1
|
Dervišević E. Hyperthermia: Is it always an accidental death? Leg Med (Tokyo) 2024; 68:102418. [PMID: 38335833 DOI: 10.1016/j.legalmed.2024.102418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024]
Abstract
INTRODUCTION The research aimed to determine individual variations in different core temperature measurements before the experiment, after submersion, after 20 min of exposure for heat stroke. METHODS Rats were divided into three groups depending on the temperature and length of exposure to water: CG, G41-20 and G41-UD. The protocol was made according to the earlier described methodology of heat shock induction. RESULTS A significant difference was observed in the G41-UD group; p < 0.0005. The lowest body temperature of the rats was observed, from normothermia, and the highest temperature after death, 37.87 ± 0.62 °C vs 41.20 ± 0.76 °C, the difference between all three groups is p < 0.0005. CONCLUSION Exposure of Wistar rats to water temperatures in the CG and G41 groups led to a significant change in core temperature. In the control group, the thermoregulatory mechanism firmly established normothermia, while hyperthermia was revealed in the G41 group during the 20-minute exposure.
Collapse
Affiliation(s)
- Emina Dervišević
- Department of Forensic Medicine, Faculty of Medicine, University of Sarajevo, Sarajevo, Bosnia and Herzegovina
| |
Collapse
|
2
|
Lesku JA, Barker RG, Elmes H, Robert KA, Tworkowski L, Dutka TL. Wild white-capped noddies keep a cool head in a heated situation. J Therm Biol 2023; 118:103754. [PMID: 38000146 DOI: 10.1016/j.jtherbio.2023.103754] [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: 07/27/2023] [Revised: 11/02/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023]
Abstract
Sunning, or sunbathing, is a behavior observed in diverse birds from at least 50 taxonomic families. While sunning, birds exhibit signs of heat stress, notably panting, indicating a risk of overheating. Given that even modest increases in brain temperature can impair brain function, sunning birds may have mechanisms that selectively cool the brain. Sunning birds could cool the brain using active physiological mechanisms (e.g., an ophthalmic rete or sleeping) or passive adaptations, such as light-colored plumage over the cranium. White-capped noddies are tropical seabirds that sunbathe in direct sunlight on cloudless days. Using infrared thermography on wild birds, we found that the white cap is 20 °C cooler than that of the black back while sunning. A deceased bird showed the same thermal profile, indicating that this difference arises from dichromatic coloration and not underlying physiology. Thus, the white cap may extend the duration of time noddies can sunbathe and keep the brain cool, near core body temperature, while allowing the rest of the body to heat up, perhaps to displace or kill parasites.
Collapse
Affiliation(s)
- John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia; Research Centre for Future Landscapes, La Trobe University, Melbourne, Australia
| | - Robert G Barker
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Hannah Elmes
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Kylie A Robert
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia; Research Centre for Future Landscapes, La Trobe University, Melbourne, Australia
| | - Lauren Tworkowski
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia
| | - Travis L Dutka
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Australia; Research Centre for Future Landscapes, La Trobe University, Melbourne, Australia.
| |
Collapse
|
3
|
Cameron-Burr KT, Bola RA, Kiyatkin EA. Dantrolene sodium fails to reverse robust brain hyperthermia induced by MDMA and methamphetamine in rats. Psychopharmacology (Berl) 2023; 240:785-795. [PMID: 36700960 DOI: 10.1007/s00213-023-06321-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/19/2023] [Indexed: 01/27/2023]
Abstract
RATIONALE Hyperthermia induced by psychomotor stimulants may cause leakage of the blood-brain barrier, vasogenic edema, and lethality in extreme cases. Current treatments such as whole-body cooling are only symptomatic and a clear need to develop pharmacological interventions exists. Dantrolene sodium, a peripheral muscle relaxant used in the treatment of malignant hyperthermia, has been proposed as potentially effective to treat MDMA-hyperthermia in emergency rooms. However, debate around its efficacy for this indication persists. OBJECTIVES To investigate dantrolene as a treatment for illicit hyperthermia induced by psychomotor stimulant drugs, we examined how Ryanodex®, a concentrated formulation of dantrolene sodium produced by Eagle Pharmaceuticals, influences 3,4-methylenedioxymethamphetamine (MDMA)- and methamphetamine (METH)-induced hyperthermia in awake freely moving rats. We injected rats with moderate doses of MDMA (9 mg/kg) and METH (9 mg/kg) and administered Ryanodex® intravenously (6 mg/kg) after the development of robust hyperthermia (>2.5 °C) mimicking clinical acute intoxication. We conducted simultaneous temperature recordings in the brain, temporal muscle, and skin to determine the basic mechanisms underlying temperature responses. To assess the efficacy of dantrolene in attenuating severe hyperthermia, we administered MDMA to rats maintained in a warm ambient environment (29 °C), conditions which produce robust brain and body hyperthermia (>40 °C) and lethality. RESULTS Dantrolene failed to attenuate MDMA- and METH-induced hyperthermia, though locomotor activity was significantly reduced. All animals maintained at warm ambient temperatures that received dantrolene during severe drug-induced hyperthermia died within or soon after the recording session. CONCLUSIONS Our results suggest that dantrolene sodium formulations are not mechanistically suited to treat MDMA- and METH-induced hyperthermia.
Collapse
Affiliation(s)
- Keaton T Cameron-Burr
- Behavioral Neuroscience Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, DHHS, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| | - R Aaron Bola
- Behavioral Neuroscience Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, DHHS, 251 Bayview Blvd, Baltimore, MD, 21224, USA
| | - Eugene A Kiyatkin
- Behavioral Neuroscience Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, DHHS, 251 Bayview Blvd, Baltimore, MD, 21224, USA.
| |
Collapse
|
4
|
Donaldson AC, Fuller A, Meyer LCR, Buss PE. Chemical immobilisation of lions: weighing up drug effectiveness versus clinical effects. J S Afr Vet Assoc 2023; 94:23-32. [PMID: 37358315 DOI: 10.36303/jsava.544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023] Open
Abstract
Selection of an effective drug combination to immobilise African lions (Panthera leo) requires balancing immobilisation effectiveness with potential side effects. We compared the immobilisation effectiveness and changes to physiological variables induced by three drug combinations used for free-ranging African lions. The lions (12 animals per drug combination) were immobilised with tiletamine-zolazepam-medetomidine (TZM), ketamine-medetomidine (KM) or ketamine-butorphanol-medetomidine (KBM). Induction, immobilisation, and recovery were timed, evaluated using a scoring system, and physiological variables were monitored. The drugs used for immobilisation were antagonised with atipamezole and naltrexone. The quality of induction was rated as excellent for all drug combinations and induction times (mean ± SD) did not differ between the groups (10.54 ± 2.67 min for TZM, 10.49 ± 2.63 min for KM, and 11.11 ± 2.91 min for KBM). Immobilisation depth was similar over the immobilisation period in the TZM and KBM groups, and initially light, progressing to deeper in lions administered KM. Heart rate, respiratory rate and peripheral arterial haemoglobin saturation with oxygen were within the expected range for healthy, awake lions in all groups. All lions were severely hypertensive and hyperthermic throughout the immobilisation. Following antagonism of immobilising drugs, lions immobilised with KM and KBM recovered to walking sooner than those immobilised with TZM, at 15.29 ± 10.68 min, 10.88 ± 4.29 min and 29.73 ± 14.46 min, respectively. Only one lion in the KBM group exhibited ataxia during recovery compared to five and four lions in the TZM and KM groups, respectively. All three drug combinations provided smooth inductions and effective immobilisations but resulted in hypertension. KBM had an advantage of allowing for shorter, less ataxic recoveries.
Collapse
Affiliation(s)
- A C Donaldson
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa and Centre for Veterinary Wildlife Research, Faculty of Veterinary Science, University of Pretoria, South Africa and Center for Zoo and Wild Animal Health, Copenhagen Zoo, Denmark and Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - A Fuller
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa and Centre for Veterinary Wildlife Research, Faculty of Veterinary Science, University of Pretoria, South Africa and Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - L C R Meyer
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, South Africa and Centre for Veterinary Wildlife Research, Faculty of Veterinary Science, University of Pretoria, South Africa and Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, South Africa
| | - P E Buss
- Centre for Veterinary Wildlife Research, Faculty of Veterinary Science, University of Pretoria, South Africa and Veterinary Wildlife Services, South African National Parks, Kruger National Park, South Africa and Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, South Africa
| |
Collapse
|
5
|
Szlasa W, Janicka N, Sauer N, Michel O, Nowak B, Saczko J, Kulbacka J. Chemotherapy and Physical Therapeutics Modulate Antigens on Cancer Cells. Front Immunol 2022; 13:889950. [PMID: 35874714 PMCID: PMC9299262 DOI: 10.3389/fimmu.2022.889950] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 06/06/2022] [Indexed: 12/29/2022] Open
Abstract
Cancer cells possess specific properties, such as multidrug resistance or unlimited proliferation potential, due to the presence of specific proteins on their cell membranes. The release of proliferation-related proteins from the membrane can evoke a loss of adaptive ability in cancer cells and thus enhance the effects of anticancer therapy. The upregulation of cancer-specific membrane antigens results in a better outcome of immunotherapy. Moreover, cytotoxic T-cells may also become more effective when stimulated ex-vivo toward the anticancer response. Therefore, the modulation of membrane proteins may serve as an interesting attempt in anticancer therapy. The presence of membrane antigens relies on various physical factors such as temperature, exposure to radiation, or drugs. Therefore, changing the tumor microenvironment conditions may lead to cancer cells becoming sensitized to subsequent therapy. This paper focuses on the therapeutic approaches modulating membrane antigens and enzymes in anticancer therapy. It aims to analyze the possible methods for modulating the antigens, such as pharmacological treatment, electric field treatment, photodynamic reaction, treatment with magnetic field or X-ray radiation. Besides, an overview of the effects of chemotherapy and immunotherapy on the immunophenotype of cancer cells is presented. Finally, the authors review the clinical trials that involved the modulation of cell immunophenotype in anticancer therapy.
