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Misrani A, Tabassum S, Wang T, Huang H, Jiang J, Diao H, Zhao Y, Huang Z, Tan S, Long C, Yang L. Vibration-reduced anxiety-like behavior relies on ameliorating abnormalities of the somatosensory cortex and medial prefrontal cortex. Neural Regen Res 2024; 19:1351-1359. [PMID: 37905885 DOI: 10.4103/1673-5374.385840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/19/2023] [Indexed: 11/02/2023] Open
Abstract
Abstract
JOURNAL/nrgr/04.03/01300535-202406000-00040/inline-graphic1/v/2023-10-30T152229Z/r/image-tiff
Tibetan singing bowls emit low-frequency sounds and produce perceptible harmonic tones and vibrations through manual tapping. The sounds the singing bowls produce have been shown to enhance relaxation and reduce anxiety. However, the underlying mechanism remains unclear. In this study, we used chronic restraint stress or sleep deprivation to establish mouse models of anxiety that exhibit anxiety-like behaviors. We then supplied treatment with singing bowls in a bottomless cage placed on the top of a cushion. We found that unlike in humans, the combination of harmonic tones and vibrations did not improve anxiety-like behaviors in mice, while individual vibration components did. Additionally, the vibration of singing bowls increased the level of N-methyl-D-aspartate receptor 1 in the somatosensory cortex and prefrontal cortex of the mice, decreased the level of γ-aminobutyric acid A (GABA) receptor α 1 subtype, reduced the level of CaMKII in the prefrontal cortex, and increased the number of GABAergic interneurons. At the same time, electrophysiological tests showed that the vibration of singing bowls significantly reduced the abnormal low-frequency gamma oscillation peak frequency in the medial prefrontal cortex caused by stress restraint pressure and sleep deprivation. Results from this study indicate that the vibration of singing bowls can alleviate anxiety-like behaviors by reducing abnormal molecular and electrophysiological events in somatosensory and medial prefrontal cortex.
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Affiliation(s)
- Afzal Misrani
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
- School of Life Sciences, Guangzhou University, Guangzhou, Guangdong Province, China
- School of Life Sciences, South China Normal University, Guangzhou, Guangdong Province, China
| | - Sidra Tabassum
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
- School of Life Sciences, Guangzhou University, Guangzhou, Guangdong Province, China
- School of Life Sciences, South China Normal University, Guangzhou, Guangdong Province, China
| | - Tintin Wang
- Guangzhou Hongai Cultural Development, Inc., Guangzhou, Guangdong Province, China
- Yinguo Health Management Team, Guangzhou, Guangdong Province, China
| | - Huixian Huang
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
- School of Life Sciences, South China Normal University, Guangzhou, Guangdong Province, China
| | - Jinxiang Jiang
- School of Life Sciences, Guangzhou University, Guangzhou, Guangdong Province, China
- School of Life Sciences, South China Normal University, Guangzhou, Guangdong Province, China
| | - Hongjun Diao
- Guangzhou Hongai Cultural Development, Inc., Guangzhou, Guangdong Province, China
- Yinguo Health Management Team, Guangzhou, Guangdong Province, China
| | - Yanping Zhao
- College of Biophotonics, South China Normal University, Guangzhou, Guangdong Province, China
| | - Zhen Huang
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
| | - Shaohua Tan
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
| | - Cheng Long
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, Guangdong Province, China
- School of Life Sciences, South China Normal University, Guangzhou, Guangdong Province, China
| | - Li Yang
- School of Life Sciences, Guangzhou University, Guangzhou, Guangdong Province, China
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Tap SC. The potential of 5-methoxy-N,N-dimethyltryptamine in the treatment of alcohol use disorder: A first look at therapeutic mechanisms of action. Addict Biol 2024; 29:e13386. [PMID: 38600715 PMCID: PMC11007263 DOI: 10.1111/adb.13386] [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: 09/27/2023] [Revised: 12/24/2023] [Accepted: 02/13/2024] [Indexed: 04/12/2024]
Abstract
Alcohol use disorder (AUD) remains one of the most prevalent psychiatric disorders worldwide with high economic costs. Current treatment options show modest efficacy and relapse rates are high. Furthermore, there are increases in the treatment gap and few new medications have been approved in the past 20 years. Recently, psychedelic-assisted therapy with psilocybin and lysergic acid diethylamide has garnered significant attention in the treatment of AUD. Yet, they require significant amounts of therapist input due to prolonged subjective effects (~4-12 h) leading to high costs and impeding implementation. Accordingly, there is an increasing interest in the rapid and short-acting psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). This paper offers a first look at potential therapeutic mechanisms for AUD by reviewing the current literature on 5-MeO-DMT. Primarily, 5-MeO-DMT is able to induce mystical experiences and ego-dissolution together with increases in psychological flexibility and mindfulness. This could decrease AUD symptoms through the alleviation of psychiatric mood-related comorbidities consistent with the negative reinforcement and self-medication paradigms. In addition, preliminary evidence indicates that 5-MeO-DMT modulates neural oscillations that might subserve ego-dissolution (increases in gamma), psychological flexibility and mindfulness (increases in theta), and the reorganization of executive control networks (increases in coherence across frequencies) that could improve emotion regulation and inhibition. Finally, animal studies show that 5-MeO-DMT is characterized by neuroplasticity, anti-inflammation, 5-HT2A receptor agonism, and downregulation of metabotropic glutamate receptor 5 with clinical implications for AUD and psychiatric mood-related comorbidities. The paper concludes with several recommendations for future research to establish the purported therapeutic mechanisms of action.
