1
|
Dunn MJ, Alexander RG, Amiebenomo OM, Arblaster G, Atan D, Erichsen JT, Ettinger U, Giardini ME, Gilchrist ID, Hamilton R, Hessels RS, Hodgins S, Hooge ITC, Jackson BS, Lee H, Macknik SL, Martinez-Conde S, Mcilreavy L, Muratori LM, Niehorster DC, Nyström M, Otero-Millan J, Schlüssel MM, Self JE, Singh T, Smyrnis N, Sprenger A. Author Correction: Minimal reporting guideline for research involving eye tracking (2023 edition). Behav Res Methods 2024:10.3758/s13428-024-02438-9. [PMID: 38691219 DOI: 10.3758/s13428-024-02438-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Affiliation(s)
- Matt J Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
| | - Robert G Alexander
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | | | - Gemma Arblaster
- Health Sciences School, University of Sheffield, Sheffield, UK
- Orthoptic Department, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Denize Atan
- Bristol Medical School, University of Bristol, Bristol, UK
| | | | | | - Mario E Giardini
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Iain D Gilchrist
- School of Psychological Science, University of Bristol, Bristol, UK
| | - Ruth Hamilton
- Department of Clinical Physics & Bioengineering, Royal Hospital for Children, NHS Greater Glasgow & Clyde, Glasgow, UK
- College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Roy S Hessels
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | | | - Ignace T C Hooge
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | - Brooke S Jackson
- Department of Psychology, University of Georgia, Athens, GA, USA
| | - Helena Lee
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Stephen L Macknik
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Susana Martinez-Conde
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Lee Mcilreavy
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Lisa M Muratori
- Department of Physical Therapy, School of Health Professions, Stony Brook University, Stony Brook, NY, USA
| | - Diederick C Niehorster
- Lund University Humanities Lab, Lund University, Lund, Sweden
- Department of Psychology, Lund University, Lund, Sweden
| | - Marcus Nyström
- Lund University Humanities Lab, Lund University, Lund, Sweden
| | - Jorge Otero-Millan
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Michael M Schlüssel
- UK EQUATOR Centre, Centre for Statistics in Medicine (CSM), Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK
| | - Jay E Self
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Tarkeshwar Singh
- Department of Kinesiology, Pennsylvania State University, University Park, PA, USA
| | - Nikolaos Smyrnis
- 2nd Department of Psychiatry, National and Kapodistrian University of Athens, Medical School, General University Hospital Attikon, Athens, Greece
| | - Andreas Sprenger
- Department of Neurology and Institute of Psychology II, Center of Brain, Behavior and Metabolism (CBBM), University of Luebeck, Luebeck, Germany
| |
Collapse
|
2
|
Thomas N, Acton JH, Erichsen JT, Redmond T, Dunn MJ. Reliability of gaze-contingent perimetry. Behav Res Methods 2023:10.3758/s13428-023-02225-y. [PMID: 37697208 DOI: 10.3758/s13428-023-02225-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2023] [Indexed: 09/13/2023]
Abstract
Standard automated perimetry, a psychophysical task performed routinely in eyecare clinics, requires observers to maintain fixation for several minutes at a time in order to measure visual field sensitivity. Detection of visual field damage is confounded by eye movements, making the technique unreliable in poorly attentive individuals and those with pathologically unstable fixation, such as nystagmus. Microperimetry, which utilizes 'partial gaze-contingency' (PGC), aims to counteract eye movements but only corrects for gaze position errors prior to each stimulus onset. Here, we present a novel method of visual field examination in which stimulus position is updated during presentation, which we refer to as 'continuous gaze-contingency' (CGC). In the first part of this study, we present three case examples that demonstrate the ability of CGC to measure the edges of the physiological blind spot in infantile nystagmus with greater accuracy than PGC and standard 'no gaze-contingency' (NoGC), as initial proof-of-concept for the utility of the paradigm in measurements of absolute scotomas in these individuals. The second part of this study focused on healthy observers, in which we demonstrate that CGC has the lowest stimulus positional error (gaze-contingent precision: CGC = ± 0.29°, PGC = ± 0.54°, NoGC = ± 0.81°). CGC test-retest variability was shown to be at least as good as both PGC and NoGC. Overall, CGC is supported as a reliable method of visual field examination in healthy observers. Preliminary findings demonstrate the spatially accurate estimation of visual field thresholds related to retinal structure using CGC in individuals with infantile nystagmus.
Collapse
Affiliation(s)
- Nikita Thomas
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK
- Vision and Hearing Sciences Research Centre, Anglia Ruskin University, East Road, Cambridge, UK
| | - Jennifer H Acton
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK
| | - Tony Redmond
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK
| | - Matt J Dunn
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, CF24 4HQ, UK.
| |
Collapse
|
3
|
Dunn MJ, Alexander RG, Amiebenomo OM, Arblaster G, Atan D, Erichsen JT, Ettinger U, Giardini ME, Gilchrist ID, Hamilton R, Hessels RS, Hodgins S, Hooge ITC, Jackson BS, Lee H, Macknik SL, Martinez-Conde S, Mcilreavy L, Muratori LM, Niehorster DC, Nyström M, Otero-Millan J, Schlüssel MM, Self JE, Singh T, Smyrnis N, Sprenger A. Minimal reporting guideline for research involving eye tracking (2023 edition). Behav Res Methods 2023:10.3758/s13428-023-02187-1. [PMID: 37507649 DOI: 10.3758/s13428-023-02187-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2023] [Indexed: 07/30/2023]
Abstract
A guideline is proposed that comprises the minimum items to be reported in research studies involving an eye tracker and human or non-human primate participant(s). This guideline was developed over a 3-year period using a consensus-based process via an open invitation to the international eye tracking community. This guideline will be reviewed at maximum intervals of 4 years.
Collapse
Affiliation(s)
- Matt J Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
| | - Robert G Alexander
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | | | - Gemma Arblaster
- Health Sciences School, University of Sheffield, Sheffield, UK
- Orthoptic Department, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Denize Atan
- Bristol Medical School, University of Bristol, Bristol, UK
| | | | | | - Mario E Giardini
- Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK
| | - Iain D Gilchrist
- School of Psychological Science, University of Bristol, Bristol, UK
| | - Ruth Hamilton
- Department of Clinical Physics & Bioengineering, Royal Hospital for Children, NHS Greater Glasgow & Clyde, Glasgow, UK
- College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | - Roy S Hessels
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | | | - Ignace T C Hooge
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
| | - Brooke S Jackson
- Department of Psychology, University of Georgia, Athens, GA, USA
| | - Helena Lee
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Stephen L Macknik
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Susana Martinez-Conde
- Departments of Ophthalmology, Neurology, and Physiology/Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Lee Mcilreavy
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Lisa M Muratori
- Department of Physical Therapy, School of Health Professions, Stony Brook University, Stony Brook, NY, USA
| | - Diederick C Niehorster
- Lund University Humanities Lab, Lund University, Lund, Sweden
- Department of Psychology, Lund University, Lund, Sweden
| | - Marcus Nyström
- Lund University Humanities Lab, Lund University, Lund, Sweden
| | - Jorge Otero-Millan
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - Michael M Schlüssel
- UK EQUATOR Centre, Centre for Statistics in Medicine (CSM), Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK
| | - Jay E Self
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Tarkeshwar Singh
- Department of Kinesiology, Pennsylvania State University, University Park, PA, USA
| | - Nikolaos Smyrnis
- 2nd Department of Psychiatry, National and Kapodistrian University of Athens, Medical School, General University Hospital Attikon, Athens, Greece
| | - Andreas Sprenger
- Department of Neurology and Institute of Psychology II, Center of Brain, Behavior and Metabolism (CBBM), University of Luebeck, Luebeck, Germany
| |
Collapse
|
4
|
Chawner SJRA, Paine AL, Dunn MJ, Walsh A, Sloane P, Thomas M, Evans A, Hopkins‐Jones L, Struik S, Hall J, Erichsen JT, Leekam SR, Owen MJ, Hay D, van den Bree MBM. Neurodevelopmental dimensional assessment of young children at high genomic risk of neuropsychiatric conditions. JCPP Adv 2023; 3:e12162. [PMID: 37753151 PMCID: PMC10519742 DOI: 10.1002/jcv2.12162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/13/2023] [Indexed: 09/28/2023] Open
Abstract
Background Individuals with 22q11.2 deletion are at considerably increased risk of neurodevelopmental and psychiatric conditions. There have been very few studies investigating how this risk manifests in early childhood and what factors may underlie developmental variability. Insights into this can elucidate transdiagnostic markers of risk that may underlie later development of neuropsychiatric outcomes. Methods Thirty two children with 22q11.2 Deletion Syndrome (22q11.2DS) (mean age = 4.1 [SD = 1.2] years) and 12 sibling controls (mean age = 4.1 [SD = 1.5] years) underwent in-depth dimensional phenotyping across several developmental domains selected as being potential early indicators of neurodevelopmental and psychiatric liability. Comparisons were conducted of the dimensional developmental phenotype of 22q11.2DS and sibling controls. For autistic traits, both parents and children were phenotyped using the Social Responsiveness Scale. Results Young children with 22q11.2DS exhibited large impairments (Hedge's g ≥ 0.8) across a range of developmental domains relative to sibling controls, as well as high rates of transdiagnostic neurodevelopmental and psychiatric traits. Cluster analysis revealed a subgroup of children with 22q11.2DS (n = 16; 53%) in whom neurodevelopmental and psychiatric liability was particularly increased and who differed from other children with 22q11.2DS and non-carrier siblings. Exploratory analyses revealed that early motor and sleep impairments indexed liability for neurodevelopmental and psychiatric outcomes. Maternal autism trait scores were predictive of autism traits in children with 22q11.2DS (intraclass correlation coefficients = 0.47, p = 0.046, n = 31). Conclusions Although psychiatric conditions typically emerge later in adolescence and adulthood in 22q11.2DS, our exploratory study was able to identify a range of early risk indicators. Furthermore, findings indicate the presence of a subgroup who appeared to have increased neurodevelopmental and psychiatric liability. Our findings highlight the scope for future studies of early risk mechanisms and early intervention within this high genetic risk patient group.