Collapse
Affiliation(s)
- Wojciech Szlasa
- Faculty of Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Natalia Janicka
- Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Natalia Sauer
- Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Olga Michel
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Bernadetta Nowak
- Faculty of Medicine, Wroclaw Medical University, Wroclaw, Poland
| | - Jolanta Saczko
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Julita Kulbacka
- Department of Molecular and Cellular Biology, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| |
Collapse
|
6
|
Hassani Moghaddam M, Eskandarian Boroujeni M, Vakili K, Fathi M, Abdollahifar MA, Eskandari N, Esmaeilpour T, Aliaghaei A. Functional and structural alternations in the choroid plexus upon methamphetamine exposure. Neurosci Lett 2021; 764:136246. [PMID: 34530114 DOI: 10.1016/j.neulet.2021.136246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 08/27/2021] [Accepted: 09/09/2021] [Indexed: 12/13/2022]
Abstract
Choroid plexus (CP) is the principal source of cerebrospinal fluid. CP can produce and release a wide range of materials including growth factors, neurotrophic factors, etc. all of which play an important role in the maintenance and proper functioning of the brain. Methamphetamine (METH) is a CNS neurostimulant that causes brain dysfunction. Herein, we investigated the potential effects of METH exposure on CP structure and function. Stereological analysis revealed a significant alteration in CP volume, epithelial cells and capillary number upon METH treatment. Electron microscopy exhibited changes in ultrastructure. Moreover, the upregulation of neurotrophic factors such as BDNF and VEGF as well as autophagy and apoptosis gene following METH administration were observed. We also identified several signaling cascades related to autophagy. In conclusion, gene expression changes coupled with structural alterations of the CP in response to METH suggested METH-induced autophagy in CP.
Collapse
Affiliation(s)
- Meysam Hassani Moghaddam
- Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mahdi Eskandarian Boroujeni
- Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - Kimia Vakili
- Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mobina Fathi
- Student Research Committee, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Amin Abdollahifar
- Department of Cell Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Neda Eskandari
- Department of Cell Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Tahereh Esmaeilpour
- Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Abbas Aliaghaei
- Department of Cell Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
7
|
Tirri M, Frisoni P, Bilel S, Arfè R, Trapella C, Fantinati A, Corli G, Marchetti B, De-Giorgio F, Camuto C, Mazzarino M, Gaudio RM, Serpelloni G, Schifano F, Botrè F, Marti M. Worsening of the Toxic Effects of (±) Cis-4,4'-DMAR Following Its Co-Administration with (±) Trans-4,4'-DMAR: Neuro-Behavioural, Physiological, Immunohistochemical and Metabolic Studies in Mice. Int J Mol Sci 2021; 22:ijms22168771. [PMID: 34445476 PMCID: PMC8395767 DOI: 10.3390/ijms22168771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/13/2021] [Accepted: 08/14/2021] [Indexed: 11/16/2022] Open
Abstract
4,4’-Dimethylaminorex (4,4’-DMAR) is a new synthetic stimulant, and only a little information has been made available so far regarding its pharmaco-toxicological effects. The aim of this study was to investigate the effects of the systemic administration of both the single (±)cis (0.1–60 mg/kg) and (±)trans (30 and 60 mg/kg) stereoisomers and their co-administration (e.g., (±)cis at 1, 10 or 60 mg/kg + (±)trans at 30 mg/kg) in mice. Moreover, we investigated the effect of 4,4′-DMAR on the expression of markers of oxidative/nitrosative stress (8-OHdG, iNOS, NT and NOX2), apoptosis (Smac/DIABLO and NF-κB), and heat shock proteins (HSP27, HSP70, HSP90) in the cerebral cortex. Our study demonstrated that the (±)cis stereoisomer dose-dependently induced psychomotor agitation, sweating, salivation, hyperthermia, stimulated aggression, convulsions and death. Conversely, the (±)trans stereoisomer was ineffective whilst the stereoisomers’ co-administration resulted in a worsening of the toxic (±)cis stereoisomer effects. This trend of responses was confirmed by immunohistochemical analysis on the cortex. Finally, we investigated the potentially toxic effects of stereoisomer co-administration by studying urinary excretion. The excretion study showed that the (±)trans stereoisomer reduced the metabolism of the (±)cis form and increased its amount in the urine, possibly reflecting its increased plasma levels and, therefore, the worsening of its toxicity.
Collapse
Affiliation(s)
- Micaela Tirri
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Paolo Frisoni
- Department of Medical Sciences, University of Ferrara, 44121 Ferrara, Italy;
| | - Sabrine Bilel
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Raffaella Arfè
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Claudio Trapella
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy; (C.T.); (A.F.)
| | - Anna Fantinati
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy; (C.T.); (A.F.)
| | - Giorgia Corli
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Beatrice Marchetti
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Fabio De-Giorgio
- Department of Health Care Surveillance and Bioetics, Section of Legal Medicine, Università Cattolica del Sacro Cuore, 00168 Rome, Italy;
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Cristian Camuto
- Laboratorio Antidoping FMSI, Largo Giulio Onesti 1, 00197 Rome, Italy; (C.C.); (M.M.); (F.B.)
| | - Monica Mazzarino
- Laboratorio Antidoping FMSI, Largo Giulio Onesti 1, 00197 Rome, Italy; (C.C.); (M.M.); (F.B.)
| | - Rosa Maria Gaudio
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
| | - Giovanni Serpelloni
- Neuroscience Clinical Center & TMS Unit, 37138 Verona, Italy;
- Department of Psychiatry in the College of Medicine, Drug Policy Institute, University of Florida, Gainesville, FL 32611, USA
| | - Fabrizio Schifano
- Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, School of Life and Medical Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK;
| | - Francesco Botrè
- Laboratorio Antidoping FMSI, Largo Giulio Onesti 1, 00197 Rome, Italy; (C.C.); (M.M.); (F.B.)
- Institute of Sport Science, University of Lausanne (ISSUL), Synathlon, 1015 Lausanne, Switzerland
| | - Matteo Marti
- LTTA Center and University Center of Gender Medicine, Department of Translational Medicine, Section of Legal Medicine, University of Ferrara, 44121 Ferrara, Italy; (M.T.); (S.B.); (R.A.); (G.C.); (B.M.); (R.M.G.)
- Collaborative Center for the Italian National Early Warning System, Department of Anti-Drug Policies, Presidency of the Council of Ministers, 00186 Rome, Italy
- Correspondence:
| |
Collapse
|
8
|
Thermally tolerant intertidal triplefin fish (Tripterygiidae) sustain ATP dynamics better than subtidal species under acute heat stress. Sci Rep 2021; 11:11074. [PMID: 34040122 PMCID: PMC8155050 DOI: 10.1038/s41598-021-90575-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 04/30/2021] [Indexed: 11/18/2022] Open
Abstract
Temperature is a key factor that affects all levels of organization. Minute shifts away from thermal optima result in detrimental effects that impact growth, reproduction and survival. Metabolic rates of ectotherms are especially sensitive to temperature and for organisms exposed to high acute temperature changes, in particular intertidal species, energetic processes are often negatively impacted. Previous investigations exploring acute heat stress have implicated cardiac mitochondrial function in determining thermal tolerance. The brain, however, is by weight, one of the most metabolically active and arguably the most temperature sensitive organ. It is essentially aerobic and entirely reliant on oxidative phosphorylation to meet energetic demands, and as temperatures rise, mitochondria become less efficient at synthesising the amount of ATP required to meet the increasing demands. This leads to an energetic crisis. Here we used brain homogenate of three closely related triplefin fish species (Bellapiscis medius, Forsterygion lapillum, and Forsterygion varium) and measured respiration and ATP dynamics at three temperatures (15, 25 and 30 °C). We found that the intertidal B. medius and F. lapillum were able to maintain rates of ATP production above rates of ATP hydrolysis at high temperatures, compared to the subtidal F. varium, which showed no difference in rates at 30 °C. These results showed that brain mitochondria became less efficient at temperatures below their respective species thermal limits, and that energetic surplus of ATP synthesis over hydrolysis narrows. In subtidal species synthesis matches hydrolysis, leaving no scope to elevate ATP supply.
Collapse
|
9
|
Abstract
Movement is a key feature of the surveillance and protective roles of microglia. This dynamic process is highly modulated by the surrounding environment. We discovered that microglia movement is temperature dependent in vitro and in vivo. Our investigation of thermosensitive TRP channel involvement in this phenomenon revealed several candidates including TRPM2, TRPM4, and TRPV4 channels. Using pharmacological tools and transgenic mice, we showed that the temperature dependency of microglia movement mainly relies on TRPV4 channel activity. Understanding the mechanisms by which temperature modulates microglia movement will improve our comprehension of pathological processes and allow the identification of new leads for the treatment of brain pathologies. Microglia maintain central nervous system homeostasis by monitoring changes in their environment (resting state) and by taking protective actions to equilibrate such changes (activated state). These surveillance and protective roles both require constant movement of microglia. Interestingly, induced hypothermia can reduce microglia migration caused by ischemia, suggesting that microglia movement can be modulated by temperature. Although several ion channels and transporters are known to support microglia movement, the precise molecular mechanism that regulates temperature-dependent movement of microglia remains unclear. Some members of the transient receptor potential (TRP) channel superfamily exhibit thermosensitivity and thus are strong candidates for mediation of this phenomenon. Here, we demonstrate that mouse microglia exhibit temperature-dependent movement in vitro and in vivo that is mediated by TRPV4 channels within the physiological range of body temperature. Our findings may provide a basis for future research into the potential clinical application of temperature regulation to preserve cell function via manipulation of ion channel activity.
Collapse
|
10
|
Iyasere OS, Oyetunji DE, Wheto M, Durosaro SO, Adigun TT, Muraina HA, Akinyemi OO, Daramola JO. Effect of acute heat stress on cognitive performance of chickens in a feed-related discriminant task. J Therm Biol 2021; 98:102914. [PMID: 34016341 DOI: 10.1016/j.jtherbio.2021.102914] [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: 10/13/2020] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
Little is known about immediate and long-lasting effect of acute heat stress on chicken cognition. Thirty-five, 9-week-old birds were trained to differentiate two cone colours; white (rewarded, R; with feed underneath) and black (unrewarded, UR; empty). The sixteen birds that learnt the task were randomly assigned to three temperature regimens (TR: 22-24 °C (control), 30-32 and 36-38 °C for 3h/day) for three consecutive days during which rectal (RT), wing (WT) and eye (ET) temperatures were monitored. After the 3 h of exposure, birds were allowed to rest for 1 h before the commencement of the discriminant task. The latencies to open the cones (R and UR) and proportion of cones opened were recorded. A long-lasting effect was tested a week after exposure to TR. TR had a significant effect on RT, WT and ET. The motivation to turn over R cones was weaker in birds exposed to 36-38 °C than birds exposed to 22-24 °C. Also, the proportion of R cones opened were fewer in birds that experienced TR of 36-38 °C compared to birds exposed to 22-24 °C and 30-32 °C specifically on two out of the three cognitive test days (Days 1 and 3). Latency and proportion of UR cones opened was not affected by TR. RT, WT and ET were all negatively and significantly correlated with latency to open the UR cones. Previous exposure of birds to three TR had no effect on the latency to open both cones but the proportion of R cones opened was greater in birds exposed to 30-32 °C compared to the 22-24 °C birds. In conclusion, an immediate (36-38 °C) and long-lasting effect (30-32 °C) of acute heat stress was associated with a weak motivation to perform feed related discrimination task.