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Affiliation(s)
- Stephan C. Tap
- Department of PsychiatryGroningen University Medical CenterGroningenThe Netherlands
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Peng X, Mao Y, Liu Y, Dai Q, Tai Y, Luo B, Liang Y, Guan R, Zhou W, Chen L, Zhang Z, Shen G, Wang H. Microglial activation in the lateral amygdala promotes anxiety-like behaviors in mice with chronic moderate noise exposure. CNS Neurosci Ther 2024; 30:e14674. [PMID: 38468130 PMCID: PMC10927919 DOI: 10.1111/cns.14674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 01/26/2024] [Accepted: 02/24/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Long-term non-traumatic noise exposure, such as heavy traffic noise, can elicit emotional disorders in humans. However, the underlying neural substrate is still poorly understood. METHODS We exposed mice to moderate white noise for 28 days to induce anxiety-like behaviors, measured by open-field, elevated plus maze, and light-dark box tests. In vivo multi-electrode recordings in awake mice were used to examine neuronal activity. Chemogenetics were used to silence specific brain regions. Viral tracing, immunofluorescence, and confocal imaging were applied to define the neural circuit and characterize the morphology of microglia. RESULTS Exposure to moderate noise for 28 days at an 85-dB sound pressure level resulted in anxiety-like behaviors in open-field, elevated plus maze, and light-dark box tests. Viral tracing revealed that fibers projecting from the auditory cortex and auditory thalamus terminate in the lateral amygdala (LA). A noise-induced increase in spontaneous firing rates of the LA and blockade of noise-evoked anxiety-like behaviors by chemogenetic inhibition of LA glutamatergic neurons together confirmed that the LA plays a critical role in noise-induced anxiety. Noise-exposed animals were more vulnerable to anxiety induced by acute noise stressors than control mice. In addition to these behavioral abnormalities, ionized calcium-binding adaptor molecule 1 (Iba-1)-positive microglia in the LA underwent corresponding morphological modifications, including reduced process length and branching and increased soma size following noise exposure. Treatment with minocycline to suppress microglia inhibited noise-associated changes in microglial morphology, neuronal electrophysiological activity, and behavioral changes. Furthermore, microglia-mediated synaptic phagocytosis favored inhibitory synapses, which can cause an imbalance between excitation and inhibition, leading to anxiety-like behaviors. CONCLUSIONS Our study identifies LA microglial activation as a critical mediator of noise-induced anxiety-like behaviors, leading to neuronal and behavioral changes through selective synapse phagocytosis. Our results highlight the pivotal but previously unrecognized roles of LA microglia in chronic moderate noise-induced behavioral changes.
