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Behroozi M, Graïc JM, Gerussi T. Beyond the surface: how ex-vivo diffusion-weighted imaging reveals large animal brain microstructure and connectivity. Front Neurosci 2024; 18:1411982. [PMID: 38988768 PMCID: PMC11233460 DOI: 10.3389/fnins.2024.1411982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/12/2024] [Indexed: 07/12/2024] Open
Abstract
Diffusion-weighted Imaging (DWI) is an effective and state-of-the-art neuroimaging method that non-invasively reveals the microstructure and connectivity of tissues. Recently, novel applications of the DWI technique in studying large brains through ex-vivo imaging enabled researchers to gain insights into the complex neural architecture in different species such as those of Perissodactyla (e.g., horses and rhinos), Artiodactyla (e.g., bovids, swines, and cetaceans), and Carnivora (e.g., felids, canids, and pinnipeds). Classical in-vivo tract-tracing methods are usually considered unsuitable for ethical and practical reasons, in large animals or protected species. Ex-vivo DWI-based tractography offers the chance to examine the microstructure and connectivity of formalin-fixed tissues with scan times and precision that is not feasible in-vivo. This paper explores DWI's application to ex-vivo brains of large animals, highlighting the unique insights it offers into the structure of sometimes phylogenetically different neural networks, the connectivity of white matter tracts, and comparative evolutionary adaptations. Here, we also summarize the challenges, concerns, and perspectives of ex-vivo DWI that will shape the future of the field in large brains.
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Affiliation(s)
- Mehdi Behroozi
- Department of Biopsychology, Faculty of Psychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum, Bochum, Germany
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Italy
| | - Tommaso Gerussi
- Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Legnaro, Italy
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
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2
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Cook PF, Reichmuth C. An Ecological and Neural Argument for Developing Pursuit-Based Cognitive Enrichment for Sea Lions in Human Care. Animals (Basel) 2024; 14:797. [PMID: 38473182 DOI: 10.3390/ani14050797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
While general enrichment strategies for captive animals attempt to elicit variable and species-typical behaviors, approaches to cognitive enrichment have been disappointingly one-size-fits-all. In this commentary, we address the potential benefit of tailoring cognitive enrichment to the "cognitive niche" of the species, with a particular focus on a reasonably well-studied marine carnivore, the sea lion. Sea lions likely share some cognitive evolutionary pressures with primates, including complex social behavior. Their foraging ecology, however, like that of many terrestrial carnivores, is based on the rapid and behaviorally flexible pursuit of avoidant prey. Unlike terrestrial carnivores, sea lions carry out this pursuit in a truly fluid three-dimensional field, computing and executing sensorimotor transformations from any solid angle to any other. The cognitive demands of flexible prey pursuit are unlikely to be fully elicited by typical stationary puzzle box style foraging enrichment devices or screen-based interactive games. With this species, we recommend exploring more water-based movement activities generally, and complex pursuit challenges specifically.
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Affiliation(s)
- Peter F Cook
- Social Sciences Division, New College of Florida, Sarasota, FL 34243, USA
| | - Colleen Reichmuth
- Long Marine Laboratory, Institute for Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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3
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Graïc JM, Mazzariol S, Casalone C, Petrella A, Gili C, Gerussi T, Orekhova K, Centelleghe C, Cozzi B. Report on the brain of the monk seal (Monachus monachus, Hermann, 1779). Anat Histol Embryol 2024; 53:e12986. [PMID: 37843436 DOI: 10.1111/ahe.12986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 09/28/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023]
Abstract
The Mediterranean monk seal (Monachus monachus, Hermann, 1779) is an endangered species of pinniped endemic to few areas of the Mediterranean Sea. Extensive hunting and poaching over the last two centuries have rendered it a rare sight, scattered mainly in the Aegean Sea and the western coast of North Africa. In a rare event, a female monk seal calf stranded and died in southern Italy (Brindisi, Puglia). During due necropsy, the brain was extracted and fixed. The present report is the first of a monk seal brain. The features reported are remarkably typical of a true seal brain, with some specific characteristics. The brain cortical circonvolutions, main fissures and the external parts are described, and an EQ was calculated. Overall, this carnivore adapted to aquatic life shares some aspects of its neuroanatomy and physiology with other seemingly distant aquatic mammals.
