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Wasilczuk AZ, Rinehart C, Aggarwal A, Stone ME, Mashour GA, Avidan MS, Kelz MB, Proekt A. Hormonal basis of sex differences in anesthetic sensitivity. Proc Natl Acad Sci U S A 2024; 121:e2312913120. [PMID: 38190526 PMCID: PMC10801881 DOI: 10.1073/pnas.2312913120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/20/2023] [Indexed: 01/10/2024] Open
Abstract
General anesthesia-a pharmacologically induced reversible state of unconsciousness-enables millions of life-saving procedures. Anesthetics induce unconsciousness in part by impinging upon sexually dimorphic and hormonally sensitive hypothalamic circuits regulating sleep and wakefulness. Thus, we hypothesized that anesthetic sensitivity should be sex-dependent and modulated by sex hormones. Using distinct behavioral measures, we show that at identical brain anesthetic concentrations, female mice are more resistant to volatile anesthetics than males. Anesthetic sensitivity is bidirectionally modulated by testosterone. Castration increases anesthetic resistance. Conversely, testosterone administration acutely increases anesthetic sensitivity. Conversion of testosterone to estradiol by aromatase is partially responsible for this effect. In contrast, oophorectomy has no effect. To identify the neuronal circuits underlying sex differences, we performed whole brain c-Fos activity mapping under anesthesia in male and female mice. Consistent with a key role of the hypothalamus, we found fewer active neurons in the ventral hypothalamic sleep-promoting regions in females than in males. In humans, we demonstrate that females regain consciousness and recover cognition faster than males after identical anesthetic exposures. Remarkably, while behavioral and neurocognitive measures in mice and humans point to increased anesthetic resistance in females, cortical activity fails to show sex differences under anesthesia in either species. Cumulatively, we demonstrate that sex differences in anesthetic sensitivity are evolutionarily conserved and not reflected in conventional electroencephalographic-based measures of anesthetic depth. This covert resistance to anesthesia may explain the higher incidence of unintended awareness under general anesthesia in females.
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Affiliation(s)
- Andrzej Z. Wasilczuk
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA19104
| | - Cole Rinehart
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
| | - Adeeti Aggarwal
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA19104
| | - Martha E. Stone
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA19104
| | - George A. Mashour
- Center for Consciousness Science, Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI48105
| | - Michael S. Avidan
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO63110
| | - Max B. Kelz
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA19104
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Alex Proekt
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Neuroscience of Unconsciousness and Reanimation Research Alliance, Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA19104
- Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - ReCCognition Study Group
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA19104
- Center for Consciousness Science, Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI48105
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO63110
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Vincent KF, Mallari OG, Dillon EJ, Stewart VG, Cho AJ, Dong Y, Edlow AG, Ichinose F, Xie Z, Solt K. Oestrous cycle affects emergence from anaesthesia with dexmedetomidine, but not propofol, isoflurane, or sevoflurane, in female rats. Br J Anaesth 2023; 131:67-78. [PMID: 37142466 PMCID: PMC10308440 DOI: 10.1016/j.bja.2023.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 02/17/2023] [Accepted: 03/13/2023] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND Although sex differences in anaesthetic sensitivity have been reported, what underlies these differences is unknown. In rodents, one source of variability in females is the oestrous cycle. Here we test the hypothesis that the oestrous cycle impacts emergence from general anaesthesia. METHODS Time to emergence was measured after isoflurane (2 vol% for 1 h), sevoflurane (3 vol% for 20 min), dexmedetomidine (50 μg kg-1 i.v., infused over 10 min), or propofol (10 mg kg-1 i.v. bolus) during proestrus, oestrus, early dioestrus, and late dioestrus in female Sprague-Dawley rats (n=24). EEG recordings were taken during each test for power spectral analysis. Serum was analysed for 17β-oestradiol and progesterone concentrations. The effect of oestrous cycle stage on return of righting latency was assessed using a mixed model. The association between righting latency and serum hormone concentration was tested by linear regression. Mean arterial blood pressure and arterial blood gases were assessed in a subset of rats after dexmedetomidine and compared in a mixed model. RESULTS Oestrous cycle did not affect righting latency after isoflurane, sevoflurane, or propofol. When in the early dioestrus stage, rats emerged more rapidly from dexmedetomidine than in the proestrus (P=0.0042) or late dioestrus (P=0.0230) stage and showed reduced overall power in frontal EEG spectra 30 min after dexmedetomidine (P=0.0049). 17β-Oestradiol and progesterone serum concentrations did not correlate with righting latency. Oestrous cycle did not affect mean arterial blood pressure or blood gases during dexmedetomidine. CONCLUSIONS In female rats, the oestrous cycle significantly impacts emergence from dexmedetomidine-induced unconsciousness. However, 17β-oestradiol and progesterone serum concentrations do not correlate with the observed changes.
