korea
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80
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Wu T, Grandjean J, Bosshard SC, Rudin M, Reutens D, Jiang T. Altered regional connectivity reflecting effects of different anaesthesia protocols in the mouse brain. Neuroimage 2017; 149:190-199. [PMID: 28159688 DOI: 10.1016/j.neuroimage.2017.01.074] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 01/17/2017] [Accepted: 01/30/2017] [Indexed: 01/19/2023] Open
Abstract
Studies in mice using resting-state functional magnetic resonance imaging (rs-fMRI) have provided opportunities to investigate the effects of pharmacological manipulations on brain function and map the phenotypes of mouse models of human brain disorders. Mouse rs-fMRI is typically performed under anaesthesia, which induces both regional suppression of brain activity and disruption of large-scale neural networks. Previous comparative studies using rodents investigating various drug effects on long-distance functional connectivity (FC) have reported agent-specific FC patterns, however, effects of regional suppression are sparsely explored. Here we examined changes in regional connectivity under six different anaesthesia conditions using mouse rs-fMRI with the goal of refining the framework of understanding the brain activation under anaesthesia at a local level. Regional homogeneity (ReHo) was used to map local synchronization in the brain, followed by analysis of several brain areas based on ReHo maps. The results revealed high local coherence in most brain areas. The primary somatosensory cortex and caudate-putamen showed agent-specific properties. Lower local coherence in the cingulate cortex was observed under medetomidine, particularly when compared to the combination of medetomidine and isoflurane. The thalamus was associated with retained local coherence across anaesthetic levels and multiple nuclei. These results show that anaesthesia induced by the investigated anaesthetics through different molecular targets promote agent-specific regional connectivity. In addition, ReHo is a data-driven method with minimum user interaction, easy to use and fast to compute. Given that examination of the brain at a local level is widely applied in human rs-fMRI studies, our results show its sensitivity to extract information on varied neuronal activity under six different regimens relevant to mouse functional imaging. These results, therefore, will inform future rs-fMRI studies on mice and the type of anaesthetic agent used, and will help to bridge observations between this burgeoning research field and ongoing human research across analytical scales.
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Affiliation(s)
- Tong Wu
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Joanes Grandjean
- Molecular Imaging and Functional Pharmacology, Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; Singapore BioImaging Consortium, Agency for Science, Technology and Research, Singapore
| | - Simone C Bosshard
- The Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Markus Rudin
- Molecular Imaging and Functional Pharmacology, Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - David Reutens
- The Centre for Advanced Imaging, The University of Queensland, Brisbane, Queensland, Australia
| | - Tianzi Jiang
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia; Brainnetome Centre, Institute of Automation, Chinese Academy of Sciences, Beijing, China; Key Laboratory for NeuroInformation of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 625014, China
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81
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Zhuang J, Gao X, Gao F, Xu F. Mu-opioid receptors in the caudomedial NTS are critical for respiratory responses to stimulation of bronchopulmonary C-fibers and carotid body in conscious rats. Respir Physiol Neurobiol 2017; 235:71-78. [DOI: 10.1016/j.resp.2016.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 10/06/2016] [Accepted: 10/09/2016] [Indexed: 01/08/2023]
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Carletti F, Gambino G, Rizzo V, Ferraro G, Sardo P. Involvement of TRPV1 channels in the activity of the cannabinoid WIN 55,212-2 in an acute rat model of temporal lobe epilepsy. Epilepsy Res 2016; 122:56-65. [PMID: 26970948 DOI: 10.1016/j.eplepsyres.2016.02.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/18/2016] [Accepted: 02/09/2016] [Indexed: 10/21/2022]
Abstract
The exogenous cannabinoid agonist WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN), has revealed to play a role on modulating the hyperexcitability phenomena in the hippocampus. Cannabinoid-mediated mechanisms of neuroprotection have recently been found to imply the modulation of transient receptor potential vanilloid 1 (TRPV1), a cationic channel subfamily that regulate synaptic excitation. In our study, we assessed the influence of pharmacological manipulation of TRPV1 function, alone and on WIN antiepileptic activity, in the Maximal Dentate Activation (MDA) acute model of temporal lobe epilepsy. Our results showed that the TRPV1 agonist, capsaicin, increased epileptic outcomes; whilst antagonizing TRPV1 with capsazepine exerts a protective role on paroxysmal discharge. When capsaicin is co-administered with WIN effective dose of 10mg/kg is able to reduce its antiepileptic strength, especially on the triggering of MDA response. Accordingly, capsazepine at the protective dose of 2mg/kg managed to potentiate WIN antiepileptic effects, when co-treated. Moreover, WIN subeffective dose of 5mg/kg was turned into effective when capsazepine comes into play. This evidence suggests that systemic administration of TRPV1-active drugs influences electrically induced epilepsy, with a noticeable protective activity for capsazepine. Furthermore, results from the pharmacological interaction with WIN support an interplay between cannabinoid and TRPV1 signaling that could represent a promising approach for a future pharmacological strategy to challenge hyperexcitability-based diseases.
