My laboratory focuses on understanding the potential mechanisms for two types of eye movement disorders: strabismus and nystagmus. Untreated these result in decreased visual acuity. Both involve the ocular motor system and the specialized skeletal muscles that move the eye, the extraocular muscles (EOM). We focus on the ability of retrogradely transported neurotrophic factors to alter the function and structure of the ocular motor system with the goal of developing a permanent therapeutic approach for these movement disorders. We have used RNAseq data to identify potential new therapeutic targets for development of treatments.
A second focus is the study of the muscle stem cell populations in the EOM that cause their differential sparing in degenerative disorders such as muscular dystrophy and amyotrophic lateral sclerosis. We have identified a specific stem cell, expressing Pitx2, which we have implicated in this differential sparing. Further work will focus on using these stem cells to prevent limb muscle degeneration in these currently untreatable diseases.
Finally, we have started a new project looking at the electroretinogram (ERG) in various mouse models of disease. Our recent studies show a significant difference in ERG characteristics in a mouse model of schizophrenia compared to controls, suggesting a specific method by which differences in the brain can be measured in the retina. More surprising was the discovery of sex differences in the ERG when retinal function is examined in mesopic illumination. We are following up on these studies.
Lab Website: https://lmcloon.umn.edu/
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
- Johnson LL, Kueppers RB, Shen E, Rudell JC, McLoon LK. Development of nystagmus with the absence of MYOD expression in the extraocular muscles. Invest Ophthalmol Vis Sci. 2021 Oct 4;62(13):3.
- Torres Jimenez N, Miller RF, McLoon LK. Effects of D-serine treatment on outer retinal function. Exp Eye Res. 2021 Aug 20;211:108732.
- Rudell JC, McLoon LK. The effect of fibroblast growth factor 2 on extraocular muscle structure and function. Invest Ophthalmol Vis Sci. 2021 Jul 1;62(9):34.
- Rudell JC, Fleuriet J, Mustari MJ, McLoon LK. Childhood onset strabismus: a neurotrophic factor hypothesis. Invited review. Journal of Binocular Vision and Ocular Motility. 2021 Apr 19:1-6.
- Hampe CS, Wesley J, Lund TC, Orchard PJ, Polgreen LE, Eisengart JB, McLoon LK, Cureoglu S, Schachern P, McIvor RS. Mucopolysaccharidosis type I: Current treatments, limitations, and prospects for improvement. Biomolecules. 2021 Jan 29;11(2):189.
- Fleuriet J, Willoughby Cl, Kueppers RB, Mustari MJ, McLoon LK. Eye alignment changes caused by sustained GDNF treatment of an extraocular muscle in infant non-human primates. Sci Rep. 2020 Jul 17;10(1):11927.
- Rudell JC, Stager D, Felius J, McLoon LK. Morphological differencs in the inferior oblique muscles from subjects with over-elevation in adduction. Invest Ophthalmol Vis Sci. 2020;61(6):33.
- Torres Jimenez N, Lines JW, Kueppers RB, Kofuji P, Wei H, Rankila A, Coyle JT, Miller RF, McLoon LK. Electroretinographic abnormalities and sex differences detected with mesopic adaptation in a mouse model of schizophrenia: a and b wave analysis. Invest Ophthalmol Vis Sci. 2020 Feb 7;61(2):16.
- Moghimi P*, Torres Jimenez N*, McLoon LK, Netoff TI, Lee MS, MacDonald III, A, Miller RG. Electroretinographic evidence of altered retinal function in schizophrenia. Schizophr. Res. 2020;219:34-46. * co-first authors
- Olson RM, Mokhtarzadeh A, McLoon LK, Harrison AR. Effects of repeated eyelid injections with botulinum toxin A on innervation of treated muscles in patients with blepharospasm. Curr Eye Res. Current Eye Res. 2019;44:257-263.
- Fleuriet J, McLoon LK. Visualizing neuronal adaptation in real time after treatment of strabismus. Invest Ophthalmol Vis Sci. 2018;59:5022-5024.
- Verma M, Asakura Y, Murakonda BSR, Pengo T, Latroche C, Chazaud B, McLoon LK. Asakura A. Muscle satellite cell cross-talk with a vascular niche maintains quiescence via VEGF and notch aignaling. Cell Stem Cell. 2018;23(4):530-543.
- McLoon LK, Redish AD. Demystifying graduate school: Navigating a PhD in neuroscience and beyond. J Undergrad Neurosci Educ. 2018;16:A203-A209.