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Affiliation(s)
- Kathleen F Vincent
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Olivia G Mallari
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anesthesiology, Columbia University, New York, NY, USA
| | - Emmaline J Dillon
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Brigham Young University, Provo, UT, USA
| | - Victoria G Stewart
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Brigham Young University, Provo, UT, USA
| | - Angel J Cho
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Touro College of Osteopathic Medicine, New York, NY, USA
| | - Yuanlin Dong
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Andrea G Edlow
- Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA; Department of Obstetrics, Gynecology, and Reproductive Biology, Harvard Medical School, Boston, MA, USA
| | - Fumito Ichinose
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Zhongcong Xie
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Ken Solt
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA.
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Fine-Raquet B, Manzella FM, Joksimovic SM, Dietz RM, Orfila JE, Sampath D, Tesic V, Atluri N, Covey DF, Raol YH, Jevtovic-Todorovic V, Herson PS, Todorovic SM. Neonatal exposure to a neuroactive steroid alters low-frequency oscillations in the subiculum. Exp Biol Med (Maywood) 2023; 248:578-587. [PMID: 37309730 PMCID: PMC10350800 DOI: 10.1177/15353702231177009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023] Open
Abstract
Preclinical studies have established that neonatal exposure to contemporary sedative/hypnotic drugs causes neurotoxicity in the developing rodent and primate brains. Our group recently reported that novel neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) induced effective hypnosis in both neonatal and adult rodents but did not cause significant neurotoxicity in vulnerable brain regions such as subiculum, an output region of hippocampal formation particularly sensitive to commonly used sedatives/hypnotics. Despite significant emphasis on patho-morphological changes, little is known about long-term effects on subicular neurophysiology after neonatal exposure to neuroactive steroids. Hence, we explored the lasting effects of neonatal exposure to 3β-OH on sleep macrostructure as well as subicular neuronal oscillations in vivo and synaptic plasticity ex vivo in adolescent rats. At postnatal day 7, we exposed rat pups to either 10 mg/kg of 3β-OH over a period of 12 h or to volume-matched cyclodextrin vehicle. At weaning age, a cohort of rats was implanted with a cortical electroencephalogram (EEG) and subicular depth electrodes. At postnatal day 30-33, we performed in vivo assessment of sleep macrostructure (divided into wake, non-rapid eye movement, and rapid eye movement sleep) and power spectra in cortex and subiculum. In a second cohort of 3β-OH exposed animals, we conducted ex vivo studies of long-term potentiation (LTP) in adolescent rats. Overall, we found that neonatal exposure to 3β-OH decreased subicular delta and sigma oscillations during non-rapid eye movement sleep without altering sleep macrostructure. Furthermore, we observed no significant changes in subicular synaptic plasticity. Interestingly, our previous study found that neonatal exposure to ketamine increased subicular gamma oscillations during non-rapid eye movement sleep and profoundly suppressed subicular LTP in adolescent rats. Together these results suggest that exposure to different sedative/hypnotic agents during a critical period of brain development may induce distinct functional changes in subiculum circuitry that may persist into adolescent age.