Collapse
Affiliation(s)
- Oluwaseun S Iyasere
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.
| | - Damilola E Oyetunji
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Mathew Wheto
- Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Samuel O Durosaro
- Department of Animal Breeding and Genetics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Taiwo T Adigun
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Habeeb A Muraina
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - Olaoluwa O Akinyemi
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| | - James O Daramola
- Department of Animal Physiology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
| |
Collapse
|
11
|
van den Heuvel AMJ, Haberley BJ, Hoyle DJR, Taylor NAS, Croft RJ. Hyperthermia, but not dehydration, alters the electrical activity of the brain. Eur J Appl Physiol 2020; 120:2797-2811. [DOI: 10.1007/s00421-020-04492-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 09/03/2020] [Indexed: 11/28/2022]
|
12
|
Mwanda L, Ikusika OO, Mpendulo CT, Okoh AI. Effects of fossil shell flour supplementation on heat tolerance of dohne merino rams. Vet Anim Sci 2020; 10:100133. [PMID: 32734033 PMCID: PMC7386667 DOI: 10.1016/j.vas.2020.100133] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/25/2020] [Accepted: 06/25/2020] [Indexed: 11/13/2022] Open
Abstract
This study evaluated the effects of fossil shell flour (FSF) supplementation on heat tolerance of Dohne Merino sheep. Twenty-four (n = 24) Dohne Merino rams of about 4 months old, weighing 22.3 ± 0.43 kg were confined in individual pens using complete randomized design for a period of 100 days. The rams were subjected to four varying inclusion levels of fossil shell flour (0 g/kg, 20 g/kg, 40 g/kg and 60 g/kg. Water and feed intake were recorded throughout the period of successive feeding. On days 0, 45 and 90, blood samples were collected for analyses. The parameters monitored included the average daily water intake (ADWI), average feed intake (ADFI), skin temperature (ST), respiration rate (RR), pulse rate (PR), rectal temperature (RT), total plasma protein (TPP), blood glucose (GLU), red blood cell (RBC),white blood cell (WBC), Heamaglobin (Hb), mean corpuscular hemoglobin concentration (MCHC), Packed cell volume (PCV), and mean corpuscular volume (MCV). The inclusion levels of FSF affected ADWI and ADFI, revealing high water intake and feed intake in rams subjected to 40 g/kg of FSF followed by 60 g FSF/kg, 20 g FSF/kg and 0 g FSF/kg (P< 0.01) respectively. All the physiological parameters (ST, RT, RR and PR) decreased with increase in inclusion levels of FSF (P< 0.01). The TPP and GLU increased as the levels of FSF increases (P< 0.01). The RBC and WBC were higher in rams subjected to FSF supplemented diets compared to the control (p<0.05). We conclude that water and feed intake increase with increasing levels of the FSF while the physiological parameters decline as levels of FSF increases. Hence, fossil shell flour could be used as a supplement in Dohne-Merino rams’ diet to mitigate heat stress and promote overall productivity of the sheep.
Collapse
Affiliation(s)
- Lwazi Mwanda
- Department of Livestock and Pasture Science, Faculty of Science and Agriculture, University of Fort Hare, Alice, South Africa
| | - Olusegun O Ikusika
- Department of Livestock and Pasture Science, Faculty of Science and Agriculture, University of Fort Hare, Alice, South Africa.,SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa
| | - Conference T Mpendulo
- Department of Livestock and Pasture Science, Faculty of Science and Agriculture, University of Fort Hare, Alice, South Africa
| | - Anthony I Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa.,Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa
| |
Collapse
|
13
|
Zwartsen A, Hondebrink L, de Lange DW, Westerink RHS. Hyperthermia exacerbates the acute effects of psychoactive substances on neuronal activity measured using microelectrode arrays (MEAs) in rat primary cortical cultures in vitro. Toxicol Appl Pharmacol 2020; 397:115015. [PMID: 32320794 DOI: 10.1016/j.taap.2020.115015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 04/15/2020] [Accepted: 04/17/2020] [Indexed: 11/21/2022]
Abstract
Hyperthermia is a well-known, potentially life-threatening, side effect of stimulant psychoactive substances that worsens the neurological outcome of hospitalized patients. However, current in vitro methods to assess the hazard of psychoactive substances do not account for hyperthermia. Therefore, this study determined the potency of five psychoactive substances (cocaine, MDMA (3,4-methylenedioxymethamphetamine), methamphetamine, 3-MMC (3-methylmethcathinone) and TFMPP (3-trifluoromethylphenylpiperazine)) to affect neuronal activity at physiological and hyperthermic conditions. Neuronal activity of rat cortical cultures grown on microelectrode arrays (MEAs) was recorded at 37 °C before exposure. Following 30 min and 4.5 h drug exposure (1-1000 μM) at 37 °C or 41 °C, neuronal activity was measured at either 37 °C or 41 °C. Without drug exposure, hyperthermia induced a modest decrease in neuronal activity. Following acute (30 min) exposure at 37 °C, all drugs concentration-dependently inhibited neuronal activity. Increasing the temperature to 41 °C significantly exacerbated the reduction of neuronal activity ~ 2-fold for all drugs compared to 37 °C. Prolonged (4.5 h) exposure at 41 °C decreased neuronal activity comparable to 37 °C. Neuronal activity (partly) recovered following drug exposure at both temperatures, although recovery from exposure at 41 °C was less pronounced for most drugs. None of the exposure conditions affected viability. Since acute exposure at hyperthermic conditions exacerbates the decrease in neuronal activity induced by psychoactive substances, effects of hyperthermia should be included in future hazard assessment of illicit drugs and new psychoactive substances (NPS).
Collapse
Affiliation(s)
- Anne Zwartsen
- Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands; Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Laura Hondebrink
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Dylan W de Lange
- Dutch Poisons Information Center (DPIC), University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Remco H S Westerink
- Neurotoxicology Research Group, Division Toxicology, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands.
| |
Collapse
|
14
|
Kiyatkin EA. Brain temperature and its role in physiology and pathophysiology: Lessons from 20 years of thermorecording. Temperature (Austin) 2019; 6:271-333. [PMID: 31934603 PMCID: PMC6949027 DOI: 10.1080/23328940.2019.1691896] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 10/29/2019] [Accepted: 10/30/2019] [Indexed: 12/11/2022] Open
Abstract
It is well known that temperature affects the dynamics of all physicochemical processes governing neural activity. It is also known that the brain has high levels of metabolic activity, and all energy used for brain metabolism is finally transformed into heat. However, the issue of brain temperature as a factor reflecting neural activity and affecting various neural functions remains in the shadow and is usually ignored by most physiologists and neuroscientists. Data presented in this review demonstrate that brain temperature is not stable, showing relatively large fluctuations (2-4°C) within the normal physiological and behavioral continuum. I consider the mechanisms underlying these fluctuations and discuss brain thermorecording as an important tool to assess basic changes in neural activity associated with different natural (sexual, drinking, eating) and drug-induced motivated behaviors. I also consider how naturally occurring changes in brain temperature affect neural activity, various homeostatic parameters, and the structural integrity of brain cells as well as the results of neurochemical evaluations conducted in awake animals. While physiological hyperthermia appears to be adaptive, enhancing the efficiency of neural functions, under specific environmental conditions and following exposure to certain psychoactive drugs, brain temperature could exceed its upper limits, resulting in multiple brain abnormalities and life-threatening health complications.
Collapse
Affiliation(s)
- Eugene A Kiyatkin
- Behavioral Neuroscience Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| |
Collapse
|
15
|
Ruszkiewicz JA, Tinkov AA, Skalny AV, Siokas V, Dardiotis E, Tsatsakis A, Bowman AB, da Rocha JBT, Aschner M. Brain diseases in changing climate. ENVIRONMENTAL RESEARCH 2019; 177:108637. [PMID: 31416010 PMCID: PMC6717544 DOI: 10.1016/j.envres.2019.108637] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/06/2019] [Accepted: 08/07/2019] [Indexed: 05/12/2023]
Abstract
Climate change is one of the biggest and most urgent challenges for the 21st century. Rising average temperatures and ocean levels, altered precipitation patterns and increased occurrence of extreme weather events affect not only the global landscape and ecosystem, but also human health. Multiple environmental factors influence the onset and severity of human diseases and changing climate may have a great impact on these factors. Climate shifts disrupt the quantity and quality of water, increase environmental pollution, change the distribution of pathogens and severely impacts food production - all of which are important regarding public health. This paper focuses on brain health and provides an overview of climate change impacts on risk factors specific to brain diseases and disorders. We also discuss emerging hazards in brain health due to mitigation and adaptation strategies in response to climate changes.