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Affiliation(s)
- Xiaoqi Peng
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Yunfeng Mao
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Yehao Liu
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Qian Dai
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Yingju Tai
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Bin Luo
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
- Department of PsychiatryThe First Affiliated Hospital of USTCHefeiChina
| | - Yue Liang
- Department of OtolaryngologyThe First Affiliated Hospital of USTCHefeiChina
| | - Ruirui Guan
- Department of OtolaryngologyThe First Affiliated Hospital of USTCHefeiChina
| | - Wenjie Zhou
- Songjiang Research InstituteShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Lin Chen
- Auditory Research Laboratory, Department of Neurobiology and Biophysics, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Zhi Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiChina
| | - Guoming Shen
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
| | - Haitao Wang
- School of Integrated Chinese and Western MedicineAnhui University of Chinese MedicineHefeiChina
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4
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Videira NB, Nair V, Paquet V, Calhoun D. The changing outlook of psychedelic drugs: The importance of risk assessment and occupational exposure limits. J Appl Toxicol 2024; 44:216-234. [PMID: 37646119 DOI: 10.1002/jat.4533] [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: 05/26/2023] [Revised: 07/25/2023] [Accepted: 08/11/2023] [Indexed: 09/01/2023]
Abstract
Serotonergic psychedelics, such as lysergic acid diethylamide (LSD), psilocybin, dimethyltryptamine (DMT), and 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), are currently being investigated for the treatment of psychiatric disorders such as depression and anxiety. Clinical trials with psilocybin and LSD have shown improvement in emotional and psychological scores. Although these drugs are reported to be safe in a controlled environment (such as clinical trials), exposure to low doses of these drugs can result in psychedelic effects, and therefore, occupational safety is an important consideration to prevent adverse effects in the workplace from low daily exposure. This article will discuss the factors involved in the derivation of occupational exposure limits (OELs) and risk assessment of these psychedelic drugs. To support the OEL derivations of psychedelic drugs, information regarding their mechanism of action, adverse effect profiles, pharmacokinetics, clinical effects, and nonclinical toxicity were considered. Additionally, psilocybin and LSD, which are the most extensively researched psychedelic substances, are employed as illustrative examples in case studies. The OELs derived for psilocybin and for LSD are 0.05 and 0.002 μg/m3 , respectively, which indicates that these are highly hazardous compounds, and it is important to take into account suitable safety measures and risk-management strategies in order to minimize workplace exposure.
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Affiliation(s)
| | | | - Valérie Paquet
- formerly Affygility Solutions, Broomfield, Colorado, USA
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5
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Jefferson SJ, Gregg I, Dibbs M, Liao C, Wu H, Davoudian PA, Woodburn SC, Wehrle PH, Sprouse JS, Sherwood AM, Kaye AP, Pittenger C, Kwan AC. 5-MeO-DMT modifies innate behaviors and promotes structural neural plasticity in mice. Neuropsychopharmacology 2023; 48:1257-1266. [PMID: 37015972 PMCID: PMC10354037 DOI: 10.1038/s41386-023-01572-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 02/26/2023] [Accepted: 03/20/2023] [Indexed: 04/06/2023]
Abstract
Serotonergic psychedelics are gaining increasing interest as potential therapeutics for a range of mental illnesses. Compounds with short-lived subjective effects may be clinically useful because dosing time would be reduced, which may improve patient access. One short-acting psychedelic is 5-MeO-DMT, which has been associated with improvement in depression and anxiety symptoms in early phase clinical studies. However, relatively little is known about the behavioral and neural mechanisms of 5-MeO-DMT, particularly the durability of its long-term effects. Here we characterized the effects of 5-MeO-DMT on innate behaviors and dendritic architecture in mice. We showed that 5-MeO-DMT induces a dose-dependent increase in head-twitch response that is shorter in duration than that induced by psilocybin at all doses tested. 5-MeO-DMT also substantially suppresses social ultrasonic vocalizations produced during mating behavior. 5-MeO-DMT produces long-lasting increases in dendritic spine density in the mouse medial frontal cortex that are driven by an elevated rate of spine formation. However, unlike psilocybin, 5-MeO-DMT did not affect the size of dendritic spines. These data provide insights into the behavioral and neural consequences underlying the action of 5-MeO-DMT and highlight similarities and differences with those of psilocybin.
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Affiliation(s)
- Sarah J Jefferson
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Ian Gregg
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Mark Dibbs
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Clara Liao
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Hao Wu
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Pasha A Davoudian
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, 06511, USA
- Medical Scientist Training Program, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Samuel C Woodburn
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Patrick H Wehrle
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
| | | | | | - Alfred P Kaye
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
- VA National Center for PTSD Clinical Neuroscience Division, West Haven, CT, 06516, USA
| | - Christopher Pittenger
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA
- Child Study Center, Yale University School of Medicine, New Haven, CT, 06511, USA
| | - Alex C Kwan
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA.
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, 14853, USA.
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, 06511, USA.
