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Landvater J, Kim S, Caswell K, Kwon C, Odafe E, Roe G, Tripathi A, Vukovics C, Wang J, Ryan K, Cocozza V, Brock M, Tchopev Z, Tonkin B, Capaldi V, Collen J, Creamer J, Irfan M, Wickwire E, Williams S, Werner JK. Traumatic brain injury and sleep in military and veteran populations: A literature review. NeuroRehabilitation 2024:NRE230380. [PMID: 39121144 DOI: 10.3233/nre-230380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2024]
Abstract
BACKGROUND Traumatic brain injury (TBI) is a hallmark of wartime injury and is related to numerous sleep wake disorders (SWD), which persist long term in veterans. Current knowledge gaps in pathophysiology have hindered advances in diagnosis and treatment. OBJECTIVE We reviewed TBI SWD pathophysiology, comorbidities, diagnosis and treatment that have emerged over the past two decades. METHODS We conducted a literature review of English language publications evaluating sleep disorders (obstructive sleep apnea, insomnia, hypersomnia, parasomnias, restless legs syndrome and periodic limb movement disorder) and TBI published since 2000. We excluded studies that were not specifically evaluating TBI populations. RESULTS Highlighted areas of interest and knowledge gaps were identified in TBI pathophysiology and mechanisms of sleep disruption, a comparison of TBI SWD and post-traumatic stress disorder SWD. The role of TBI and glymphatic biomarkers and management strategies for TBI SWD will also be discussed. CONCLUSION Our understanding of the pathophysiologic underpinnings of TBI and sleep health, particularly at the basic science level, is limited. Developing an understanding of biomarkers, neuroimaging, and mixed-methods research in comorbid TBI SWD holds the greatest promise to advance our ability to diagnose and monitor response to therapy in this vulnerable population.
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Affiliation(s)
- Jeremy Landvater
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Sharon Kim
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Keenan Caswell
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Caroline Kwon
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Emamoke Odafe
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Grace Roe
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Ananya Tripathi
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | | | - Johnathan Wang
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Keith Ryan
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Victoria Cocozza
- Wilford Hall Ambulatory Surgical Center Center, San Antonio, TX, USA
| | - Matthew Brock
- Wilford Hall Ambulatory Surgical Center Center, San Antonio, TX, USA
| | - Zahari Tchopev
- Wilford Hall Ambulatory Surgical Center Center, San Antonio, TX, USA
| | - Brionn Tonkin
- University of Minnesota, Minneapolis, MN, USA
- Minneapolis Veterans Administration Medical Center, Minneapolis, MN, USA
| | - Vincent Capaldi
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Jacob Collen
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | | | - Muna Irfan
- University of Minnesota, Minneapolis, MN, USA
- Minneapolis Veterans Administration Medical Center, Minneapolis, MN, USA
| | - Emerson Wickwire
- Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Scott Williams
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Defense Health Headquarters, Falls Church, VA, USA
| | - J Kent Werner
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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McKenzie S, Sommer AL, Pimentel I, Kakani M, Choi IJ, Newman EL, English DF. Event boundaries drive norepinephrine release and distinctive neural representations of space in the rodent hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.30.605900. [PMID: 39131365 PMCID: PMC11312532 DOI: 10.1101/2024.07.30.605900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
Episodic memories are temporally segmented around event boundaries that tend to coincide with moments of environmental change. During these times, the state of the brain should change rapidly, or reset, to ensure that the information encountered before and after an event boundary is encoded in different neuronal populations. Norepinephrine (NE) is thought to facilitate this network reorganization. However, it is unknown whether event boundaries drive NE release in the hippocampus and, if so, how NE release relates to changes in hippocampal firing patterns. The advent of the new GRAB NE sensor now allows for the measurement of NE binding with sub-second resolution. Using this tool in mice, we tested whether NE is released into the dorsal hippocampus during event boundaries defined by unexpected transitions between spatial contexts and presentations of novel objections. We found that NE binding dynamics were well explained by the time elapsed after each of these environmental changes, and were not related to conditioned behaviors, exploratory bouts of movement, or reward. Familiarity with a spatial context accelerated the rate in which phasic NE binding decayed to baseline. Knowing when NE is elevated, we tested how hippocampal coding of space differs during these moments. Immediately after context transitions we observed relatively unique patterns of neural spiking which settled into a modal state at a similar rate in which NE returned to baseline. These results are consistent with a model wherein NE release drives hippocampal representations away from a steady-state attractor. We hypothesize that the distinctive neural codes observed after each event boundary may facilitate long-term memory and contribute to the neural basis for the primacy effect.
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Chen L, Deng Z, Asamoah B, Laughlin MM. Trigeminal nerve direct current stimulation causes sustained increase in neural activity in the rat hippocampus. Brain Stimul 2024; 17:648-659. [PMID: 38740183 DOI: 10.1016/j.brs.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/02/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024] Open
Abstract
BACKGROUND Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation method that can modulate many brain functions including learning and memory. Recent evidence suggests that tDCS memory effects may be caused by co-stimulation of scalp nerves such as the trigeminal nerve (TN), and not the electric field in the brain. The TN gives input to brainstem nuclei, including the locus coeruleus that controls noradrenaline release across brain regions, including hippocampus. However, the effects of TN direct current stimulation (TN-DCS) are currently not well understood. HYPOTHESIS In this study we tested the hypothesis that stimulation of the trigeminal nerve with direct current manipulates hippocampal activity via an LC pathway. METHODS We recorded neural activity in rat hippocampus using multichannel silicon probes. We applied 3 min of 0.25 mA or 1 mA TN-DCS, monitored hippocampal activity for up to 1 h and calculated spikes-rate and spike-field coherence metrics. Subcutaneous injections of xylocaine were used to block TN, while intraperitoneal and intracerebral injection of clonidine were used to block the LC pathway. RESULTS We found that 1 mA TN-DCS caused a significant increase in hippocampal spike-rate lasting 45 min in addition to significant changes in spike-field coherence, while 0.25 mA TN-DCS did not. TN blockage prevented spike-rate increases, confirming effects were not caused by the electric field in the brain. When 1 mA TN-DCS was delivered during clonidine blockage no increase in spike-rate was observed, suggesting an important role for the LC-noradrenergic pathway. CONCLUSION These results support our hypothesis and provide a neural basis to understand the tDCS TN co-stimulation mechanism. TN-DCS emerges as an important tool to potentially modulate learning and memory.
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Affiliation(s)
- Liyi Chen
- Exp ORL, Department of Neurosciences, The Leuven Brain Institute, KU Leuven, Belgium
| | - Zhengdao Deng
- Experimental Neurosurgery and Neuroanatomy, Department of Neurosciences, KU Leuven, Belgium
| | - Boateng Asamoah
- Exp ORL, Department of Neurosciences, The Leuven Brain Institute, KU Leuven, Belgium
| | - Myles Mc Laughlin
- Exp ORL, Department of Neurosciences, The Leuven Brain Institute, KU Leuven, Belgium.
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Rohner VL, Lamothe-Molina PJ, Patriarchi T. Engineering, applications, and future perspectives of GPCR-based genetically encoded fluorescent indicators for neuromodulators. J Neurochem 2024; 168:163-184. [PMID: 38288673 DOI: 10.1111/jnc.16045] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 02/23/2024]
Abstract
This review explores the evolving landscape of G-protein-coupled receptor (GPCR)-based genetically encoded fluorescent indicators (GEFIs), with a focus on their development, structural components, engineering strategies, and applications. We highlight the unique features of this indicator class, emphasizing the importance of both the sensing domain (GPCR structure and activation mechanism) and the reporting domain (circularly permuted fluorescent protein (cpFP) structure and fluorescence modulation). Further, we discuss indicator engineering approaches, including the selection of suitable cpFPs and expression systems. Additionally, we showcase the diversity and flexibility of their application by presenting a summary of studies where such indicators were used. Along with all the advantages, we also focus on the current limitations as well as common misconceptions that arise when using these indicators. Finally, we discuss future directions in indicator engineering, including strategies for screening with increased throughput, optimization of the ligand-binding properties, structural insights, and spectral diversity.
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Affiliation(s)
- Valentin Lu Rohner
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | | | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
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5
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Wiesman AI, Madge V, Fon EA, Dagher A, Collins DL, Baillet S. Associations between neuromelanin depletion and cortical rhythmic activity in Parkinson's disease. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.02.16.24302958. [PMID: 38405952 PMCID: PMC10889029 DOI: 10.1101/2024.02.16.24302958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Background and Objectives Parkinson's disease (PD) is marked by the death of neuromelanin-rich dopaminergic and noradrenergic cells in the substantia nigra (SN) and the locus coeruleus (LC), respectively, resulting in motor and cognitive impairments. While SN dopamine dysfunction has clear neurophysiological effects, the impact of reduced LC norepinephrine signaling on brain activity in PD remains to be established. Methods We used neuromelanin-sensitive T1-weighted MRI (NPD = 58; NHC = 27) and task-free magnetoencephalography (NPD = 58; NHC = 65) to identify neuropathophysiological factors related to the degeneration of the LC and SN in patients with PD. Results We found pathological increases in rhythmic alpha (8 - 12 Hz) activity in patients with decreased LC neuromelanin, with a stronger association in patients with worse attentional impairments. This negative alpha-LC neuromelanin relationship is also stronger in fronto-motor cortices, which are regions with high densities of norepinephrine transporters in the healthy brain, and where alpha activity is negatively related to attention scores. These observations support a noradrenergic association between LC integrity and alpha band activity. Our data also show that rhythmic beta (15 - 29 Hz) activity in the left somato-motor cortex decreases with lower levels of SN neuromelanin; the same regions where beta activity reflects axial motor symptoms. Discussion Together, our findings clarify the association of well-documented alterations of rhythmic neurophysiology in PD with cortical and subcortical neurochemical systems. Specifically, attention-related alpha activity reflects dysfunction of the noradrenergic system, and beta activity with relevance to motor impairments reflects dopaminergic dysfunction.