Collapse
Affiliation(s)
- Joanna A Ruszkiewicz
- Molecular Toxicology Group, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Alexey A Tinkov
- Yaroslavl State University, Yaroslavl, Russia; IM Sechenov First Moscow State Medical University, Moscow, Russia; Institute of Cellular and Intracellular Symbiosis, Russian Academy of Sciences, Orenburg, Russia
| | - Anatoly V Skalny
- Yaroslavl State University, Yaroslavl, Russia; IM Sechenov First Moscow State Medical University, Moscow, Russia; Trace Element Institute for UNESCO, Lyon, France
| | - Vasileios Siokas
- Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece
| | - Efthimios Dardiotis
- Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece
| | - Aristidis Tsatsakis
- Laboratory of Toxicology, School of Medicine, University of Crete, 71003, Heraklion, Greece
| | - Aaron B Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - João B T da Rocha
- Department of Biochemistry, Federal University of Santa Maria, Santa Maria, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
| |
Collapse
|
16
|
Kim NJ, Ryu Y, Lee BH, Chang S, Fan Y, Gwak YS, Yang CH, Bills KB, Steffensen SC, Koo JS, Jang EY, Kim HY. Acupuncture inhibition of methamphetamine-induced behaviors, dopamine release and hyperthermia in the nucleus accumbens: mediation of group II mGluR. Addict Biol 2019; 24:206-217. [PMID: 29363229 DOI: 10.1111/adb.12587] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/22/2017] [Accepted: 11/20/2017] [Indexed: 01/19/2023]
Abstract
Methamphetamine (METH) increases metabolic neuronal activity in the mesolimbic dopamine (DA) system and mediates the reinforcing effect. To explore the underlying mechanism of acupuncture intervention in reducing METH-induced behaviors, we investigated the effect of acupuncture on locomotor activity, ultrasonic vocalizations, extracellular DA release in the nucleus accumbens (NAcs) using fast-scan cyclic voltammetry and alterations of brain temperature (an indicator of local brain metabolic activity) produced by METH administration. When acupuncture was applied to HT7, but not TE4, both locomotor activity and 50-kHz ultrasonic vocalizations were suppressed in METH-treated rats. Acupuncture at HT7 attenuated the enhancement of electrically stimulated DA release in the NAc of METH-treated rats. Systemic injection of METH produced a sustained increase in NAc temperature, which was reversed by the DA D1 receptor antagonist SCH 23390 or acupuncture at HT7. Acupuncture inhibition of METH-induced NAc temperature was prevented by pre-treatment with a group II metabotropic glutamate receptors (mGluR2/3) antagonist EGLU into the NAc or mimicked by injection of an mGluR2/3 agonist DCG-IV into the NAc. These results suggest that acupuncture reduces extracellular DA release and metabolic neuronal activity in the NAc through activation of mGluR2/3 and suppresses METH-induced affective states and locomotor behavior.
Collapse
Affiliation(s)
- Nam Jun Kim
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Yeonhee Ryu
- Acupuncture, Moxibustion & Meridian Research Center, Division of Standard Research; Korea Institute of Oriental Medicine; Daejeon Korea
| | - Bong Hyo Lee
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Suchan Chang
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Yu Fan
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Young S. Gwak
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Chae Ha Yang
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Kyle B. Bills
- Department of Psychology and Neuroscience; Brigham Young University; Provo UT USA
| | - Scott C. Steffensen
- Department of Psychology and Neuroscience; Brigham Young University; Provo UT USA
| | - Jin Suk Koo
- Department of Bioresource Science; Andong National University; Andong Korea
| | - Eun Young Jang
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| | - Hee Young Kim
- College of Korean Medicine; Daegu Haany University; Daegu Korea
| |
Collapse
|
17
|
Musolino ST, Schartner EP, Hutchinson MR, Salem A. Improved method for optical fiber temperature probe implantation in brains of free-moving rats. J Neurosci Methods 2019; 313:24-28. [DOI: 10.1016/j.jneumeth.2018.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 12/18/2018] [Accepted: 12/18/2018] [Indexed: 11/30/2022]
|
18
|
Cernych M, Satas A, Brazaitis M. Post-sauna recovery enhances brain neural network relaxation and improves cognitive economy in oddball tasks. Int J Hyperthermia 2018; 35:375-382. [DOI: 10.1080/02656736.2018.1504992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Margarita Cernych
- Institute of Sport Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| | - Andrius Satas
- Institute of Sport Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| | - Marius Brazaitis
- Institute of Sport Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| |
Collapse
|
19
|
Dubois A, Chiang CC, Smekens F, Jan S, Cuplov V, Palfi S, Chuang KS, Senova S, Pain F. Optical and thermal simulations for the design of optodes for minimally invasive optogenetics stimulation or photomodulation of deep and large cortical areas in non-human primate brain. J Neural Eng 2018; 15:065004. [PMID: 30190446 DOI: 10.1088/1741-2552/aadf97] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The use of optogenetics or photobiomodulation in non-human primate (NHP) requires the ability to noninvasively stimulate large and deep cortical brain tissues volumes. In this context, the optical and geometrical parameters of optodes are critical. Methods and general guidelines to optimize these parameters have to be defined. OBJECTIVE We propose the design of an optode for safe and efficient optical stimulation of a large volume of NHP cortex, down to 3-5 mm depths without inserting fibers into the cortex. APPROACH Monte Carlo simulations of optical and thermal transport have been carried out using the Geant4 application for tomographic emission (GATE) platform. Parameters such as the fiber diameter, numerical aperture, number of fibers and their geometrical arrangement have been studied. Optimal hardware parameters are proposed to obtain homogeneous fluence above the fluence threshold for opsin activation without detrimental thermal effects. MAIN RESULTS The simulations show that a large fiber diameter and a large numerical aperture are preferable since they allow limiting power concentration and hence the resulting thermal increases at the brain surface. To obtain a volume of 200-500 mm3 of brain tissues receiving a fluence above the opsin activation threshold for optogenetics or below a phototocixity threshold for photobiomodulation, a 4 fibers configuration is proposed. The optimal distance between the fibers was found to be 4 mm. A practical implementation of the optode has been performed and the corresponding fluence and thermal maps have been simulated. SIGNIFICANCE The present study defines a method to optimize the design of optode and the choice of stimulation parameters for optogenetics and more generally light delivery to deep and large volumes of tissues in NHP brain with a controlled irradiance dosimetry. The general guidelines are the use of silica fibers with a large numerical aperture and a large diameter. The combination of several fibers is required if large volumes need to be stimulated while avoiding thermal effects.
Collapse
Affiliation(s)
- A Dubois
- IMNC, CNRS, Université Paris-Sud, Université Paris Saclay, Orsay F-91405, France
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Champagne PO, Westwick H, Bouthillier A, Sawan M. Colloidal stability of superparamagnetic iron oxide nanoparticles in the central nervous system: a review. Nanomedicine (Lond) 2018; 13:1385-1400. [DOI: 10.2217/nnm-2018-0021] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Superparamagnetic iron oxide nanoparticles (SPIONs) consist of nanosized metallic-based particles with unique magnetic properties. Their potential in both diagnostic and therapeutic applications in the CNS is at the source of an expanding body of the literature in recent years. Colloidal stability of nanoparticles represents their ability to resist aggregation and is a central aspect for the use of SPION in biological environment such as the CNS. This review gives a comprehensive update of the recent developments and knowledge on the determinants of colloidal stability of SPIONs in the CNS. Factors leading to aggregate formation and the repercussions of colloidal instability of SPION are reviewed in detail pertaining to their use in the CNS.
Collapse
Affiliation(s)
- Pierre-Olivier Champagne
- Polystim Neurotech Laboratory, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, H3T 1J4, Canada
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Harrison Westwick
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Alain Bouthillier
- Department of Neurosurgery, University of Montreal Medical Center, Montreal, H2X 0C1, Canada
| | - Mohamad Sawan
- Polystim Neurotech Laboratory, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, H3T 1J4, Canada
| |
Collapse
|
21
|
Concentration-related metabolic rate and behavioral thermoregulatory adaptations to serial administrations of nitrous oxide in rats. PLoS One 2018; 13:e0194794. [PMID: 29672605 PMCID: PMC5909668 DOI: 10.1371/journal.pone.0194794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/10/2018] [Indexed: 11/19/2022] Open
Abstract
Background Initial administration of ≥60% nitrous oxide (N2O) to rats evokes hypothermia, but after repeated administrations the gas instead evokes hyperthermia. This sign reversal is driven mainly by increased heat production. To determine whether rats will behaviorally oppose or assist the development of hyperthermia, we previously performed thermal gradient testing. Inhalation of N2O at ≥60% causes rats to select cooler ambient temperatures both during initial administrations and during subsequent administrations in which the hyperthermic state exists. Thus, an available behavioral response opposes (but does not completely prevent) the acquired hyperthermia that develops over repeated high-concentration N2O administrations. However, recreational and clinical uses of N2O span a wide range of concentrations. Therefore, we sought to determine the thermoregulatory adaptations to chronic N2O administration over a wide range of concentrations. Methods This study had two phases. In the first phase we adapted rats to twelve 3-h N2O administrations at either 0%, 15%, 30%, 45%, 60% or 75% N2O (n = 12 per group); outcomes were core temperature (via telemetry) and heat production (via respirometry). In the second phase, we used a thermal gradient (range 8°C—38°C) to assess each adapted group’s thermal preference, core temperature and locomotion on a single occasion during N2O inhalation at the assigned concentration. Results In phase 1, repeated N2O administrations led to dose related hyperthermic and hypermetabolic states during inhalation of ≥45% N2O compared to controls (≥ 30% N2O compared to baseline). In phase 2, rats in these groups selected cooler ambient temperatures during N2O inhalation but still developed some hyperthermia. However, a concentration-related increase of locomotion was evident in the gradient, and theoretical calculations and regression analyses both suggest that locomotion contributed to the residual hyperthermia. Conclusions Acquired N2O hyperthermia in rats is remarkably robust, and occurs even despite the availability of ambient temperatures that might fully counter the hyperthermia. Increased locomotion in the gradient may contribute to hyperthermia. Our data are consistent with an allostatic dis-coordination of autonomic and behavioral thermoregulatory mechanisms during drug administration. Our results have implications for research on N2O abuse as well as research on the role of allostasis in drug addiction.
Collapse
|
22
|
Kiyatkin EA. Brain temperature: from physiology and pharmacology to neuropathology. HANDBOOK OF CLINICAL NEUROLOGY 2018; 157:483-504. [DOI: 10.1016/b978-0-444-64074-1.00030-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
23
|
Galvan A, Stauffer WR, Acker L, El-Shamayleh Y, Inoue KI, Ohayon S, Schmid MC. Nonhuman Primate Optogenetics: Recent Advances and Future Directions. J Neurosci 2017; 37:10894-10903. [PMID: 29118219 PMCID: PMC5678022 DOI: 10.1523/jneurosci.1839-17.2017] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 09/29/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Optogenetics is the use of genetically coded, light-gated ion channels or pumps (opsins) for millisecond resolution control of neural activity. By targeting opsin expression to specific cell types and neuronal pathways, optogenetics can expand our understanding of the neural basis of normal and pathological behavior. To maximize the potential of optogenetics to study human cognition and behavior, optogenetics should be applied to the study of nonhuman primates (NHPs). The homology between NHPs and humans makes these animals the best experimental model for understanding human brain function and dysfunction. Moreover, for genetic tools to have translational promise, their use must be demonstrated effectively in large, wild-type animals such as Rhesus macaques. Here, we review recent advances in primate optogenetics. We highlight the technical hurdles that have been cleared, challenges that remain, and summarize how optogenetic experiments are expanding our understanding of primate brain function.