Collapse
Affiliation(s)
- Samuel J. R. A. Chawner
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
- Cardiff University Centre for Human Developmental ScienceSchool of PsychologyCardiff UniversityCardiffUK
| | - Amy L. Paine
- Cardiff University Centre for Human Developmental ScienceSchool of PsychologyCardiff UniversityCardiffUK
| | - Matt J. Dunn
- School of Optometry and Vision SciencesCardiff UniversityCardiffUK
| | - Alice Walsh
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Poppy Sloane
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Megan Thomas
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Alexandra Evans
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Lucinda Hopkins‐Jones
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Siske Struik
- Immunodeficiency Centre for WalesUniversity Hospital of WalesCardiffUK
| | - Jeremy Hall
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | | | - Susan R. Leekam
- Cardiff University Centre for Human Developmental ScienceSchool of PsychologyCardiff UniversityCardiffUK
| | - Michael J. Owen
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| | - Dale Hay
- Cardiff University Centre for Human Developmental ScienceSchool of PsychologyCardiff UniversityCardiffUK
| | - Marianne B. M. van den Bree
- Medical Research Council Centre for Neuropsychiatric Genetics and GenomicsDivision of Psychological Medicine and Clinical NeurosciencesCardiff UniversityCardiffUK
| |
Collapse
|
5
|
Zahidi AAA, McIlreavy L, Erichsen JT, Woodhouse JM. Visual and Refractive Status of Children With Down's Syndrome and Nystagmus. Invest Ophthalmol Vis Sci 2022; 63:28. [PMID: 35195683 PMCID: PMC8883157 DOI: 10.1167/iovs.63.2.28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Purpose Children with Down's syndrome (DS) are known to have poorer visual acuity than neurotypical children. One report has shown that children with DS and nystagmus also have poor acuity when compared to typical children with nystagmus. What has not been established is the extent of any acuity deficit due to nystagmus and whether nystagmus affects refractive error within a population with DS. Methods Clinical records from the Cardiff University Down's Syndrome Vision Research Unit were examined retrospectively. Binocular visual acuity and refraction data were available for 50 children who had DS and nystagmus and 176 children who had DS but no nystagmus. Data were compared between the two groups and with published data for neurotypical children with nystagmus. Results The study confirms the deficit in acuity in DS, compared to neurotypical children, of approximately 0.2 logMAR and shows a deficit attributable to nystagmus of a further 0.2 logMAR beyond the first year of life. Children with both DS and nystagmus clearly have a significant additional impairment. Children with DS have a wide range of refractive errors, but nystagmus increases the likelihood of myopia. Prevalence and axis direction of astigmatism, on the other hand, appear unaffected by nystagmus. Conclusions Nystagmus confers an additional visual impairment on children with DS and must be recognized as such by families and educators. Children with both DS and nystagmus clearly need targeted support.
Collapse
Affiliation(s)
- Asma A A Zahidi
- Optometry Programme, School of Health Professions, University of Plymouth, Plymouth, United Kingdom
| | - Lee McIlreavy
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - J Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
6
|
Cutsuridis V, Jiang S, Dunn MJ, Rosser A, Brawn J, Erichsen JT. Neural modeling of antisaccade performance of healthy controls and early Huntington's disease patients. Chaos 2021; 31:013121. [PMID: 33754760 DOI: 10.1063/5.0021584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Huntington's disease (HD), a genetically determined neurodegenerative disease, is positively correlated with eye movement abnormalities in decision making. The antisaccade conflict paradigm has been widely used to study response inhibition in eye movements, and reliable performance deficits in HD subjects have been observed, including a greater number and timing of direction errors. We recorded the error rates and response latencies of early HD patients and healthy age-matched controls performing the mirror antisaccade task. HD participants displayed slower and more variable antisaccade latencies and increased error rates relative to healthy controls. A competitive accumulator-to-threshold neural model was then employed to quantitatively simulate the controls' and patients' reaction latencies and error rates and uncover the mechanisms giving rise to the observed HD antisaccade deficits. Our simulations showed that (1) a more gradual and noisy rate of accumulation of evidence by HD patients is responsible for the observed prolonged and more variable antisaccade latencies in early HD; (2) the confidence level of early HD patients making a decision is unaffected by the disease; and (3) the antisaccade performance of healthy controls and early HD patients is the end product of a neural lateral competition (inhibition) between a correct and an erroneous decision process, and not the end product of a third top-down stop signal suppressing the erroneous decision process as many have speculated.
Collapse
Affiliation(s)
- Vassilis Cutsuridis
- School of Computer Science, University of Lincoln, Lincoln LN6 7TS, United Kingdom
| | - Shouyong Jiang
- School of Computer Science, University of Lincoln, Lincoln LN6 7TS, United Kingdom
| | - Matt J Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, United Kingdom
| | - Anne Rosser
- Division of Psychological Medicine and Clinical Neurosciences, School of Medicine, Cardiff University, Cardiff CF14 4XN, United Kingdom
| | - James Brawn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, United Kingdom
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, United Kingdom
| |
Collapse
|
7
|
Self JE, Dunn MJ, Erichsen JT, Gottlob I, Griffiths HJ, Harris C, Lee H, Owen J, Sanders J, Shawkat F, Theodorou M, Whittle JP. Management of nystagmus in children: a review of the literature and current practice in UK specialist services. Eye (Lond) 2020; 34:1515-1534. [PMID: 31919431 PMCID: PMC7608566 DOI: 10.1038/s41433-019-0741-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/24/2019] [Indexed: 11/09/2022] Open
Abstract
Nystagmus is an eye movement disorder characterised by abnormal, involuntary rhythmic oscillations of one or both eyes, initiated by a slow phase. It is not uncommon in the UK and regularly seen in paediatric ophthalmology and adult general/strabismus clinics. In some cases, it occurs in isolation, and in others, it occurs as part of a multisystem disorder, severe visual impairment or neurological disorder. Similarly, in some cases, visual acuity can be normal and in others can be severely degraded. Furthermore, the impact on vision goes well beyond static acuity alone, is rarely measured and may vary on a minute-to-minute, day-to-day or month-to-month basis. For these reasons, management of children with nystagmus in the UK is varied, and patients report hugely different experiences and investigations. In this review, we hope to shine a light on the current management of children with nystagmus across five specialist centres in the UK in order to present, for the first time, a consensus on investigation and clinical management.
Collapse
Affiliation(s)
- J E Self
- University Hospital Southampton, Southampton, UK.
- Clinical and Experimental Sciences, School of Medicine, University of Southampton, Southampton, UK.
| | - M J Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - J T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - I Gottlob
- Ulverscroft Eye Unit, Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - H J Griffiths
- Division of Ophthalmology and Orthoptics, Health Sciences School, University of Sheffield, Sheffield, UK
| | - C Harris
- Royal Eye Infirmary, Derriford Hospital, Plymouth, UK
| | - H Lee
- University Hospital Southampton, Southampton, UK
- Clinical and Experimental Sciences, School of Medicine, University of Southampton, Southampton, UK
| | - J Owen
- Royal Eye Infirmary, Derriford Hospital, Plymouth, UK
| | - J Sanders
- Patient Representative, Plymouth, UK
| | - F Shawkat
- University Hospital Southampton, Southampton, UK
| | - M Theodorou
- Paediatric Ophthalmology and Strabismus, Moorfields Eye Hospital, London, UK
- National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital, London, UK
| | - J P Whittle
- Eye Department, Sheffield Children's Hospital, Sheffield, UK
| |
Collapse
|
8
|
Mcilreavy L, Freeman TCA, Erichsen JT. Two-Dimensional Analysis of Horizontal and Vertical Pursuit in Infantile Nystagmus Reveals Quantitative Deficits in Accuracy and Precision. Invest Ophthalmol Vis Sci 2020; 61:15. [PMID: 32526031 PMCID: PMC7415281 DOI: 10.1167/iovs.61.6.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Infantile nystagmus (IN) presents with continuous, predominantly horizontal eye oscillations. It remains controversial whether those with IN have normal horizontal pursuit, while vertical pursuit has rarely been studied. We examined whether there are pursuit deficits associated with IN by investigating the effect of target direction, velocity, and amplitude. Methods Twelve adults with idiopathic IN performed a pursuit task, a 0.4° dot moved either horizontally or vertically at 8 or 16°/s, through amplitudes of 8°, 16°, or 32°. Accuracy and precision errors were computed as bivariate probability density functions of target-relative eye velocities. Results Eye velocity was less precise along the horizontal axis during both horizontal and vertical pursuit, reflecting the primary axis of the eye oscillation. Mean accuracy error along the target trajectory during vertical pursuit was just as impaired as during horizontal pursuit. There was a greater error in accuracy along the target trajectory for 16°/s targets than 8°/s. Finally, targets that oscillated at 2.0 Hz had a greater error in accuracy along the target trajectory than frequencies of 1.0 Hz or 0.5 Hz. When studied using the same experimental protocol, pursuit performance for typical observers was always better. Conclusions These findings strongly support our hypothesis of severe deficits in pursuit accuracy in observers with IN for horizontally and vertically moving targets, as well as for targets that move at higher speeds or oscillate more quickly. Overall, IN pursuit impairment appears to have previously been underestimated, highlighting a need for further quantitative studies of dynamic visual function in those with IN.
Collapse
|
9
|
Mcilreavy L, Freeman TCA, Erichsen JT. Two-Dimensional Analysis of Smooth Pursuit Eye Movements Reveals Quantitative Deficits in Precision and Accuracy. Transl Vis Sci Technol 2019; 8:7. [PMID: 31588372 PMCID: PMC6753966 DOI: 10.1167/tvst.8.5.7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 06/23/2019] [Indexed: 01/30/2023] Open
Abstract
Purpose Small moving targets are followed by pursuit eye movements, with success ubiquitously defined by gain. Gain quantifies accuracy, rather than precision, and only for eye movements along the target trajectory. Analogous to previous studies of fixation, we analyzed pursuit performance in two dimensions as a function of target direction, velocity, and amplitude. As a subsidiary experiment, we compared pursuit performance against that of fixation. Methods Eye position was recorded from 15 observers during pursuit. The target was a 0.4° dot that moved across a large screen at 8°/s or 16°/s, either horizontally or vertically, through peak-to-peak amplitudes of 8°, 16°, or 32°. Two-dimensional eye velocity was expressed relative to the target, and a bivariate probability density function computed to obtain accuracy and precision. As a comparison, identical metrics were derived from fixation data. Results For all target directions, eye velocity was less precise along the target trajectory. Eye velocities orthogonal to the target trajectory were more accurate during vertical pursuit than horizontal. Pursuit accuracy and precision along and orthogonal to the target trajectory decreased at the higher target velocity. Accuracy along the target trajectory decreased with smaller target amplitudes. Conclusions Orthogonal to the target trajectory, pursuit was inaccurate and imprecise. Compared to fixation, pursuit was less precise and less accurate even when following the stimulus that gave the best performance. Translational Relevance This analytical approach may help the detection of subtle deficits in slow phase eye movements that could be used as biomarkers for disease progression and/or treatment.