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Affiliation(s)
- Brier Fine-Raquet
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Francesca M Manzella
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Srdjan M Joksimovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert M Dietz
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - James E Orfila
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Dayalan Sampath
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University, College Station, TX 77843, USA
| | - Vesna Tesic
- Department of Neurology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - Navya Atluri
- Department of Anesthesiology, University of Virginia, Charlottesville, VA 22903, USA
| | - Douglas F Covey
- Department of Developmental Biology, St. Louis School of Medicine, Washington University, St. Louis, MO 63130, USA
- Taylor Family Institute for Innovative Psychiatric Research, St. Louis School of Medicine, Washington University, St. Louis, MO 63130, USA
| | - Yogendra H Raol
- Department of Pediatrics, Division of Neurology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Rockville, MD 20824, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Paco S Herson
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Manzella FM, Cabrera OH, Wilkey D, Fine-Raquet B, Klawitter J, Krishnan K, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Sex-specific hypnotic effects of the neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile are mediated by peripheral metabolism into an active hypnotic steroid. Br J Anaesth 2023; 130:154-164. [PMID: 36428160 PMCID: PMC10080470 DOI: 10.1016/j.bja.2022.09.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 08/01/2022] [Accepted: 09/24/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND The novel synthetic neuroactive steroid (3β,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3β-OH) blocks T-type calcium channels but does not directly modulate neuronal γ-aminobutyric acid type A (GABAA) currents like other anaesthetic neurosteroids. As 3β-OH has sex-specific hypnotic effects in adult rats, we studied the mechanism contributing to sex differences in its effects. METHODS We used a combination of behavioural loss of righting reflex, neuroendocrine, pharmacokinetic, in vitro patch-clamp electrophysiology, and in vivo electrophysiological approaches in wild-type mice and in genetic knockouts of the CaV3.1 T-type calcium channel isoform to study the mechanisms by which 3β-OH and its metabolite produces sex-specific hypnotic effects. RESULTS Adult male mice were less sensitive to the hypnotic effects of 3β-OH compared with female mice, and these differences appeared during development. Adult males had higher 3β-OH brain concentrations despite being less sensitive to its hypnotic effects. Females metabolised 3β-OH into the active GABAA receptor positive allosteric modulator (3α,5β,17β)-3-hydroxyandrostane-17-carbonitrile (3α-OH) to a greater extent than males. The 3α-OH metabolite has T-channel blocking properties with sex-specific hypnotic and pharmacokinetic effects. Sex-dependent suppression of the cortical electroencephalogram is more pronounced with 3α-OH compared with 3β-OH. CONCLUSIONS The sex-specific differences in the hypnotic effect of 3β-OH in mice are attributable to differences in its peripheral metabolism into the more potent hypnotic metabolite 3α-OH.
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Affiliation(s)
- Francesca M Manzella
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Omar H Cabrera
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Davis Wilkey
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Brier Fine-Raquet
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jelena Klawitter
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA; Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M Todorovic
- Department of Anaesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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Lambert PM, Ni R, Benz A, Rensing NR, Wong M, Zorumski CF, Mennerick S. Non-sedative cortical EEG signatures of allopregnanolone and functional comparators. Neuropsychopharmacology 2023; 48:371-379. [PMID: 36168047 PMCID: PMC9751067 DOI: 10.1038/s41386-022-01450-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/13/2022] [Accepted: 08/31/2022] [Indexed: 12/26/2022]
Abstract
Neurosteroids that positively modulate GABAA receptors are among a growing list of rapidly acting antidepressants, including ketamine and psychedelics. To develop increasingly specific treatments with fewer side effects, we explored the possibility of EEG signatures in mice, which could serve as a cross-species screening tool. There are few studies of the impact of non-sedative doses of rapid antidepressants on EEG in either rodents or humans. Here we hypothesize that EEG features may separate a rapid antidepressant neurosteroid, allopregnanolone, from other GABAA positive modulators, pentobarbital and diazepam. Further, we compared the actions GABA modulators with those of ketamine, an NMDA antagonist and prototype rapid antidepressant. We examined EEG spectra during active exploration at two cortical locations and examined cross-regional and cross-frequency interactions. We found that at comparable doses, the effects of allopregnanolone, despite purported selectivity for certain GABAAR subtypes, was indistinguishable from pentobarbital during active waking exploration. The actions of diazepam had recognizable common features with allopregnanolone and pentobarbital but was also distinct, consistent with subunit selectivity of benzodiazepines. Finally, ketamine exhibited no distinguishing overlap with allopregnanolone in the parameters examined. Our results suggest that rapid antidepressants with different molecular substrates may remain separated at the level of large-scale ensemble activity, but the studies leave open the possibility of commonalities in more discrete circuits and/or in the context of a dysfunctional brain.