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Affiliation(s)
- Alex I. Wiesman
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Victoria Madge
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Edward A. Fon
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Alain Dagher
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - D Louis Collins
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Sylvain Baillet
- Montreal Neurological Institute, McGill University, Montreal, Canada
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6
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Hodes GE, Bangasser D, Sotiropoulos I, Kokras N, Dalla C. Sex Differences in Stress Response: Classical Mechanisms and Beyond. Curr Neuropharmacol 2024; 22:475-494. [PMID: 37855285 PMCID: PMC10845083 DOI: 10.2174/1570159x22666231005090134] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/28/2023] [Accepted: 08/09/2023] [Indexed: 10/20/2023] Open
Abstract
Neuropsychiatric disorders, which are associated with stress hormone dysregulation, occur at different rates in men and women. Moreover, nowadays, preclinical and clinical evidence demonstrates that sex and gender can lead to differences in stress responses that predispose males and females to different expressions of similar pathologies. In this curated review, we focus on what is known about sex differences in classic mechanisms of stress response, such as glucocorticoid hormones and corticotrophin-releasing factor (CRF), which are components of the hypothalamicpituitary- adrenal (HPA) axis. Then, we present sex differences in neurotransmitter levels, such as serotonin, dopamine, glutamate and GABA, as well as indices of neurodegeneration, such as amyloid β and Tau. Gonadal hormone effects, such as estrogens and testosterone, are also discussed throughout the review. We also review in detail preclinical data investigating sex differences caused by recentlyrecognized regulators of stress and disease, such as the immune system, genetic and epigenetic mechanisms, as well neurosteroids. Finally, we discuss how understanding sex differences in stress responses, as well as in pharmacology, can be leveraged into novel, more efficacious therapeutics for all. Based on the supporting evidence, it is obvious that incorporating sex as a biological variable into preclinical research is imperative for the understanding and treatment of stress-related neuropsychiatric disorders, such as depression, anxiety and Alzheimer's disease.
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Affiliation(s)
| | - Debra Bangasser
- Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA, USA
| | - Ioannis Sotiropoulos
- Institute of Biosciences & Applications NCSR “Demokritos”, Athens, Greece
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Nikolaos Kokras
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- First Department of Psychiatry, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Christina Dalla
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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7
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Chen L, Deng Z, Asamoah B, Laughlin MM. Trigeminal nerve direct current stimulation causes sustained increase in neural activity in the rat hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.571341. [PMID: 38168241 PMCID: PMC10760027 DOI: 10.1101/2023.12.12.571341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation method that can modulate many brain functions including learning and memory. Recent evidence suggests that tDCS memory effects may be caused by co-stimulation of scalp nerves such as the trigeminal nerve (TN), and not the electric field in the brain. The TN gives input to brainstem nuclei, including the locus coeruleus that controls noradrenaline release across brain regions, including hippocampus. However, the effects of TN direct current stimulation (TN-DCS) are currently not well understood. In this study we hypothesized that TN-DCS manipulates hippocampal activity via an LC-noradrenergic bottom-up pathway. We recorded neural activity in rat hippocampus using multichannel silicon probes. We applied 3 minutes of 0.25 mA or 1 mA TN-DCS, monitored hippocampal activity for up to 1 hour and calculated spikes-rate and spike-field coherence metrics. Subcutaneous injections of xylocaine were used to block TN and intraperitoneal injection of clonidine to block the LC pathway. We found that 1 mA TN-DCS caused a significant increase in hippocampal spike-rate lasting 45 minutes in addition to significant changes in spike-field coherence, while 0.25 mA TN-DCS did not. TN blockage prevented spike-rate increases, confirming effects were not caused by the electric field in the brain. When 1 mA TN-DCS was delivered during clonidine blockage no increase in spike-rate was observed, suggesting an important role for the LC-noradrenergic pathway. These results provide a neural basis to support a tDCS TN co-stimulation mechanism. TN-DCS emerges as an important tool to potentially modulate learning and memory. Highlights Trigeminal nerve direct current stimulation (TN-DCS) boosts hippocampal spike ratesTN-DCS alters spike-field coherence in theta and gamma bands across the hippocampus.Blockade experiments indicate that TN-DCS modulated hippocampal activity via the LC-noradrenergic pathway.TN-DCS emerges as a potential tool for memory manipulation. Figure Graphic Abstract
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Kumagai S, Shiramatsu TI, Matsumura A, Ishishita Y, Ibayashi K, Onuki Y, Kawai K, Takahashi H. Frequency-specific modulation of oscillatory activity in the rat auditory cortex by vagus nerve stimulation. Brain Stimul 2023; 16:1476-1485. [PMID: 37777110 DOI: 10.1016/j.brs.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 09/21/2023] [Accepted: 09/21/2023] [Indexed: 10/02/2023] Open
Abstract
BACKGROUND We previously found that vagus nerve stimulation (VNS) strengthened stimulus-evoked activity in the superficial layer of the sensory cortex but not in the deep layer, suggesting that VNS altered the balance between the feedforward (FF) and feedback (FB) pathways. Band-specific oscillatory activities in the cortex could serve as an index of the FF-FB balance, but whether VNS affects cortical oscillations along sensory pathways through neuromodulators remains unclear. HYPOTHESIS VNS modulates the FF-FB balance through the cholinergic and noradrenergic systems, which modulate stimulus gain in the cortex. METHODS We investigated the effects of VNS using electrocorticography in the auditory cortex of 34 Wistar rats under general anesthesia while presenting click stimuli. In the time-frequency analyses, the putative modulation of the FF and FB pathways was estimated using high- and low-frequency power. We assessed, using analysis of variance, how VNS modulates auditory-evoked activities and how the modulation changes with cholinergic and noradrenergic antagonists. RESULTS VNS increased auditory cortical evoked potentials, consistent with results of our previous work. Furthermore, VNS increased auditory-evoked gamma and beta powers and decreased theta power. Local administration of cholinergic antagonists in the auditory cortex selectively disrupted the VNS-induced increase in gamma and beta power, while noradrenergic antagonists disrupted the decrease in theta power. CONCLUSIONS VNS might strengthen the FF pathway through the cholinergic system and attenuate the FB pathway through the noradrenergic system in the auditory cortex. Cortical gain modulation through the VNS-induced neuromodulatory system provides new mechanistic insights into the effect of VNS on auditory processing.
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Affiliation(s)
- Shinichi Kumagai
- Department of Neurosurgery, Jichi Medical University, Tochigi, Japan; Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Tomoyo Isoguchi Shiramatsu
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Akane Matsumura
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Yohei Ishishita
- Department of Neurosurgery, Jichi Medical University, Tochigi, Japan
| | - Kenji Ibayashi
- Department of Neurosurgery, Jichi Medical University, Tochigi, Japan
| | - Yoshiyuki Onuki
- Department of Neurosurgery, Jichi Medical University, Tochigi, Japan
| | - Kensuke Kawai
- Department of Neurosurgery, Jichi Medical University, Tochigi, Japan
| | - Hirokazu Takahashi
- Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan.
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9
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Arulchelvan E, Vanneste S. Promising neurostimulation routes for targeting the hippocampus to improve episodic memory: A review. Brain Res 2023:148457. [PMID: 37315722 DOI: 10.1016/j.brainres.2023.148457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023]
Abstract
This review aims to highlight modern neurostimulation approaches that are effectively activating the hippocampus and enhancing episodic memory performance. The hippocampus is a brain region known to play an essential role in episodic memory processes. However, as it is nestled deep within the brain, it has been a challenging target for traditional neurostimulation approaches, with studies reporting inconsistent memory effects. Recent studies suggest more than half of the electrical current from non-invasive transcranial electrical stimulation (tES) methods may be attenuated by the human scalp, skull, and cerebral spinal fluid. Thus, this review aims to highlight novel neurostimulation approaches that are showing promise as alternative routes for activating hippocampal circuitry. Early evidence suggests temporal interference, closed-loop and individualized protocols, sensory stimulation and peripheral nerve-targeted tES protocols warrant further investigation. These approaches each provide promising routes for activating the hippocampus by a) increasing its functional connectiveness to key brain regions, b) strengthening synaptic plasticity mechanisms, or c) enhancing neural entrainment specifically within and between theta and gamma frequencies in these regions. Importantly, these three functional mechanisms and the hippocampus' structural integrity are negatively impacted throughout the progression of Alzheimer's Disease, with episodic memory deficits likewise evident in early stages. Consequently, depending on further validation of the approaches reviewed here, these techniques could offer significant applied therapeutic value for patients suffering from memory deficits or neurodegenerative diseases including amnestic Mild Cognitive Impairment or Alzheimer's disease.
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Affiliation(s)
- Elva Arulchelvan
- Lab for Clinical and Integrative Neuroscience, Trinity Institute for Neuroscience, School of Psychology, Trinity College Dublin, Ireland
| | - Sven Vanneste
- Global Brain Health Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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10
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Kuo CC, Chan H, Hung WC, Chen RF, Yang HW, Min MY. Carbachol increases locus coeruleus activation by targeting noradrenergic neurons, inhibitory interneurons and inhibitory synaptic transmission. Eur J Neurosci 2023; 57:32-53. [PMID: 36382388 DOI: 10.1111/ejn.15866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/11/2022] [Accepted: 11/10/2022] [Indexed: 11/18/2022]
Abstract
The locus coeruleus (LC) consists of noradrenergic (NA) neurons and plays an important role in controlling behaviours. Although much of the knowledge regarding LC functions comes from studying behavioural outcomes upon administration of muscarinic acetylcholine receptor (mAChR) agonists into the nucleus, the exact mechanisms remain unclear. Here, we report that the application of carbachol (CCh), an mAChR agonist, increased the spontaneous action potentials (sAPs) of both LC-NA neurons and local inhibitory interneurons (LC I-INs) in acute brain slices by activating M1/M3 mAChRs (m1/3 AChRs). Optogenetic activation of LC I-INs evoked inhibitory postsynaptic currents (IPSCs) in LC-NA neurons that were mediated by γ-aminobutyric acid type A (GABAA ) and glycine receptors, and CCh application decreased the IPSC amplitude through a presynaptic mechanism by activating M4 mAChRs (m4 AChRs). LC-NA neurons also exhibited spontaneous phasic-like activity (sPLA); CCh application increased the incidence of this activity. This effect of CCh application was not observed with blockade of GABAA and glycine receptors, suggesting that the sPLA enhancement occurred likely because of the decreased synaptic transmission of LC I-INs onto LC-NA neurons by the m4 AChR activation and/or increased spiking rate of LC I-INs by the m1/3 AChR activation, which could lead to fatigue of the synaptic transmission. In conclusion, we report that CCh application, while inhibiting their synaptic transmission, increases sAP rates of LC-NA neurons and LC I-INs. Collectively, these effects provide insight into the cellular mechanisms underlying the behaviour modulations following the administration of muscarinic receptor agonists into the LC reported by the previous studies.