Collapse
Affiliation(s)
- Lee Mcilreavy
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | | | | |
Collapse
|
10
|
Vinuela-Navarro V, Erichsen JT, Williams C, Woodhouse JM. Quantitative Characterization of Smooth Pursuit Eye Movements in School-Age Children Using a Child-Friendly Setup. Transl Vis Sci Technol 2019; 8:8. [PMID: 31588373 PMCID: PMC6753964 DOI: 10.1167/tvst.8.5.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 07/05/2019] [Indexed: 11/24/2022] Open
Abstract
PURPOSE It could be argued that current studies investigating smooth pursuit development in children do not provide an optimal measure of smooth pursuit characteristics, given that a significant number have failed to adjust their setup and procedures to the child population. This study aimed to characterize smooth pursuit in children using child-friendly stimuli and procedures. METHODS Eye movements were recorded in 169 children (4-11 years) and 10 adults, while a customized, animated stimulus was presented moving horizontally and vertically at 6°/s and 12°/s. Eye movement recordings from 43 children with delayed reading, two with nystagmus, two with strabismus, and two with unsuccessful calibration were excluded from the analysis. Velocity gain, proportion of smooth pursuit, and the number and amplitude of saccades during smooth pursuit were calculated for the remaining participants. Median and quartiles were calculated for each age group and pursuit condition. ANOVA was used to investigate the effect of age on smooth pursuit parameters. RESULTS Differences across ages were found in velocity gain (6°/s P < 0.01; 12°/s P < 0.05), as well as the number (12°/s P < 0.05) and amplitude of saccades (12°/s P < 0.05), for horizontal smooth pursuit. Post hoc tests showed that these parameters were different between children aged 7 or younger and adults. No significant differences were found across ages in any smooth pursuit parameter for the vertical direction (P > 0.05). CONCLUSIONS Using child-friendly methods, children over the age of 7 to 8 years demonstrated adultlike smooth pursuit. TRANSLATIONAL RELEVANCE Child-friendly procedures are critical for appropriately characterizing smooth pursuit eye movements in children.
Collapse
Affiliation(s)
| | | | - Cathy Williams
- Population Health Sciences, Bristol Medical School, Bristol University, Bristol, UK
| | | |
Collapse
|
11
|
Abstract
Infantile nystagmus (IN), previously known as congenital nystagmus, is an involuntary to-and-fro movement of the eyes that persists throughout life. IN is one of three types of early-onset nystagmus that begin in infancy, alongside fusion maldevelopment nystagmus syndrome and spasmus nutans syndrome. Optometrists may also encounter patients with acquired nystagmus. The features of IN overlap largely with those of fusion maldevelopment nystagmus syndrome, spasmus nutans syndrome, and acquired nystagmus, yet the management for each subtype is different. Therefore, the optometrist's role is to accurately discern IN from other forms of nystagmus and to manage accordingly. As IN is a lifelong condition, its presence not only affects the visual function of the individual but also their quality of life, both socially and psychologically. In this report, we focus on the approaches that involve optometrists in the investigation and management of patients with IN. Management includes the prescription of optical treatments, low-vision rehabilitation, and other interventions such as encouraging the use of the null zone and referral to support groups. Other treatments available via ophthalmologists are also briefly discussed in the article.
Collapse
Affiliation(s)
- Asma Aa Zahidi
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - J Margaret Woodhouse
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - Jonathan T Erichsen
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| | - Matt J Dunn
- Research Unit for Nystagmus, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,
| |
Collapse
|
12
|
Vinuela-Navarro V, Erichsen JT, Williams C, Woodhouse JM. Saccades and fixations in children with delayed reading skills. Ophthalmic Physiol Opt 2017; 37:531-541. [DOI: 10.1111/opo.12392] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 04/24/2017] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Cathy Williams
- School of Social and Community Medicine; University of Bristol; Bristol UK
| | | |
Collapse
|
13
|
Dunn MJ, Wiggins D, Woodhouse JM, Margrain TH, Harris CM, Erichsen JT. The Effect of Gaze Angle on Visual Acuity in Infantile Nystagmus. ACTA ACUST UNITED AC 2017; 58:642-650. [DOI: 10.1167/iovs.16-20370] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Matt J. Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Debbie Wiggins
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - J. Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Tom H. Margrain
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Christopher M. Harris
- Centre for Robotics and Neural Systems, Plymouth University, Plymouth, United Kingdom
| | - Jonathan T. Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
14
|
Abstract
A number of authors have suggested that attention control may be a suitable target for cognitive training in children with autism spectrum disorder. This study provided the first evidence of the feasibility of such training using a battery of tasks intended to target visual attentional control in children with autism spectrum disorder within school-based settings. Twenty-seven children were recruited and randomly assigned to either training or an active control group. Of these, 19 completed the initial assessment, and 17 (9 trained and 8 control) completed all subsequent training sessions. Training of 120 min was administered per participant, spread over six sessions (on average). Compliance with the training tasks was generally high, and evidence of within-task training improvements was found. A number of untrained tasks to assess transfer of training effects were administered pre- and post-training. Changes in the trained group were assessed relative to an active control group. Following training, significant and selective changes in visual sustained attention were observed. Trend training effects were also noted on disengaging visual attention, but no convincing evidence of transfer was found to non-trained assessments of saccadic reaction time and anticipatory looking. Directions for future development and refinement of these new training techniques are discussed.
Collapse
Affiliation(s)
| | - Sam V Wass
- Medical Research Council (MRC) Cognition and Brain Sciences Unit, UK
| | | | | |
Collapse
|
15
|
Bruce LL, Erichsen JT, Reiner A. Neurochemical compartmentalization within the pigeon basal ganglia. J Chem Neuroanat 2016; 78:65-86. [PMID: 27562515 DOI: 10.1016/j.jchemneu.2016.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/15/2016] [Accepted: 08/16/2016] [Indexed: 01/20/2023]
Abstract
The goals of this study were to use multiple informative markers to define and characterize the neurochemically distinct compartments of the pigeon basal ganglia, especially striatum and accumbens. To this end, we used antibodies against 12 different neuropeptides, calcium-binding proteins or neurotransmitter-related enzymes that are enriched in the basal ganglia. Our results clarify boundaries between previously described basal ganglia subdivisions in birds, and reveal considerable novel heterogeneity within these previously described subdivisions. Sixteen regions were identified that each displayed a unique neurochemical organization. Four compartments were identified within the dorsal striatal region. The neurochemical characteristics support previous comparisons to part of the central extended amygdala, somatomotor striatum, and associational striatum of mammals, respectively. The medialmost part of the medial striatum, however, has several unique features, including prominent pallidal-like woolly fibers and thus may be a region unique to birds. Four neurochemically distinct regions were identified within the pigeon ventral striatum: the accumbens, paratubercular striatum, ventrocaudal striatum, and the ventral area of the lateral part of the medial striatum that is located adjacent to these regions. The pigeon accumbens is neurochemically similar to the mammalian rostral accumbens. The pigeon paratubercular and ventrocaudal striatal regions are similar to the mammalian accumbens shell. The ventral portions of the medial and lateral parts of the medial striatum, which are located adjacent to accumbens shell-like areas, have neurochemical characteristics as well as previously reported limbic connections that are comparable to the accumbens core. Comparisons to neurochemically identified compartments in reptiles, mammals, and amphibians indicate that, although most of the basic compartments of the basal ganglia were highly conserved during tetrapod evolution, uniquely avian compartments may exist as well.
Collapse
Affiliation(s)
- Laura L Bruce
- Department of Biomedical Sciences, Creighton University, Omaha NE, 68178, USA.
| | | | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
16
|
McGuigan C, Jukes A, Blewett S, Barucki H, Erichsen JT, Andrei G, Snoeck R, De Clercq E, Balzarini J. Halophenyl Furanopyrimidines as Potent and Selective Anti-VZV Agents. ACTA ACUST UNITED AC 2016; 14:165-70. [PMID: 14521333 DOI: 10.1177/095632020301400306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Bicyclic furano pyrimidines have been previously reported by us to be highly potent and selective inhibitors of varicella zoster virus (VZV). p-Alkyl phenyl analogues are particularly potent with EC50 values below 1nM. In this article we report the synthesis and anti-VZV activity of a series of halophenyl analogues, with variation in the nature (F, Cl, Br) and location (o, m, p) of the halogen substituent. The compounds show a range of activities from ca. 10 nM to >50 μM. In most cases, ortho substitution leads to greatest activity, meta substitution is in general poor, and the effect of p-substitution shows a marked dependence on the halogen atom. The p-fluorophenyl compound is unique amongst compounds of this class in being inactive as an antiviral. The possible origins of these marked SARs are discussed.
Collapse
|
17
|
Snowden RJ, O'Farrell KR, Burley D, Erichsen JT, Newton NV, Gray NS. The pupil's response to affective pictures: Role of image duration, habituation, and viewing mode. Psychophysiology 2016; 53:1217-23. [PMID: 27172997 PMCID: PMC5031225 DOI: 10.1111/psyp.12668] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 03/31/2016] [Indexed: 11/29/2022]
Abstract
The pupil has been shown to be sensitive to the emotional content of stimuli. We examined this phenomenon by comparing fearful and neutral images carefully matched in the domains of luminance, image contrast, image color, and complexity of content. The pupil was more dilated after viewing affective pictures, and this effect was (a) shown to be independent of the presentation time of the images (from 100–3,000 ms), (b) not diminished by repeated presentations of the images, and (c) not affected by actively naming the emotion of the stimuli in comparison to passive viewing. Our results show that the emotional modulation of the pupil is present over a range of variables that typically vary from study to study (image duration, number of trials, free viewing vs. task), and encourages the use of pupillometry as a measure of emotional processing in populations where alternative techniques may not be appropriate.
Collapse
Affiliation(s)
| | | | - Daniel Burley
- School of Psychology, Cardiff University, Cardiff, UK
| | | | | | | |
Collapse
|
18
|
Jankowski MM, Passecker J, Islam MN, Vann S, Erichsen JT, Aggleton JP, O'Mara SM. Evidence for spatially-responsive neurons in the rostral thalamus. Front Behav Neurosci 2015; 9:256. [PMID: 26528150 PMCID: PMC4602090 DOI: 10.3389/fnbeh.2015.00256] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/07/2015] [Indexed: 12/30/2022] Open
Abstract
Damage involving the anterior thalamic and adjacent rostral thalamic nuclei may result in a severe anterograde amnesia, similar to the amnesia resulting from damage to the hippocampal formation. Little is known, however, about the information represented in these nuclei. To redress this deficit, we recorded units in three rostral thalamic nuclei in freely-moving rats [the parataenial nucleus (PT), the anteromedial nucleus (AM) and nucleus reuniens NRe]. We found units in these nuclei possessing previously unsuspected spatial properties. The various cell types show clear similarities to place cells, head direction cells, and perimeter/border cells described in hippocampal and parahippocampal regions. Based on their connectivity, it had been predicted that the anterior thalamic nuclei process information with high spatial and temporal resolution while the midline nuclei have more diffuse roles in attention and arousal. Our current findings strongly support the first prediction but directly challenge or substantially moderate the second prediction. The rostral thalamic spatial cells described here may reflect direct hippocampal/parahippocampal inputs, a striking finding of itself, given the relative lack of place cells in other sites receiving direct hippocampal formation inputs. Alternatively, they may provide elemental thalamic spatial inputs to assist hippocampal spatial computations. Finally, they could represent a parallel spatial system in the brain.