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
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Nogueira I, Lima TZ, Malfatti T, Leao KE. Loud noise-exposure changes the firing frequency of subtypes of layer 5 pyramidal neurons and Martinotti cells in the mouse auditory cortex. Front Aging Neurosci 2023; 15:1152497. [PMID: 37213542 PMCID: PMC10192617 DOI: 10.3389/fnagi.2023.1152497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/17/2023] [Indexed: 05/23/2023] Open
Abstract
Introduction Loud noise-exposure can generate noise-induced tinnitus in both humans and animals. Imaging and in vivo studies show that noise exposure affects the auditory cortex; however, cellular mechanisms of tinnitus generation are unclear. Methods Here we compare membrane properties of layer 5 (L5) pyramidal cells (PCs) and Martinotti cells expressing the cholinergic receptor nicotinic alpha 2 subunit gene (Chrna2) of the primary auditory cortex (A1) from control and noise-exposed (4-18 kHz, 90 dB, 1.5 h, followed by 1.5 h silence) 5-8 week old mice. PCs were furthermore classified in type A or type B based on electrophysiological membrane properties, and a logistic regression model predicting that afterhyperpolarization (AHP) and afterdepolarization (ADP) are sufficient to predict cell type, and these features are preserved after noise trauma. Results One week after a loud noise-exposure no passive membrane properties of type A or B PCs were altered but principal component analysis showed greater separation between type A PCs from control and noise-exposed mice. When comparing individual firing properties, noise exposure differentially affected type A and B PC firing frequency in response to depolarizing current steps. Specifically, type A PCs decreased initial firing frequency in response to +200 pA steps (p = 0.020) as well as decreased steady state firing frequency (p = 0.050) while type B PCs, on the contrary, significantly increased steady state firing frequency (p = 0.048) in response to a + 150 pA step 1 week after noise exposure. In addition, L5 Martinotti cells showed a more hyperpolarized resting membrane potential (p = 0.04), higher rheobase (p = 0.008) and an increased initial (p = 8.5 × 10-5) and steady state firing frequency (p = 6.3 × 10-5) in slices from noise-exposed mice compared to control. Discussion These results show that loud noise can cause distinct effects on type A and B L5 PCs and inhibitory Martinotti cells of the primary auditory cortex 1 week following noise exposure. As the L5 comprises PCs that send feedback to other areas, loud noise exposure appears to alter levels of activity of the descending and contralateral auditory system.
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Ornelas IM, Cini FA, Wießner I, Marcos E, de Araújo D, Goto-Silva L, Nascimento J, Silva SRB, Costa MN, Falchi M, Olivieri R, Palhano-Fontes F, Sequerra E, Martins-de-Souza D, Feilding A, Rennó-Costa C, Tófoli LF, Rehen SK, Ribeiro S. Nootropic effects of LSD: Behavioral, molecular and computational evidence. Exp Neurol 2022; 356:114148. [PMID: 35732217 DOI: 10.1016/j.expneurol.2022.114148] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 06/03/2022] [Accepted: 06/14/2022] [Indexed: 11/26/2022]
Abstract
The therapeutic use of classical psychedelic substances such as d-lysergic acid diethylamide (LSD) surged in recent years. Studies in rodents suggest that these effects are produced by increased neural plasticity, including stimulation of the mTOR pathway, a key regulator of metabolism, plasticity, and aging. Could psychedelic-induced neural plasticity be harnessed to enhance cognition? Here we show that LSD treatment enhanced performance in a novel object recognition task in rats, and in a visuo-spatial memory task in humans. A proteomic analysis of human brain organoids showed that LSD affected metabolic pathways associated with neural plasticity, including mTOR. To gain insight into the relation of neural plasticity, aging and LSD-induced cognitive gains, we emulated the experiments in rats and humans with a neural network model of a cortico-hippocampal circuit. Using the baseline strength of plasticity as a proxy for age and assuming an increase in plasticity strength related to LSD dose, the simulations provided a good fit for the experimental data. Altogether, the results suggest that LSD has nootropic effects.
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Affiliation(s)
- Isis M Ornelas
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
| | - Felipe A Cini
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Isabel Wießner
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil; Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Encarni Marcos
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, San Juan de Alicante, Spain
| | - Dráulio de Araújo
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Livia Goto-Silva
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
| | - Juliana Nascimento
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil; Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Sergio R B Silva
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Marcelo N Costa
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil; Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Marcelo Falchi
- Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | - Rodolfo Olivieri
- Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil
| | | | - Eduardo Sequerra
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Daniel Martins-de-Souza
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil; Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil; Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Científico e Tecnológico, São Paulo, Brazil; Experimental Medicine Research Cluster (EMRC), University of Campinas, Campinas, Brazil
| | | | - César Rennó-Costa
- Digital Metropolis Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil.
| | - Luis Fernando Tófoli
- Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, Brazil.
| | - Stevens K Rehen
- D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil; Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil.