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Affiliation(s)
- Chao-Cheng Kuo
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hao Chan
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Wei-Chen Hung
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Ruei-Feng Chen
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
| | - Hsiu-Wen Yang
- Department of Biomedical Sciences, Chung-Shan Medical University, Taichung, Taiwan.,Department of Medical Research, Chung-Shan Medical University Hospital, Taichung, Taiwan
| | - Ming-Yuan Min
- Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan.,Neurobiology and Cognitive Science Center, National Taiwan University, Taipei, Taiwan
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11
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Xiang L, Harel A, Todorova R, Gao H, Sara SJ, Wiener SI. Locus coeruleus noradrenergic neurons phase-lock to prefrontal and hippocampal infra-slow rhythms that synchronize to behavioral events. Front Cell Neurosci 2023; 17:1131151. [PMID: 37025702 PMCID: PMC10070758 DOI: 10.3389/fncel.2023.1131151] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 02/23/2023] [Indexed: 04/08/2023] Open
Abstract
The locus coeruleus (LC) is the primary source of noradrenergic projections to the forebrain, and, in prefrontal cortex, is implicated in decision-making and executive function. LC neurons phase-lock to cortical infra-slow wave oscillations during sleep. Such infra-slow rhythms are rarely reported in awake states, despite their interest, since they correspond to the time scale of behavior. Thus, we investigated LC neuronal synchrony with infra-slow rhythms in awake rats performing an attentional set-shifting task. Local field potential (LFP) oscillation cycles in prefrontal cortex and hippocampus on the order of 0.4 Hz phase-locked to task events at crucial maze locations. Indeed, successive cycles of the infra-slow rhythms showed different wavelengths, as if they are periodic oscillations that can reset phase relative to salient events. Simultaneously recorded infra-slow rhythms in prefrontal cortex and hippocampus could show different cycle durations as well, suggesting independent control. Most LC neurons (including optogenetically identified noradrenergic neurons) recorded here were phase-locked to these infra-slow rhythms, as were hippocampal and prefrontal units recorded on the LFP probes. The infra-slow oscillations also phase-modulated gamma amplitude, linking these rhythms at the time scale of behavior to those coordinating neuronal synchrony. This would provide a potential mechanism where noradrenaline, released by LC neurons in concert with the infra-slow rhythm, would facilitate synchronization or reset of these brain networks, underlying behavioral adaptation.
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Affiliation(s)
- Liyang Xiang
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
- Zhejiang Key Laboratory of Neuroelectronics and Brain Computer Interface Technology, Hangzhou, China
| | - Antoine Harel
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - Ralitsa Todorova
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - HongYing Gao
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
| | - Susan J. Sara
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
- Department of Child and Adolescent Psychiatry, New York University Medical School, New York, NY, United States
| | - Sidney I. Wiener
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France
- *Correspondence: Sidney I. Wiener,
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Liebe T, Dordevic M, Kaufmann J, Avetisyan A, Skalej M, Müller N. Investigation of the functional pathogenesis of mild cognitive impairment by localisation-based locus coeruleus resting-state fMRI. Hum Brain Mapp 2022; 43:5630-5642. [PMID: 36441846 PMCID: PMC9704796 DOI: 10.1002/hbm.26039] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/27/2022] [Accepted: 07/25/2022] [Indexed: 01/15/2023] Open
Abstract
Dementia as one of the most prevalent diseases urges for a better understanding of the central mechanisms responsible for clinical symptoms, and necessitates improvement of actual diagnostic capabilities. The brainstem nucleus locus coeruleus (LC) is a promising target for early diagnosis because of its early structural alterations and its relationship to the functional disturbances in the patients. In this study, we applied our improved method of localisation-based LC resting-state fMRI to investigate the differences in central sensory signal processing when comparing functional connectivity (fc) of a patient group with mild cognitive impairment (MCI, n = 28) and an age-matched healthy control group (n = 29). MCI and control participants could be differentiated in their Mini-Mental-State-Examination (MMSE) scores (p < .001) and LC intensity ratio (p = .010). In the fMRI, LC fc to anterior cingulate cortex (FDR p < .001) and left anterior insula (FDR p = .012) was elevated, and LC fc to right temporoparietal junction (rTPJ, FDR p = .012) and posterior cingulate cortex (PCC, FDR p = .021) was decreased in the patient group. Importantly, LC to rTPJ connectivity was also positively correlated to MMSE scores in MCI patients (p = .017). Furthermore, we found a hyperactivation of the left-insula salience network in the MCI patients. Our results and our proposed disease model shed new light on the functional pathogenesis of MCI by directing to attentional network disturbances, which could aid new therapeutic strategies and provide a marker for diagnosis and prediction of disease progression.
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Affiliation(s)
- Thomas Liebe
- Department of PsychiatryMedical University of ViennaViennaAustria
- Department of RadiologyUniversity Hospital JenaJenaGermany
- Department of PsychiatryUniversity Hospital JenaJenaGermany
- Clinical Affective Neuroimaging LaboratoryLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Milos Dordevic
- Department of Degenerative and Chronic DiseasesUniversity PotsdamPotsdamGermany
| | - Jörn Kaufmann
- Department of NeurologyUniversity Hospital MagdeburgMagdeburgGermany
| | - Araks Avetisyan
- Neuroprotection LabGerman Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Martin Skalej
- Department of Neuroradiology, Clinic and Policlinic of RadiologyUniversity Hospital HalleHalleGermany
| | - Notger Müller
- Department of Degenerative and Chronic DiseasesUniversity PotsdamPotsdamGermany
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13
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Woodward SH. Autonomic regulation during sleep in PTSD. Neurobiol Stress 2022; 21:100483. [DOI: 10.1016/j.ynstr.2022.100483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 08/01/2022] [Accepted: 08/25/2022] [Indexed: 10/31/2022] Open
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14
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Kovac M, Vladimirovna Ippolitova T, Pozyabin S, Aliev R, Lobanova V, Drakul N, S. Rutland C. Equine Stress: Neuroendocrine Physiology and Pathophysiology. Vet Med Sci 2022. [DOI: 10.5772/intechopen.105045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This review presents new aspects to understanding the neuroendocrine regulation of equine stress responses, and their influences on the physiological, pathophysiological, and behavioral processes. Horse management, in essence, is more frequently confirmed by external and internal stress factors, than in other domestic animals. Regardless of the nature of the stimulus, the equine stress response is an effective and highly conservative set of interconnected relationships designed to maintain physiological integrity even in the most challenging circumstances (e.g., orthopedic injuries, abdominal pain, transport, competitions, weaning, surgery, and inflammation). The equine stress response is commonly a complementary homeostatic mechanism that provides protection (not an adaptation) when the body is disturbed or threatened. It activates numerous neural and hormonal networks to optimize metabolic, cardiovascular, musculoskeletal, and immunological functions. This review looks into the various mechanisms involved in stress responses, stress-related diseases, and assessment, prevention or control, and management of these diseases and stress. Stress-related diseases can not only be identified and assessed better, given the latest research and techniques but also prevented or controlled.
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15
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Osorio-Forero A, Cherrad N, Banterle L, Fernandez LMJ, Lüthi A. When the Locus Coeruleus Speaks Up in Sleep: Recent Insights, Emerging Perspectives. Int J Mol Sci 2022; 23:ijms23095028. [PMID: 35563419 PMCID: PMC9099715 DOI: 10.3390/ijms23095028] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 12/03/2022] Open
Abstract
For decades, numerous seminal studies have built our understanding of the locus coeruleus (LC), the vertebrate brain’s principal noradrenergic system. Containing a numerically small but broadly efferent cell population, the LC provides brain-wide noradrenergic modulation that optimizes network function in the context of attentive and flexible interaction with the sensory environment. This review turns attention to the LC’s roles during sleep. We show that these roles go beyond down-scaled versions of the ones in wakefulness. Novel dynamic assessments of noradrenaline signaling and LC activity uncover a rich diversity of activity patterns that establish the LC as an integral portion of sleep regulation and function. The LC could be involved in beneficial functions for the sleeping brain, and even minute alterations in its functionality may prove quintessential in sleep disorders.
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16
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David M, Malhotra PA. New approaches for the quantification and targeting of noradrenergic dysfunction in Alzheimer's disease. Ann Clin Transl Neurol 2022; 9:582-596. [PMID: 35293158 PMCID: PMC8994981 DOI: 10.1002/acn3.51539] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/14/2022] Open
Abstract
There is clear, early noradrenergic dysfunction in Alzheimer's disease. This is likely secondary to pathological tau deposition in the locus coeruleus, the pontine nucleus that produces and releases noradrenaline, prior to involvement of cortical brain regions. Disruption of noradrenergic pathways affects cognition, especially attention, impacting memory and broader functioning. Additionally, it leads to autonomic and neuropsychiatric symptoms. Despite the strong evidence of noradrenergic involvement in Alzheimer's, there are no clear trial data supporting the clinical use of any noradrenergic treatments. Several approaches have been tried, including proof-of-principle studies and (mostly small scale) randomised controlled trials. Treatments have included pharmacotherapies as well as stimulation. The lack of clear positive findings is likely secondary to limitations in gauging locus coeruleus integrity and dysfunction at an individual level. However, the recent development of several novel biomarkers holds potential and should allow quantification of dysfunction. This may then inform inclusion criteria and stratification for future trials. Imaging approaches have improved greatly following the development of neuromelanin-sensitive sequences, enabling the use of structural MRI to estimate locus coeruleus integrity. Additionally, functional MRI scanning has the potential to quantify network dysfunction. As well as neuroimaging, EEG, fluid biomarkers and pupillometry techniques may prove useful in assessing noradrenergic tone. Here, we review the development of these biomarkers and how they might augment clinical studies, particularly randomised trials, through identification of patients most likely to benefit from treatment. We outline the biomarkers with most potential, and how they may transform symptomatic therapy for people living with Alzheimer's disease.