Collapse
Affiliation(s)
| | | | - Md Nurul Islam
- Institute of Neuroscience, Trinity College Dublin Dublin, Ireland
| | | | | | | | - Shane M O'Mara
- Institute of Neuroscience, Trinity College Dublin Dublin, Ireland
| |
Collapse
|
19
|
Dillingham CM, Holmes JD, Wright NF, Erichsen JT, Aggleton JP, Vann SD. Calcium-binding protein immunoreactivity in Gudden's tegmental nuclei and the hippocampal formation: differential co-localization in neurons projecting to the mammillary bodies. Front Neuroanat 2015; 9:103. [PMID: 26300741 PMCID: PMC4523888 DOI: 10.3389/fnana.2015.00103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/13/2015] [Indexed: 11/13/2022] Open
Abstract
The principal projections to the mammillary bodies arise from just two sites, Gudden’s tegmental nuclei (dorsal and ventral nuclei) and the hippocampal formation (subiculum and pre/postsubiculum). The present study sought to compare the neurochemical properties of these mammillary body inputs in the rat, with a focus on calcium-binding proteins. Neuronal calretinin (CR) immunoreactivity was sparse in Gudden’s tegmental nuclei and showed no co-localization with neurons projecting to the mammillary bodies. In contrast, many of the ventral tegmental nucleus of Gudden cell that project to the mammillary bodies were parvalbumin (PV)-positive whereas a smaller number of mammillary inputs stained for calbindin (CB). Only a few mammillary body projection cells in the dorsal tegmental nucleus of Gudden co-localized with PV and none co-localized with CB. A very different pattern was found in the hippocampal formation. Here, a large proportion of postsubiculum cells that project to the mammillary bodies co-localized with CR, but not CB or PV. While many neurons in the dorsal and ventral subiculum projected to the mammillary bodies, these cells did not co-localize with the immunofluorescence of any of the three tested proteins. These findings highlight marked differences between hippocampal and tegmental inputs to the rat mammillary bodies as well as differences between the medial and lateral mammillary systems. These findings also indicate some conserved neurochemical properties in Gudden’s tegmental nuclei across rodents and primates.
Collapse
Affiliation(s)
- Christopher M Dillingham
- Behavioural Neuroscience, School of Psychology, Cardiff University Cardiff, UK ; Visual Neuroscience and Molecular Biology, School of Optometry and Vision Sciences, Cardiff University Cardiff, UK
| | - Joshua D Holmes
- Behavioural Neuroscience, School of Psychology, Cardiff University Cardiff, UK
| | - Nicholas F Wright
- Behavioural Neuroscience, School of Psychology, Cardiff University Cardiff, UK
| | - Jonathan T Erichsen
- Visual Neuroscience and Molecular Biology, School of Optometry and Vision Sciences, Cardiff University Cardiff, UK
| | - John P Aggleton
- Behavioural Neuroscience, School of Psychology, Cardiff University Cardiff, UK
| | - Seralynne D Vann
- Behavioural Neuroscience, School of Psychology, Cardiff University Cardiff, UK
| |
Collapse
|
20
|
|
21
|
Dillingham CM, Erichsen JT, O'Mara SM, Aggleton JP, Vann SD. Fornical and nonfornical projections from the rat hippocampal formation to the anterior thalamic nuclei. Hippocampus 2015; 25:977-92. [PMID: 25616174 PMCID: PMC4737193 DOI: 10.1002/hipo.22421] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 11/24/2022]
Abstract
The hippocampal formation and anterior thalamic nuclei form part of an interconnected network thought to support memory. A central pathway in this mnemonic network comprises the direct projections from the hippocampal formation to the anterior thalamic nuclei, projections that, in the primate brain, originate in the subicular cortices to reach the anterior thalamic nuclei by way of the fornix. In the rat brain, additional pathways involving the internal capsule have been described, linking the dorsal subiculum to the anteromedial thalamic nucleus, as well as the postsubiculum to the anterodorsal thalamic nucleus. Confirming such pathways is essential in order to appreciate how information is transferred from the hippocampal formation to the anterior thalamus and how it may be disrupted by fornix pathology. Accordingly, in the present study, pathway tracers were injected into the anterior thalamic nuclei and the dorsal subiculum of rats with fornix lesions. Contrary to previous descriptions, projections from the subiculum to the anteromedial thalamic nucleus overwhelmingly relied on the fornix. Dorsal subiculum projections to the majority of the anteroventral nucleus also predominantly relied on the fornix, although postsubicular inputs to the lateral dorsal part of the anteroventral nucleus, as well as to the anterodorsal and laterodorsal thalamic nuclei, largely involved a nonfornical pathway, via the internal capsule. © 2015 The Authors Hippocampus Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Shane M O'Mara
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | - John P Aggleton
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
22
|
Harrison JJ, Sumner P, Dunn MJ, Erichsen JT, Freeman TCA. Quick phases of infantile nystagmus show the saccadic inhibition effect. Invest Ophthalmol Vis Sci 2015; 56:1594-600. [PMID: 25670485 PMCID: PMC4351650 DOI: 10.1167/iovs.14-15655] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/29/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Infantile nystagmus (IN) is a pathological, involuntary oscillation of the eyes consisting of slow, drifting eye movements interspersed with rapid reorienting quick phases. The extent to which quick phases of IN are programmed similarly to saccadic eye movements remains unknown. We investigated whether IN quick phases exhibit 'saccadic inhibition,' a phenomenon typically related to normal targeting saccades, in which the initiation of the eye movement is systematically delayed by task-irrelevant visual distractors. METHODS We recorded eye position from 10 observers with early-onset idiopathic nystagmus while task-irrelevant distractor stimuli were flashed along the top and bottom of a large screen at ±10° eccentricity. The latency distributions of quick phases were measured with respect to these distractor flashes. Two additional participants, one with possible albinism and one with fusion maldevelopment nystagmus syndrome, were also tested. RESULTS All observers showed that a distractor flash delayed the execution of quick phases that would otherwise have occurred approximately 100 ms later, exactly as in the standard saccadic inhibition effect. The delay did not appear to differ between the two main nystagmus types under investigation (idiopathic IN with unidirectional and bidirectional jerk). CONCLUSIONS The presence of the saccadic inhibition effect in IN quick phases is consistent with the idea that quick phases and saccades share a common programming pathway. This could allow quick phases to take on flexible, goal-directed behavior, at odds with the view that IN quick phases are stereotyped, involuntary eye movements.
Collapse
Affiliation(s)
| | - Petroc Sumner
- School of Psychology, Cardiff University, Cardiff, United Kingdom
- Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Matt J. Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jonathan T. Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | | |
Collapse
|
23
|
Villar D, Berthelot C, Aldridge S, Rayner TF, Lukk M, Pignatelli M, Park TJ, Deaville R, Erichsen JT, Jasinska AJ, Turner JMA, Bertelsen MF, Murchison EP, Flicek P, Odom DT. Enhancer evolution across 20 mammalian species. Cell 2015; 160:554-66. [PMID: 25635462 PMCID: PMC4313353 DOI: 10.1016/j.cell.2015.01.006] [Citation(s) in RCA: 445] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 10/31/2014] [Accepted: 12/15/2014] [Indexed: 12/21/2022]
Abstract
The mammalian radiation has corresponded with rapid changes in noncoding regions of the genome, but we lack a comprehensive understanding of regulatory evolution in mammals. Here, we track the evolution of promoters and enhancers active in liver across 20 mammalian species from six diverse orders by profiling genomic enrichment of H3K27 acetylation and H3K4 trimethylation. We report that rapid evolution of enhancers is a universal feature of mammalian genomes. Most of the recently evolved enhancers arise from ancestral DNA exaptation, rather than lineage-specific expansions of repeat elements. In contrast, almost all liver promoters are partially or fully conserved across these species. Our data further reveal that recently evolved enhancers can be associated with genes under positive selection, demonstrating the power of this approach for annotating regulatory adaptations in genomic sequences. These results provide important insight into the functional genetics underpinning mammalian regulatory evolution.
Collapse
Affiliation(s)
- Diego Villar
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, UK
| | - Camille Berthelot
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Sarah Aldridge
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, UK
| | - Tim F Rayner
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, UK
| | - Margus Lukk
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, UK
| | - Miguel Pignatelli
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK
| | - Thomas J Park
- Department of Biological Sciences, University of Illinois at Chicago (UIC), 845 West Taylor Street, Chicago, IL 60607, USA
| | - Robert Deaville
- UK Cetacean Strandings Investigation Programme (CSIP) and Institute of Zoology, Zoological Society of London, Outer Circle, Regent's Park, London NW1 4RY, UK
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, UK
| | - Anna J Jasinska
- UCLA Center for Neurobehavioral Genetics, 695 Charles E. Young Drive South, Los Angeles, CA 90095, USA
| | - James M A Turner
- Division of Stem Cell Biology and Developmental Genetics, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
| | - Mads F Bertelsen
- Center for Zoo and Wild Animal Health, Copenhagen Zoo, Roskildevej 38, DK-2000 Frederiksberg, Denmark
| | - Elizabeth P Murchison
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, UK
| | - Paul Flicek
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK.
| | - Duncan T Odom
- University of Cambridge, Cancer Research UK Cambridge Institute, Robinson Way, Cambridge, CB2 0RE, UK; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK.
| |
Collapse
|
24
|
Erichsen JT, Wright NF, May PJ. Morphology and ultrastructure of medial rectus subgroup motoneurons in the macaque monkey. J Comp Neurol 2014; 522:626-41. [PMID: 23897455 DOI: 10.1002/cne.23437] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/09/2013] [Accepted: 07/18/2013] [Indexed: 12/21/2022]
Abstract
There are two muscle fiber types in extraocular muscles: those receiving a single motor endplate, termed singly innervated fibers (SIFs), and those receiving multiple small terminals along their length, termed multiply innervated fibers (MIFs). In monkeys, these two fiber types receive input from different motoneuron pools: SIF motoneurons found within the extraocular motor nuclei, and MIF motoneurons found along their periphery. For the monkey medial rectus muscle, MIF motoneurons are found in the C-group, while SIF motoneurons lie in the A- and B-groups. We analyzed the somatodendritic morphology and ultrastructure of these three subgroups of macaque medial rectus motoneurons to better understand the structural determinants controlling the two muscle fiber types. The dendrites of A- and B-group motoneurons lay within the oculomotor nucleus, but those of the C-group motoneurons were located outside the nucleus, and extended into the preganglionic Edinger-Westphal nucleus. A- and B-group motoneurons were very similar ultrastructurally. In contrast, C-group motoneurons displayed significantly fewer synaptic contacts on their somata and proximal dendrites, and those contacts were smaller in size and lacked dense-cored vesicles. However, the synaptic structure of C-group distal dendrites was quite similar to that observed for A- and B-group motoneurons. Our anatomical findings suggest that C-group MIF motoneurons have different physiological properties than A- and B-group SIF motoneurons, paralleling their different muscle fiber targets. Moreover, primate C-group motoneurons have evolved a special relationship with the preganglionic Edinger-Westphal nucleus, suggesting these motoneurons play an important role in near triad convergence to support increased near work requirements.