Collapse
Affiliation(s)
- Adriana Galvan
- Yerkes National Primate Research Center and Department of Neurology, School of Medicine, Emory University, Atlanta, Georgia 30329,
| | - William R Stauffer
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Leah Acker
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Yasmine El-Shamayleh
- Department of Physiology and Biophysics, Washington National Primate Research Center, University of Washington, Seattle, Washington 98195
| | - Ken-Ichi Inoue
- Department of Neuroscience, Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012, Japan
| | - Shay Ohayon
- McGovern Institute for Brain Research, Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and
| | - Michael C Schmid
- Institute of Neuroscience, Newcastle University, Newcastle, United Kingdom NE2 4HH
| |
Collapse
|
24
|
Xue Y, Li L, Qian S, Liu K, Zhou XJ, Li B, Jiang Q, Wu Z, Du L, Sun G. The effects of head-cooling on brain function during passive hyperthermia: an fMRI study. Int J Hyperthermia 2017; 34:1010-1019. [PMID: 29025324 DOI: 10.1080/02656736.2017.1392046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Yan Xue
- Graduate School, Jinzhou Medical University, Jinzhou, China
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Li Li
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
- Institute of Postgraduates, The Second Military Medical University, Shanghai, China
| | - Shaowen Qian
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Kai Liu
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Xiaohong Joe Zhou
- Center for MR Research, and Department of Radiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Bo Li
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Qingjun Jiang
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Zhuanzhuan Wu
- Graduate School, Jinzhou Medical University, Jinzhou, China
| | - Lexia Du
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| | - Gang Sun
- Department of Medical Imaging, Jinan Military General Hospital, Jinan, China
| |
Collapse
|
25
|
Yawning, a thermoregulatory mechanism during fever? A study of yawning frequency and its predictors during experimentally induced sickness. Physiol Behav 2017; 182:27-33. [PMID: 28939427 DOI: 10.1016/j.physbeh.2017.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/16/2017] [Accepted: 09/18/2017] [Indexed: 12/31/2022]
Abstract
Yawning has been proposed to serve both physiological and social functions, the latter likely to have developed later in its evolution. A central hypothesis is that yawning cools the brain but whether yawning is a thermoregulatory mechanism that is activated during hyperthermia (i.e., thermoregulatory failure) or is activated in any instance of brain temperature increase (e.g., also during fever) is unclear and experimental assessments of yawning during fever are lacking. In this study, we determined the effect of experimentally induced fever on yawning frequency. We also explored alternative predictors of yawning during sickness (sleepiness, autonomic nervous system indexes and sickness symptoms). Twenty-two healthy human subjects participated in a randomized, placebo-controlled, cross-over study, where the subjects received an injection of the bacterial endotoxin lipopolysaccharide (LPS) at a dose of 2ng/kg body weight in one condition and placebo in the other. Yawning was scored from video recordings from 30min before to 4h after the injection. Body temperature was measured frequently, alongside with heart rate, blood pressure, nausea and overall sickness symptoms. Yawning frequency was found to significantly increase over time during experimentally induced sickness, but not in the placebo condition. In particular, yawning frequency was increased during the rising phase of body temperature induced by LPS administration, although no significant correlation was found between body temperature increase and yawning frequency. In addition, exploratory analyses showed that a higher yawning frequency was associated with less increase in sickness symptoms and nausea intensity. While the current study adds to previous research showing significant increase in yawning frequency during hyperthermia, further studies are needed if we are to properly characterize the brain cooling role of yawning in humans. The investigation of other functions, such as being a vasovagal inhibitory, may shed stronger light on the functions of yawning.
Collapse
|
26
|
Abstract
Optogenetic methods have been highly effective for suppressing neural activity and modulating behavior in rodents, but effects have been much smaller in primates, which have much larger brains. Here, we present a suite of technologies to use optogenetics effectively in primates and apply these tools to a classic question in oculomotor control. First, we measured light absorption and heat propagation in vivo, optimized the conditions for using the red-light-shifted halorhodopsin Jaws in primates, and developed a large-volume illuminator to maximize light delivery with minimal heating and tissue displacement. Together, these advances allowed for nearly universal neuronal inactivation across more than 10 mm3 of the cortex. Using these tools, we demonstrated large behavioral changes (i.e., up to several fold increases in error rate) with relatively low light power densities (≤100 mW/mm2) in the frontal eye field (FEF). Pharmacological inactivation studies have shown that the FEF is critical for executing saccades to remembered locations. FEF neurons increase their firing rate during the three epochs of the memory-guided saccade task: visual stimulus presentation, the delay interval, and motor preparation. It is unclear from earlier work, however, whether FEF activity during each epoch is necessary for memory-guided saccade execution. By harnessing the temporal specificity of optogenetics, we found that FEF contributes to memory-guided eye movements during every epoch of the memory-guided saccade task (the visual, delay, and motor periods).
Collapse
|
27
|
Podgorski K, Ranganathan G. Brain heating induced by near-infrared lasers during multiphoton microscopy. J Neurophysiol 2016; 116:1012-23. [PMID: 27281749 PMCID: PMC5009202 DOI: 10.1152/jn.00275.2016] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/08/2016] [Indexed: 12/27/2022] Open
Abstract
Two-photon imaging and optogenetic stimulation rely on high illumination powers, particularly for state-of-the-art applications that target deeper structures, achieve faster measurements, or probe larger brain areas. However, little information is available on heating and resulting damage induced by high-power illumination in the brain. In the current study we used thermocouple probes and quantum dot nanothermometers to measure temperature changes induced by two-photon microscopy in the neocortex of awake and anaesthetized mice. We characterized heating as a function of wavelength, exposure time, and distance from the center of illumination. Although total power is highest near the surface of the brain, heating was most severe hundreds of micrometers below the focal plane, due to heat dissipation through the cranial window. Continuous illumination of a 1-mm(2) area produced a peak temperature increase of ∼1.8°C/100 mW. Continuous illumination with powers above 250 mW induced lasting damage, detected with immunohistochemistry against Iba1, glial fibrillary acidic protein, heat shock proteins, and activated caspase-3. Higher powers were usable in experiments with limited duty ratios, suggesting an approach to mitigate damage in high-power microscopy experiments.
Collapse
Affiliation(s)
- Kaspar Podgorski
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia
| | | |
Collapse
|
28
|
Trang PM, Rocklöv J, Giang KB, Kullgren G, Nilsson M. Heatwaves and Hospital Admissions for Mental Disorders in Northern Vietnam. PLoS One 2016; 11:e0155609. [PMID: 27195473 PMCID: PMC4873187 DOI: 10.1371/journal.pone.0155609] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 05/02/2016] [Indexed: 11/18/2022] Open
Abstract
Studies in high-income countries have shown an association between heatwaves and hospital admissions for mental disorders. It is unknown whether such associations exist in subtropical nations like Vietnam. The study aim was to investigate whether hospital admissions for mental disorders may be triggered, or exacerbated, by heat exposure and heatwaves, in a low- and middle-income country, Vietnam. For this, we used data from the Hanoi Mental Hospital over five years (2008–2012) to estimate the effect of heatwaves on admissions for mental disorders. A zero-inflated negative binomial regression model accounting for seasonality, time trend, days of week, and mean humidity was used to analyse the relationship. Heatwave events were mainly studied as periods of three or seven consecutive days above the threshold of 35°C daily maximum temperature (90th percentile). The study result showed heatwaves increased the risk for admission in the whole group of mental disorders (F00-79) for more persistent heatwaves of at least 3 days when compared with non-heatwave periods. The relative risks were estimated at 1.04 (0.95–1.13), 1.15 (1.005–1.31), and 1.36 (1–1.90) for a one-, three- and seven-day heatwave, respectively. Admissions for mental disorders increased among men, residents in rural communities, and the elderly population during heatwaves. The groups of organic mental disorders, including symptomatic illnesses (F0-9) and mental retardation (F70-79), had increased admissions during heatwaves. The findings are novel in their focus on heatwave impact on mental diseases in a population habituating in a subtropical low- and middle-income country characterized by rapid epidemiological transitions and environmental changes.
Collapse
Affiliation(s)
- Phan Minh Trang
- Department of Public Health and Clinical Medicine, Unit of Epidemiology and Global Health, Umeå University, Sweden
- * E-mail:
| | - Joacim Rocklöv
- Department of Public Health and Clinical Medicine, Unit of Epidemiology and Global Health, Umeå University, Sweden
| | - Kim Bao Giang
- Institute for Preventive Medicine and Public Health, Hanoi Medical University, Vietnam
| | - Gunnar Kullgren
- Department of Psychiatry Clinical Sciences, Umeå University, Umeå, Sweden
| | - Maria Nilsson
- Department of Public Health and Clinical Medicine, Unit of Epidemiology and Global Health, Umeå University, Sweden
| |
Collapse
|
29
|
Cheshire WP. Thermoregulatory disorders and illness related to heat and cold stress. Auton Neurosci 2016; 196:91-104. [DOI: 10.1016/j.autneu.2016.01.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/17/2015] [Accepted: 01/05/2016] [Indexed: 01/22/2023]
|
30
|
Clarke ND, Duncan MJ, Smith M, Hankey J. Pre-cooling moderately enhances visual discrimination during exercise in the heat. J Sports Sci 2016; 35:355-360. [PMID: 27008467 DOI: 10.1080/02640414.2016.1164885] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Pre-cooling has been reported to attenuate the increase in core temperature, although, information regarding the effects of pre-cooling on cognitive function is limited. The present study investigated the effects of pre-cooling on visual discrimination during exercise in the heat. Eight male recreational runners completed 90 min of treadmill running at 65% [Formula: see text]2max in the heat [32.4 ± 0.9°C and 46.8 ± 6.4% relative humidity (r.h.)] on two occasions in a randomised, counterbalanced crossover design. Participants underwent pre-cooling by means of water immersion (20.3 ± 0.3°C) for 60 min or remained seated for 60 min in a laboratory (20.2 ± 1.7°C and 60.2 ± 2.5% r.h.). Rectal temperature (Trec) and mean skin temperature (Tskin) were monitored throughout the protocol. At 30-min intervals participants performed a visual discrimination task. Following pre-cooling, Trec (P = 0.040; [Formula: see text] = 0.48) was moderately lower at 0 and 30 min and Tskin (P = 0.003; [Formula: see text] = 0.75) lower to a large extent at 0 min of exercise. Visual discrimination was moderately more accurate at 60 and 90 min of exercise following pre-cooling (P = 0.067; [Formula: see text] = 0.40). Pre-cooling resulted in small improvements in visual discrimination sensitivity (F1,7 = 2.188; P = 0.183; [Formula: see text] = 0.24), criterion (F1,7 = 1.298; P = 0.292; [Formula: see text] = 0.16) and bias (F1,7 = 2.202; P = 0.181; [Formula: see text] = 0.24). Pre-cooling moderately improves visual discrimination accuracy during exercise in the heat.