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Malfatti T, Ciralli B, Hilscher MM, Leao RN, Leao KE. Decreasing dorsal cochlear nucleus activity ameliorates noise-induced tinnitus perception in mice. BMC Biol 2022; 20:102. [PMID: 35550106 PMCID: PMC9097071 DOI: 10.1186/s12915-022-01288-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 03/30/2022] [Indexed: 01/05/2023] Open
Abstract
Background The dorsal cochlear nucleus (DCN) is a region known to integrate somatosensory and auditory inputs and is identified as a potential key structure in the generation of phantom sound perception, especially noise-induced tinnitus. Yet, how altered homeostatic plasticity of the DCN induces and maintains the sensation of tinnitus is not clear. Here, we chemogenetically decrease activity of a subgroup of DCN neurons, Ca2+/Calmodulin kinase 2 α (CaMKII α)-positive DCN neurons, using Gi-coupled human M4 Designer Receptors Exclusively Activated by Designer Drugs (hM4Di DREADDs), to investigate their role in noise-induced tinnitus. Results Mice were exposed to loud noise (9–11kHz, 90dBSPL, 1h, followed by 2h of silence), and auditory brainstem responses (ABRs) and gap prepulse inhibition of acoustic startle (GPIAS) were recorded 2 days before and 2 weeks after noise exposure to identify animals with a significantly decreased inhibition of startle, indicating tinnitus but without permanent hearing loss. Neuronal activity of CaMKII α+ neurons expressing hM4Di in the DCN was lowered by administration of clozapine-N-oxide (CNO). We found that acutely decreasing firing rate of CaMKII α+ DCN units decrease tinnitus-like responses (p = 3e −3, n = 11 mice), compared to the control group that showed no improvement in GPIAS (control virus; CaMKII α-YFP + CNO, p = 0.696, n = 7 mice). Extracellular recordings confirmed CNO to decrease unit firing frequency of CaMKII α-hM4Di+ mice and alter best frequency and tuning width of response to sound. However, these effects were not seen if CNO had been previously administered during the noise exposure (n = 6 experimental and 6 control mice). Conclusion We found that lowering DCN activity in mice displaying tinnitus-related behavior reduces tinnitus, but lowering DCN activity during noise exposure does not prevent noise-induced tinnitus. Our results suggest that CaMKII α-positive cells in the DCN are not crucial for tinnitus induction but play a significant role in maintaining tinnitus perception in mice. Supplementary Information The online version contains supplementary material available at (10.1186/s12915-022-01288-1).
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Affiliation(s)
- Thawann Malfatti
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Barbara Ciralli
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Markus M Hilscher
- Institute for Analysis and Scientific Computing, Vienna University of Technology, Vienna, Austria
| | - Richardson N Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Katarina E Leao
- Hearing and Neuronal activity Lab, Brain Institute, Federal University of Rio Grande do Norte, Natal, Brazil.
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9
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Abstract
BACKGROUND 5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a naturally occurring, short-acting psychedelic tryptamine, produced by a variety of plant and animal species. Plants containing 5-MeO-DMT have been used throughout history for ritual and spiritual purposes. The aim of this article is to review the available literature about 5-MeO-DMT and inform subsequent clinical development. METHODS We searched PubMed database for articles about 5-MeO-DMT. Search results were cross-checked against earlier reviews and reference lists were hand searched. Findings were synthesised using a narrative synthesis approach. This review covers the pharmacology, chemistry and metabolism of 5-MeO-DMT, as well epidemiological studies, and reported adverse and beneficial effects. RESULTS 5-MeO-DMT is serotonergic agonist, with highest affinity for 5-HT1A receptors. It was studied in a variety of animal models, but clinical studies with humans are lacking. Epidemiological studies indicate that, like other psychedelics, 5-MeO-DMT induces profound alterations in consciousness (including mystical experiences), with potential beneficial long-term effects on mental health and well-being. CONCLUSION 5-MeO-DMT is a potentially useful addition to the psychedelic pharmacopoeia because of its short duration of action, relative lack of visual effects and putatively higher rates of ego-dissolution and mystical experiences. We conclude that further clinical exploration is warranted, using similar precautions as with other classic psychedelics.