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Affiliation(s)
- Fabio Carletti
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Giuditta Gambino
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Valerio Rizzo
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Giuseppe Ferraro
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
| | - Pierangelo Sardo
- Department of "Biomedicina Sperimentale e Neuroscienze Cliniche" (Bio.Ne.C.), "Sezione di Fisiologia umana G. Pagano", University of Palermo, Corso Tukory 129-90134 Palermo, Italy.
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83
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Chen TI, Chen MYC. Zinc Is Indispensable in Exercise-Induced Cardioprotection against Intermittent Hypoxia-Induced Left Ventricular Function Impairment in Rats. PLoS One 2016; 11:e0168600. [PMID: 27977796 PMCID: PMC5158066 DOI: 10.1371/journal.pone.0168600] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 12/03/2016] [Indexed: 01/19/2023] Open
Abstract
In obstructive sleep apnea (OSA), recurrent obstruction of the upper airway leads to intermittent hypoxia (IH) during sleep, which can result in impairment of cardiac function. Although exercise can have beneficial effects against IH-induced cardiac dysfunction, the mechanism remains unclear. This study aimed to investigate the interactions of zinc and exercise on IH-triggered left ventricular dysfunction in a rat model that mimics IH in OSA patients. Nine-week-old male Sprague-Dawley rats were randomly assigned to either a control group (CON) or to a group receiving 10 weeks of exercise training (EXE). During weeks 9 and 10, half the rats in each group were subjected to IH for 8 h per day for 14 days (IHCON, IHEXE), whereas the remainder continued to breathe room air. Rats within each of the CON, IHCON, EXE, and IHEXE groups were further randomly assigned to receive intraperitoneal injections of either zinc chloride, the zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), or injection vehicle only. IH induced a lower left ventricular fractional shortening, reduced ejection fraction, higher myocardial levels of inflammatory factors, increased levels oxidative stress, and lower levels of antioxidative capacity, all of which were abolished by zinc treatment. IHEXE rats exhibited higher levels of cardiac function and antioxidant capacity and lower levels of inflammatory factors and oxidative stress than IHCON rats; however, IHEXE rats receiving TPEN did not exhibit these better outcomes. In conclusion, zinc is required for protecting against IH-induced LV functional impairment and likely plays a critical role in exercise-induced cardioprotection by exerting a dual antioxidant and anti-inflammatory effect.
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Affiliation(s)
- Tsung-I Chen
- Center of Physical Education, Office of General and Basic Education, Tzu Chi University, Hualien, Taiwan
- * E-mail:
| | - Michael Yu-Chih Chen
- Department of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
- PhD Program in Institute of Medicine, Tzu Chi University, Hualien, Taiwan
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84
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The Effects of Urethane on Rat Outer Hair Cells. Neural Plast 2016; 2016:3512098. [PMID: 28050287 PMCID: PMC5165230 DOI: 10.1155/2016/3512098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 10/16/2016] [Indexed: 11/17/2022] Open
Abstract
The cochlea converts sound vibration into electrical impulses and amplifies the low-level sound signal. Urethane, a widely used anesthetic in animal research, has been shown to reduce the neural responses to auditory stimuli. However, the effects of urethane on cochlea, especially on the function of outer hair cells, remain largely unknown. In the present study, we compared the cochlear microphonic responses between awake and urethane-anesthetized rats. The results revealed that the amplitude of the cochlear microphonic was decreased by urethane, resulting in an increase in the threshold at all of the sound frequencies examined. To deduce the possible mechanism underlying the urethane-induced decrease in cochlear sensitivity, we examined the electrical response properties of isolated outer hair cells using whole-cell patch-clamp recording. We found that urethane hyperpolarizes the outer hair cell membrane potential in a dose-dependent manner and elicits larger outward current. This urethane-induced outward current was blocked by strychnine, an antagonist of the α9 subunit of the nicotinic acetylcholine receptor. Meanwhile, the function of the outer hair cell motor protein, prestin, was not affected. These results suggest that urethane anesthesia is expected to decrease the responses of outer hair cells, whereas the frequency selectivity of cochlea remains unchanged.
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85
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Sensory responses in the medial prefrontal cortex of anesthetized rats. Implications for sensory processing. Neuroscience 2016; 339:109-123. [DOI: 10.1016/j.neuroscience.2016.09.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 09/26/2016] [Accepted: 09/26/2016] [Indexed: 12/26/2022]
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86
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Sykes M, Matheson NA, Brownjohn PW, Tang AD, Rodger J, Shemmell JBH, Reynolds JNJ. Differences in Motor Evoked Potentials Induced in Rats by Transcranial Magnetic Stimulation under Two Separate Anesthetics: Implications for Plasticity Studies. Front Neural Circuits 2016; 10:80. [PMID: 27766073 PMCID: PMC5052269 DOI: 10.3389/fncir.2016.00080] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/26/2016] [Indexed: 11/25/2022] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is primarily used in humans to change the state of corticospinal excitability. To assess the efficacy of different rTMS stimulation protocols, motor evoked potentials (MEPs) are used as a readout due to their non-invasive nature. Stimulation of the motor cortex produces a response in a targeted muscle, and the amplitude of this twitch provides an indirect measure of the current state of the cortex. When applied to the motor cortex, rTMS can alter MEP amplitude, however, results are variable between participants and across studies. In addition, the mechanisms underlying any change and its locus are poorly understood. In order to better understand these effects, MEPs have been investigated in vivo in animal models, primarily in rats. One major difference in protocols between rats and humans is the use of general anesthesia in animal experiments. Anesthetics are known to affect plasticity-like mechanisms and so may contaminate the effects of an rTMS protocol. In the present study, we explored the effect of anesthetic on MEP amplitude, recorded before and after intermittent theta burst stimulation (iTBS), a patterned rTMS protocol with reported facilitatory effects. MEPs were assessed in the brachioradialis muscle of the upper forelimb under two anesthetics: a xylazine/zoletil combination and urethane. We found MEPs could be induced under both anesthetics, with no differences in the resting motor threshold or the average baseline amplitudes. However, MEPs were highly variable between animals under both anesthetics, with the xylazine/zoletil combination showing higher variability and most prominently a rise in amplitude across the baseline recording period. Interestingly, application of iTBS did not facilitate MEP amplitude under either anesthetic condition. Although it is important to underpin human application of TMS with mechanistic examination of effects in animals, caution must be taken when selecting an anesthetic and in interpreting results during prolonged TMS recording.