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Affiliation(s)
- Michael David
- Imperial College London and the University of SurreyUK Dementia Research Institute Care Research and Technology CentreSir Michael Uren Hub, 86 Wood LaneLondonW12 0BZUK
- Imperial College London, Brain SciencesSouth KensingtonLondonSW7 2AZUK
- Imperial College Healthcare NHS Trust, Clinical NeurosciencesCharing Cross HospitalLondonW2 1NYUK
| | - Paresh A. Malhotra
- Imperial College London and the University of SurreyUK Dementia Research Institute Care Research and Technology CentreSir Michael Uren Hub, 86 Wood LaneLondonW12 0BZUK
- Imperial College London, Brain SciencesSouth KensingtonLondonSW7 2AZUK
- Imperial College Healthcare NHS Trust, Clinical NeurosciencesCharing Cross HospitalLondonW2 1NYUK
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17
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Lee S, Lee HJ, Cho CH. Mediation Effect of Insomnia Symptoms on Relation Between Stress and Quality of Life. Psychiatry Investig 2022; 19:229-238. [PMID: 35291194 PMCID: PMC8958211 DOI: 10.30773/pi.2021.0344] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/23/2022] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE Among various causes of insomnia, stress is the most common and representative cause. Insomnia is also known to negatively affect the quality of life (QoL). The objective of this study was to explore the effect of stress on QoL and the mediating role of insomnia symptoms in the relationship between stress and QoL. METHODS In this study, the mediating effect of insomnia symptoms on the relationship between stress and QoL was analyzed by enrolling 3,714 participants from the Ansung and Ansan cohorts of the Korea Association Resource project from 2001 to 2004. These cohort participants were asked about how much they felt stressed during their everyday life. Insomnia symptoms were evaluated by asking participants whether they had trouble sleeping such as difficulty in falling asleep, disrupted sleep, and early morning awakening due to the lack of a validated questionnaire for this cohort. QoL was evaluated using the World Health Organization QoL Scale Brief Version. RESULTS In total, stress was positively associated with insomnia symptoms, which in turn predicted QoL. The same result could be derived from subgroup analysis according to sex, and it was confirmed that insomnia symptoms acted as a mediating factor more significantly in female than in male. CONCLUSION In this study, insomnia symptoms were confirmed to act as a significant mediating factor between stress and QoL, suggesting that insomnia symptoms should be actively identified and controlled to alleviate the negative effect of stress on QoL in clinical practice.
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Affiliation(s)
- Seulki Lee
- Department of Psychiatry, College of Medicine, Chungnam National University, Daejeon, Republic of Korea.,Department of Psychiatry, Chungnam National University Sejong Hospital, Sejong, Republic of Korea
| | - Heon-Jeong Lee
- Department of Psychiatry, Chronobiology Institute, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Chul-Hyun Cho
- Department of Psychiatry, College of Medicine, Chungnam National University, Daejeon, Republic of Korea.,Department of Psychiatry, Chungnam National University Sejong Hospital, Sejong, Republic of Korea
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18
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Megemont M, McBurney-Lin J, Yang H. Pupil diameter is not an accurate real-time readout of locus coeruleus activity. eLife 2022; 11:70510. [PMID: 35107419 PMCID: PMC8809893 DOI: 10.7554/elife.70510] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 12/30/2021] [Indexed: 12/21/2022] Open
Abstract
Pupil diameter is often treated as a noninvasive readout of activity in the locus coeruleus (LC). However, how accurately it can be used to index LC activity is not known. To address this question, we established a graded relationship between pupil size changes and LC spiking activity in mice, where pupil dilation increased monotonically with the number of LC spikes. However, this relationship exists with substantial variability such that pupil diameter can only be used to accurately predict a small fraction of LC activity on a moment-by-moment basis. In addition, pupil exhibited large session-to-session fluctuations in response to identical optical stimulation in the LC. The variations in the pupil–LC relationship were strongly correlated with decision bias-related behavioral variables. Together, our data show that substantial variability exists in an overall graded relationship between pupil diameter and LC activity, and further suggest that the pupil–LC relationship is dynamically modulated by brain states, supporting and extending our previous findings (Yang et al., 2021).
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Affiliation(s)
- Marine Megemont
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States
| | - Jim McBurney-Lin
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States.,Neuroscience Graduate Program, University of California, Riverside, Riverside, United States
| | - Hongdian Yang
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, Riverside, United States.,Neuroscience Graduate Program, University of California, Riverside, Riverside, United States
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19
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Siraji MA, Kalavally V, Schaefer A, Haque S. Effects of Daytime Electric Light Exposure on Human Alertness and Higher Cognitive Functions: A Systematic Review. Front Psychol 2022; 12:765750. [PMID: 35069337 PMCID: PMC8766646 DOI: 10.3389/fpsyg.2021.765750] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
This paper reports the results of a systematic review conducted on articles examining the effects of daytime electric light exposure on alertness and higher cognitive functions. For this, we selected 59 quantitative research articles from 11 online databases. The review protocol was registered with PROSPERO (CRD42020157603). The results showed that both short-wavelength dominant light exposure and higher intensity white light exposure induced alertness. However, those influences depended on factors like the participants' homeostatic sleep drive and the time of day the participants received the light exposure. The relationship between light exposure and higher cognitive functions was not as straightforward as the alerting effect. The optimal light property for higher cognitive functions was reported dependent on other factors, such as task complexity and properties of control light. Among the studies with short-wavelength dominant light exposure, ten studies (morning: 3; afternoon: 7) reported beneficial effects on simple task performances (reaction time), and four studies (morning: 3; afternoon: 1) on complex task performances. Four studies with higher intensity white light exposure (morning: 3; afternoon: 1) reported beneficial effects on simple task performance and nine studies (morning: 5; afternoon: 4) on complex task performance. Short-wavelength dominant light exposure with higher light intensity induced a beneficial effect on alertness and simple task performances. However, those effects did not hold for complex task performances. The results indicate the need for further studies to understand the influence of short-wavelength dominant light exposure with higher illuminance on alertness and higher cognitive functions.
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Affiliation(s)
- Mushfiqul Anwar Siraji
- Department of Psychology, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
| | - Vineetha Kalavally
- Department of Electrical and Computer Systems Engineering, School of Engineering, Monash University Malaysia, Subang Jaya, Malaysia
| | - Alexandre Schaefer
- Department of Psychology, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia.,School of Medical and Life Sciences, Sunway University, Subang Jaya, Malaysia
| | - Shamsul Haque
- Department of Psychology, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Subang Jaya, Malaysia
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20
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Skirzewski M, Molotchnikoff S, Hernandez LF, Maya-Vetencourt JF. Multisensory Integration: Is Medial Prefrontal Cortex Signaling Relevant for the Treatment of Higher-Order Visual Dysfunctions? Front Mol Neurosci 2022; 14:806376. [PMID: 35110996 PMCID: PMC8801884 DOI: 10.3389/fnmol.2021.806376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/17/2021] [Indexed: 11/29/2022] Open
Abstract
In the mammalian brain, information processing in sensory modalities and global mechanisms of multisensory integration facilitate perception. Emerging experimental evidence suggests that the contribution of multisensory integration to sensory perception is far more complex than previously expected. Here we revise how associative areas such as the prefrontal cortex, which receive and integrate inputs from diverse sensory modalities, can affect information processing in unisensory systems via processes of down-stream signaling. We focus our attention on the influence of the medial prefrontal cortex on the processing of information in the visual system and whether this phenomenon can be clinically used to treat higher-order visual dysfunctions. We propose that non-invasive and multisensory stimulation strategies such as environmental enrichment and/or attention-related tasks could be of clinical relevance to fight cerebral visual impairment.
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Affiliation(s)
- Miguel Skirzewski
- Rodent Cognition Research and Innovation Core, University of Western Ontario, London, ON, Canada
| | - Stéphane Molotchnikoff
- Département de Sciences Biologiques, Université de Montréal, Montreal, QC, Canada
- Département de Génie Electrique et Génie Informatique, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Luis F. Hernandez
- Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, United States
| | - José Fernando Maya-Vetencourt
- Department of Biology, University of Pisa, Pisa, Italy
- Centre for Synaptic Neuroscience, Istituto Italiano di Tecnologia (IIT), Genova, Italy
- *Correspondence: José Fernando Maya-Vetencourt
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21
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Broncel A, Bocian R, Kłos-Wojtczak P, Konopacki J. Noradrenergic Profile of Hippocampal Formation Theta Rhythm in Anaesthetized Rats. Neuroscience 2021; 473:13-28. [PMID: 34418519 DOI: 10.1016/j.neuroscience.2021.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 10/20/2022]
Abstract
The present study was undertaken to identify the noradrenergic receptors underlying the production of hippocampal formation (HPC) type 2 theta rhythm. The experiments were performed on urethanized rats wherein type 2 theta is the only rhythm present. In three independent stages of experiments, the effects of noradrenaline (NE) and selective noradrenergic α and β agonists and antagonists were tested. We indicate that the selective activation of three HPC noradrenergic receptors, α1, α2 and β1, induced a similar effect (i.e., inhibition) on type 2 theta rhythm. The remaining HPC β2 and β3 noradrenergic receptors do not seem to be directly involved in the pharmacological mechanism responsible for the suppression of theta rhythm in anaesthetized rats. Obtained results provide evidence for the suppressant effect of exogenous NE on HPC type 2 theta rhythm and show the crucial role of α1, α2 and β1 noradrenergic receptors in the modulation of HPC mechanisms of oscillations and synchrony. This finding is in contrast to the effects of endogenous NE produced by electrical stimulation of the locus coeruleus (LC) and procaine injection into the LC (Broncel et al., 2020).
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Affiliation(s)
- A Broncel
- Neuromedical, Research Department, Natolin 15, 92-701 Lodz, Poland.
| | - R Bocian
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
| | - P Kłos-Wojtczak
- Neuromedical, Research Department, Natolin 15, 92-701 Lodz, Poland.
| | - J Konopacki
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
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22
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Engelbregt H, Barmentlo M, Keeser D, Pogarell O, Deijen JB. Effects of binaural and monaural beat stimulation on attention and EEG. Exp Brain Res 2021; 239:2781-2791. [PMID: 34245340 PMCID: PMC8448709 DOI: 10.1007/s00221-021-06155-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 06/17/2021] [Indexed: 11/07/2022]
Abstract
Nowadays a popular technique to improve mood and cognition is auditory beat stimulation (ABS), which is thought to induce a frequency-following response of brainwaves. The main types of ABS are monaural beats (MB) and binaural beats (BB). BB involves the presentation of a specific frequency to one ear and another frequency to the other ear which may induce neural entrainment. A difference between the frequencies of 40 Hz is assumed to improve cognition. The present study examined the effect of 40 Hz binaural beats (BB) and monaural beats (MB) on attention and electroencephalography (EEG). A total of 25 first-year psychology students (11 males, 14 females) performed a Flanker task while EEG was recorded during the 5 min-presentation of pink noise (PN), MB and BB. With respect to attention, as measured by the Flanker task, the number of false responses in the BB condition was smaller than that in the PN condition while the number of false responses in the MB condition was larger as compared to the PN condition. As there was no association of BB with a consistent increase in absolute 40 or 45 Hz power compared to PN or MB, EEG recordings could not confirm the hypothesized neural entrainment in the brain. Overall, the current findings show that listening to 40 Hz BB improves attention but do not show the occurrence of neural entrainment. Future research is recommended to include a larger sample, to use a broader cognitive test battery and to present auditory beats with a longer duration.