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Affiliation(s)
- Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
| | - Sandro Mazzariol
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
| | - Cristina Casalone
- Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Torino, Italy
| | - Antonio Petrella
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Foggia, Italy
| | | | - Tommaso Gerussi
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
| | - Ksenia Orekhova
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
| | - Cinzia Centelleghe
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
| | - Bruno Cozzi
- Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, Legnaro, Italy
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4
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Williams DC, Haulena M, Dennison S, Waugh L, Goldstein T, Nutter F, Bonn BV, Hoard V, Laxer KD, Buckmaster PS, Gulland FMD, Tharp B. Pinniped electroencephalography: Methodology and findings in California sea lions ( Zalophus californianus). Front Vet Sci 2023; 10:1040125. [PMID: 37065231 PMCID: PMC10102506 DOI: 10.3389/fvets.2023.1040125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/06/2023] [Indexed: 04/03/2023] Open
Abstract
This study was designed to identify abnormalities in the electroencephalograms (EEGs) recorded from stranded California sea lions (Zalophus californianus) with suspected domoic acid (DA) toxicosis. Recordings from animals presenting for non-neurological issues were also obtained to better understand the normal EEG (background activity and transient events) in this species, as, to date, studies have focused on examining natural sleep in pinnipeds. Most animals were sedated for electrode placement and EEG acquisition with some receiving antiepileptic medications or isoflurane during the procedure. A total of 103 recordings were read and scored from 0 (normal) to 3 (severely abnormal). Epileptiform discharges, consisting of spikes, sharp waves, slow waves, and/or spike waves, were present in all EEGs with scores of 1, 2, or 3. The distribution of these events over the scalp varied. While often generalized, others were lateralized over one hemisphere, bifrontal, bioccipital, and/or bitemporal, while some discharges were multifocal. Findings were different between sea lions and occasionally changed within the EEG on a given sea lion. No clinical seizures were observed during the recording but a few sea lions had findings consistent with electroencephalographic seizures. When available, supporting diagnostic results obtained from magnetic resonance imaging (MRI) and/or necropsy/histopathology were described, as well as the status of those sea lions that recovered and were released with satellite tags.
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Affiliation(s)
- D. Colette Williams
- Vet EDX, Retired Veterinary Medical Teaching Hospital, University of California, Davis, Davis, CA, United States
| | | | | | - Lynnette Waugh
- UC Davis School of Veterinary Medicine, Davis, CA, United States
| | - Tracey Goldstein
- Zoological Pathology Program, University of Illinois at Urbana-Champaign, Brookfield, IL, United States
| | - Felicia Nutter
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, United States
| | - Bill Van Bonn
- A. Watson Armour III Center for Animal Health and Welfare, Animal Care and Science Division, John G. Shedd Aquarium, Chicago, IL, United States
| | - Vanessa Hoard
- Department of Neurology, The Pacific Marine Mammal Center, Laguna Beach, CA, United States
| | - Kenneth D. Laxer
- Sutter Pacific Medical Foundation, San Francisco, CA, United States
| | - Paul S. Buckmaster
- Departments of Comparative Medicine and Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States
| | - Frances M. D. Gulland
- The Marine Mammal Center, Sausalito, CA, United States
- Wildlife Health Center, University of California, Davis, Davis, CA, United States
| | - Barry Tharp
- Emeritus, Department of Neurology, University of California Davis Medical Center, Sacramento, CA, United States
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5
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De Vreese S, Sørensen K, Biolsi K, Fasick JI, Reidenberg JS, Hanke FD. Open questions in marine mammal sensory research. Biol Open 2023; 12:297288. [PMID: 36942843 PMCID: PMC10084856 DOI: 10.1242/bio.059904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023] Open
Abstract
Although much research has focused on marine mammal sensory systems over the last several decades, we still lack basic knowledge for many of the species within this diverse group of animals. Our conference workshop allowed all participants to present recent developments in the field and culminated in discussions on current knowledge gaps. This report summarizes open questions regarding marine mammal sensory ecology and will hopefully serve as a platform for future research.