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Affiliation(s)
- Peter M Lambert
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.,Medical Scientist Training Program, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Richard Ni
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Ann Benz
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Nicholas R Rensing
- Department of Neurology, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Michael Wong
- Department of Neurology, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Charles F Zorumski
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA
| | - Steven Mennerick
- Department of Psychiatry, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA. .,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, 660S. Euclid Ave., MSC 8134-0181-0G, St. Louis, MO, 63110, USA.
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Joksimovic SL, Jevtovic-Todorovic V, Todorovic SM. The role of voltage-gated calcium channels in the mechanisms of anesthesia and perioperative analgesia. Curr Opin Anaesthesiol 2022; 35:436-441. [PMID: 35787588 PMCID: PMC9616208 DOI: 10.1097/aco.0000000000001159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW A family of neuronal voltage-gated calcium channels (VGCCs) have received only recently a significant consideration regarding the mechanisms of anesthesia because VGCC inhibition may be important in anesthetic action by decreasing neuronal excitability and presynaptic excitatory transmission. The T-type VGCCs channels (T-channels), although rarely involved in synaptic neurotransmitter release, play an important role in controlling neuronal excitability and in generating spontaneous oscillatory bursting of groups of neurons in the thalamus thought to be involved in regulating the state of arousal and sleep. Furthermore, these channels are important regulators of neuronal excitability in pain pathway. This review will provide an overview of historic perspective and the recent literature on the role of VGCCs and T-channel inhibition in particular in the mechanisms of action of anesthetics and analgesics. RECENT FINDINGS Recent research in the field of novel mechanisms of hypnotic action of anesthetics revealed significant contribution of the Ca V 3.1 isoform of T-channels expressed in the thalamus. Furthermore, perioperative analgesia can be achieved by targeting Ca V 3.2 isoform of these channels that is abundantly expressed in pain pathways. SUMMARY The review summarizes current knowledge regarding the contribution of T-channels in hypnosis and analgesia. Further preclinical and clinical studies are needed to validate their potential for developing novel anesthetics and new perioperative pain therapies.
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Affiliation(s)
- Sonja L. Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M. Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
- Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
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Thalamic T-Type Calcium Channels as Targets for Hypnotics and General Anesthetics. Int J Mol Sci 2022; 23:ijms23042349. [PMID: 35216466 PMCID: PMC8876360 DOI: 10.3390/ijms23042349] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/19/2022] Open
Abstract
General anesthetics mainly act by modulating synaptic inhibition on the one hand (the potentiation of GABA transmission) or synaptic excitation on the other (the inhibition of NMDA receptors), but they can also have effects on numerous other proteins, receptors, and channels. The effects of general anesthetics on ion channels have been the subject of research since the publication of reports of direct actions of these drugs on ion channel proteins. In particular, there is considerable interest in T-type voltage-gated calcium channels that are abundantly expressed in the thalamus, where they control patterns of cellular excitability and thalamocortical oscillations during awake and sleep states. Here, we summarized and discussed our recent studies focused on the CaV3.1 isoform of T-channels in the nonspecific thalamus (intralaminar and midline nuclei), which acts as a key hub through which natural sleep and general anesthesia are initiated. We used mouse genetics and in vivo and ex vivo electrophysiology to study the role of thalamic T-channels in hypnosis induced by a standard general anesthetic, isoflurane, as well as novel neuroactive steroids. From the results of this study, we conclude that CaV3.1 channels contribute to thalamocortical oscillations during anesthetic-induced hypnosis, particularly the slow-frequency range of δ oscillations (0.5–4 Hz), by generating “window current” that contributes to the resting membrane potential. We posit that the role of the thalamic CaV3.1 isoform of T-channels in the effects of various classes of general anesthetics warrants consideration.