- Fitzpatrick KR, Cucak A, McLoon LK. Changing muscle function with sustained glial derived neurotrophic factor treatment of rabbit extraocular muscle. PLoS One. 2018 Aug 24;13(8):e0202861.
- McLoon LK, Vincente A, Fitzpatrick KR, Lindström M, Pedrosa-Domellöf F. Composition, architecture, and functional implications of the connective tissue network of the extraocular muscles. Invest Ophthalmol Vis Sci. 2018;59:322-329.
- Hebert SL*, Fitzpatrick KR*, McConnell SA, Cucak A, Yuan C, McLoon LK. Effects of retinoic acid signaling on extraocular muscle myogenic precursor cells in vitro. Exp Cell Res. 2017;361:101-111.
- Verma M, Fitzpatrick KR, McLoon LK. Extraocular muscle repair and regeneration. Current Ophthalmology Reports. Invited review. 2017;5:207-215.
- McLoon LK*, Christiansen SP, Ghose GM, Das VE*, Mustari MJ*. Improvement in eye alignment in adult strabismic monkeys by sustained IGF-1 treatment. Invest Ophthalmol Vis Sci. 2016;57:6070-6078.
- Nelson KR, Stevens SM, McLoon LK. Prolongation of relaxation time in extraocular muscles with brain derived neurotrophic factor in adult rabbit. Invest Ophthalmol Vis Sci. 2016;57:5834-5842.
- Yuan C, Bothun ED, Hardten DR, Tolar J, McLoon LK. A novel component of corneal opacification in a bone marrow transplant-treated patient with Hurler syndrome. Exp Eye Res. 2016;148:83-89.
- McLoon LK, Willoughby CL, Anderson JS, Bothun ED, Stager DR, Felius J, Lee H, Gottlob I. Abnormally small neuromuscular junctions in the extraocular muscles from subjects with idiopathic infantile nystagmus and nystagmus associated with albinism. Invest Ophthalmol Vis Sci. 2016;57:1912-1920.
- McDonald AA, Hebert SL, McLoon LK. Sparing of the extraocular muscles in mdx mice with absent or reduced utrophin expression: A life span analysis. Neuromusc Disord. 2015;25:873-887.
- Graber TG, Kim JH, Grange RW, McLoon LK, Thompson LV. C57BL/6 life span study: age-related declines in muscle power production and contractile velocity. Age. 2015;37(3):9773.
- Willoughby CL, Fleuriet J, Walton MM, Mustari MJ, McLoon LK. Adaptability of the immature ocular motor control system: Unilateral IGF-1 medial rectus treatment. Invest Ophthalmol Vis Sci. 2015;56:3484-96.
- Willoughby CL, Fleuriet J, Walton MM, Mustari MJ, McLoon LK. Adaptation of slow myofibers: the effect of sustained BDNF treatment of extraocular muscles in infant nonhuman primates. Invest Ophthalmol Vis Sci. 2015;56:3467-83.
- McDonald AA, Hebert SL, Kunz MD, Ralles SJ, McLoon LK. Disease course in mdx:utrophin+/- mice: comparison of three mouse models of Duchenne muscular dystrophy. Physiol Rep. 2015;3(4):e12391.
- Walton MM, Mustari MJ, Willoughby CL, McLoon LK. Abnormal activity of neurons in abducens nucleus of strabismic monkeys. Invest Ophthalmol Vis Sci. 2014;56:10-19.
- McLoon LK, Harandi VM, Brännström T, Andersen PM, Liu JX. Wnt and extraocular muscle sparing in amyotrophic lateral sclerosis. Invest Ophthalmol Vis Sci. 2014;55(9):5482-5496.
- McDonald AA, Kunz MD, McLoon LK. Dystrophic changes in extraocular muscles after gamma irradiation in mdx:utrophin+/- mice. PLoS One. 2014;9(1):e86424.
Current Graduate Students:
Former Graduate Students:
Nathalia Torres Jimenez (Ph.D. 2019, Neuroscience, University of Minnesota).
Christy Willoughby (Ph.D. 2015, Neuroscience, University of Minnesota).
Abby McDonald (Ph.D. 2013; Molecular, Cellular, Developmental Biology and Genetics, University of Minnesota)
Sandra Alcala (Ph.D. 2009, Neuroscience, University of Minnesota).
Kristen Kallestad (Ph.D. 2009, Neuroscience, University of Minnesota).