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Affiliation(s)
- Steffen De Vreese
- Laboratory of Applied Bioacoustics, Technical University of Catalonia (BarcelonaTech), 08800 Vilanova i la Geltrù, Spain
| | - Kenneth Sørensen
- University of Rostock, Institute for Biosciences, Neuroethology, Albert-Einstein-Str. 3, 18059 Rostock, Germany
| | - Kristy Biolsi
- Department of Psychology, St. Francis College, Brooklyn NY 11201, USA
- Center for the Study of Pinniped Ecology and Cognition (C-SPEC), Brooklyn Heights, USA
| | - Jeffry I Fasick
- Department of Biological Sciences, University of Tampa, Tampa, FL 33606, USA
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, Mail Box 1007, New York, NY 10029-6574, USA
| | - Frederike D Hanke
- University of Rostock, Institute for Biosciences, Neuroethology, Albert-Einstein-Str. 3, 18059 Rostock, Germany
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Krucik DDR, Cook P, Cathey M, Meegan JM, Gomez FM, Bonn WV, Le-Bert C. Adult-onset epilepsy and hippocampal pathology in a California sea lion (Zalophus californianus): A case study of suspected in utero exposure to domoic acid. Neurotoxicology 2023; 96:13-18. [PMID: 36871906 DOI: 10.1016/j.neuro.2023.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023]
Abstract
Domoic acid (DA) is a naturally occurring marine neurotoxin produced by Pseudo-nitzschia diatoms. Adult California sea lions (Zalophus californianus) can experience multiple post-exposure syndromes, including acute toxicosis and chronic epilepsy. Additionally, a delayed-onset epileptic syndrome is proposed for California sea lions (CSL) exposed in utero. This brief report explores a case of a CSL developing adult-onset epilepsy with progressive hippocampal neuropathology. Initial brain magnetic resonance imaging (MRI) and hippocampal volumetric analyses relative to brain size were normal. Approximately 7 years later, MRI studies to evaluate a newly developed epileptic syndrome demonstrated unilateral hippocampal atrophy. While other causes of unilateral hippocampal atrophy cannot be completely excluded, this case may represent in vivo evidence of adult-onset epileptiform DA toxicosis in a CSL. By estimating in utero DA exposure time period, and extrapolating from studies conducted on laboratory species, this case provides circumstantial evidence for a neurodevelopmental explanation correlating in utero exposure to adult-onset disease. Evidence of delayed disease development secondary to gestational exposure to naturally occurring DA has broad implications for marine mammal medicine and public health.
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Affiliation(s)
- David D R Krucik
- Cummings School of Veterinary Medicine at Tufts University, Grafton, MA 01581, USA
| | - Peter Cook
- New College of Florida, Sarasota, FL 34243, USA
| | | | | | | | | | - Carolina Le-Bert
- US Navy Marine Mammal Program, Naval Information Warfare Center Pacific, San Diego, CA 92152, USA.