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Affiliation(s)
- Hessel Engelbregt
- Hersencentrum Mental Health Institute, Amsterdam, the Netherlands
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University of Munich, Munich, Germany
| | | | - Daniel Keeser
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Oliver Pogarell
- Department of Psychiatry and Psychotherapy, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jan Berend Deijen
- Hersencentrum Mental Health Institute, Amsterdam, the Netherlands.
- Faculty of Behavioural and Movement Sciences, Section Clinical Neuropsychology, Vrije Universiteit, van der Boechorststraat 7, 1081 BT, Amsterdam, the Netherlands.
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23
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Wimmer ME, Cui R, Blackwell JM, Abel T. Cyclic AMP response element-binding protein is required in excitatory neurons in the forebrain to sustain wakefulness. Sleep 2021; 44:6024523. [PMID: 33277644 DOI: 10.1093/sleep/zsaa267] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 10/15/2020] [Indexed: 12/11/2022] Open
Abstract
The molecular and intracellular signaling processes that control sleep and wake states remain largely unknown. A consistent observation is that the cyclic adenosine monophosphate (AMP) response element-binding protein (CREB), an activity-dependent transcription factor, is differentially activated during sleep and wakefulness. CREB is phosphorylated by the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway as well as other kinases, and phosphorylated CREB promotes the transcription of target genes. Genetic studies in flies and mice suggest that CREB signaling influences sleep/wake states by promoting and stabilizing wakefulness. However, it remains unclear where in the brain CREB is required to drive wakefulness. In rats, CREB phosphorylation increases in the cerebral cortex during wakefulness and decreases during sleep, but it is not known if this change is functionally relevant to the maintenance of wakefulness. Here, we used the Cre/lox system to conditionally delete CREB in the forebrain (FB) and in the locus coeruleus (LC), two regions known to be important for the production of arousal and wakefulness. We used polysomnography to measure sleep/wake levels and sleep architecture in conditional CREB mutant mice and control littermates. We found that FB-specific deletion of CREB decreased wakefulness and increased non-rapid eye movement sleep. Mice lacking CREB in the FB were unable to sustain normal periods of wakefulness. On the other hand, deletion of CREB from LC neurons did not change sleep/wake levels or sleep/wake architecture. Taken together, these results suggest that CREB is required in neurons within the FB but not in the LC to promote and stabilize wakefulness.
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Affiliation(s)
- Mathieu E Wimmer
- Department of Psychology and Program in Neuroscience, Temple University, Philadelphia, PA
| | - Rosa Cui
- Neuroscience Graduate Group, Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Jennifer M Blackwell
- Neuroscience Graduate Group, Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Ted Abel
- Department of Neuroscience and Pharmacology, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA
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24
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van Kempen J, Gieselmann MA, Boyd M, Steinmetz NA, Moore T, Engel TA, Thiele A. Top-down coordination of local cortical state during selective attention. Neuron 2021; 109:894-904.e8. [PMID: 33406410 PMCID: PMC7927916 DOI: 10.1016/j.neuron.2020.12.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/20/2020] [Accepted: 12/16/2020] [Indexed: 11/30/2022]
Abstract
Spontaneous fluctuations in cortical excitability influence sensory processing and behavior. These fluctuations, long thought to reflect global changes in cortical state, were recently found to be modulated locally within a retinotopic map during spatially selective attention. We report that periods of vigorous (On) and faint (Off) spiking activity, the signature of cortical state fluctuations, are coordinated across brain areas with retinotopic precision. Top-down attention enhanced interareal local state coordination, traversing along the reverse cortical hierarchy. The extent of local state coordination between areas was predictive of behavioral performance. Our results show that cortical state dynamics are shared across brain regions, modulated by cognitive demands and relevant for behavior.
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Affiliation(s)
- Jochem van Kempen
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
| | - Marc A Gieselmann
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Michael Boyd
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Nicholas A Steinmetz
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Tirin Moore
- Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Tatiana A Engel
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Alexander Thiele
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
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25
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Petit JM, Eren-Koçak E, Karatas H, Magistretti P, Dalkara T. Brain glycogen metabolism: A possible link between sleep disturbances, headache and depression. Sleep Med Rev 2021; 59:101449. [PMID: 33618186 DOI: 10.1016/j.smrv.2021.101449] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/27/2022]
Abstract
The functions of sleep and its links with neuropsychiatric diseases have long been questioned. Among the numerous hypotheses on sleep function, early studies proposed that sleep helps to replenish glycogen stores consumed during waking. Later studies found increased brain glycogen after sleep deprivation, leading to "glycogenetic" hypothesis, which states that there is a parallel increase in synthesis and utilization of glycogen during wakefulness, whereas decrease in the excitatory transmission creates an imbalance causing accumulation of glycogen during sleep. Glycogen is a vital energy reservoir to match the synaptic demand particularly for re-uptake of potassium and glutamate during intense glutamatergic transmission. Therefore, sleep deprivation-induced transcriptional changes may trigger migraine by reducing glycogen availability, which slows clearance of extracellular potassium and glutamate, hence, creates susceptibility to cortical spreading depolarization, the electrophysiological correlate of migraine aura. Interestingly, chronic stress accompanied by increased glucocorticoid levels and locus coeruleus activity and leading to mood disorders in which sleep disturbances are prevalent, also affects brain glycogen turnover via glucocorticoids, noradrenaline, serotonin and adenosine. These observations altogether suggest that inadequate astrocytic glycogen turnover may be one of the mechanisms linking migraine, mood disorders and sleep.
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Affiliation(s)
- J-M Petit
- Lausanne University Hospital, Center for Psychiatric Neuroscience, Prilly, Switzerland.
| | - E Eren-Koçak
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, and Faculty of Medicine, Department of Psychiatry, Ankara, Turkey.
| | - H Karatas
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey.
| | - P Magistretti
- King Abdullah University of Science and Technology, Saudi Arabia.
| | - T Dalkara
- Hacettepe University, Institute of Neurological Sciences and Psychiatry, Ankara, Turkey.
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Babić Leko M, Hof PR, Šimić G. Alterations and interactions of subcortical modulatory systems in Alzheimer's disease. PROGRESS IN BRAIN RESEARCH 2021; 261:379-421. [PMID: 33785136 DOI: 10.1016/bs.pbr.2020.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pathogenesis of Alzheimer's disease (AD) is not fully understood. Here we summarize current knowledge on the involvement of the serotonergic, noradrenergic, dopaminergic, cholinergic, and opioid systems in AD, emphasizing the importance of interactions between the serotonergic and the other subcortical modulatory systems during the progression of AD. In physiological conditions, all neurotransmitter systems function in concert and are interdependent at both the neuroanatomical and molecular levels. Through their early involvement in AD, cognitive and behavioral abilities that rely on their interactions also become disrupted. Considering that serotonin (5HT) regulates the release of noradrenaline (NA), dopamine (DA) and acetylcholine (ACh), any alteration in 5HT levels leads to disturbance of NA, DA, and ACh homeostasis in the brain. One of the earliest pathological changes during the prodromal phase of AD is a decrease of serotonergic transmission throughout the brain, with serotonergic receptors being also affected. Additionally, serotonergic and noradrenergic as well as serotonergic and dopaminergic nuclei are reciprocally interconnected. As the serotonergic dorsal raphe nucleus (DRN) is affected by pathological changes early in AD, and the noradrenergic locus coeruleus (LC) and dopaminergic ventral tegmental area (VTA) exhibit AD-related pathological changes, their connectivity also becomes altered in AD. Such disrupted interactions among neurotransmitter systems in AD can be used in the development of multi-target drugs. Some of the potential AD therapeutics (such as ASS234, RS67333, tropisetron) target multiple neurotransmitter systems to achieve the best possible improvement of cognitive and behavioral deficits observed in AD. Here, we review how serotonergic system interacts with other subcortical modulatory systems (noradrenergic, dopaminergic, cholinergic, and opioid systems) during AD.
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Affiliation(s)
- Mirjana Babić Leko
- Department for Neuroscience, Croatian Institute for Brain Research, University of Zagreb Medical School, Zagreb, Croatia
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Friedman Brain Institute, and Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Goran Šimić
- Department for Neuroscience, Croatian Institute for Brain Research, University of Zagreb Medical School, Zagreb, Croatia.
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Guajardo HM, Valentino RJ. Sex differences in μ-opioid regulation of coerulear-cortical transmission. Neurosci Lett 2021; 746:135651. [PMID: 33482313 DOI: 10.1016/j.neulet.2021.135651] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 11/26/2022]
Abstract
Stress-induced activation of locus coeruleus (LC)-norepinephrine (NE) projections to the prefrontal cortex are thought to promote cognitive responses to stressors. LC activation by stressors is modulated by endogenous opioids that restrain LC activation and facilitate a return to baseline activity upon stress termination. Sex differences in this opioid influence could be a basis for sex differences in stress vulnerability. Consistent with this, we recently demonstrated that μ-opioid receptor (MOR) expression is decreased in the female rat LC compared to the male LC, and this was associated with sexually distinct consequences of activating MOR in the LC on cognitive flexibility. Given that the LC-NE system affects cognitive flexibility through its projections to the medial prefrontal cortex (mPFC), the present study quantified and compared the effects of LC-MOR activation on mPFC neural activity in male and female rats. Local field potential (LFPs) were recorded from the mPFC of freely behaving male and female rats before and following local LC microinjection of the MOR agonist, DAMGO, or vehicle. Intra-LC DAMGO altered the LFP power spectrum selectively in male but not female rats, resulting in a time-dependent increase in the power in delta and alpha frequency bands. LC microinfusion of ACSF had no effect on either sex. Together, the results are consistent with previous evidence for decreased MOR function in the female rat LC and demonstrate that this translates to a diminished effect on cortical activity that can account for sex differences in cognitive consequences. Decreased LC-MOR function in females could contribute to greater stress-induced activation of the LC and increased vulnerability of females to hyperarousal symptoms of stress-related neuropsychiatric pathologies.