Collapse
Affiliation(s)
- Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, Wales, UK
| | | | | |
Collapse
|
25
|
Tsanov M, Chah E, Noor MS, Egan C, Reilly RB, Aggleton JP, Erichsen JT, Vann SD, O'Mara SM. The irregular firing properties of thalamic head direction cells mediate turn-specific modulation of the directional tuning curve. J Neurophysiol 2014; 112:2316-31. [PMID: 25122712 PMCID: PMC4274931 DOI: 10.1152/jn.00583.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Head direction cells encode an animal's heading in the horizontal plane. However, it is not clear
why the directionality of a cell's mean firing rate differs for clockwise, compared with
counterclockwise, head turns (this difference is known as the “separation angle”) in
anterior thalamus. Here we investigated in freely behaving rats whether intrinsic neuronal firing
properties are linked to this phenomenon. We found a positive correlation between the separation
angle and the spiking variability of thalamic head direction cells. To test whether this link is
driven by hyperpolarization-inducing currents, we investigated the effect of thalamic reticular
inhibition during high-voltage spindles on directional spiking. While the selective directional
firing of thalamic neurons was preserved, we found no evidence for entrainment of thalamic head
direction cells by high-voltage spindle oscillations. We then examined the role of
depolarization-inducing currents in the formation of separation angle. Using a single-compartment
Hodgkin-Huxley model, we show that modeled neurons fire with higher frequencies during the ascending
phase of sinusoidal current injection (mimicking the head direction tuning curve) when simulated
with higher high-threshold calcium channel conductance. These findings demonstrate that the
turn-specific encoding of directional signal strongly depends on the ability of thalamic neurons to
fire irregularly in response to sinusoidal excitatory activation. Another crucial factor for
inducing phase lead to sinusoidal current injection was the presence of spike-frequency adaptation
current in the modeled neurons. Our data support a model in which intrinsic biophysical properties
of thalamic neurons mediate the physiological encoding of directional information.
Collapse
Affiliation(s)
- Marian Tsanov
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; School of Psychology, Trinity College Dublin, Dublin, Ireland
| | - Ehsan Chah
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
| | - Muhammad S Noor
- Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
| | - Catriona Egan
- Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
| | - Richard B Reilly
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College Dublin, Dublin, Ireland
| | - John P Aggleton
- School of Psychology, Cardiff University, Cardiff, United Kingdom; and
| | - Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff, United Kingdom; and
| | - Shane M O'Mara
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland; School of Psychology, Trinity College Dublin, Dublin, Ireland;
| |
Collapse
|
26
|
Dunn MJ, Margrain TH, Woodhouse JM, Ennis FA, Harris CM, Erichsen JT. Author Response: Grating Visual Acuity in Infantile Nystagmus in the Absence of Image Motion. Invest Ophthalmol Vis Sci 2014; 55:4955-7. [DOI: 10.1167/iovs.14-15070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Matt J. Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; and the
| | - Tom H. Margrain
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; and the
| | - J. Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; and the
| | - Fergal A. Ennis
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; and the
| | - Christopher M. Harris
- Centre for Robotics and Neural Systems, Plymouth University, Plymouth, United Kingdom
| | - Jonathan T. Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; and the
| |
Collapse
|
27
|
Jankowski MM, Islam MN, Wright NF, Vann SD, Erichsen JT, Aggleton JP, O'Mara SM. Nucleus reuniens of the thalamus contains head direction cells. eLife 2014; 3:e03075. [PMID: 25024427 PMCID: PMC4115655 DOI: 10.7554/elife.03075] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 07/11/2014] [Indexed: 11/13/2022] Open
Abstract
Discrete populations of brain cells signal heading direction, rather like a compass. These 'head direction' cells are largely confined to a closely-connected network of sites. We describe, for the first time, a population of head direction cells in nucleus reuniens of the thalamus in the freely-moving rat. This novel subcortical head direction signal potentially modulates the hippocampal CA fields directly and, thus, informs spatial processing and memory.
Collapse
Affiliation(s)
| | - Md Nurul Islam
- Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| | | | - Seralynne D Vann
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Jonathan T Erichsen
- Department of Optometry and Visual Science, Cardiff University, Cardiff, United Kingdom
| | - John P Aggleton
- School of Psychology, Cardiff University, Cardiff, United Kingdom
| | - Shane M O'Mara
- Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
28
|
Dunn MJ, Margrain TH, Woodhouse JM, Ennis FA, Harris CM, Erichsen JT. Grating Visual Acuity in Infantile Nystagmus in the Absence of Image Motion. ACTA ACUST UNITED AC 2014; 55:2682-6. [DOI: 10.1167/iovs.13-13455] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Matt J. Dunn
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Tom H. Margrain
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - J. Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Fergal A. Ennis
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Christopher M. Harris
- Centre for Robotics and Neural Systems, Plymouth University, Plymouth, United Kingdom
| | - Jonathan T. Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
29
|
Wright NF, Vann SD, Erichsen JT, O'Mara SM, Aggleton JP. Segregation of parallel inputs to the anteromedial and anteroventral thalamic nuclei of the rat. J Comp Neurol 2014; 521:2966-86. [PMID: 23504917 DOI: 10.1002/cne.23325] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 02/21/2013] [Accepted: 02/26/2013] [Indexed: 11/12/2022]
Abstract
Many brain structures project to both the anteroventral thalamic nucleus and the anteromedial thalamic nucleus. In the present study, pairs of different tracers were placed into these two thalamic sites in the same rats to determine the extent to which these nuclei receive segregated inputs. Only inputs from the laterodorsal tegmental nucleus, the principal extrinsic cholinergic source for these thalamic nuclei, showed a marked degree of collateralization, with approximately 13% of all cells labeled in this tegmental area projecting to both nuclei. Elsewhere, double-labeled cells were very scarce, making up ∼1% of all labeled cells. Three general patterns of anterior thalamic innervation were detected in these other areas. In some sites, e.g., prelimbic cortex, anterior cingulate cortex, and secondary motor area, cells projecting to the anteromedial and anteroventral thalamic nuclei were closely intermingled, with often only subtle distribution differences. These same projections were also often intermingled with inputs to the mediodorsal thalamic nucleus, but again there was little or no collateralization. In other sites, e.g., the subiculum and retrosplenial cortex, there was often less overlap of cells projecting to the two anterior thalamic nuclei. A third pattern related to the dense inputs from the medial mammillary nucleus, where well-defined topographies ensured little intermingling of the neurons that innervate the two thalamic nuclei. The finding that a very small minority of cortical and limbic inputs bifurcates to innervate both anterior thalamic nuclei highlights the potential for parallel information streams to control their functions, despite arising from common regions.
Collapse
|
30
|
Jones PH, Harris CM, Woodhouse JM, Margrain TH, Ennis FA, Erichsen JT. Stress and Visual Function in Infantile Nystagmus Syndrome. ACTA ACUST UNITED AC 2013; 54:7943-51. [DOI: 10.1167/iovs.13-12560] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Philip H. Jones
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Christopher M. Harris
- Centre for Robotics and Neural Systems and Plymouth Cognition Institute, Plymouth University, Plymouth, United Kingdom
| | - J. Margaret Woodhouse
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Tom H. Margrain
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Fergal A. Ennis
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Jonathan T. Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
31
|
Jankowski MM, Ronnqvist KC, Tsanov M, Vann SD, Wright NF, Erichsen JT, Aggleton JP, O'Mara SM. The anterior thalamus provides a subcortical circuit supporting memory and spatial navigation. Front Syst Neurosci 2013; 7:45. [PMID: 24009563 PMCID: PMC3757326 DOI: 10.3389/fnsys.2013.00045] [Citation(s) in RCA: 175] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 08/08/2013] [Indexed: 12/03/2022] Open
Abstract
The anterior thalamic nuclei (ATN), a central component of Papez' circuit, are generally assumed to be key constituents of the neural circuits responsible for certain categories of learning and memory. Supporting evidence for this contention is that damage to either of two brain regions, the medial temporal lobe and the medial diencephalon, is most consistently associated with anterograde amnesia. Within these respective regions, the hippocampal formation and the ATN (anteromedial, anteroventral, and anterodorsal) are the particular structures of interest. The extensive direct and indirect hippocampal-anterior thalamic interconnections and the presence of theta-modulated cells in both sites further support the hypothesis that these structures constitute a neuronal network crucial for memory and cognition. The major tool in understanding how the brain processes information is the analysis of neuronal output at each hierarchical level along the pathway of signal propagation coupled with neuroanatomical studies. Here, we discuss the electrophysiological properties of cells in the ATN with an emphasis on their role in spatial navigation. In addition, we describe neuroanatomical and functional relationships between the ATN and hippocampal formation.