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7
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Cook PF, Berns G. Volumetric and connectivity assessment of the caudate nucleus in California sea lions and coyotes. Anim Cogn 2022; 25:1231-1240. [DOI: 10.1007/s10071-022-01685-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/27/2022] [Accepted: 08/16/2022] [Indexed: 12/01/2022]
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8
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Petroff RL, Williams C, Li JL, MacDonald JW, Bammler TK, Richards T, English CN, Baldessari A, Shum S, Jing J, Isoherranen N, Crouthamel B, McKain N, Grant KS, Burbacher TM, Harry GJ. Prolonged, Low-Level Exposure to the Marine Toxin, Domoic Acid, and Measures of Neurotoxicity in Nonhuman Primates. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:97003. [PMID: 36102641 PMCID: PMC9472675 DOI: 10.1289/ehp10923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 07/21/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The excitotoxic molecule, domoic acid (DA), is a marine algal toxin known to induce overt hippocampal neurotoxicity. Recent experimental and epidemiological studies suggest adverse neurological effects at exposure levels near the current regulatory limit (20 ppm, ∼0.075-0.1mg/kg). At these levels, cognitive effects occur in the absence of acute symptoms or evidence of neuronal death. OBJECTIVES This study aimed to identify adverse effects on the nervous system from prolonged, dietary DA exposure in adult, female Macaca fascicularis monkeys. METHODS Monkeys were orally exposed to 0, 0.075, and 0.15mg/kg per day for an average of 14 months. Clinical blood counts, chemistry, and cytokine levels were analyzed in the blood. In-life magnetic resonance (MR) imaging assessed volumetric and tractography differences in and between the hippocampus and thalamus. Histology of neurons and glia in the fornix, fimbria, internal capsule, thalamus, and hippocampus was evaluated. Hippocampal RNA sequencing was used to identify differentially expressed genes. Enrichment of gene networks for neuronal health, excitotoxicity, inflammation/glia, and myelin were assessed with Gene Set Enrichment Analysis. RESULTS Clinical blood counts, chemistry, and cytokine levels were not altered with DA exposure in nonhuman primates. Transcriptome analysis of the hippocampus yielded 748 differentially expressed genes (fold change≥1.5; p≤0.05), reflecting differences in a broad molecular profile of intermediate early genes (e.g., FOS, EGR) and genes related to myelin networks in DA animals. Between exposed and control animals, MR imaging showed comparable connectivity of the hippocampus and thalamus and histology showed no evidence of hypomyelination. Histological examination of the thalamus showed a larger microglia soma size and an extension of cell processes, but suggestions of a GFAP+astrocyte response showed no indication of astrocyte hypertrophy. DISCUSSION In the absence of overt hippocampal excitotoxicity, chronic exposure of Macaca fascicularis monkeys to environmentally relevant levels of DA suggested a subtle shift in the molecular profile of the hippocampus and the microglia phenotype in the thalamus that was possibly reflective of an adaptive response due to prolonged DA exposure. https://doi.org/10.1289/EHP10923.
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Affiliation(s)
- Rebekah L. Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Christopher Williams
- Mechanistic Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Jian-Liang Li
- Epigenetics & Stem Cell Biology Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - James W. MacDonald
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Theo K. Bammler
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Todd Richards
- Department of Radiology, University of Washington, Seattle, Washington, USA
| | | | - Audrey Baldessari
- Washington National Primate Research Center, Seattle, Washington, USA
| | - Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Jing Jing
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
- Center on Human Development and Disability, University of Washington, Seattle, Washington, USA
| | - Brenda Crouthamel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Noelle McKain
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Kimberly S. Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
- Washington National Primate Research Center, Seattle, Washington, USA
| | - Thomas M. Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
- Washington National Primate Research Center, Seattle, Washington, USA
- Center on Human Development and Disability, University of Washington, Seattle, Washington, USA
| | - G. Jean Harry
- Mechanistic Toxicology Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
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9
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Petroff R, Hendrix A, Shum S, Grant KS, Lefebvre KA, Burbacher TM. Public health risks associated with chronic, low-level domoic acid exposure: A review of the evidence. Pharmacol Ther 2021; 227:107865. [PMID: 33930455 DOI: 10.1016/j.pharmthera.2021.107865] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/13/2022]
Abstract
Domoic acid (DA), the causative agent for the human syndrome Amnesic Shellfish Poisoning (ASP), is a potent, naturally occurring neurotoxin produced by common marine algae. DA accumulates in seafood, and humans and wildlife alike can subsequently be exposed when consuming DA-contaminated shellfish or finfish. While strong regulatory limits protect people from the acute effects associated with ASP, DA is an increasingly significant public health concern, particularly for coastal dwelling populations, and there is a growing body of evidence suggesting that there are significant health consequences following repeated exposures to levels of the toxin below current safety guidelines. However, gaps in scientific knowledge make it difficult to precisely determine the risks of contemporary low-level exposure scenarios. The present review characterizes the toxicokinetics and neurotoxicology of DA, discussing results from clinical and preclinical studies after both adult and developmental DA exposure. The review also highlights crucial areas for future DA research and makes the case that DA safety limits need to be reassessed to best protect public health from deleterious effects of this widespread marine toxin.