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Affiliation(s)
- Herminio M Guajardo
- Neuroscience Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
| | - Rita J Valentino
- Neuroscience Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
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Noradrenergic activation induced by yohimbine decreases interoceptive accuracy in healthy individuals with childhood adversity. Dev Psychopathol 2021; 34:1013-1024. [PMID: 33446284 DOI: 10.1017/s0954579420001613] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Acute stress affects interoception, but it remains unclear if this is due to activation of the sympatho-adreno-medullary (SAM) or hypothalamic-pituitary-adrenocortical axis. This study aimed to investigate the effect of SAM axis activation on interoceptive accuracy (IAcc). Central alpha2-adrenergic receptors represent a negative feedback mechanism of the SAM axis. Major depressive disorder and adverse childhood experiences (ACE) are associated with alterations in the biological stress systems, including central alpha2-adrenergic receptors. Here, healthy individuals with and without ACE as well as depressive patients with and without ACE (n = 114; all without antidepressant medication) were tested after yohimbine (alpha2-adrenergic antagonist) and placebo. We assessed IAcc and sensibility in a heartbeat counting task. Increases in systolic and diastolic blood pressure after yohimbine confirmed successful SAM axis activation. IAcc decreased after yohimbine only in the healthy group with ACE, but remained unchanged in all other groups (Group × Drug interaction). This effect may be due to selective upregulation of alpha2-adrenergic receptors after childhood trauma, which reduces capacity for attention focus on heartbeats. The sympathetic neural pathway including alpha2-adrenergic circuitries may be essential for mediating interoceptive signal transmission. Suppressed processing of physical sensations in stressful situations may represent an adaptive response in healthy individuals who experienced ACE.
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Vanneste S, Mohan A, Yoo HB, Huang Y, Luckey AM, McLeod SL, Tabet MN, Souza RR, McIntyre CK, Chapman S, Robertson IH, To WT. The peripheral effect of direct current stimulation on brain circuits involving memory. SCIENCE ADVANCES 2020; 6:6/45/eaax9538. [PMID: 33148657 PMCID: PMC7673706 DOI: 10.1126/sciadv.aax9538] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/31/2020] [Indexed: 05/11/2023]
Abstract
An ongoing debate surrounding transcranial direct current stimulation (tDCS) of the scalp is whether it modulates brain activity both directly and in a regionally constrained manner enough to positively affect symptoms in patients with neurological disorders. One alternative explanation is that direct current stimulation affects neural circuits mainly indirectly, i.e., via peripheral nerves. Here, we report that noninvasive direct current stimulation indirectly affects neural circuits via peripheral nerves. In a series of studies, we show that direct current stimulation can cause activation of the greater occipital nerve (ON-tDCS) and augments memory via the ascending fibers of the occipital nerve to the locus coeruleus, promoting noradrenaline release. This noradrenergic pathway plays a key role in driving hippocampal activity by modifying functional connectivity supporting the consolidation of a memory event.
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Affiliation(s)
- Sven Vanneste
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA.
- Center for Brain Health, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Anusha Mohan
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Hye Bin Yoo
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Yuefeng Huang
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Alison M Luckey
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - S Lauren McLeod
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Michel N Tabet
- Neurobiology of Memory Lab, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Rimenez R Souza
- Neurobiology of Memory Lab, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Christa K McIntyre
- Neurobiology of Memory Lab, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Sandra Chapman
- Center for Brain Health, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
| | - Ian H Robertson
- Center for Brain Health, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - Wing Ting To
- Lab for Clinical and Integrative Neuroscience, School for Behavioral and Brain Sciences, University of Texas at Dallas, Richardson, TX, USA
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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Bostanciklioğlu M. Unexpected awakenings in severe dementia from case reports to laboratory. Alzheimers Dement 2020; 17:125-136. [PMID: 33064369 DOI: 10.1002/alz.12162] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/17/2020] [Accepted: 07/07/2020] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Case report notions of unexpected memory retrieval in patients with severe dementia near to death are starting to alter the central "irreversible" paradigm of dementia and locate dementia as a problem of memory retrieval, not consolidation. We suggest that the most likely central tenet of this paradoxical memory retrieval is the fluctuation of neuromodulators projecting from the brain stem to the medial prefrontal cortex and the hippocampus. The neuromodulation-centric explanation of this phenomenon aims to open the "irreversible" paradigm of dementia up for discussion and suggest a plausible treatment strategy by questioning how the devastating process of death fluctuates memory performance in severe dementia. BACKGROUND Supporting demented patients, who are mostly unresponsive, without making demands or asking a question and regarding them as valuable human beings unexpectedly improve their memory performance around the time of death. NEW LUCIDITY HYPOTHESIS Around the time of death, neurological signs (hyper-arousal and -attention) of demented people point out that neurotransmitter discharges are dramatically changed. Relatively resistant neuromodulator circuits to neurodegeneration can maintain optimal levels of arousal and attention for memory processing. In this way, unexpected episodes of lucidity can be triggered. Also, corticotropin-releasing peptides might increase mental clarity by increasing the excitability of the neuromodulator circuits. The science of memory retrieval is more complicated and nuanced than retrieval observations in case reports, but the rapid development of new techniques holds promise for future understanding of lucidity in severe dementia. MAJOR CHALLENGE FOR THE MODEL There is no an animal or human model to test this hypothesis; however, the similarities between neurological signs (instantaneous cognitive fluctuations) of delirium and paradoxical lucidity could provide a unique window to understand neural events of terminal lucidity on a modified animal model of delirium. Likewise, similarities between unexpected consciousness signs of terminal lucidity and lucid dreaming suggest that lucid dreaming episodes might be considered a human model for terminal lucidity research.
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Broncel A, Bocian R, Kłos-Wojtczak P, Konopacki J. Effects of locus coeruleus activation and inactivation on hippocampal formation theta rhythm in anesthetized rats. Brain Res Bull 2020; 162:180-190. [DOI: 10.1016/j.brainresbull.2020.05.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/23/2020] [Accepted: 05/12/2020] [Indexed: 02/05/2023]
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Park SH, Weber F. Neural and Homeostatic Regulation of REM Sleep. Front Psychol 2020; 11:1662. [PMID: 32793050 PMCID: PMC7385183 DOI: 10.3389/fpsyg.2020.01662] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 06/18/2020] [Indexed: 12/11/2022] Open
Abstract
Rapid eye movement (REM) sleep is a distinct, homeostatically controlled brain state characterized by an activated electroencephalogram (EEG) in combination with paralysis of skeletal muscles and is associated with vivid dreaming. Understanding how REM sleep is controlled requires identification of the neural circuits underlying its initiation and maintenance, and delineation of the homeostatic processes regulating its expression on multiple timescales. Soon after its discovery in humans in 1953, the pons was demonstrated to be necessary and sufficient for the generation of REM sleep. But, especially within the last decade, researchers have identified further neural populations in the hypothalamus, midbrain, and medulla that regulate REM sleep by either promoting or suppressing this brain state. The discovery of these populations was greatly facilitated by the availability of novel technologies for the dissection of neural circuits. Recent quantitative models integrate findings about the activity and connectivity of key neurons and knowledge about homeostatic mechanisms to explain the dynamics underlying the recurrence of REM sleep. For the future, combining quantitative with experimental approaches to directly test model predictions and to refine existing models will greatly advance our understanding of the neural and homeostatic processes governing the regulation of REM sleep.
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Affiliation(s)
| | - Franz Weber
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, United States
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Extracellular Signal-Regulated Kinases Mediate an Autoregulation of GABA B-Receptor-Activated Whole-Cell Current in Locus Coeruleus Neurons. Sci Rep 2020; 10:7869. [PMID: 32398643 PMCID: PMC7217949 DOI: 10.1038/s41598-020-64292-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 04/09/2020] [Indexed: 11/09/2022] Open
Abstract
The norepinephrine-releasing neurons in the locus coeruleus (LC) are well known to regulate wakefulness/arousal. They display active firing during wakefulness and a decreased discharge rate during sleep. We have previously reported that LC neurons express large numbers of GABAB receptors (GABABRs) located at peri-/extrasynaptic sites and are subject to tonic inhibition due to the continuous activation of GABABRs by ambient GABA, which is significantly higher during sleep than during wakefulness. In this study, we further showed using western blot analysis that the activation of GABABRs with baclofen could increase the level of phosphorylated extracellular signal-regulated kinase 1 (ERK1) in LC tissue. Recordings from LC neurons in brain slices showed that the inhibition of ERK1/2 with U0126 and FR180204 accelerated the decay of whole-cell membrane current induced by prolonged baclofen application. In addition, the inhibition of ERK1/2 also increased spontaneous firing and reduced tonic inhibition of LC neurons after prolonged exposure to baclofen. These results suggest a new role of GABABRs in mediating ERK1-dependent autoregulation of the stability of GABABR-activated whole-cell current, in addition to its well-known effect on gated potassium channels, to cause a tonic current in LC neurons.
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GABAB receptor-mediated tonic inhibition of locus coeruleus neurons plays a role in deep anesthesia induced by isoflurane. Neuroreport 2020; 31:557-564. [PMID: 32282581 DOI: 10.1097/wnr.0000000000001450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Noradrenergic neurons in the locus coeruleus referred to as locus coeruleus neurons, provide the major supply of norepinephrine to the forebrain and play important roles in behavior through regulation of wakefulness and arousal. In a previous study using brain slice preparations, we reported that locus coeruleus neurons are subject to tonic inhibition mediated by γ-aminobutyric acid B receptors (GABABRs) and that the extent of tonic inhibition varies with ambient GABA levels. Since ambient GABA in the locus coeruleus was reported to fluctuate during the sleep-wakefulness cycle, here we tested whether GABABR-mediated tonic inhibition of locus coeruleus neurons could be a mechanism underlying changes in brain arousal. We first demonstrated that GABABR-mediated tonic inhibition of locus coeruleus neurons also exists in vivo by showing that local infusion of CGP35348, a GABABR antagonist, into the locus coeruleus increased the firing rate of locus coeruleus neurons in anesthetized rats. We then showed that this manipulation accelerated the behavioral emergence of rats from deep anesthesia induced by isoflurane. Together, these observations show that GABABR-mediated tonic inhibition of locus coeruleus neurons occurs in vivo and support the idea that this effect may be important in regulating the functional state of the brain.