Collapse
Affiliation(s)
- Maciej M Jankowski
- Trinity College Institute of Neuroscience, Trinity College Dublin Dublin 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Abstract
PURPOSE We determined the distribution of cells containing synthetic enzymes for the unconventional neurotransmitter, nitric oxide, with respect to the known populations within the oculomotor complex. METHODS The oculomotor complex was investigated in monkeys and cats by use of histochemistry to demonstrate nicotinamide adenine dinucleotide phosphate diaphorase positive (NADPHd(+)) cells and antibodies to localize neuronal nitric oxide synthase positive (NOS(+)) cells. In some cases, wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP) was injected into extraocular muscles to allow comparison of retrogradely labeled and NADPHd(+) cell distributions. RESULTS The distribution of the NADPHd(+) and NOS(+) neurons did not coincide with that of preganglionic and extraocular motoneurons in the oculomotor complex. However, labeled perioculomotor neurons were observed. Specifically, in monkeys, they lay in an arc that extended from between the oculomotor nuclei into the supraoculomotor area (SOA). Comparison of WGA-HRP-labeled medial and superior rectus motoneurons with NADPHd staining confirmed that the distributions overlapped, but showed that the C- and S-group cells were not NADPHd(+). This suggested that NADPHd(+) cells are part of the centrally projecting Edinger-Westphal population (EWcp). Examination of the NADPHd(+) cell distribution in the cat showed that these cells were indeed found primarily within its well-defined EWcp. CONCLUSIONS Based on their similar distributions, it appears that the peptidergic EWcp neurons, which project widely in the brain, also may be nitridergic. While the preganglionic and C- and S-group motoneuron populations do not use this nonsynaptic neurotransmitter, nitric oxide produced by surrounding NADPHd(+) cells may modulate the activity of these motoneurons.
Collapse
Affiliation(s)
- Jonathan T Erichsen
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| | | |
Collapse
|
33
|
Chen YP, Hocking PM, Wang L, Považay B, Prashar A, To CH, Erichsen JT, Feldkaemper M, Hofer B, Drexler W, Schaeffel F, Guggenheim JA. Selective Breeding for Susceptibility to Myopia Reveals a Gene–Environment Interaction. ACTA ACUST UNITED AC 2011; 52:4003-11. [DOI: 10.1167/iovs.10-7044] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Yen-Po Chen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; the 2Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Paul M. Hocking
- the Department of Genetics and Genomics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Ling Wang
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Boris Považay
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; the 4Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Ankush Prashar
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; the 5Scottish Crop Research Institute, Invergowrie, Scotland, United Kingdom
| | - Chi-Ho To
- the Center for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong, SAR China; the 7State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Peoples Republic of China; and
| | - Jonathan T. Erichsen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| | - Marita Feldkaemper
- the Ophthalmic Research Institute, Section of Neurobiology of the Eye, University of Tübingen, Tübingen, Germany
| | - Bernd Hofer
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; the 4Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Drexler
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom; the 4Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Frank Schaeffel
- the Ophthalmic Research Institute, Section of Neurobiology of the Eye, University of Tübingen, Tübingen, Germany
| | - Jeremy A. Guggenheim
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
34
|
Chen YP, Prashar A, Erichsen JT, To CH, Hocking PM, Guggenheim JA. Heritability of Ocular Component Dimensions in Chickens: Genetic Variants Controlling Susceptibility to Experimentally Induced Myopia and Pretreatment Eye Size Are Distinct. ACTA ACUST UNITED AC 2011; 52:4012-20. [DOI: 10.1167/iovs.10-7045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Yen-Po Chen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom; the 2Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ankush Prashar
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom; the 4Scottish Crop Research Institute (SCRI), Dundee, Scotland, United Kingdom
| | - Jonathan T. Erichsen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Chi-Ho To
- the Center for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong, SAR China; the 6State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Peoples Republic of China; and
| | - Paul M. Hocking
- the Department of Genetics and Genomics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Scotland, United Kingdom
| | - Jeremy A. Guggenheim
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| |
Collapse
|
35
|
Tsanov M, Vann SD, Erichsen JT, Wright N, Aggleton JP, O'Mara SM. Differential regulation of synaptic plasticity of the hippocampal and the hypothalamic inputs to the anterior thalamus. Hippocampus 2011; 21:1-8. [PMID: 20043283 DOI: 10.1002/hipo.20749] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The hippocampus projects to the anterior thalamic nuclei both directly and indirectly via the mammillary bodies, but little is known about the electrophysiological properties of these convergent pathways. Here we demonstrate, for the first time, the presence of long-term plasticity in anterior thalamic nuclei synapses in response to high- and low-frequency stimulation (LFS) in urethane-anesthetized rats. We compared the synaptic changes evoked via the direct vs. the indirect hippocampal pathways to the anterior thalamus, and found that long-term potentiation (LTP) of the thalamic field response is induced predominantly through the direct hippocampal projections. Furthermore, we have estimated that that long-term depression (LTD) can be induced only after stimulation of the indirect connections carried by the mammillothalamic tract. Interestingly, basal synaptic transmission mediated by the mammillothalamic tract undergoes use-dependent, BDNF-mediated potentiation, revealing a distinct form of plasticity specific to the diencephalic region. Our data indicate that the thalamus does not passively relay incoming information, but rather acts as a synaptic network, where the ability to integrate hippocampal and mammillary body inputs is dynamically modified as a result of previous activity in the circuit. The complementary properties of these two parallel pathways upon anterior thalamic activity reveal that they do not have duplicate functions.
Collapse
Affiliation(s)
- Marian Tsanov
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | | | | | | | | | | |
Collapse
|
36
|
Tsanov M, Wright N, Vann SD, Erichsen JT, Aggleton JP, O'Mara SM. Hippocampal inputs mediate theta-related plasticity in anterior thalamus. Neuroscience 2011; 187:52-62. [PMID: 21459129 DOI: 10.1016/j.neuroscience.2011.03.055] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 03/24/2011] [Accepted: 03/24/2011] [Indexed: 10/18/2022]
Abstract
Hippocampally-driven oscillatory activity at theta frequency is found in the diencephalon, but an understanding of the fundamental role of theta in the hippocampo-diencephalic circuit remains elusive. An important strategy in determining how activity modifies oscillatory properties of hippocampo-diencephalic circuitry comprises investigations of anterior thalamic responses to their main inputs: the descending dorsal fornix and the ascending mammillothalamic tract. Here, we show that the amplitude of thalamic theta spectral power selectively increases after plasticity-inducing stimulation of the dorsal fornix, but not of the mammillothalamic tract in urethane-anaesthetized young male rats. Furthermore, we show that low-frequency stimulation (LFS) significantly augments the fornix-driven theta ratio (theta over delta power, T-ratio), in parallel with depressing thalamic synaptic responses. However, the mammillothalamic synaptic response after LFS did not correlate with the slow band of theta oscillation (low T-ratio), but did correlate positively with the fast band of theta oscillation (high T-ratio). Our data demonstrate that the descending direct fornix projection is a pathway that modulates theta rhythm in the hippocampo-diencephalic circuit, resulting in dynamic augmentation of thalamic neuronal responsiveness. These findings suggest that hippocampal theta differentially affects synaptic integration in the different structures with which the hippocampus is reciprocally connected.
Collapse
Affiliation(s)
- M Tsanov
- Trinity College Institute of Neuroscience, Trinity College Dublin, Ireland; School of Psychology, Trinity College Dublin, Ireland
| | | | | | | | | | | |
Collapse
|
37
|
Guggenheim JA, Chen YP, Yip E, Hayet H, Druel V, Wang L, Erichsen JT, Tumlinson AR, Povazay B, Drexler W, Hocking PM. Pre-treatment choroidal thickness is not predictive of susceptibility to form-deprivation myopia in chickens. Ophthalmic Physiol Opt 2011; 31:516-28. [PMID: 21446921 DOI: 10.1111/j.1475-1313.2011.00827.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE Chicks developing experimentally-induced myopia show profound thinning of the choroid. We observed a wide range of choroidal thicknesses in a sample of normal chicks prior to their use in a pedigree-based study of form-deprivation myopia. Hence, we tested whether pre-treatment choroidal thickness predicted susceptibility to myopia. METHODS Retinal, choroidal and scleral thickness were measured using A-scan ultrasonography in normal White Leghorn chicks (n= 891) aged 4 days old, and again (n=498) after 4 days of monocular form-deprivation at age 8 days of age. Refractive error was assessed by retinoscopy. Relationships between pre-treatment choroidal thickness and other variables were investigated using general linear models and variance components analysis. RESULTS Untreated 4 day-old male chicks had choroids approximately 10% thinner than females (p<0.001), but sex explained <2% of the overall variability in choroidal thickness. Axial eye length in these untreated chicks was not significantly associated with choroidal thickness (p=0.25). Moreover, pre-treatment choroidal thickness was not predictive of susceptibility to form-deprivation myopia (p=0.89). Heritability analysis suggested that at least 50% of the variation in pre-treatment choroidal thickness was determined by additive genetic effects (p<0.001). CONCLUSIONS Parental choroidal thickness is the major determinant of choroidal thickness in untreated 4-day old chicks. Despite choroidal thickness potentially being indicative of ongoing emmetropisation to innate refractive errors, in this study it was not predictive of subsequent susceptibility to form-deprivation myopia.
Collapse
|
38
|
Samsel PA, Kisiswa L, Erichsen JT, Cross SD, Morgan JE. A Novel Method for the Induction of Experimental Glaucoma Using Magnetic Microspheres. ACTA ACUST UNITED AC 2011; 52:1671-5. [DOI: 10.1167/iovs.09-3921] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
| | | | | | | | - James E. Morgan
- From the Schools of Optometry and Vision Sciences and 2Medicine, Cardiff University, Cardiff, United Kingdom
| |
Collapse
|
39
|
Taylor S, Calder CJ, Albon J, Erichsen JT, Boulton ME, Morgan JE. Involvement of the CD200 receptor complex in microglia activation in experimental glaucoma. Exp Eye Res 2011; 92:338-43. [PMID: 21296076 DOI: 10.1016/j.exer.2011.01.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 12/02/2010] [Accepted: 01/28/2011] [Indexed: 01/22/2023]
Abstract
The interaction of the myeloid restricted molecule CD200R with its widely expressed ligand CD200 is involved in the down-regulation of microglia activation. In the present study, we examined the involvement of CD200R in microglia activation in experimental ocular hypertension to determine the role of microglia activation in retinal ganglion cell (RGC) death, the key pathological event in glaucoma. Experimental glaucoma was induced in adult Brown Norway rats by sclerosis of the episcleral veins with the injection of hypertonic saline. Immunohistochemical methods were used to determine the involvement of microglia using GFAP, CD45, OX42 and OX41 and the involvement of CD200 and CD200R in the optic nerve head. Our data demonstrate the increased presence of microglia within the optic nerve head during ocular hypertension, identified by positive staining with OX42 and OX41. The peak of microglia correlates with peak in RGC death at days 20-27 (T3) post OHT induction. In addition, CD200 and CD200R positive cells were increased in ocular hypertensive eyes. Increased expression of CD200 was detected in the early phase (days 1-7; T1) of OHT and decreased over time, whilst the expression of CD200R was detected in the middle phase (days 20-27; T3) of OHT, correlating with the increase in microglia markers. Changes in the expression of CD200R/CD200 occur early in experimental glaucoma and precede the peak in microglia infiltration and RGC death, suggesting that CD200R-positive microglia play an important role in the initiation of RGC death during OHT, indicating a potential area for therapeutic intervention in treating glaucoma.