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Affiliation(s)
- Rebekah Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Alicia Hendrix
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Kimberly S Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, University of Washington, Seattle, WA, USA
| | - Kathi A Lefebvre
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, 2725 Montlake Blvd. East, Seattle, WA, USA
| | - Thomas M Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, University of Washington, Seattle, WA, USA; Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle,WA, USA.
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10
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Cook PF, Hoard VA, Dolui S, Frederick BD, Redfern R, Dennison SE, Halaska B, Bloom J, Kruse-Elliott KT, Whitmer ER, Trumbull EJ, Berns GS, Detre JA, D'Esposito M, Gulland FMD, Reichmuth C, Johnson SP, Field CL, Inglis BA. An MRI protocol for anatomical and functional evaluation of the California sea lion brain. J Neurosci Methods 2021; 353:109097. [PMID: 33581216 DOI: 10.1016/j.jneumeth.2021.109097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/29/2021] [Accepted: 02/04/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Domoic acid (DOM) is a neurotoxin produced by some harmful algae blooms in coastal waters. California sea lions (Zalophus californianus) exposed to DOM often strand on beaches where they exhibit a variety of symptoms, including seizures. These animals typically show hippocampal atrophy on MRI scans. NEW METHOD We describe an MRI protocol for comprehensive evaluation of DOM toxicosis in the sea lion brain. We intend to study brain development in pups exposed in utero. The protocol depicts the hippocampal formation as the primary region of interest. We include scans for quantitative morphometry, functional and structural connectivity, and a cerebral blood flow map. RESULTS High-resolution 3D anatomical scans facilitate post hoc slicing in arbitrary planes and accurate morphometry. We demonstrate the first cerebral blood flow map using MRI, and the first structural tractography from a live sea lion brain. COMPARISON WITH EXISTING METHODS Scans were compared to prior anatomical and functional studies in live sea lions, and structural connectivity in post mortem specimens. Hippocampal volumes were broadly in line with prior studies, with differences likely attributable to the 3D approach used here. Functional connectivity of the dorsal left hippocampus matched that found in a prior study conducted at a lower magnetic field, while structural connectivity in the live brain agreed with findings observed in post mortem studies. CONCLUSIONS Our protocol provides a comprehensive, longitudinal view of the functional and anatomical changes expected to result from DOM toxicosis. It can also screen for other common neurological pathologies and is suitable for any pinniped that can fit inside an MRI scanner.