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Affiliation(s)
- Matthew Sykes
- Brain Health Research Centre and Brain Research New Zealand Centre of Research ExcellenceDunedin, New Zealand; Department of Anatomy, University of OtagoDunedin, New Zealand; Experimental and Regenerative Neuroscience, School of Animal Biology, University of Western AustraliaPerth, WA, Australia
| | - Natalie A Matheson
- Brain Health Research Centre and Brain Research New Zealand Centre of Research ExcellenceDunedin, New Zealand; Department of Anatomy, University of OtagoDunedin, New Zealand
| | - Philip W Brownjohn
- Brain Health Research Centre and Brain Research New Zealand Centre of Research ExcellenceDunedin, New Zealand; School of Physical Education, Sport and Exercise Sciences, University of OtagoDunedin, New Zealand
| | - Alexander D Tang
- Experimental and Regenerative Neuroscience, School of Animal Biology, University of Western Australia Perth, WA, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neuroscience, School of Animal Biology, University of Western Australia Perth, WA, Australia
| | - Jonathan B H Shemmell
- Brain Health Research Centre and Brain Research New Zealand Centre of Research ExcellenceDunedin, New Zealand; School of Physical Education, Sport and Exercise Sciences, University of OtagoDunedin, New Zealand
| | - John N J Reynolds
- Brain Health Research Centre and Brain Research New Zealand Centre of Research ExcellenceDunedin, New Zealand; Department of Anatomy, University of OtagoDunedin, New Zealand
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87
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Yanagawa Y, Osanai H, Tateno T. Transcranial flavoprotein-autofluorescence imaging of sound-evoked responses in the mouse auditory cortex under three types of anesthesia. Neurosci Lett 2016; 633:189-195. [PMID: 27641319 DOI: 10.1016/j.neulet.2016.09.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 09/09/2016] [Accepted: 09/14/2016] [Indexed: 11/26/2022]
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88
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Krause A, Nowak Z, Srbu R, Bell H. Respiratory autoresuscitation following severe acute hypoxemia in anesthetized adult rats. Respir Physiol Neurobiol 2016; 232:43-53. [DOI: 10.1016/j.resp.2016.06.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/28/2016] [Accepted: 06/30/2016] [Indexed: 01/16/2023]
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89
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Kim JS, Brown CH, Anderson GM. Anti-opioid Effects of RFRP-3 on Magnocellular Neuron Activity in Morphine-naïve and Morphine-treated Female Rats. Endocrinology 2016; 157:4003-4011. [PMID: 27533886 DOI: 10.1210/en.2016-1374] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neuropeptide FF receptors (NPFFR1 and NPFFR2) have been proposed to possess anti-opioid properties, and be involved in the development of opiate tolerance and dependence. However, there is no evidence to date supporting such opioid effects at the cellular level in vivo. Using in vivo electrophysiological recordings from vasopressin and oxytocin neurons in the supraoptic nucleus, we aimed to determine the effects of NPFFRs on opiate inhibition, tolerance, and dependence at a cellular level. Both vasopressin and oxytocin neurons are acutely inhibited by opioids and develop opiate tolerance. Oxytocin neurons also develop cellular opiate dependence and undergo withdrawal hyperexcitation upon cessation of opiate administration. Here, the classical μ-opioid receptor agonist, morphine robustly inhibited the spontaneous firing rate of vasopressin and oxytocin neurons, and this inhibition was attenuated by pretreatment with the NPFFR1 agonist, RFamide-related peptide-3. In rats infused with morphine for 6 d, vasopressin neurons were unresponsive to morphine, indicating the development of cellular tolerance, but pretreatment with the NPFFR antagonist, GJ14, restored acute morphine inhibition. In morphine-infused rats, RFamide related peptide-3 did not induce withdrawal excitation in oxytocin neurons and GJ14 did not reverse naloxone-precipitated withdrawal excitation. This is the first evidence of anti-opioid effects of the NPFFR system at a cellular level in vivo. Our results suggest that the anti-opioid properties of the NPFFR system reduce morphine sensitivity during tolerance but that it is not involved in dependence.