Collapse
Affiliation(s)
- Neil D Clarke
- a School of Life Sciences, Faculty Health and Life Sciences , Coventry University , Coventry , UK
| | - Michael J Duncan
- a School of Life Sciences, Faculty Health and Life Sciences , Coventry University , Coventry , UK
| | - Mike Smith
- a School of Life Sciences, Faculty Health and Life Sciences , Coventry University , Coventry , UK
| | - Joanne Hankey
- a School of Life Sciences, Faculty Health and Life Sciences , Coventry University , Coventry , UK
| |
Collapse
|
31
|
Clinically Relevant Pharmacological Strategies That Reverse MDMA-Induced Brain Hyperthermia Potentiated by Social Interaction. Neuropsychopharmacology 2016; 41:549-59. [PMID: 26105141 PMCID: PMC5130130 DOI: 10.1038/npp.2015.182] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/02/2015] [Accepted: 06/17/2015] [Indexed: 11/08/2022]
Abstract
MDMA-induced hyperthermia is highly variable, unpredictable, and greatly potentiated by the social and environmental conditions of recreational drug use. Current strategies to treat pathological MDMA-induced hyperthermia in humans are palliative and marginally effective, and there are no specific pharmacological treatments to counteract this potentially life-threatening condition. Here, we tested the efficacy of mixed adrenoceptor blockers carvedilol and labetalol, and the atypical antipsychotic clozapine, in reversing MDMA-induced brain and body hyperthermia. We injected rats with a moderate non-toxic dose of MDMA (9 mg/kg) during social interaction, and we administered potential treatment drugs after the development of robust hyperthermia (>2.5 °C), thus mimicking the clinical situation of acute MDMA intoxication. Brain temperature was our primary focus, but we also simultaneously recorded temperatures from the deep temporal muscle and skin, allowing us to determine the basic physiological mechanisms of the treatment drug action. Carvedilol was modestly effective in attenuating MDMA-induced hyperthermia by moderately inhibiting skin vasoconstriction, and labetalol was ineffective. In contrast, clozapine induced a marked and immediate reversal of MDMA-induced hyperthermia via inhibition of brain metabolic activation and blockade of skin vasoconstriction. Our findings suggest that clozapine, and related centrally acting drugs, might be highly effective for reversing MDMA-induced brain and body hyperthermia in emergency clinical situations, with possible life-saving results.
Collapse
|
32
|
Kiyatkin EA, Sharma HS. Breakdown of Blood-Brain and Blood-Spinal Cord Barriers During Acute Methamphetamine Intoxication: Role of Brain Temperature. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2016; 15:1129-1138. [PMID: 27658516 PMCID: PMC6092929 DOI: 10.2174/1871527315666160920112445] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/15/2016] [Accepted: 08/08/2016] [Indexed: 11/22/2022]
Abstract
Methamphetamine (METH) is a powerful and often-abused stimulant with potent addictive and neurotoxic properties. While it is generally believed that structural brain damage induced by METH results from oxidative stress, in this work we present data suggesting robust disruption of blood-brain and blood-spinal cord barriers during acute METH intoxication in rats. We demonstrate the relationships between METH-induced brain hyperthermia and widespread but structure-specific barrier leakage, acute glial cell activation, changes in brain water and ionic homeostasis, and structural damage of different types of cells in the brain and spinal cord. Therefore, METH-induced leakage of the blood-brain and blood-spinal cord barriers is a significant contributor to different types of functional and structural brain abnormalities that determine acute toxicity of this drug and possibly neurotoxicity during its chronic use.
Collapse
Affiliation(s)
- Eugene A Kiyatkin
- Behavioral Neuroscience Branch, NIDA-IRP, NIH, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | | |
Collapse
|
33
|
Clark T, Malpas S, Heppner P, McCormick D, Budgett D. Intracranial temperature and pressure measurement: in vitro temperature sensing characteristics of the dual sensing element. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2013:620-3. [PMID: 24109763 DOI: 10.1109/embc.2013.6609576] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A pressure sensor has been used to measure temperature concurrently. We have designed, and characterized the measurement of temperature from the same sensor to allow simultaneous monitoring of intracranial temperature and pressure. The temperature measurement has a sensitivity of 85.08 mV/°C across the measurement range 20-45 °C. The time constant of the temperature sensor is 150 ms. We have evaluated the accuracy of the temperature measurement and the long term drift of 13 sensors over 28 days. The mean difference of the temperature measurements from the reference measurements was less than 0.2 °C.
Collapse
|
34
|
Santin JM, Hartzler LK. Activation state of the hyperpolarization-activated current modulates temperature-sensitivity of firing in locus coeruleus neurons from bullfrogs. Am J Physiol Regul Integr Comp Physiol 2015; 308:R1045-61. [PMID: 25833936 DOI: 10.1152/ajpregu.00036.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/30/2015] [Indexed: 12/18/2022]
Abstract
Locus coeruleus neurons of anuran amphibians contribute to breathing control and have spontaneous firing frequencies that, paradoxically, increase with cooling. We previously showed that cooling inhibits a depolarizing membrane current, the hyperpolarization-activated current (I h) in locus coeruleus neurons from bullfrogs, Lithobates catesbeianus (Santin JM, Watters KC, Putnam RW, Hartzler LK. Am J Physiol Regul Integr Comp Physiol 305: R1451-R1464, 2013). This suggests an unlikely role for I h in generating cold activation, but led us to hypothesize that inhibition of I h by cooling functions as a physiological brake to limit the cold-activated response. Using whole cell electrophysiology in brain slices, we employed 2 mM Cs(+) (an I h antagonist) to isolate the role of I h in spontaneous firing and cold activation in neurons recorded with either control or I h agonist (cyclic AMP)-containing artificial intracellular fluid. I h did not contribute to the membrane potential (V m) and spontaneous firing at 20°C. Although voltage-clamp analysis confirmed that cooling inhibits I h, its lack of involvement in setting baseline firing and V m precluded its ability to regulate cold activation as hypothesized. In contrast, neurons dialyzed with cAMP exhibited greater baseline firing frequencies at 20°C due to I h activation. Our hypothesis was supported when the starting level of I h was enhanced by elevating cAMP because cold activation was converted to more ordinary cold inhibition. These findings indicate that situations leading to enhancement of I h facilitate firing at 20°C, yet the hyperpolarization associated with inhibiting a depolarizing cation current by cooling blunts the net V m response to cooling to oppose normal cold-depolarizing factors. This suggests that the influence of I h activation state on neuronal firing varies in the poikilothermic neuronal environment.
Collapse
Affiliation(s)
- Joseph M Santin
- Department of Biological Sciences, Wright State University, Dayton, Ohio
| | - Lynn K Hartzler
- Department of Biological Sciences, Wright State University, Dayton, Ohio
| |
Collapse
|
35
|
Choi TY, Denton ML, Noojin GD, Estlack LE, Shrestha R, Rockwell BA, Thomas R, Kim D. Thermal evaluation of laser exposures in an in vitro retinal model by microthermal sensing. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:97003. [PMID: 25222532 DOI: 10.1117/1.jbo.19.9.097003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 08/25/2014] [Indexed: 06/03/2023]
Abstract
A temperature detection system using a micropipette thermocouple sensor was developed for use within mammalian cells during laser exposure with an 8.6-μm beam at 532 nm. We have demonstrated the capability of measuring temperatures at a single-cell level in the microscale range by inserting micropipettebased thermal sensors of size ranging from 2 to 4 μm into the membrane of a live retinal pigment epithelium (RPE) cell subjected to a laser beam. We setup the treatment groups of 532-nm laser-irradiated single RPE cell and in situ temperature recordings were made over time. Thermal profiles are given for representative cells experiencing damage resulting from exposures of 0.2 to 2 s. The measured maximum temperature rise for each cell ranges from 39 to 73°C; the RPE cells showed a signature of death for all the cases reported herein. In order to check the cell viability, real-time fluorescence microscopy was used to identify the transition of pigmented RPE cells between viable and damaged states due to laser exposure.
Collapse
Affiliation(s)
- Tae Y Choi
- University of North Texas, Department of Mechanical and Energy Engineering, 3940 N. Elm Street Denton, Texas 76207, United States
| | - Michael L Denton
- TASC, Inc., Department of Biomedical Sciences and Technologies, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Gary D Noojin
- TASC, Inc., Department of Biomedical Sciences and Technologies, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Larry E Estlack
- Conceptual MindWorks, Inc., 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Ramesh Shrestha
- University of North Texas, Department of Mechanical and Energy Engineering, 3940 N. Elm Street Denton, Texas 76207, United States
| | - Benjamin A Rockwell
- 711th Human Performance Wing, Bioeffects Division, Optical Radiation Bioeffects Branch, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Robert Thomas
- 711th Human Performance Wing, Bioeffects Division, Optical Radiation Bioeffects Branch, 4141 Petroleum Road, JBSA Fort Sam Houston, Texas 78234, United States
| | - Dongsik Kim
- POSTECH, Department of Mechanical Engineering, San 31 Hyoja-Dong, Nam-Gu, Pohang, Gyungbuk 790-784, Republic of Korea
| |
Collapse
|
36
|
Alzeer AH, Al Otair HA. Sweat chloride concentration in patients with heat stroke. J Taibah Univ Med Sci 2014. [DOI: 10.1016/j.jtumed.2013.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
37
|
Ersen A, Abdo A, Sahin M. Temperature elevation profile inside the rat brain induced by a laser beam. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:15009. [PMID: 24474503 PMCID: PMC3902302 DOI: 10.1117/1.jbo.19.1.015009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/14/2013] [Accepted: 12/18/2013] [Indexed: 05/22/2023]
Abstract
The thermal effect may be a desired outcome or a concerning side effect in laser-tissue interactions. Research in this area is particularly motivated by recent advances in laser applications in diagnosis and treatment of neurological disorders. Temperature as a side effect also limits the maximum power of optical transfer and harvesting of energy in implantable neural prostheses. The main objective was to investigate the thermal effect of a near-infrared laser beam directly aimed at the brain cortex. A small, custom-made thermal probe was inserted into the rat brain to make direct measurements of temperature elevations induced by a free-air circular laser beam. The time dependence and the spatial distribution of the temperature increases were studied and the maximum allowable optical power was determined to be 2.27 W/cm2 for a corresponding temperature increase of 0.5°C near the cortical surface. The results can be extrapolated for other temperature elevations, where the margin to reach potentially damaging temperatures is more relaxed, by taking advantage of linearity. It is concluded that the thermal effect depends on several factors such as the thermal properties of the neural tissue and of its surrounding structures, the optical properties of the particular neural tissue, and the laser beam size and shape. Because so many parameters play a role, the thermal effect should be investigated for each specific application separately using realistic in vivo models.