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Affiliation(s)
- Peter F Cook
- Department of Biopsychology, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, 34243, USA
| | - Vanessa A Hoard
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Sudipto Dolui
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - Blaise deB Frederick
- Department of Psychiatry, Harvard University Medical School, 25 Shattuck St, Boston, MA, 02115, USA; McLean Hospital Brain Imaging Center, 115 Mill St., Belmont, MA, 02478, USA
| | - Richard Redfern
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA
| | | | - Barbie Halaska
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Josh Bloom
- AnimalScan Advanced Veterinary Imaging, 934 Charter St, Redwood City, CA, 94063, USA
| | - Kris T Kruse-Elliott
- AnimalScan Advanced Veterinary Imaging, 934 Charter St, Redwood City, CA, 94063, USA
| | - Emily R Whitmer
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Emily J Trumbull
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Gregory S Berns
- Psychology Department, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - John A Detre
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA; Department of Neurology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Mark D'Esposito
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA; Helen Wills Neuroscience Institute, University of California, 132 Barker Hall, Berkeley, CA, 94720, USA
| | - Frances M D Gulland
- School of Veterinary Medicine Wildlife Health Center, University of California at Davis, 1089 Veterinary Medicine Dr, Davis, CA, 95616, USA
| | - Colleen Reichmuth
- Long Marine Laboratory, Institute of Marine Sciences, University of California at Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Shawn P Johnson
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Cara L Field
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Ben A Inglis
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA.
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11
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Bauer GB, Cook PF, Harley HE. The Relevance of Ecological Transitions to Intelligence in Marine Mammals. Front Psychol 2020; 11:2053. [PMID: 33013519 PMCID: PMC7505747 DOI: 10.3389/fpsyg.2020.02053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/24/2020] [Indexed: 12/26/2022] Open
Abstract
Macphail's comparative approach to intelligence focused on associative processes, an orientation inconsistent with more multifaceted lay and scientific understandings of the term. His ultimate emphasis on associative processes indicated few differences in intelligence among vertebrates. We explore options more attuned to common definitions by considering intelligence in terms of richness of representations of the world, the interconnectivity of those representations, the ability to flexibly change those connections, and knowledge. We focus on marine mammals, represented by the amphibious pinnipeds and the aquatic cetaceans and sirenians, as animals that transitioned from a terrestrial existence to an aquatic one, experiencing major changes in ecological pressures. They adapted with morphological transformations related to streamlining the body, physiological changes in respiration and thermoregulation, and sensory/perceptual changes, including echolocation capabilities and diminished olfaction in many cetaceans, both in-air and underwater visual focus, and enhanced senses of touch in pinnipeds and sirenians. Having a terrestrial foundation on which aquatic capacities were overlaid likely affected their cognitive abilities, especially as a new reliance on sound and touch, and the need to surface to breath changed their interactions with the world. Vocal and behavioral observational learning capabilities in the wild and in laboratory experiments suggest versatility in group coordination. Empirical reports on aspects of intelligent behavior like problem-solving, spatial learning, and concept learning by various species of cetaceans and pinnipeds suggest rich cognitive abilities. The high energy demands of the brain suggest that brain-intelligence relationships might be fruitful areas for study when specific hypotheses are considered, e.g., brain mapping indicates hypertrophy of specific sensory areas in marine mammals. Modern neuroimaging techniques provide ways to study neural connectivity, and the patterns of connections between sensory, motor, and other cortical regions provide a biological framework for exploring how animals represent and flexibly use information in navigating and learning about their environment. At this stage of marine mammal research, it would still be prudent to follow Macphail's caution that it is premature to make strong comparative statements without more empirical evidence, but an approach that includes learning more about how animals flexibly link information across multiple representations could be a productive way of comparing species by allowing them to use their specific strengths within comparative tasks.