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Affiliation(s)
- Joon S Kim
- Centre for Neuroendocrinology and Departments of Anatomy (J.S.K., G.M.A.) and Physiology (C.H.B.), University of Otago, Dunedin 9054, New Zealand
| | - Colin H Brown
- Centre for Neuroendocrinology and Departments of Anatomy (J.S.K., G.M.A.) and Physiology (C.H.B.), University of Otago, Dunedin 9054, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology and Departments of Anatomy (J.S.K., G.M.A.) and Physiology (C.H.B.), University of Otago, Dunedin 9054, New Zealand
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90
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Cervera-Ferri A, Teruel-Martí V, Barceló-Molina M, Martínez-Ricós J, Luque-García A, Martínez-Bellver S, Adell A. Characterization of oscillatory changes in hippocampus and amygdala after deep brain stimulation of the infralimbic prefrontal cortex. Physiol Rep 2016; 4:4/14/e12854. [PMID: 27449812 PMCID: PMC4962070 DOI: 10.14814/phy2.12854] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 06/16/2016] [Indexed: 01/14/2023] Open
Abstract
Deep brain stimulation (DBS) is a new investigational therapy that has generated positive results in refractory depression. Although the neurochemical and behavioral effects of DBS have been examined, less attention has been paid to the influence of DBS on the network dynamics between different brain areas, which could contribute to its therapeutic effects. Herein, we set out to identify the effects of 1 h DBS in the infralimbic cortex (IL) on the oscillatory network dynamics between hippocampus and basolateral amygdala (BLA), two regions implicated in depression and its treatment. Urethane-anesthetized rats with bilaterally implanted electrodes in the IL were exposed to 1 h constant stimulation of 130 Hz of frequency, 60 μA of constant current intensity and biphasic pulse width of 80 μsec. After a period of baseline recording, local field potentials (LFP) were recorded with formvar-insulated stainless steel electrodes. DBS of the IL increased the power of slow wave (SW, <1.5 Hz) and theta (3-12 Hz) frequencies in the hippocampus and BLA Furthermore, IL DBS caused a precise coupling in different frequency bands between both brain structures. The increases in SW band synchronization in hippocampus and BLA after DBS suggest that these changes may be important for the improvement of depressive behavior. In addition, the augmentation in theta synchrony might contribute to improvement in emotional and cognitive processes.
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Affiliation(s)
- Ana Cervera-Ferri
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain
| | - Vicent Teruel-Martí
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain
| | - Moises Barceló-Molina
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain Instituto de Investigación Sanitaria La Fe, Valencia, 46026, Spain
| | - Joana Martínez-Ricós
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain
| | - Aina Luque-García
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain Instituto de Investigación Sanitaria La Fe, Valencia, 46026, Spain
| | - Sergio Martínez-Bellver
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embriology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain Department of Cell Biology and Parasitology, Faculty of Medicine and Odontology University of Valencia, Valencia, 46010, Spain
| | - Albert Adell
- Institute of Biomedicine and Biotechnology of Cantabria, IBBTEC (CSIC University of Cantabria), Santander, 39011, Spain
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91
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Lewis TL, Turi GF, Kwon SK, Losonczy A, Polleux F. Progressive Decrease of Mitochondrial Motility during Maturation of Cortical Axons In Vitro and In Vivo. Curr Biol 2016; 26:2602-2608. [PMID: 27641765 DOI: 10.1016/j.cub.2016.07.064] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 07/21/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
Abstract
The importance of mitochondria for neuronal function is evident by the large number of neurodegenerative diseases that have been associated with a disruption of mitochondrial function or transport (reviewed in [1, 2]). Mitochondria are essential for proper biological function as a result of their ability to produce ATP through oxidative phosphorylation, buffer cytoplasmic calcium, regulate lipid biosynthesis, and trigger apoptosis (reviewed in [2]). Efficient transport of mitochondria is thought to be particularly important in neurons in light of their compartmentalization, length of axonal processes, and high-energy requirements (reviewed in [3]). However, the majority of these results were obtained using short-term, in vitro neuronal culture models, and very little is currently known about mitochondrial dynamics in mature axons of the mammalian CNS in vitro or in vivo. Furthermore, recent evidence has demonstrated that mitochondrial immobilization at specific points along the axon, such as presynaptic boutons, play critical roles in axon morphogenesis [4, 5]. We report that as cortical axons mature, motility of mitochondria (but not other cargoes) is dramatically reduced and this coincides with increased localization to presynaptic sites. We also demonstrate using photo-conversion that in vitro mature axons display surprisingly limited long-range mitochondrial transport. Finally, using in vivo two-photon microscopy in anesthetized or awake-behaving mice, we document for the first time that mitochondrial motility is also remarkably low in distal cortical axons in vivo. These results argue that mitochondrial immobilization and presynaptic localization are important hallmarks of mature CNS axons both in vitro and in vivo.