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Affiliation(s)
- Anna O Ermakova
- Beckley Psytech, Beckley, UK,Psychedelic Trials Group, Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK,Anna O Ermakova, Psychedelic Trials Group, Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, 16 De Crespigny Park, London SE5 8AF, UK.
| | | | - James Rucker
- Psychedelic Trials Group, Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
| | - Matthew W Johnson
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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10
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Glavonic E, Mitic M, Adzic M. Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction. J Neurosci Res 2022; 100:947-969. [PMID: 35165930 DOI: 10.1002/jnr.25017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/17/2021] [Accepted: 01/05/2022] [Indexed: 12/29/2022]
Abstract
Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.
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Affiliation(s)
- Emilija Glavonic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Milos Mitic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Miroslav Adzic
- Department of Molecular Biology and Endocrinology, "VINČA" Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
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Motaghi S, Moghaddam Dizaj Herik H, Sepehri G, Abbasnejad M, Esmaeli-Mahani S. The anxiolytic effect of salicylic acid is mediated via the GABAergic system in the fear potentiated plus maze behavior in rats. Mol Biol Rep 2021; 49:1133-1139. [PMID: 34797490 DOI: 10.1007/s11033-021-06939-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 11/05/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Salicylic acid (SA) is a natural phenolic compound in plants with many beneficial effects for humans. The anxiolytic effect of this compound has been reported in animal models, but its mechanism of action remains unclear. In this study, by using the fear potentiated plus maze test, we evaluated the effect of salicylic acid on the gene expression of the main form of GABA (gamma aminobutyric acid) synthesizing enzyme i.e., the enzyme glutamic acid decarboxylase 67 (GAD67) which is called GAD1, in the ventral subiculum of the hippocampus, one of the main brain structures, in anxiety circuits. Also, the hypnotic effect of Salicylic acid was evaluated. METHODS Animals were divided into the solvent, (SA) and diazepam treated groups (n = 6). For evaluating the anxiolytic effect of Salicylic acid, animals were subjected to 2 h of isolation, before placing them in the elevated plus maze (EPM). Afterward, the ventral part of the hippocampus was removed for evaluating the change in GAD1 gene expression by the reverse transcription-quantitative polymerase chain reaction (RTqPCR) technique. The hypnotic effect of Salicylic acid was evaluated in the ketamine induced sleeping test. RESULTS Salicylic acid at 10 and 30 (mg/kg) increased time spent and entries to the open arms in the (EPM) (p < 0.05). (RTqPCR) revealed that 30 mg/kg of Salicylic acid increased GAD1 gene expression (p < 0.001). Salicylic acid (30 and 300 mg/kg) also increased the duration of sleep, in ketamine induced sleeping test (p < 0.05). CONCLUSION Our results showed that Salicylic acid has anxiolytic and hypnotic effects and it exerts its anxiolytic effect partly, via up the regulation of GAD1 in the ventral part of the hippocampus.
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Affiliation(s)
- Sahel Motaghi
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.
| | - Hadi Moghaddam Dizaj Herik
- Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Gholamreza Sepehri
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Saeed Esmaeli-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
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Diab H, Malcolm B. Persistent Tinnitus after Inhaled N,N-dimethyltryptamine (DMT). J Psychoactive Drugs 2020; 53:140-145. [PMID: 33242285 DOI: 10.1080/02791072.2020.1847366] [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: 10/22/2022]
Abstract
This case report describes a 39-year-old male with remote history of polysubstance use disorder and depression who developed tinnitus after use of inhaled N,N-dimethyltryptamine (DMT). Although development of ear ringing was attributed to use on a single occasion, tinnitus occurred within the context of a larger self-experiment involving weekly microdoses of lysergic acid diethylamide (LSD). Distress and anxiety over the ear ringing prompted evaluation by an audiologist, primary care physician, and consultant psychopharmacologist. Tinnitus persisted for several months, although intensity and ability to cope with symptoms improved over time. A microdose of psilocybin mushrooms exacerbated tinnitus on two separate occasions, after which psychedelics were discontinued. Psychedelics are associated with a range of acute sensory changes including auditory phenomenon, although have not previously been associated with tinnitus in medical literature. Here, we present a probable case of tinnitus associated with DMT use and review potential underlying mechanisms connecting psychedelics and tinnitus.
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Affiliation(s)
- Heba Diab
- Western University of Health Sciences, College of Pharmacy, Pomona, CA, USA
| | - Benjamin Malcolm
- Western University of Health Sciences, College of Pharmacy, Pomona, CA, USA
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