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Affiliation(s)
- Gordon B. Bauer
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
| | - Peter F. Cook
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
| | - Heidi E. Harley
- Division of Social Sciences, New College of Florida, Sarasota, FL, United States
- Mote Marine Laboratory, Sarasota, FL, United States
- The Seas, Epcot, Walt Disney World Resorts, Lake Buena Vista, FL, United States
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12
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Shum S, Jing J, Petroff R, Crouthamel B, Grant KS, Burbacher TM, Isoherranen N. Maternal-fetal disposition of domoic acid following repeated oral dosing during pregnancy in nonhuman primate. Toxicol Appl Pharmacol 2020; 398:115027. [PMID: 32360744 PMCID: PMC7445014 DOI: 10.1016/j.taap.2020.115027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/22/2020] [Accepted: 04/26/2020] [Indexed: 01/17/2023]
Abstract
Domoic acid (DA) is a marine algal toxin that causes acute and chronic neurotoxicity in animals and humans. Prenatal exposure to DA has been associated with neuronal damage and cognitive and behavioral deficits in juvenile California sea lions, cynomolgus monkeys and rodents. Yet, the toxicokinetics (TK) of DA during pregnancy and the maternal-fetal disposition of DA have not been fully elucidated. In this study, we investigated the TK before, during, and after pregnancy and the maternal-fetal disposition of DA in 22 cynomolgus monkeys following daily oral doses of 0.075 or 0.15 mg/kg/day of DA. The AUC0-τ of DA was not changed while the renal clearance of DA was increased by 30-90% during and after pregnancy when compared to the pre-pregnancy values. DA was detected in the infant plasma and in the amniotic fluid at delivery. The infant plasma concentrations correlated positively with both the maternal plasma and the amniotic fluid concentrations. The paired infant-to-maternal plasma DA concentration ratios ranged from 0.3 to 0.6 and increased as a function of time which suggests placental efflux and longer apparent fetal half-life than the maternal half-life. The paired amniotic fluid-to-infant plasma DA concentration ratios ranged from 4.5 to 7.5 which indicates significant accumulation of DA in the amniotic fluid. A maternal-fetal TK model was developed to explore the processes that give the observed maternal-fetal disposition of DA. The final model suggests that placental transport and recirculation of DA between the fetus and amniotic fluid are major determining factors of the maternal-fetal TK of DA.
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Affiliation(s)
- Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Jing Jing
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Rebekah Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Brenda Crouthamel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Kimberly S Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA; Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle, Washington, USA
| | - Thomas M Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA; Center on Human Development and Disability, University of Washington, Seattle, Washington, USA; Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle, Washington, USA
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA; Center on Human Development and Disability, University of Washington, Seattle, Washington, USA.
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13
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Hoard VF, Janech MG. Neurological deficits in stranded California sea lions. Vet Rec 2019; 185:301-303. [DOI: 10.1136/vr.l5400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Michael G. Janech
- Hollings Marine Laboratory, Department of Biology; College of Charleston; Charleston South Carolina USA
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14
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Simeone C, Fauquier D, Skidmore J, Cook P, Colegrove K, Gulland F, Dennison S, Rowles TK. Clinical signs and mortality of non-released stranded California sea lions housed in display facilities: the suspected role of prior exposure to algal toxins. Vet Rec 2019; 185:304. [PMID: 31427410 PMCID: PMC6817987 DOI: 10.1136/vr.105371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/28/2019] [Accepted: 07/09/2019] [Indexed: 01/19/2023]
Abstract
Stranded California sea lions considered unable to survive in the wild are often placed in public display facilities. Exposure to the biotoxin domoic acid (DA) is a common cause of stranding, and chronic effects are observed long after initial exposure. Medical records for 171 sea lions placed in US institutions between 2000 and 2016 were reviewed, including results from clinical examinations, histopathology, behavioural testing and advanced imaging. There was a statistically significant increase in neurological disease detected in neonates (24%) compared with other age classes (11%). Sixty per cent of all neurological cases died during the study period. In the 11 neurological neonate cases, six died (55%) and five are still alive with three of five developing epilepsy during placement. Of the six neurological neonate cases that died, one was attributed to DA toxicosis, one to seizures and four to acute unexplained neurological disease. This survey suggests delayed neurological disease can develop in sea lions after stranding as neonates. These data coupled with stranding records and epidemiological data on DA-producing algal blooms suggest further research into effects of neonatal exposure to DA on risk of neurological disease in later life is warranted. California sea lions offer a natural model of DA exposure to study such effects.