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Affiliation(s)
- Tommy L Lewis
- Department of Neuroscience, Columbia University Medical Center, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, 550 West 120(th) Street, 1103 NWC Building, New York, NY 10027, USA
| | - Gergely F Turi
- Department of Neuroscience, Columbia University Medical Center, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, 550 West 120(th) Street, 1103 NWC Building, New York, NY 10027, USA
| | - Seok-Kyu Kwon
- Department of Neuroscience, Columbia University Medical Center, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, 550 West 120(th) Street, 1103 NWC Building, New York, NY 10027, USA
| | - Attila Losonczy
- Department of Neuroscience, Columbia University Medical Center, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, 550 West 120(th) Street, 1103 NWC Building, New York, NY 10027, USA
| | - Franck Polleux
- Department of Neuroscience, Columbia University Medical Center, Mortimer B. Zuckerman Mind Brain Behavior Institute, Kavli Institute for Brain Science, 550 West 120(th) Street, 1103 NWC Building, New York, NY 10027, USA.
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92
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Neural response differences in the rat primary auditory cortex under anesthesia with ketamine versus the mixture of medetomidine, midazolam and butorphanol. Hear Res 2016; 339:69-79. [DOI: 10.1016/j.heares.2016.06.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/08/2016] [Accepted: 06/15/2016] [Indexed: 11/18/2022]
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93
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Gersner R, Dhamne SC, Zangen A, Pascual-Leone A, Rotenberg A. Bursts of high-frequency repetitive transcranial magnetic stimulation (rTMS), together with lorazepam, suppress seizures in a rat kainate status epilepticus model. Epilepsy Behav 2016; 62:136-9. [PMID: 27467275 DOI: 10.1016/j.yebeh.2016.05.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/05/2016] [Accepted: 05/24/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND Status epilepticus (SE) is a condition of prolonged or recurrent and often drug-resistant seizures where nonsedating SE therapy remains an important unmet need. Repetitive transcranial magnetic stimulation (rTMS) is emerging as a means to suppress seizures but has not been extensively studied in models. OBJECTIVES We aimed to test the antiepileptic potential of high-frequency rTMS in SE. As a step toward eventual coupling of rTMS with antiepileptic pharmacotherapy, we also tested whether high-frequency rTMS in combination with a low (ineffective but less likely to cause a side effect) lorazepam dose is as effective as a full lorazepam dose in suppressing seizures in a rat SE model. METHODS EEG was recorded to measure epileptic spike frequency in the rat kainate SE model. Epileptic spikes were counted before, during, and after either high-frequency rTMS treatment alone or high-frequency rTMS treatment in combination with lorazepam, a firstline SE treatment. RESULTS We found that rTMS alone decreases epileptic spike frequency only acutely. However, combinatory treatment with half-dose lorazepam together with rTMS was as effective as a full lorazepam dose. CONCLUSION We report that high-frequency rTMS has modest antiepileptic potential alone but acts in complement with lorazepam to suppress seizures.
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Affiliation(s)
- Roman Gersner
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sameer C Dhamne
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Abraham Zangen
- Department of Life Sciences and the Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Alexander Rotenberg
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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94
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Marinho de Souza TK, E Silva-Gondim MB, Rodrigues MCA, Guedes RCA. The facilitating effect of unfavorable lactation on the potentiation of electrocorticogram after spreading depression in awake and anesthetized adult rats. Nutr Neurosci 2016; 21:16-24. [PMID: 27442245 DOI: 10.1080/1028415x.2016.1210878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVES Cortical spreading depression (CSD) is a brain excitability-related phenomenon that can be affected by unfavorable conditions of lactation and by anesthetic agents. We have previously demonstrated that after CSD the electrocorticogram (ECoG) amplitude increases significantly (ECoG potentiation). Here, we investigated this potentiation in awake and anesthetized adult rats that were previously suckled among different lactation conditions. METHODS Newborn rats were suckled in litters with 6 pups or 12 pups (L6 or L12 condition, respectively). At adulthood, we evaluated the ECoG potentiation after CSD at two cortical points (one point near, and another remote to the CSD-eliciting site). The amplitude of the ECoG waves was averaged with the support of an algorithm implemented in Matlab™ software. In both L6 and L12 condition, awake animals were compared with anesthetized groups that received either tribromoethanol- or urethane + chloralose-anesthesia. RESULTS L12 rats presented significantly lower body- and brain weights than L6 rats (P < 0.01), indicating a nutritional deficiency. The anesthetized L6 groups presented with ECoG potentiation (P < 0.05) only in the near cortical recording point (28.0% and 32.6% increase for the tribromoethanol and urethane + chloralose groups, respectively), whereas the L12 groups displayed ECoG potentiation in both near (67.0% and 55.0%) and remote points (37.0% and 20.0%), in comparison with the baseline values (before CSD). DISCUSSION The results suggest a facilitating effect of unfavorable lactation on the potentiation of ECoG after spreading depression in anesthetized adult rats. The potential implications for the human neurological health remain to be investigated.