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Hwu T, Krichmar JL. A neural model of schemas and memory encoding. BIOLOGICAL CYBERNETICS 2020; 114:169-186. [PMID: 31686197 DOI: 10.1007/s00422-019-00808-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
The ability to rapidly assimilate new information is essential for survival in a dynamic environment. This requires experiences to be encoded alongside the contextual schemas in which they occur. Tse et al. (Science 316(5821):76-82, 2007) showed that new information matching a preexisting schema is learned rapidly. To better understand the neurobiological mechanisms for creating and maintaining schemas, we constructed a biologically plausible neural network to learn context in a spatial memory task. Our model suggests that this occurs through two processing streams of indexing and representation, in which the medial prefrontal cortex and hippocampus work together to index cortical activity. Additionally, our study shows how neuromodulation contributes to rapid encoding within consistent schemas. The level of abstraction of our model further provides a basis for creating context-dependent memories while preventing catastrophic forgetting in artificial neural networks.
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Affiliation(s)
- Tiffany Hwu
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA.
- HRL Laboratories, LLC, Malibu, CA, USA.
| | - Jeffrey L Krichmar
- Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA
- Department of Computer Science, University of California, Irvine, Irvine, CA, USA
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Zuend M, Saab AS, Wyss MT, Ferrari KD, Hösli L, Looser ZJ, Stobart JL, Duran J, Guinovart JJ, Barros LF, Weber B. Arousal-induced cortical activity triggers lactate release from astrocytes. Nat Metab 2020; 2:179-191. [PMID: 32694692 DOI: 10.1038/s42255-020-0170-4] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 01/15/2020] [Indexed: 01/01/2023]
Abstract
It has been suggested that, in states of arousal, release of noradrenaline and β-adrenergic signalling affect long-term memory formation by stimulating astrocytic lactate production from glycogen. However, the temporal relationship between cortical activity and cellular lactate fluctuations upon changes in arousal remains to be fully established. Also, the role of β-adrenergic signalling and brain glycogen metabolism on neural lactate dynamics in vivo is still unknown. Here, we show that an arousal-induced increase in cortical activity triggers lactate release into the extracellular space, and this correlates with a fast and prominent lactate dip in astrocytes. The immediate drop in astrocytic lactate concentration and the parallel increase in extracellular lactate levels underline an activity-dependent lactate release from astrocytes. Moreover, when β-adrenergic signalling is blocked or the brain is depleted of glycogen, the arousal-evoked cellular lactate surges are significantly reduced. We provide in vivo evidence that cortical activation upon arousal triggers lactate release from astrocytes, a rise in intracellular lactate levels mediated by β-adrenergic signalling and the mobilization of lactate from glycogen stores.
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Affiliation(s)
- Marc Zuend
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Matthias T Wyss
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Kim David Ferrari
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Ladina Hösli
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Zoe J Looser
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Jillian L Stobart
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Jordi Duran
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Madrid, Spain
| | - Joan J Guinovart
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Madrid, Spain
- Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Barcelona, Spain
| | | | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.
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Restless REM Sleep Impedes Overnight Amygdala Adaptation. Curr Biol 2019; 29:2351-2358.e4. [DOI: 10.1016/j.cub.2019.06.034] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/14/2019] [Accepted: 06/11/2019] [Indexed: 11/23/2022]
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Hupalo S, Bryce CA, Bangasser DA, Berridge CW, Valentino RJ, Floresco SB. Corticotropin-Releasing Factor (CRF) circuit modulation of cognition and motivation. Neurosci Biobehav Rev 2019; 103:50-59. [PMID: 31212019 DOI: 10.1016/j.neubiorev.2019.06.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 04/08/2019] [Accepted: 06/11/2019] [Indexed: 01/04/2023]
Abstract
The neuropeptide, corticotropin-releasing factor (CRF), is a key modulator of physiological, endocrine, and behavioral responses during stress. Dysfunction of the CRF system has been observed in stress-related affective disorders including post-traumatic stress disorder, depression, and anxiety. Beyond affective symptoms, these disorders are also characterized by impaired cognition, for which current pharmacological treatments are lacking. Thus, there is a need for pro-cognitive treatments to improve quality of life for individuals suffering from mental illness. In this review, we highlight research demonstrating that CRF elicits potent modulatory effects on higher-order cognition via actions within the prefrontal cortex and subcortical monoaminergic and cholinergic systems. Additionally, we identify questions for future preclinical research on this topic, such as the need to investigate sex differences in the cognitive and microcircuit actions of CRF, and whether CRF may represent a pharmacological target to treat cognitive dysfunction. Addressing these questions will provide new insight into pathophysiology underlying cognitive dysfunction and may lead to improved treatments for neuropsychiatric disorders.
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Affiliation(s)
- Sofiya Hupalo
- Integrative Neuroscience Section, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, United States.
| | - Courtney A Bryce
- Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Debra A Bangasser
- Psychology Department and Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
| | - Craig W Berridge
- Department of Psychology, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Rita J Valentino
- National Institute on Drug Abuse, Bethesda, MD 20892, United States
| | - Stan B Floresco
- Department of Psychology and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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The locus coeruleus-norepinephrine system and sensory signal processing: A historical review and current perspectives. Brain Res 2019; 1709:1-15. [DOI: 10.1016/j.brainres.2018.08.032] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 11/22/2022]
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Sex differences in stress reactivity in arousal and attention systems. Neuropsychopharmacology 2019; 44:129-139. [PMID: 30022063 PMCID: PMC6235989 DOI: 10.1038/s41386-018-0137-2] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/21/2018] [Accepted: 06/15/2018] [Indexed: 01/04/2023]
Abstract
Women are more likely than men to suffer from psychiatric disorders with hyperarousal symptoms, including posttraumatic stress disorder (PTSD) and major depression. In contrast, women are less likely than men to be diagnosed with schizophrenia and attention deficit hyperactivity disorder (ADHD), which share attentional impairments as a feature. Stressful events exacerbate symptoms of the aforementioned disorders. Thus, researchers are examining whether sex differences in stress responses bias women and men towards different psychopathology. Here we review the preclinical literature suggesting that, compared to males, females are more vulnerable to stress-induced hyperarousal, while they are more resilient to stress-induced attention deficits. Specifically described are sex differences in receptors for the stress neuropeptide, corticotropin-releasing factor (CRF), that render the locus coeruleus arousal system of females more vulnerable to stress and less adaptable to CRF hypersecretion, a condition found in patients with PTSD and depression. Studies on the protective effects of ovarian hormones against CRF-induced deficits in sustained attention are also detailed. Importantly, we highlight how comparing males and females in preclinical studies can lead to the development of novel therapeutics to improve treatments for psychiatric disorders in both women and men.
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Accelerated muscle contractility and decreased muscle steadiness following sauna recovery do not induce greater neuromuscular fatigability during sustained submaximal contractions. Hum Mov Sci 2018; 63:10-19. [PMID: 30481721 DOI: 10.1016/j.humov.2018.11.009] [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] [Received: 09/07/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 12/20/2022]
Abstract
Acute whole-body hyperthermia (WBH) increases blood markers concentration of stress, impairs motor drive to exercising muscles, and decreases resistance to neuromuscular fatigability. The functional natural residual consequences of WBH on neuromuscular functions remain unclear. We aimed to investigate the effects of residual WBH on voluntary and electrically induced ankle plantar flexor contractility properties, motor drive transmission (reflexes), muscle torque steadiness, resistance to neuromuscular fatigability, and markers of stress as the body temperature recovers naturally to normothermia. WBH was induced by Finnish sauna bathing in 16 apparently healthy young (24 ± 4 years) adult men. Motor performance was monitored before and 2 h after the sauna, and immediately after submaximal exercise (120 s at 50% of maximal voluntary contraction). Markers of stress were monitored before and 2 h after the sauna. Finnish sauna exposure induced moderate to severe WBH (rectal temperature, 38.5-39.6 °C). At 2 h after the sauna, rectal temperature had recovered to the preheating level (preheating 37.11 ± 0.33 °C versus postheating 37.00 ± 0.29 °C, p > .05). Post-sauna recovery was accompanied by slowed salivary free cortisol diurnal kinetics, whereas noradrenaline, dopamine, and serotonin did not persist into the 2 h recovery after the sauna. Although recovery to normothermia after a sauna led to a greater acceleration of muscle contractility properties and decreased muscle steadiness, sustained isometric submaximal contraction did not provoke greater neuromuscular fatigability.
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Bidirectional and context-dependent changes in theta and gamma oscillatory brain activity in noradrenergic cell-specific Hypocretin/Orexin receptor 1-KO mice. Sci Rep 2018; 8:15474. [PMID: 30341359 PMCID: PMC6195537 DOI: 10.1038/s41598-018-33069-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 09/21/2018] [Indexed: 11/08/2022] Open
Abstract
Noradrenaline (NA) and hypocretins/orexins (HCRT), and their receptors, dynamically modulate the circuits that configure behavioral states, and their associated oscillatory activities. Salient stimuli activate spiking of locus coeruleus noradrenergic (NALC) cells, inducing NA release and brain-wide noradrenergic signalling, thus resetting network activity, and mediating an orienting response. Hypothalamic HCRT neurons provide one of the densest input to NALC cells. To functionally address the HCRT-to-NA connection, we selectively disrupted the Hcrtr1 gene in NA neurons, and analyzed resulting (Hcrtr1Dbh-CKO) mice’, and their control littermates’ electrocortical response in several contexts of enhanced arousal. Under enforced wakefulness (EW), or after cage change (CC), Hcrtr1Dbh-CKO mice exhibited a weakened ability to lower infra-θ frequencies (1–7 Hz), and mount a robust, narrow-bandwidth, high-frequency θ rhythm (~8.5 Hz). A fast-γ (55–80 Hz) response, whose dynamics closely parallelled θ, also diminished, while β/slow-γ activity (15–45 Hz) increased. Furthermore, EW-associated locomotion was lower. Surprisingly, nestbuilding-associated wakefulness, inversely, featured enhanced θ and fast-γ activities. Thus HCRT-to-NA signalling may fine-tune arousal, up in alarming conditions, and down during self-motivated, goal-driven behaviors. Lastly, slow-wave-sleep following EW and CC, but not nestbuilding, was severely deficient in slow-δ waves (0.75–2.25 Hz), suggesting that HCRT-to-NA signalling regulates the slow-δ rebound characterizing sleep after stress-associated arousal.