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Affiliation(s)
- Claire Simeone
- The Marine Mammal Center, Sausalito, California, USA .,Office of Protected Resources, National Marine Fisheries Service, Silver Spring, Maryland, USA
| | - Deborah Fauquier
- Office of Protected Resources, National Marine Fisheries Service, Silver Spring, Maryland, USA
| | - Jennifer Skidmore
- Office of Protected Resources, National Marine Fisheries Service, Silver Spring, Maryland, USA
| | - Peter Cook
- New College of Florida, Sarasota, Florida, USA
| | - Kathleen Colegrove
- Zoological Pathology Program, University of Illinois at Urbana-Champaign College of Veterinary Medicine, Urbana, Illinois, USA
| | - Frances Gulland
- The Marine Mammal Center, Sausalito, California, USA.,Wildlife Health Center, University of California-Davis, Davis, California, USA
| | | | - Teresa K Rowles
- Office of Protected Resources, National Marine Fisheries Service, Silver Spring, Maryland, USA
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15
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Petroff R, Richards T, Crouthamel B, McKain N, Stanley C, Grant KS, Shum S, Jing J, Isoherranen N, Burbacher TM. Chronic, low-level oral exposure to marine toxin, domoic acid, alters whole brain morphometry in nonhuman primates. Neurotoxicology 2019; 72:114-124. [PMID: 30826346 PMCID: PMC6527455 DOI: 10.1016/j.neuro.2019.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/22/2019] [Accepted: 02/22/2019] [Indexed: 01/09/2023]
Abstract
Domoic acid (DA) is an excitatory neurotoxin produced by marine algae and responsible for Amnesiac Shellfish Poisoning in humans. Current regulatory limits (˜0.075-0.1 mg/kg/day) protect against acute toxicity, but recent studies suggest that the chronic consumption of DA below the regulatory limit may produce subtle neurotoxicity in adults, including decrements in memory. As DA-algal blooms are increasing in both severity and frequency, we sought to better understand the effects of chronic DA exposure on reproductive and neurobehavioral endpoints in a preclinical nonhuman primate model. To this end, we initiated a long-term study using adult, female Macaca fascicularis monkeys exposed to daily, oral doses of 0.075 or 0.15 mg/kg of DA for a range of 321-381, and 346-554 days, respectively. This time period included a pre-pregnancy, pregnancy, and postpartum period. Throughout these times, trained data collectors observed intentional tremors in some exposed animals during biweekly clinical examinations. The present study explores the basis of this neurobehavioral finding with in vivo imaging techniques, including diffusion tensor magnetic resonance imaging and spectroscopy. Diffusion tensor analyses revealed that, while DA exposed macaques did not significantly differ from controls, increases in DA-related tremors were negatively correlated with fractional anisotropy, a measure of structural integrity, in the internal capsule, fornix, pons, and corpus callosum. Brain concentrations of lactate, a neurochemical closely linked with astrocytes, were also weakly, but positively associated with tremors. These findings are the first documented results suggesting that chronic oral exposure to DA at concentrations near the current human regulatory limit are related to structural and chemical changes in the adult primate brain.
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Affiliation(s)
- Rebekah Petroff
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA.
| | - Todd Richards
- Department of Radiology, University of Washington, Seattle, WA, USA; Center on Human Development and Disability, Seattle, WA, USA
| | - Brenda Crouthamel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Noelle McKain
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Courtney Stanley
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA
| | - Kimberly S Grant
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA; Center on Human Development and Disability, Seattle, WA, USA
| | - Sara Shum
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Jing Jing
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Nina Isoherranen
- Department of Pharmaceutics, University of Washington, Seattle, WA, USA
| | - Thomas M Burbacher
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, USA; Center on Human Development and Disability, Seattle, WA, USA; Infant Primate Research Laboratory, Washington National Primate Research Center, Seattle, WA, USA
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