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Affiliation(s)
| | | | | | - Rubem Carlos Araújo Guedes
- a Department of Nutrition , Universidade Federal de Pernambuco , BR-50670901 , Recife - Pernambuco , Brazil
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95
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Kohtala S, Theilmann W, Suomi T, Wigren HK, Porkka-Heiskanen T, Elo LL, Rokka A, Rantamäki T. Brief Isoflurane Anesthesia Produces Prominent Phosphoproteomic Changes in the Adult Mouse Hippocampus. ACS Chem Neurosci 2016; 7:749-56. [PMID: 27074656 DOI: 10.1021/acschemneuro.6b00002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Anesthetics are widely used in medical practice and experimental research, yet the neurobiological basis governing their effects remains obscure. We have here used quantitative phosphoproteomics to investigate the protein phosphorylation changes produced by a 30 min isoflurane anesthesia in the adult mouse hippocampus. Altogether 318 phosphorylation alterations in total of 237 proteins between sham and isoflurane anesthesia were identified. Many of the hit proteins represent primary pharmacological targets of anesthetics. However, findings also enlighten the role of several other proteins-implicated in various biological processes including neuronal excitability, brain energy homeostasis, synaptic plasticity and transmission, and microtubule function-as putative (secondary) targets of anesthetics. In particular, isoflurane increases glycogen synthase kinase-3β (GSK3β) phosphorylation at the inhibitory Ser(9) residue and regulates the phosphorylation of multiple proteins downstream and upstream of this promiscuous kinase that regulate diverse biological functions. Along with confirmatory Western blot data for GSK3β and p44/42-MAPK (mitogen-activated protein kinase; reduced phosphorylation of the activation loop), we observed increased phosphorylation of microtubule-associated protein 2 (MAP2) on residues (Thr(1620,1623)) that have been shown to render its dissociation from microtubules and alterations in microtubule stability. We further demonstrate that diverse anesthetics (sevoflurane, urethane, ketamine) produce essentially similar phosphorylation changes on GSK3β, p44/p42-MAPK, and MAP2 as observed with isoflurane. Altogether our study demonstrates the potential of quantitative phosphoproteomics to study the mechanisms of anesthetics (and other drugs) in the mammalian brain and reveals how already a relatively brief anesthesia produces pronounced phosphorylation changes in multiple proteins in the central nervous system.
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Affiliation(s)
| | | | - Tomi Suomi
- Turku
Centre for Biotechnology, University of Turku, FI-20014 Turku, Finland
| | - Henna-Kaisa Wigren
- Institute
of Biomedicine, University of Helsinki, FI-00014 Helsinki, Finland
| | | | - Laura L. Elo
- Turku
Centre for Biotechnology, University of Turku, FI-20014 Turku, Finland
| | - Anne Rokka
- Turku
Centre for Biotechnology, University of Turku, FI-20014 Turku, Finland
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96
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Potter LE, Paylor JW, Suh JS, Tenorio G, Caliaperumal J, Colbourne F, Baker G, Winship I, Kerr BJ. Altered excitatory-inhibitory balance within somatosensory cortex is associated with enhanced plasticity and pain sensitivity in a mouse model of multiple sclerosis. J Neuroinflammation 2016; 13:142. [PMID: 27282914 PMCID: PMC4901403 DOI: 10.1186/s12974-016-0609-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/01/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Chronic neuropathic pain is a common symptom of multiple sclerosis (MS). MOG35-55-induced experimental autoimmune encephalomyelitis (EAE) has been used as an animal model to investigate the mechanisms of pain in MS. Previous studies have implicated sensitization of spinal nociceptive networks in the pathogenesis of pain in EAE. However, the involvement of supraspinal sites of nociceptive integration, such as the primary somatosensory cortex (S1), has not been defined. We therefore examined functional, structural, and immunological alterations in S1 during the early stages of EAE, when pain behaviors first appear. We also assessed the effects of the antidepressant phenelzine (PLZ) on S1 alterations and nociceptive (mechanical) sensitivity in early EAE. PLZ has been shown to restore central nervous system (CNS) tissue concentrations of GABA and the monoamines (5-HT, NA) in EAE. We hypothesized that PLZ treatment would also normalize nociceptive sensitivity in EAE by restoring the balance of excitation and inhibition (E-I) in the CNS. METHODS We used in vivo flavoprotein autofluorescence imaging (FAI) to assess neural ensemble responses in S1 to vibrotactile stimulation of the limbs in early EAE. We also used immunohistochemistry (IHC), and Golgi-Cox staining, to examine synaptic changes and neuroinflammation in S1. Mechanical sensitivity was assessed at the clinical onset of EAE with Von Frey hairs. RESULTS Mice with early EAE exhibited significantly intensified and expanded FAI responses in S1 compared to controls. IHC revealed increased vesicular glutamate transporter (VGLUT1) expression and disrupted parvalbumin+ (PV+) interneuron connectivity in S1 of EAE mice. Furthermore, peri-neuronal nets (PNNs) were significantly reduced in S1. Morphological analysis of excitatory neurons in S1 revealed increased dendritic spine densities. Iba-1+ cortical microglia were significantly elevated early in the disease. Chronic PLZ treatment was found to normalize mechanical thresholds in EAE. PLZ also normalized S1 FAI responses, neuronal morphologies, and cortical microglia numbers and attenuated VGLUT1 reactivity-but did not significantly attenuate the loss of PNNs. CONCLUSIONS These findings implicate a pro-excitatory shift in the E-I balance of the somatosensory CNS, arising early in the pathogenesis EAE and leading to large-scale functional and structural plasticity in S1. They also suggest a novel antinociceptive effect of PLZ treatment.