Collapse
Affiliation(s)
- Sarah Taylor
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cathays Park, Cardiff CF24 4LU, United Kingdom
| | | | | | | | | | | |
Collapse
|
40
|
Tsanov M, Chah E, Wright N, Vann SD, Reilly R, Erichsen JT, Aggleton JP, O'Mara SM. Oscillatory entrainment of thalamic neurons by theta rhythm in freely moving rats. J Neurophysiol 2010; 105:4-17. [PMID: 20962067 DOI: 10.1152/jn.00771.2010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The anterior thalamic nuclei are assumed to support episodic memory with anterior thalamic dysfunction a core feature of diencephalic amnesia. To date, the electrophysiological characterization of this region in behaving rodents has been restricted to the anterodorsal nucleus. Here we compared single-unit spikes with population activity in the anteroventral nucleus (AV) of freely moving rats during foraging and during naturally occurring sleep. We identified AV units that synchronize their bursting activity in the 6-11 Hz range. We show for the first time in freely moving rats that a subgroup of AV neurons is strongly entrained by theta oscillations. This feature together with their firing properties and spike shape suggests they be classified as "theta" units. To prove the selectivity of AV theta cells for theta rhythm, we compared the relation of spiking rhythmicity to local field potentials during theta and non-theta periods. The most distinguishable non-theta oscillations in rodent anterior thalamus are sleep spindles. We therefore compared the firing properties of AV units during theta and spindle periods. We found that theta and spindle oscillations differ in their spatial distribution within AV, suggesting separate cellular sources for these oscillations. While theta-bursting neurons were related to the distribution of local field theta power, spindle amplitude was independent of the theta units' position. Slow- and fast-spiking bursting units that are selectively entrained to theta rhythm comprise 23.7% of AV neurons. Our results provide a framework for electrophysiological classification of AV neurons as part of theta limbic circuitry.
Collapse
Affiliation(s)
- Marian Tsanov
- Trinity College Institute of Neuroscience. Trinity College Dublin, Dublin 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Wright NF, Erichsen JT, Vann SD, O'Mara SM, Aggleton JP. Parallel but separate inputs from limbic cortices to the mammillary bodies and anterior thalamic nuclei in the rat. J Comp Neurol 2010; 518:2334-54. [PMID: 20437531 DOI: 10.1002/cne.22336] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The proposal that separate populations of subicular cells provide the direct hippocampal projections to the mammillary bodies and anterior thalamic nuclei was tested by placing two different fluorescent tracers in these two sites. In spite of varying the injection locations within the mammillary bodies and within the three principal anterior thalamic nuclei and the lateral dorsal thalamic nucleus, the overall pattern of results remained consistent. Neurons projecting to the thalamus were localized to the deepest cell populations within the subiculum while neurons projecting to the mammillary bodies consisted of more superficially placed pyramidal cells within the subiculum. Even when these two cell populations become more intermingled, e.g., in parts of the intermediate subiculum, almost no individual cells were found to project to both diencephalic targets. In adjacent limbic areas, i.e., the retrosplenial cortex, postsubiculum, and entorhinal cortex, populations of cells that project to the anterior thalamic nuclei and mammillary bodies were completely segregated. This segregated pattern included afferents to those nuclei comprising the head-direction system. The sole exception was a handful of double-labeled cells, mainly confined to the ventral subiculum, that were only found after pairs of injections in the anteromedial thalamic nucleus and mammillary bodies. The projections to the anterior thalamic nuclei also had a septal-temporal gradient with relatively fewer cells projecting from the ventral (temporal) subiculum. These limbic projections to the mammillary bodies and anterior thalamus comprise a circuit that is vital for memory, within which the two major components could convey parallel, independent information.
Collapse
Affiliation(s)
- Nicholas F Wright
- School of Psychology, Cardiff University, Cardiff, CF10 3AT, United Kingdom
| | | | | | | | | |
Collapse
|
42
|
Aggleton JP, O'Mara SM, Vann SD, Wright NF, Tsanov M, Erichsen JT. Hippocampal-anterior thalamic pathways for memory: uncovering a network of direct and indirect actions. Eur J Neurosci 2010; 31:2292-307. [PMID: 20550571 PMCID: PMC2936113 DOI: 10.1111/j.1460-9568.2010.07251.x] [Citation(s) in RCA: 314] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This review charts recent advances from a variety of disciplines that create a new perspective on why the multiple hippocampal–anterior thalamic interconnections are together vital for human episodic memory and rodent event memory. Evidence has emerged for the existence of a series of parallel temporal–diencephalic pathways that function in a reciprocal manner, both directly and indirectly, between the hippocampal formation and the anterior thalamic nuclei. These extended pathways also involve the mammillary bodies, the retrosplenial cortex and parts of the prefrontal cortex. Recent neuropsychological findings reveal the disproportionate importance of these hippocampal–anterior thalamic systems for recollective rather than familiarity-based recognition, while anatomical studies highlight the precise manner in which information streams are kept separate but can also converge at key points within these pathways. These latter findings are developed further by electrophysiological stimulation studies showing how the properties of the direct hippocampal–anterior thalamic projections are often opposed by the indirect hippocampal projections via the mammillary bodies to the thalamus. Just as these hippocampal–anterior thalamic interactions reflect an interdependent system, so it is also the case that pathology in one of the component sites within this system can induce dysfunctional changes to distal sites both directly and indirectly across the system. Such distal effects challenge more traditional views of neuropathology as they reveal how extensive covert pathology might accompany localised overt pathology, and so impair memory.
Collapse
Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, Tower Building, Park Place, Cardiff, Wales CF10 3AT, UK.
| | | | | | | | | | | |
Collapse
|
43
|
Amin E, Wright N, Poirier GL, Thomas KL, Erichsen JT, Aggleton JP. Selective lamina dysregulation in granular retrosplenial cortex (area 29) after anterior thalamic lesions: an in situ hybridization and trans-neuronal tracing study in rats. Neuroscience 2010; 169:1255-67. [PMID: 20570608 DOI: 10.1016/j.neuroscience.2010.05.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 05/21/2010] [Accepted: 05/21/2010] [Indexed: 11/26/2022]
Abstract
There is growing evidence that lesions of the anterior thalamic nuclei cause long-lasting intrinsic changes to retrosplenial cortex, with the potential to alter its functional properties. The present study had two goals. The first was to identify the pattern of changes in eight markers, as measured by in-situ hydridisation, in the granular retrosplenial cortex (area Rgb) following anterior thalamic lesions. The second was to use retrograde trans-neuronal tracing methods to identify the potential repercussions of intrinsic changes within granular retrosplenial cortex. In Experiment 1, adult rats received unilateral lesions of the anterior thalamic nuclei and were perfused 4 weeks later. Of the eight markers, four (c-fos, zif268, 5ht2rc, kcnab2) showed a very similar pattern of change, with decreased levels in superficial retrosplenial cortex (lamina II) in the ipsilateral hemisphere but little or no change in deeper layers (lamina V). A fifth marker (cox6b) showed a shift in activity levels in the opposite direction to the previous four markers. Three other markers (cox6a1, CD74, ncs-1) did not appear to change activity levels after surgery. The predominant pattern of change, a decrease in superficial cortical activity, points to potential alterations in plasticity and metabolism. In Experiment 2, wheat germ agglutin (WGA) was injected into the anterior thalamic nuclei in rats given different survival times, sometimes in combination with the retrograde, fluorescent tracer, Fast Blue. Dense aggregations of retrogradely labeled cells were always found in lamina VI of granular retrosplenial cortex, but additional labeled cells in lamina II were only found: (1) in WGA cases, that is never after Fast Blue injections, and (2) after longer WGA survival times (3 days). These layer II Rgb cells are likely to have been trans-neuronally labeled, revealing a pathway from lamina II of Rgb to those deeper retrosplenial cells that project directly to the anterior thalamic nuclei.
Collapse
Affiliation(s)
- E Amin
- School of Psychology, Cardiff University, Wales CF10 3AT, UK
| | | | | | | | | | | |
Collapse
|
44
|
Vann SD, Erichsen JT, O'Mara SM, Aggleton JP. Selective disconnection of the hippocampal formation projections to the mammillary bodies produces only mild deficits on spatial memory tasks: implications for fornix function. Hippocampus 2010; 21:945-57. [PMID: 20865745 DOI: 10.1002/hipo.20796] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2010] [Indexed: 11/06/2022]
Abstract
It is now clear that the integrity of the fornix is important for normal mnemonic function. The fornix, however, is a major white matter tract, carrying numerous hippocampal formation afferents and efferents, and it is not known which specific components support memory processes. Established theories of extended hippocampal function emphasize the sequential pathway from the hippocampal formation (i.e., subicular complex) to the mammillary bodies and, thence, to the anterior thalamus, as pathology in each of these structures is implicated in anterograde amnesia in humans and spatial memory deficits in rats. The specific importance of the hippocampal formation projections that just innervate the mammillary bodies has, however, never been tested. This study isolated these specific projections in the rat by selectively cutting the descending component of the postcommissural fornix. Two successive, cohorts of rats with these tract lesions were tested on working memory tasks in the water-maze, T-maze, and radial-arm maze. Disconnecting the descending postcommissural fornix had only a mild effect or sometimes no apparent effect on the performance of these spatial memory tasks, even though tracing experiments confirmed the loss of hippocampal formation-mammillary projections. One implication is that the spatial deficits found in rats following standard fornix lesions are only partly attributable to the loss of projections from the hippocampal formation to the mammillary bodies. Perhaps more surprising, the behavioral impact of cutting the descending postcommissural fornix in rats appeared appreciably less than the effect of either mammillary body or mammillothalamic tract lesions. The present experiments show that the mammillary bodies can still effectively support spatial memory in the absence of their dense subicular complex inputs, so revealing the importance of the other afferents for sustaining mammillary body function. This new evidence for independent functions shows that the mammillary bodies are more than just a hippocampal relay.