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8
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Manzella FM, Covey DF, Jevtovic-Todorovic V, Todorovic SM. Synthetic neuroactive steroids as new sedatives and anaesthetics: Back to the future. J Neuroendocrinol 2022; 34:e13086. [PMID: 35014105 PMCID: PMC8866223 DOI: 10.1111/jne.13086] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 12/03/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023]
Abstract
Since the 1990s, there has been waning interest in researching general anaesthetics (anaesthetics). Although currently used anaesthetics are mostly safe and effective, they are not without fault. In paediatric populations and neonatal animal models, they are associated with learning impairments and neurotoxicity. In an effort to research safer anaesthetics, we have gone back to re-examine neuroactive steroids as anaesthetics. Neuroactive steroids are steroids that have direct, local effects in the central nervous system. Since the discovery of their anaesthetic effects, neuroactive steroids have been consistently used in human or veterinary clinics as preferred anaesthetic agents. Although briefly abandoned for clinical use due to unwanted vehicle side effects, there has since been renewed interest in their therapeutic value. Neuroactive steroids are safe sedative/hypnotic and anaesthetic agents across various animal species. Importantly, unlike traditional anaesthetics, they do not cause extensive neurotoxicity in the developing rodent brain. Similar to traditional anaesthetics, neuroactive steroids are modulators of synaptic and extrasynaptic γ-aminobutyric acid type A (GABAA ) receptors and their interactions at the GABAA receptor are stereo- and enantioselective. Recent work has also shown that these agents act on other ion channels, such as high- and low-voltage-activated calcium channels. Through these mechanisms of action, neuroactive steroids modulate neuronal excitability, which results in characteristic burst suppression of the electroencephalogram, and a surgical plane of anaesthesia. However, in addition to their interactions with voltage and ligand gated ions channels, neuroactive steroids interact with membrane bound metabotropic receptors and xenobiotic receptors to facilitate signaling of prosurvival, antiapoptotic pathways. These pathways play a role in their neuroprotective effects in neuronal injury and may also prevent extensive apoptosis in the developing brain during anaesthesia. The current review explores the history of neuroactive steroids as anaesthetics in humans and animal models, their diverse mechanisms of action, and their neuroprotective properties.
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Affiliation(s)
- Francesca M Manzella
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Douglas F Covey
- Department of Developmental Biology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, USA
- Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis School of Medicine, St. Louis, Missouri, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Neuroscience Graduate Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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9
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Neudecker V, Perez-Zoghbi JF, Brambrink AM. Does inflammation mediate behavioural alterations in anaesthesia-induced developmental neurotoxicity? Br J Anaesth 2022; 128:602-605. [PMID: 35115157 DOI: 10.1016/j.bja.2021.12.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 11/30/2022] Open
Abstract
Anaesthesia exposure early in life potentially impairs neurobehavioural development. A recent study in the Journal investigated the possibility that progesterone mitigates anaesthesia-induced developmental neurotoxicity in neonatal rats exposed to sevoflurane. The novel findings show that the steroid hormone progesterone protects against development of behavioural alterations caused by sevoflurane. The protective mechanism is proposed to relate to anti-inflammatory properties of progesterone, which brings up important questions regarding the role of inflammation in mediating the neurobehavioural alterations in anaesthesia-induced developmental neurotoxicity. We discuss this mechanism and encourage new research that may clarify the underlying mechanisms of progesterone-induced protection and extend these findings into a translational model.
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Affiliation(s)
- Viola Neudecker
- Department of Anesthesiology, Columbia University Medical Center, New York, NY, USA
| | - Jose F Perez-Zoghbi
- Department of Anesthesiology, Columbia University Medical Center, New York, NY, USA
| | - Ansgar M Brambrink
- Department of Anesthesiology, Columbia University Medical Center, New York, NY, USA.
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Moody OA, Vincent KF, Solt K. Sex, drugs, and anaesthesia research. Br J Anaesth 2021; 127:340-343. [PMID: 34330415 DOI: 10.1016/j.bja.2021.06.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 11/29/2022] Open
Abstract
In this issue of the British Journal of Anaesthesia, Joksimovic and colleagues report significant sex differences in sensitivity to the behavioural and neurophysiological effects of 3β-OH, a novel neurosteroid anesthetic. Female rats were more sensitive to the effects of 3β-OH than male rats, although the mechanims remain unclear. Sex differences have been understudied in anaesthesia research, and this article by Joksimovic and colleagues emphasizes the need to devote more effort to understanding these differences.
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Affiliation(s)
- Olivia A Moody
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Kathleen F Vincent
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
| | - Ken Solt
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA; Department of Anaesthesia, Harvard Medical School, Boston, MA, USA.
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