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Affiliation(s)
- Liam E Potter
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 8-120, Edmonton, AB, T6G 2G3, Canada
| | - John W Paylor
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Psychiatry (NRU), University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Jee Su Suh
- Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 8-120, Edmonton, AB, T6G 2G3, Canada
| | - Gustavo Tenorio
- Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 8-120, Edmonton, AB, T6G 2G3, Canada
| | - Jayalakshmi Caliaperumal
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Psychology, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Fred Colbourne
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Psychology, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Glen Baker
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Psychiatry (NRU), University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Ian Winship
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada.,Department of Psychiatry (NRU), University of Alberta, Edmonton, AB, T6G 2B7, Canada
| | - Bradley J Kerr
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada. .,Department of Pharmacology, University of Alberta, Edmonton, AB, T6E 2H7, Canada. .,Department of Anesthesiology and Pain Medicine, University of Alberta, Clinical Sciences Building, 8-120, Edmonton, AB, T6G 2G3, Canada.
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97
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Duque D, Wang X, Nieto-Diego J, Krumbholz K, Malmierca MS. Neurons in the inferior colliculus of the rat show stimulus-specific adaptation for frequency, but not for intensity. Sci Rep 2016; 6:24114. [PMID: 27066835 PMCID: PMC4828641 DOI: 10.1038/srep24114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 03/21/2016] [Indexed: 11/09/2022] Open
Abstract
Electrophysiological and psychophysical responses to a low-intensity probe sound tend to be suppressed by a preceding high-intensity adaptor sound. Nevertheless, rare low-intensity deviant sounds presented among frequent high-intensity standard sounds in an intensity oddball paradigm can elicit an electroencephalographic mismatch negativity (MMN) response. This has been taken to suggest that the MMN is a correlate of true change or “deviance” detection. A key question is where in the ascending auditory pathway true deviance sensitivity first emerges. Here, we addressed this question by measuring low-intensity deviant responses from single units in the inferior colliculus (IC) of anesthetized rats. If the IC exhibits true deviance sensitivity to intensity, IC neurons should show enhanced responses to low-intensity deviant sounds presented among high-intensity standards. Contrary to this prediction, deviant responses were only enhanced when the standards and deviants differed in frequency. The results could be explained with a model assuming that IC neurons integrate over multiple frequency-tuned channels and that adaptation occurs within each channel independently. We used an adaptation paradigm with multiple repeated adaptors to measure the tuning widths of these adaption channels in relation to the neurons’ overall tuning widths.
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Affiliation(s)
- Daniel Duque
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca 37007, Spain
| | - Xin Wang
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca 37007, Spain
| | - Javier Nieto-Diego
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca 37007, Spain
| | - Katrin Krumbholz
- MRC Institute of Hearing Research, University Park, Nottingham, NG7 2RD, UK
| | - Manuel S Malmierca
- Auditory Neuroscience Laboratory, Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca 37007, Spain.,Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.,Salamanca Institute for Biomedical Research (IBSAL), Salamanca, Spain
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98
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Slack R, Boorman L, Patel P, Harris S, Bruyns-Haylett M, Kennerley A, Jones M, Berwick J. A novel method for classifying cortical state to identify the accompanying changes in cerebral hemodynamics. J Neurosci Methods 2016; 267:21-34. [PMID: 27063501 PMCID: PMC4896992 DOI: 10.1016/j.jneumeth.2016.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 03/29/2016] [Accepted: 04/06/2016] [Indexed: 11/27/2022]
Abstract
We classified brain state using a vector-based categorisation of neural frequencies. Changes in cerebral blood volume (CBV) were observed when brain state altered. During these state alterations, changes in blood oxygenation were also found. State dependent haemodynamic changes could affect blood based brain imaging.
Background Many brain imaging techniques interpret the haemodynamic response as an indirect indicator of underlying neural activity. However, a challenge when interpreting this blood based signal is how changes in brain state may affect both baseline and stimulus evoked haemodynamics. New method We developed an Automatic Brain State Classifier (ABSC), validated on data from anaesthetised rodents. It uses vectorised information obtained from the windowed spectral frequency power of the Local Field Potential. Current state is then classified by comparing this vectorised information against that calculated from state specific training datasets. Results The ABSC identified two user defined brain states (synchronised and desynchronised), with high accuracy (∼90%). Baseline haemodynamics were found to be significantly different in the two identified states. During state defined periods of elevated baseline haemodynamics we found significant decreases in evoked haemodynamic responses to somatosensory stimuli. Comparison to existing methods State classification – The ABSC (∼90%) demonstrated greater accuracy than clustering (∼66%) or ‘power threshold’ (∼64%) methods of comparison. Haemodynamic averaging – Our novel approach of selectively averaging stimulus evoked haemodynamic trials by brain state yields higher quality data than creating a single average from all trials. Conclusions The ABSC can account for some of the commonly observed trial-to-trial variability in haemodynamic responses which arises from changes in cortical state. This variability might otherwise be incorrectly attributed to alternative interpretations. A greater understanding of the effects of cortical state on haemodynamic changes could be used to inform techniques such as general linear modelling (GLM), commonly used in fMRI.