Collapse
|
45
|
Tattersall RJ, Prashar A, Singh KD, Tokarczuk PF, Erichsen JT, Hocking PM, Guggenheim JA. Ex vivo magnetic resonance imaging of crystalline lens dimensions in chicken. Mol Vis 2010; 16:144-53. [PMID: 20142845 PMCID: PMC2817010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 01/28/2010] [Indexed: 11/03/2022] Open
Abstract
PURPOSE A reduction in the power of the crystalline lens during childhood is thought to be important in the emmetropization of the maturing eye. However, in humans and model organisms, little is known about the factors that determine the dimensions of the crystalline lens and in particular whether these different parameters (axial thickness, surface curvatures, equatorial diameter, and volume) are under a common source of control or regulated independently of other aspects of eye size and shape. METHODS Using chickens from a broiler-layer experimental cross as a model system, three-dimensional magnetic resonance imaging (MRI) scans were obtained at 115-microm isotropic resolution for one eye of 501 individuals aged 3-weeks old. After fixation with paraformaldehyde, the excised eyes were scanned overnight (16 h) in groups of 16 arranged in a 2x2x4 array. Lens dimensions were calculated from each image by fitting a three-dimensional mesh model to the lens, using the semi-automated analysis program mri3dX. The lens dimensions were compared to measures of eye and body size obtained in vivo using techniques that included keratometry and A-scan ultrasonography. RESULTS A striking finding was that axial lens thickness measured using ex vivo MRI was only weakly correlated with lens thickness measured in vivo by ultrasonography (r=0.19, p<0.001). In addition, the MRI lens thickness estimates had a lower mean value and much higher variance. Indeed, about one-third of crystalline lenses showed a kidney-shaped appearance instead of the typical biconvex shape. Since repeat MRI scans of the same eye showed a high degree of reproducibility for the scanning and mri3dX analysis steps (the correlation in repeat lens thickness measurements was r=0.95, p<0.001) and a recent report has shown that paraformaldehyde fixation induces a loss of water from the human crystalline lens, it is likely that the tissue fixation step caused a variable degree of shrinkage and a change in shape to the lenses examined here. Despite this serious source of imprecision, we found significant correlations between lens volume and eye/body size (p<0.001) and between lens equatorial diameter and eye/body size (p<0.001) in these chickens. CONCLUSIONS Our results suggest that certain aspects of lens size (specifically, lens volume and equatorial diameter) are controlled by factors that also regulate the size of the eye and body (presumably, predominantly genetic factors). However, since it has been shown previously that axial lens thickness is regulated almost independently of eye and body size, these results suggest that different systems might operate to control lens volume/diameter and lens thickness in normal chickens.
Collapse
Affiliation(s)
| | - Ankush Prashar
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK,Scottish Crop Research Institute (SCRI), Dundee, UK
| | - Krish D. Singh
- Cardiff University Brain and Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, UK
| | - Pawel F. Tokarczuk
- Experimental Magnetic Resonance Imaging Centre (EMRIC), School of Biosciences, Cardiff University, Cardiff, UK
| | | | - Paul M. Hocking
- Department of Genetics and Genomics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, UK
| | | |
Collapse
|
46
|
Chen YP, Prashar A, Hocking PM, Erichsen JT, To CH, Schaeffel F, Guggenheim JA. Sex, Eye Size, and the Rate of Myopic Eye Growth Due to Form Deprivation in Outbred White Leghorn Chickens. ACTA ACUST UNITED AC 2010; 51:651-7. [DOI: 10.1167/iovs.09-3826] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Yen-Po Chen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom; the 2Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ankush Prashar
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Paul M. Hocking
- the Department of Genetics and Genomics, Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, United Kingdom
| | - Jonathan T. Erichsen
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Chi Ho To
- the Center for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong; and
| | - Frank Schaeffel
- the Ophthalmic Research Institute, Section of Neurobiology of the Eye, Tübingen, Germany
| | - Jeremy A. Guggenheim
- From the School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom
| |
Collapse
|
47
|
Goodall N, Kisiswa L, Prashar A, Faulkner S, Tokarczuk P, Singh K, Erichsen JT, Guggenheim J, Halfter W, Wride MA. 3-Dimensional modelling of chick embryo eye development and growth using high resolution magnetic resonance imaging. Exp Eye Res 2009; 89:511-21. [DOI: 10.1016/j.exer.2009.05.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 05/06/2009] [Accepted: 05/18/2009] [Indexed: 01/04/2023]
|
48
|
Prashar A, Hocking PM, Erichsen JT, Fan Q, Saw SM, Guggenheim JA. Common determinants of body size and eye size in chickens from an advanced intercross line. Exp Eye Res 2009; 89:42-8. [PMID: 19249299 DOI: 10.1016/j.exer.2009.02.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 12/31/2008] [Accepted: 02/15/2009] [Indexed: 11/29/2022]
Abstract
Myopia development is characterised by an increased axial eye length. Therefore, identifying factors that influence eye size may provide new insights into the aetiology of myopia. In humans, axial length is positively correlated to height and weight, and in mice, eye weight is positively correlated with body weight. The purpose of this study was to examine the relationship between eye size and body size in chickens from a genetic cross in which alleles with major effects on eye and body size were segregating. Chickens from a cross between a layer line (small body size and eye size) and a broiler line (large body and eye size) were interbred for 10 generations so that alleles for eye and body size would have the chance to segregate independently. At 3 weeks of age, 510 chicks were assessed using in vivo high resolution A-scan ultrasonography and keratometry. Equatorial eye diameter and eye weight were measured after enucleation. The variations in eye size parameters that could be explained by body weight (BW), body length (BL), head width (HW) and sex were examined using multiple linear regression. It was found that BW, BL and HW and sex together predicted 51-56% of the variation in eye weight, axial length, corneal radius, and equatorial eye diameter. By contrast, the same variables predicted only 22% of the variation in lens thickness. After adjusting for sex, the three body size parameters predicted 45-49% of the variation in eye weight, axial length, corneal radius, and eye diameter, but only 0.4% of the variation in lens thickness. In conclusion, about half of the variation in eye size in the chickens of this broiler-layer advanced intercross line is likely to be determined by pleiotropic genes that also influence body size. Thus, mapping the quantitative trait loci (QTL) that determine body size may be useful in understanding the genetic determination of eye size (a logical inference of this result is that the 20 or more genetic variants that have recently been shown to influence human height may also be found to influence axial eye length). Furthermore, adjusting for body size will be essential in mapping pure eye size QTL in this chicken population, and may also have value in mapping eye size QTL in humans.
Collapse
Affiliation(s)
- Ankush Prashar
- School of Optometry & Vision Sciences, Cardiff University, Maindy Road, Cardiff, Wales, UK
| | | | | | | | | | | |
Collapse
|
49
|
May PJ, Sun W, Erichsen JT. Defining the pupillary component of the perioculomotor preganglionic population within a unitary primate Edinger-Westphal nucleus. Prog Brain Res 2008; 171:97-106. [PMID: 18718287 DOI: 10.1016/s0079-6123(08)00613-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The primate Edinger-Westphal nucleus (EW) contains perioculomotor preganglionic (pIII(PG)) motoneurons that control the lens and pupil. Separate subdivisions have been described in EW and termed visceral columns, with the lateral visceral column (lvc) reportedly receiving pretectal inputs for the pupillary light reflex. However, choline acetyl transferase staining reveals a single paired column of cells dorsal to the oculomotor nucleus, suggesting the EW is not subdivided. We investigated this issue by transneuronal retrograde labelling of pIII(PG) neurons in three monkey species. In all three, pIII(PG) neurons were contained in a single column. We have also examined which part of the macaque pIII(PG) population receives pretectal input. Injections of biocytin into the pretectum anterogradely labelled terminals that lay in close association with pIII(PG) motoneurons retrogradely labelled by ciliary ganglion injections of WGA-HRP. These close associations were concentrated in the ventromedial portion of the middle third of EW, suggesting this pIII(PG) region mediates pupillary control. In other cases, pretectal WGA-HRP injections, in addition to labelling terminals in the EW, produced a circular field of labelled neurons, and terminals in the periaqueductal grey, dorsolateral to EW. This region may represent the previously designated lvc, but it does not contain pIII(PG) motoneurons.
Collapse
Affiliation(s)
- Paul J May
- Department of Anatomy, University of Mississippi Medical Center, Jackson, MS, USA.
| | | | | |
Collapse
|
50
|
Prashar A, Guggenheim JA, Erichsen JT, Hocking PM, Morgan JE. Measurement of intraocular pressure (IOP) in chickens using a rebound tonometer: quantitative evaluation of variance due to position inaccuracies. Exp Eye Res 2007; 85:563-71. [PMID: 17719031 DOI: 10.1016/j.exer.2007.07.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 06/12/2007] [Accepted: 07/06/2007] [Indexed: 11/13/2022]
Abstract
Intraocular pressure (IOP), an important risk factor for glaucoma, is a continuous trait determined by a complex set of genetic and environmental factors that are largely unknown. Genetic studies in laboratory animals may facilitate the identification of genes that affect IOP. We examined the use of the rebound tonometer for measuring IOP in non-anaesthetised birds, along with the device's robustness to alignment errors. Calibration curves were obtained by measuring the IOP of cannulated chicken eyes with the rebound tonometer over a range of pressures. To simulate different types of alignment errors that might be expected with measurement of IOP in alert chickens, for some calibrations the tonometer was positioned (1) at various distances from the cornea, (2) laterally displaced from the visual axis, or (3) angled away from the visual axis. In vivo measurements were taken on three-week-old alert chickens from a layer line, a broiler line, and a layer-broiler "advanced intercross line" (AIL) designed to facilitate QTL mapping. The rebound tonometer showed excellent linearity (R2=0.95-0.99) during calibration, as well as robustness to variation in the probe-to-cornea distance over the range 3-5mm and to lateral displacement over the range 0-2mm. However, the tonometer appeared less robust to off-axis misalignment over the range 0-20 degrees (P<0.05). Also, the slope of calibration curves sometimes differed between eyes (P<0.001), presumably reflecting differences in ocular structure. The IOP measured in non-anaesthetised three-week-old AIL chickens was 17.51+/-0.13 mmHg (mean+/-S.E.; N=105 birds). IOP was significantly associated with corneal thickness (P<0.05) and body weight (P<0.001) in a regression model. Replicate measurements were necessary in order to gauge IOP accurately in individual birds; a series of seven tonometry sessions over a 12-h period during the light phase of the light/dark cycle permitted IOP to be measured with a 95% CI of +/-0.7 mmHg. IOP did not differ significantly between the broiler and layer chicken lines which served as the progenitor lines for the AIL. In conclusion, the rebound tonometer permits rapid estimation of IOP in chickens and is well tolerated. The small alignment errors that are expected when taking measurements in non-anaesthetised animals are unlikely to affect accuracy. Since high IOP is a major risk factor for glaucoma, identifying QTL controlling IOP may offer future health benefits. However, our preliminary findings highlight several obstacles to mapping such QTL using the chicken advanced intercross line evaluated here.
Collapse
Affiliation(s)
- A Prashar
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | | | | | | | | |
Collapse
|