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Foote SL, Berridge CW. New developments and future directions in understanding locus coeruleus - Norepinephrine (LC-NE) function. Brain Res 2018; 1709:81-84. [PMID: 30267649 DOI: 10.1016/j.brainres.2018.09.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 09/24/2018] [Indexed: 12/29/2022]
Abstract
In this commentary we utilize recent observations regarding the organization and actions of the locus coeruleus-noradrenergic system to identify major issues in need of further study to more fully understand the behavioral actions of this major neurotransmitter system.
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Affiliation(s)
- Stephen L Foote
- Psychology Department, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Craig W Berridge
- Psychology Department, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Phasic locus coeruleus activity regulates cortical encoding of salience information. Proc Natl Acad Sci U S A 2018; 115:E9439-E9448. [PMID: 30232259 DOI: 10.1073/pnas.1803716115] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Phasic activation of locus coeruleus (LC)-norepinephrine (NE) neurons is associated with focused attention and behavioral responses to salient stimuli. We used cell-type-specific optogenetics and single-unit neurophysiology to identify how LC activity influences neural encoding of sensory information. We found that phasic, but not tonic, LC-NE photoactivation generated a distinct event-related potential (ERP) across cortical regions. Salient sensory stimuli (which innately trigger phasic LC activity) produced strong excitatory cortical responses during this ERP window. Application of weaker, nonsalient stimuli produced limited responses, but these responses were elevated to salient stimulus levels when they were temporally locked with phasic LC photoactivation. These results demonstrate that phasic LC activity enhances cortical encoding of salient stimuli by facilitating long-latency signals within target regions in response to stimulus intensity/salience. The LC-driven salience signal identified here provides a measure of phasic LC activity that can be used to investigate the LC's role in attentional processing across species.
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Lok R, Smolders KCHJ, Beersma DGM, de Kort YAW. Light, Alertness, and Alerting Effects of White Light: A Literature Overview. J Biol Rhythms 2018; 33:589-601. [PMID: 30191746 PMCID: PMC6236641 DOI: 10.1177/0748730418796443] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Light is known to elicit non-image-forming responses, such as effects on alertness. This has been reported especially during light exposure at night. Nighttime results might not be translatable to the day. This article aims to provide an overview of (1) neural mechanisms regulating alertness, (2) ways of measuring and quantifying alertness, and (3) the current literature specifically regarding effects of different intensities of white light on various measures and correlates of alertness during the daytime. In general, the present literature provides inconclusive results on alerting effects of the intensity of white light during daytime, particularly for objective measures and correlates of alertness. However, the various research paradigms employed in earlier studies differed substantially, and most studies tested only a limited set of lighting conditions. Therefore, the alerting potential of exposure to more intense white light should be investigated in a systematic, dose-dependent manner with multiple correlates of alertness and within one experimental paradigm over the course of day.
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Affiliation(s)
- Renske Lok
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Karin C H J Smolders
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Domien G M Beersma
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
| | - Yvonne A W de Kort
- Human-Technology Interaction, School of Innovation Sciences, Eindhoven University of Technology, Eindhoven, the Netherlands
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Abstract
PURPOSE To investigate heart rate and EEG variability and their coupling in patients with sepsis and determine their relationship to sepsis severity and severity of sepsis-associated brain dysfunction. METHODS Fifty-two patients with sepsis were prospectively identified, categorized as comatose (N = 30) and noncomatose (N = 22), and compared with 11 control subjects. In a 30-minute EEG and electrocardiogram recording, heart rate variability and EEG variability (measured by the variability of relative power in a modified alpha band = RAP) and their coupled oscillations were quantified using linear (least-square periodogram and magnitude square coherence) and nonlinear (Shannon entropy and mutual information) measures. These measures were compared between the three groups and correlated with outcome, adjusting for severity of sepsis. RESULTS Several measures of heart rate variability and EEG variability and of their coupled oscillations were significantly lower in patients with sepsis compared with controls and correlated with outcome. This correlation was not independent when adjusting for severity of sepsis. CONCLUSIONS Sepsis is associated with lower variability of both heart rate and RAP on EEG and reduction of their coupled oscillations. This uncoupling is associated with the severity of encephalopathy. Combined EEG and electrocardiogram monitoring may be used to gain insight in underlying mechanisms of sepsis and quantify brainstem or thalamic dysfunction.
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Liu Y, Rodenkirch C, Moskowitz N, Schriver B, Wang Q. Dynamic Lateralization of Pupil Dilation Evoked by Locus Coeruleus Activation Results from Sympathetic, Not Parasympathetic, Contributions. Cell Rep 2018; 20:3099-3112. [PMID: 28954227 DOI: 10.1016/j.celrep.2017.08.094] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 07/25/2017] [Accepted: 08/28/2017] [Indexed: 01/11/2023] Open
Abstract
Pupil size is collectively controlled by the sympathetic dilator and parasympathetic sphincter muscles. Locus coeruleus (LC) activation has been shown to evoke pupil dilation, but how the sympathetic and parasympathetic pathways contribute to this dilation remains unknown. We examined pupil dilation elicited by LC activation in lightly anesthetized rats. Unilateral LC activation evoked bilateral but lateralized pupil dilation; i.e., the ipsilateral dilation was significantly larger than the contralateral dilation. Surgically blocking the ipsilateral, but not contralateral, sympathetic pathway significantly reduced lateralization, suggesting that lateralization is mainly due to sympathetic contribution. Moreover, we found that sympathetic, but not parasympathetic, contribution is correlated with LC activation frequency. Together, our results unveil the frequency-dependent contributions of the sympathetic and parasympathetic pathways to LC activation-evoked pupil dilation and suggest that lateralization in task-evoked pupil dilations may be used as a biomarker for autonomic tone.
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Affiliation(s)
- Yang Liu
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Charles Rodenkirch
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Nicole Moskowitz
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Brian Schriver
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Qi Wang
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
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Ly S, Pack AI, Naidoo N. The neurobiological basis of sleep: Insights from Drosophila. Neurosci Biobehav Rev 2018; 87:67-86. [PMID: 29391183 PMCID: PMC5845852 DOI: 10.1016/j.neubiorev.2018.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 12/12/2022]
Abstract
Sleep is a biological enigma that has raised numerous questions about the inner workings of the brain. The fundamental question of why our nervous systems have evolved to require sleep remains a topic of ongoing scientific deliberation. This question is largely being addressed by research using animal models of sleep. Drosophila melanogaster, also known as the common fruit fly, exhibits a sleep state that shares common features with many other species. Drosophila sleep studies have unearthed an immense wealth of knowledge about the neuroscience of sleep. Given the breadth of findings published on Drosophila sleep, it is important to consider how all of this information might come together to generate a more holistic understanding of sleep. This review provides a comprehensive summary of the neurobiology of Drosophila sleep and explores the broader insights and implications of how sleep is regulated across species and why it is necessary for the brain.
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Affiliation(s)
- Sarah Ly
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
| | - Allan I Pack
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States
| | - Nirinjini Naidoo
- Center for Sleep and Circadian Neurobiology, 125 South 31st St., Philadelphia, PA, 19104-3403, United States; Division of Sleep Medicine/Department of Medicine, University of Pennsylvania Perelman School of Medicine, 125 South 31st St., Philadelphia, PA, 19104-3403, United States.
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Manohar A, Curtis AL, Zderic SA, Valentino RJ. Brainstem network dynamics underlying the encoding of bladder information. eLife 2017; 6. [PMID: 29199948 PMCID: PMC5714501 DOI: 10.7554/elife.29917] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/22/2017] [Indexed: 02/06/2023] Open
Abstract
Urodynamic status must interact with arousal and attentional processes so that voiding occurs under appropriate conditions. To elucidate the central encoding of this visceral demand, multisite recordings were made within a putative pontine-cortical micturition circuit from the pontine micturition center (PMC), locus coeruleus (LC) and medial prefrontal cortex (mPFC) during cystometry in unanesthetized rats. PMC neurons had homogeneous firing patterns, characterized by tonic activity and phasic bursts that were temporally associated with distinct phases of the micturition cycle. LC and cortical activation became synchronized 20-30 s prior to micturition. During this pre-micturition interval, a theta oscillation developed in the LC, the mPFC desynchronized and LC-mPFC coherence increased in the theta frequency range. The temporal offset between the shift in LC-mPFC network activity and micturition may allow time to disengage from ongoing behaviors unrelated to micturition and initiate specific voiding behaviors so that micturition occurs in environmentally and socially appropriate conditions. How do we know when we need to find a bathroom? As the bladder fills up, it sends signals to the brain to say that it needs emptying. But before the brain sends a message back to the bladder muscles telling them to contract to release urine, it first triggers a change in behavior. By increasing our alertness and arousing our senses, the brain ensures that we begin to look for a place where it is safe and appropriate to urinate. Only when we have found such a place will the brain tell the bladder to empty. Previous work has suggested that two brain regions play important roles in this process: the pontine micturition center (PMC) and its neighbor, the locus coeruleus. The PMC is thought to act as an on-off switch. When the bladder reaches a certain level of fullness the PMC activates, which tells the bladder muscles to contract. The locus coeruleus helps animals pay attention to important stimuli by making them more alert and energized whenever such stimuli are present. By recording the activity of neurons in the brains of rats while also measuring the pressure inside their bladders, Manohar et al. show that the PMC and the locus coeruleus work together to coordinate behavior and bladder emptying. Filling the bladder causes neurons in the locus coeruleus to activate in synchronized waves. This helps the locus coeruleus communicate with the brain’s outer layer, the cortex, leading to an increase in sensory alertness and arousal. This all happens before the bladder reaches the threshold fullness that activates the PMC, explaining why behavioral changes occur before urination. Manohar et al. show too that PMC neurons also activate when the rat is not urinating, suggesting that the PMC is more than an on-off switch. Healthy people experience the sensation of needing to empty their bladder well before the bladder is full, but people who do not receive these sensory signals may be unable to tell when they need to take action. This can lead to bedwetting in children and to incontinence in the elderly. Targeting the brain circuit that responds to bladder signals could lead to new treatments for these conditions.
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Affiliation(s)
- Anitha Manohar
- The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
| | - Andre L Curtis
- The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
| | - Stephen A Zderic
- The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
| | - Rita J Valentino
- The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
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