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Affiliation(s)
- R Slack
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - L Boorman
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - P Patel
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - S Harris
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - M Bruyns-Haylett
- Department of Systems Engineering, University of Reading, Whiteknights, Reading RG6 6AY, United Kingdom.
| | - A Kennerley
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - M Jones
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
| | - J Berwick
- Department of Psychology, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom.
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99
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Lu H, Yang B, Jaeger D. Cerebellar Nuclei Neurons Show Only Small Excitatory Responses to Optogenetic Olivary Stimulation in Transgenic Mice: In Vivo and In Vitro Studies. Front Neural Circuits 2016; 10:21. [PMID: 27047344 PMCID: PMC4805604 DOI: 10.3389/fncir.2016.00021] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/09/2016] [Indexed: 11/13/2022] Open
Abstract
To study the olivary input to the cerebellar nuclei (CN) we used optogenetic stimulation in transgenic mice expressing channelrhodopsin-2 (ChR2) in olivary neurons. We obtained in vivo extracellular Purkinje cell (PC) and CN recordings in anesthetized mice while stimulating the contralateral inferior olive (IO) with a blue laser (single pulse, 10-50 ms duration). Peri-stimulus histograms (PSTHs) were constructed to show the spike rate changes after optical stimulation. Among 29 CN neurons recorded, 15 showed a decrease in spike rate of variable strength and duration, and only 1 showed a transient spiking response. These results suggest that direct olivary input to CN neurons is usually overridden by stronger PC inhibition triggered by climbing fiber responses. To further investigate the direct input from the climbing fiber collaterals we also conducted whole cell recordings in brain slices, where we used local stimulation with blue light. Due to the expression of ChR2 in PC axons as well as the IO in our transgenic line, strong inhibitory responses could be readily triggered with optical stimulation (13 of 15 neurons). After blocking this inhibition with GABAzine, only in 5 of 13 CN neurons weak excitatory responses were revealed. Therefore our in vitro results support the in vivo findings that the excitatory input to CN neurons from climbing fiber collaterals in adult mice is masked by the inhibition under normal conditions.
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Affiliation(s)
- Huo Lu
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine-Georgia CampusSuwannee, GA, USA; Department of Biology, Emory UniversityAtlanta, GA, USA
| | - Bo Yang
- Department of Biology, Emory University Atlanta, GA, USA
| | - Dieter Jaeger
- Department of Biology, Emory University Atlanta, GA, USA
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100
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Topographic Distribution of Stimulus-Specific Adaptation across Auditory Cortical Fields in the Anesthetized Rat. PLoS Biol 2016; 14:e1002397. [PMID: 26950883 PMCID: PMC4780834 DOI: 10.1371/journal.pbio.1002397] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 02/01/2016] [Indexed: 01/06/2023] Open
Abstract
Stimulus-specific adaptation (SSA) in single neurons of the auditory cortex was suggested to be a potential neural correlate of the mismatch negativity (MMN), a widely studied component of the auditory event-related potentials (ERP) that is elicited by changes in the auditory environment. However, several aspects on this SSA/MMN relation remain unresolved. SSA occurs in the primary auditory cortex (A1), but detailed studies on SSA beyond A1 are lacking. To study the topographic organization of SSA, we mapped the whole rat auditory cortex with multiunit activity recordings, using an oddball paradigm. We demonstrate that SSA occurs outside A1 and differs between primary and nonprimary cortical fields. In particular, SSA is much stronger and develops faster in the nonprimary than in the primary fields, paralleling the organization of subcortical SSA. Importantly, strong SSA is present in the nonprimary auditory cortex within the latency range of the MMN in the rat and correlates with an MMN-like difference wave in the simultaneously recorded local field potentials (LFP). We present new and strong evidence linking SSA at the cellular level to the MMN, a central tool in cognitive and clinical neuroscience. This study of higher-order auditory cortex strengthens the case for long-latency stimulus-specific adaptation as a genuine neural correlate of the mismatch negativity, which flags salient stimuli. Sensory systems automatically detect salient events in a monotonous ambient background. In humans, this change detection process is indexed by the mismatch negativity (MMN), a mid-late component of the auditory-evoked potentials that has become a central tool in cognitive and clinical neuroscience over the last 40 years. However, the neuronal correlate of MMN remains controversial. Stimulus-specific adaptation (SSA) is a special type of adaptation recorded at the neuronal level in the auditory pathway. Attenuating the response only to repetitive, background stimuli is a very efficient mechanism to enhance the saliency of any upcoming deviant or novel stimulus. Thus, SSA was originally proposed as a neural correlate of the MMN, but previous studies in the auditory cortex reported SSA only at very early latencies (circa 20–30 ms) and only within the primary auditory cortex (A1), whereas MMN analogs in the rat occur later, between 50 and 100 ms after change onset, and are generated mainly within nonprimary fields. Here, we report very strong SSA in nonprimary fields within the latency range of the MMN in the rat, providing empirical evidence of the missing link between single neuron response studies in animal models and the human MMN.
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