Collapse
Affiliation(s)
- Ali Ersen
- New Jersey Institute of Technology, Neural Interface Laboratory, Biomedical Engineering Department, 323 Dr. Martin Luther King, Jr. Boulevard, University Heights, Newark, New Jersey 07102-1982
| | - Ammar Abdo
- New Jersey Institute of Technology, Neural Interface Laboratory, Biomedical Engineering Department, 323 Dr. Martin Luther King, Jr. Boulevard, University Heights, Newark, New Jersey 07102-1982
| | - Mesut Sahin
- New Jersey Institute of Technology, Neural Interface Laboratory, Biomedical Engineering Department, 323 Dr. Martin Luther King, Jr. Boulevard, University Heights, Newark, New Jersey 07102-1982
- Address all correspondence to: Mesut Sahin, E-mail:
| |
Collapse
|
38
|
Plush T, Shakespeare W, Jacobs D, Ladi L, Sethi S, Gasperino J. Cocaine-induced agitated delirium: a case report and review. J Intensive Care Med 2013; 30:49-57. [PMID: 24212597 DOI: 10.1177/0885066613507420] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cocaine use continues to be a major public health problem in the United States. Although many of the initial signs and symptoms of cocaine intoxication result from increased stimulation of the sympathetic nervous system, this condition can present as a spectrum of acuity from hypertension and tachycardia to multiorgan system failure. Classic features of acute intoxication include tachycardia, arterial vasoconstriction, enhanced thrombus formation, mydriasis, psychomotor agitation, and altered level of consciousness. At the extreme end of this toxidrome is a rare condition known as cocaine-induced agitated delirium. This syndrome is characterized by severe cardiopulmonary dysfunction, hyperthermia, and acute neurologic changes frequently leading to death. We report a case of cocaine-induced agitated delirium in a man who presented to our institution in a paradoxical form of circulatory shock. Rapid evaluation, recognition, and proper management enabled our patient not only to survive but also to leave the hospital without neurologic sequelae.
Collapse
Affiliation(s)
- Theodore Plush
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Walter Shakespeare
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Dorian Jacobs
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Larry Ladi
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Sheeba Sethi
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - James Gasperino
- Department of Medicine, Section of Critical Care Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| |
Collapse
|
39
|
Sai A, Shimono T, Sakai K, Takeda A, Shimada H, Tsukamoto T, Maeda H, Sakamoto S, Miki Y. Diffusion-weighted imaging thermometry in multiple sclerosis. J Magn Reson Imaging 2013; 40:649-54. [DOI: 10.1002/jmri.24396] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/12/2013] [Indexed: 01/29/2023] Open
Affiliation(s)
- Asari Sai
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| | - Taro Shimono
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| | - Koji Sakai
- Department of Human Health Science; Graduate School of Medicine; Kyoto University; Kyoto Japan
| | - Akitoshi Takeda
- Department of Geriatric Medicine and Neurology; Osaka City University Graduate School of Medicine; Osaka Japan
| | - Hiroyuki Shimada
- Department of Geriatric Medicine and Neurology; Osaka City University Graduate School of Medicine; Osaka Japan
| | - Taro Tsukamoto
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| | - Hiroko Maeda
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| | - Shinichi Sakamoto
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| | - Yukio Miki
- Department of Radiology; Osaka City University Graduate School of Medicine Osaka; Japan
| |
Collapse
|
40
|
The heat is on: a case of hyperthermia-induced posterior reversible encephalopathy syndrome (PRES). Neurol Sci 2013; 35:127-30. [PMID: 23959533 DOI: 10.1007/s10072-013-1525-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/07/2013] [Indexed: 10/26/2022]
|
41
|
Kiyatkin EA, Wakabayashi KT, Lenoir M. Physiological fluctuations in brain temperature as a factor affecting electrochemical evaluations of extracellular glutamate and glucose in behavioral experiments. ACS Chem Neurosci 2013; 4:652-65. [PMID: 23448428 DOI: 10.1021/cn300232m] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The rate of any chemical reaction or process occurring in the brain depends on temperature. While it is commonly believed that brain temperature is a stable, tightly regulated homeostatic parameter, it fluctuates within 1-4 °C following exposure to salient arousing stimuli and neuroactive drugs, and during different behaviors. These temperature fluctuations should affect neural activity and neural functions, but the extent of this influence on neurochemical measurements in brain tissue of freely moving animals remains unclear. In this Review, we present the results of amperometric evaluations of extracellular glutamate and glucose in awake, behaving rats and discuss how naturally occurring fluctuations in brain temperature affect these measurements. While this temperature contribution appears to be insignificant for glucose because its extracellular concentrations are large, it is a serious factor for electrochemical evaluations of glutamate, which is present in brain tissue at much lower levels, showing smaller phasic fluctuations. We further discuss experimental strategies for controlling the nonspecific chemical and physical contributions to electrochemical currents detected by enzyme-based biosensors to provide greater selectivity and reliability of neurochemical measurements in behaving animals.
Collapse
Affiliation(s)
- Eugene A. Kiyatkin
- In-Vivo Electrophysiology Unit, Behavioral Neuroscience
Branch, National Institute on Drug Abuse − Intramural Research
Program, National Institutes of Health,
DHHS, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Ken T. Wakabayashi
- In-Vivo Electrophysiology Unit, Behavioral Neuroscience
Branch, National Institute on Drug Abuse − Intramural Research
Program, National Institutes of Health,
DHHS, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Magalie Lenoir
- In-Vivo Electrophysiology Unit, Behavioral Neuroscience
Branch, National Institute on Drug Abuse − Intramural Research
Program, National Institutes of Health,
DHHS, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| |
Collapse
|
42
|
van Rhoon GC, Samaras T, Yarmolenko PS, Dewhirst MW, Neufeld E, Kuster N. CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels? Eur Radiol 2013; 23:2215-27. [PMID: 23553588 DOI: 10.1007/s00330-013-2825-y] [Citation(s) in RCA: 187] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 01/30/2013] [Accepted: 02/02/2013] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To define thresholds of safe local temperature increases for MR equipment that exposes patients to radiofrequency fields of high intensities for long duration. These MR systems induce heterogeneous energy absorption patterns inside the body and can create localised hotspots with a risk of overheating. METHODS The MRI + EUREKA research consortium organised a "Thermal Workshop on RF Hotspots". The available literature on thresholds for thermal damage and the validity of the thermal dose (TD) model were discussed. RESULTS/CONCLUSIONS The following global TD threshold guidelines for safe use of MR are proposed: 1. All persons: maximum local temperature of any tissue limited to 39 °C 2. Persons with compromised thermoregulation AND (a) Uncontrolled conditions: maximum local temperature limited to 39 °C (b) Controlled conditions: TD < 2 CEM43°C 3. Persons with uncompromised thermoregulation AND (a) Uncontrolled conditions: TD < 2 CEM43°C (b) Controlled conditions: TD < 9 CEM43°C The following definitions are applied: Controlled conditions A medical doctor or a dedicated trained person can respond instantly to heat-induced physiological stress Compromised thermoregulation All persons with impaired systemic or reduced local thermoregulation KEY POINTS • Standard MRI can cause local heating by radiofrequency absorption. • Monitoring thermal dose (in units of CEM43°C) can control risk during MRI. • 9 CEM43°C seems an acceptable thermal dose threshold for most patients. • For skin, muscle, fat and bone,16 CEM43°C is likely acceptable.
Collapse
Affiliation(s)
- Gerard C van Rhoon
- Department of Radiotherapy, Erasmus MC Cancer Center, Rotterdam, The Netherlands.
| | | | | | | | | | | |
Collapse
|
43
|
Kiyatkin EA. The hidden side of drug action: brain temperature changes induced by neuroactive drugs. Psychopharmacology (Berl) 2013; 225:765-80. [PMID: 23274506 PMCID: PMC3558565 DOI: 10.1007/s00213-012-2957-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 12/07/2012] [Indexed: 12/11/2022]
Abstract
RATIONALE Most neuroactive drugs affect brain metabolism as well as systemic and cerebral blood flow, thus altering brain temperature. Although this aspect of drug action usually remains in the shadows, drug-induced alterations in brain temperature reflect their metabolic neural effects and affect neural activity and neural functions. OBJECTIVES Here, I review brain temperature changes induced by neuroactive drugs, which are used therapeutically (general anesthetics), as a research tool (dopamine agonists and antagonists), and self-administered to induce desired psychic effects (cocaine, methamphetamine, ecstasy). I consider the mechanisms underlying these temperature fluctuations and their influence on neural, physiological, and behavioral effects of these drugs. RESULTS By interacting with neural mechanisms regulating metabolic activity and heat exchange between the brain and the rest of the body, neuroactive drugs either increase or decrease brain temperatures both within (35-39 °C) and exceeding the range of physiological fluctuations. These temperature effects differ drastically depending upon the environmental conditions and activity state during drug administration. This state-dependence is especially important for drugs of abuse that are usually taken by humans during psycho-physiological activation and in environments that prevent proper heat dissipation from the brain. Under these conditions, amphetamine-like stimulants induce pathological brain hyperthermia (>40 °C) associated with leakage of the blood-brain barrier and structural abnormalities of brain cells. CONCLUSIONS The knowledge on brain temperature fluctuations induced by neuroactive drugs provides new information to understand how they influence metabolic neural activity, why their effects depend upon the behavioral context of administration, and the mechanisms underlying adverse drug effects including neurotoxicity.
Collapse
Affiliation(s)
- Eugene A. Kiyatkin
- Correspondence should be addressed to Eugene A. Kiyatkin at the above address. Fax: (443) 740-2155; tel.: (443) 740-2844;
| |
Collapse
|
44
|
Kreuzer P, Landgrebe M, Wittmann M, Hajak G, Schecklmann M, Poeppl TB, Langguth B. [Hypothermia under olanzapine treatment: clinical case series and review of current literature]. DER NERVENARZT 2012; 83:630-7. [PMID: 21626387 DOI: 10.1007/s00115-011-3310-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Antipsychotic drugs may lead to hypothermia as well as hyperthermia. Although known for decades and clinically highly relevant, the mechanisms by which antipsychotic drugs alter thermoregulatory processes in the human body are still far from being fully understood. In clinical practice, much attention is paid to antipsychotic drug-induced elevation of body core temperature as observed in the neuroleptic malignant syndrome (NMS). But also hypothermia is a clinically highly relevant adverse reaction to antipsychotic drugs. MATERIAL AND METHODS Here we report a case series of three patients who developed severe hypothermia after administration of olanzapine. A review of the current literature is given with a focus on risk factors for the development of antipsychotic drug-induced hypothermia and its pathophysiologic mechanisms. RESULTS A 51-year-old female patient suffering from catatonic schizophrenia, cachectic nutritional condition and hypothyroidism developed severe hypothermia of 30.0°C body core temperature after administration of 30 mg olanzapine per day under comedication with lorazepam and L-thyroxine. A 48-year-old female patient with catatonic schizophrenia showed hypothermia of 31.0°C (rectal measurement) after single-dose administration of olanzapine 10 mg orally and a total of 3 mg lorazepam (1-1-1 mg). The third case report describes a 69-year-old male patient with acute delusional disorder exhibiting hypothermia of 33.0°C (rectal measurement) in combination with a reversible atrioventricular block grade III without any further comedication. CONCLUSION A review of the current literature reveals that thermoregulatory disturbances as sequelae of antipsychotic drug administration depend on individual disposition as well as various independent risk factors such as environmental temperature, somatic comorbidities, endocrinological abnormalities (e.g. hypothyroidism) and structural damage of the brain. A complex interaction of dopaminergic regulatory mechanisms in the ventral hypothalamus and peripheral vaso- and sudomotor adjustments seems to be causative. Hypothermia following antipsychotic drug administration represents a serious adverse drug reaction and a potentially life-threatening event.
Collapse
Affiliation(s)
- P Kreuzer
- Klinik und Poliklinik für Psychiatrie, Psychosomatik und Psychotherapie, Universität Regensburg am Bezirksklinikum, Universitätsstr. 84, 93053 Regensburg, Deutschland.
| | | | | | | | | | | | | |
Collapse
|
45
|
Yu Y, Hill AP, McCormick DA. Warm body temperature facilitates energy efficient cortical action potentials. PLoS Comput Biol 2012; 8:e1002456. [PMID: 22511855 PMCID: PMC3325181 DOI: 10.1371/journal.pcbi.1002456] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 02/18/2012] [Indexed: 12/13/2022] Open
Abstract
The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na(+) channel inactivation, resulting in a marked reduction in overlap of the inward Na(+), and outward K(+), currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na(+) entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37-42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code.
Collapse
Affiliation(s)
- Yuguo Yu
- Department of Neurobiology and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut, United States of America
- Center for Computational Systems Biology, Fudan University, Shanghai, People's Republic of China
| | - Adam P. Hill
- Department of Neurobiology and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - David A. McCormick
- Department of Neurobiology and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
| |
Collapse
|
46
|
Environmental conditions modulate neurotoxic effects of psychomotor stimulant drugs of abuse. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2012; 102:147-71. [PMID: 22748829 DOI: 10.1016/b978-0-12-386986-9.00006-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Psychomotor stimulants such as methamphetamine (METH), amphetamine, and 3,4-metylenedioxymethamphetamine (MDMA or ecstasy) are potent addictive drugs. While it is known that their abuse could result in adverse health complications, including neurotoxicity, both the environmental conditions and activity states associated with their intake could strongly enhance drug toxicity, often resulting in life-threatening health complications. In this review, we analyze results of animal experiments that suggest that even moderate increases in environmental temperatures and physiological activation, the conditions typical of human raves parties, dramatically potentiate brain hyperthermic effects of METH and MDMA. We demonstrate that METH also induces breakdown of the blood-brain barrier, acute glial activation, brain edema, and structural abnormalities of various subtypes of brain cells; these effects are also strongly enhanced when the drug is used at moderately warm environmental conditions. We consider the mechanisms underlying environmental modulation of acute drug neurotoxicity and focus on the role of brain temperature, a critical homeostatic parameter that could be affected by metabolism-enhancing drugs and environmental conditions and affect neural activity and functions.
Collapse
|
47
|
Kreuzer P, Landgrebe M, Wittmann M, Schecklmann M, Poeppl TB, Hajak G, Langguth B. Hypothermia associated with antipsychotic drug use: a clinical case series and review of current literature. J Clin Pharmacol 2011; 52:1090-7. [PMID: 21956608 DOI: 10.1177/0091270011409233] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Hypothermia as an adverse reaction of antipsychotic drug use represents a potentially life-threatening complication. However, the mechanisms by which antipsychotic drugs alter thermoregulatory processes in the human body are far from being fully understood. Here we present a case series of 5 patients developing severe hypothermia after administration of olanzapine and benperidol. Controlled by a network of neural structures, body temperature is physiologically regulated in far more narrow boundaries than are other vital functions, and its homeostasis is critical for survival. The preoptic region in the ventral hypothalamus is assumed to act as a coordinating center that is endowed with thermosensory units that constantly compare actual body temperature with target values and initiate regulatory and compensatory mechanisms in case of mismatch. Hypothermia risk seems to increase in the first days after initiation of antipsychotic drug therapy or increases in the daily dose. Schizophrenic patients bear a higher risk than nonschizophrenic patients treated with antipsychotic drugs (such as patients with dementia or depression). Antipsychotic drugs with strong 5-HT2 antagonism seem to be more frequently associated with hypothermia. These cases demonstrate the clinical relevance of hypothermia as an adverse reaction to antipsychotic treatment and the importance of careful monitoring of body temperature.
Collapse
Affiliation(s)
- Peter Kreuzer
- Department of Psychiatry, Psychotherapy and Psychosomatics, University of Regensburg, Regensburg, Germany.
| | | | | | | | | | | | | |
Collapse
|
48
|
Li M, Miao P, Zhu Y, Tong S. Functional laser speckle imaging of cerebral blood flow under hypothermia. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:086011. [PMID: 21895323 DOI: 10.1117/1.3610995] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Hypothermia can unintentionally occur in daily life, e.g., in cardiovascular surgery or applied as therapeutics in the neurosciences critical care unit. So far, the temperature-induced spatiotemporal responses of the neural function have not been fully understood. In this study, we investigated the functional change in cerebral blood flow (CBF), accompanied with neuronal activation, by laser speckle imaging (LSI) during hypothermia. Laser speckle images from Sprague-Dawley rats (n = 8, male) were acquired under normothermia (37°C) and moderate hypothermia (32°C). For each animal, 10 trials of electrical hindpaw stimulation were delivered under both temperatures. Using registered laser speckle contrast analysis and temporal clustering analysis (TCA), we found a delayed response peak and a prolonged response window under hypothermia. Hypothermia also decreased the activation area and the amplitude of the peak CBF. The combination of LSI and TCA is a high-resolution functional imaging method to investigate the spatiotemporal neurovascular coupling in both normal and pathological brain functions.
Collapse
Affiliation(s)
- Minheng Li
- Shanghai Jiao Tong University, School of Biomedical Engineering, Shanghai 200240, China
| | | | | | | |
Collapse
|
49
|
Methamphetamine toxicity and its implications during HIV-1 infection. J Neurovirol 2011; 17:401-15. [PMID: 21786077 DOI: 10.1007/s13365-011-0043-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 06/22/2011] [Indexed: 10/18/2022]
Abstract
Over the past two decades methamphetamine (MA) abuse has seen a dramatic increase. The abuse of MA is particularly high in groups that are at higher risk for HIV-1 infection, especially men who have sex with men (MSM). This review is focused on MA toxicity in the CNS as well as in the periphery. In the CNS, MA toxicity is comprised of numerous effects, including, but not limited to, oxidative stress produced by dysregulation of the dopaminergic system, hyperthermia, apoptosis, and neuroinflammation. Multiple lines of evidence demonstrate that these effects exacerbate the neurodegenerative damage caused by CNS infection of HIV perhaps because both MA and HIV target the frontostriatal regions of the brain. MA has also been demonstrated to increase viral load in the CNS of SIV-infected macaques. Using transgenic animal models, as well as cultured cells, the HIV proteins Tat and gp120 have been demonstrated to have neurotoxic properties that are aggravated by MA. In addition, MA has been shown to exhibit detrimental effects on the blood-brain barrier (BBB) that have the potential to increase the probability of CNS infection by HIV. Although the effects of MA in the periphery have not been as extensively studied as have the effects on the CNS, recent reports demonstrate the potential effects of MA on HIV infection in the periphery including increased expression of HIV co-receptors and increased expression of inflammatory cytokines.
Collapse
|
50
|
Abstract
The physiological responses of thermal stress and its consequences on health have been well documented. However, the effect on cognitive function remains equivocal despite a substantial number of studies conducted in the area. Methodological discrepancies across different studies have made it difficult to conclude whether or not heat exposure per se has an adverse effect upon cognitive function and under what specific environmental and physiological conditions these alterations appear. This article gives an overview of the different confounding factors that have made it difficult to make conclusive interpretations. In addition, the current state of knowledge is presented and discussed with reference to the Global Workspace theory. Although previously presented conclusions are promising, much remains to be completed before understanding the mechanisms that could explain the relationship between heat exposure and cognitive function. Finally, recommendations are presented for further research in this area.
Collapse
Affiliation(s)
- N Gaoua
- Research and Education Centre, ASPETAR-Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
| |
Collapse
|