Prof. Dr. Anja Horn-Bochtler

Keywords: neuroanatomy of eye movements

Research methods: Immunocytochemical methods on human paraffin sections.

Brief research description: 1. Role of palisade endings in extraocular musces: Despite the lack of a stretch reflex sensory information reaches the brain from the eye muscle. However, most vertebrates lack classical proprioceptors. One current research project is the investigation of the sensory innervation of the extraocular muscles including the role of the specialized palisade endings at the myotendinous junction only present in eye muscles. A malfunction of these endings may contribute to strabismus and/or congenital nystagmus. 2.The unique anatomical accessibility of the saccadic and vestibular functional cell groups allows the investigation of their chemical signature including transmitter-related molecules, ion-channels and the specialized extracellular matrix in the form of perineuronal nets on a cellular level in the human brainstem. This knowledge is used in comparative post-mortem studies on the corresponding cell groups in clinical cases with well-documented eye movement deficits, such as PSP or NP-C. Knowledge of the chemical signature of the oculomotor and vestibular neurons and their potential alterations in diseased brains may offer explanations for the mechanism of eye movement dysfunction, but may also form the basis for a pharmacological therapy at least for some of the oculomotor symptoms.

Current or graduated GSN students: Ümit Suat Mayadali

Selected publications:

Eberhorn A, Ardeleanu P, Büttner-Ennever JA, Horn, AKE (2005) Histochemical differences between motoneurons supplying multiply and singly innervated extraocular muscle fibers. J. Comp. Neurol. 491:352-366; https://doi.org/10.1002/cne.20715

Horn AKE, Eberhorn A, Härtig W, Ardeleanu P, Messoudi A, Büttner-Ennever JA (2008) Perioculomotor cell groups in monkey and man defined by their histochemical and functional properties: a reappraisal of the Edinger-Westphal nucleus. J. Comp. Neurol. 507: 1317-1335; https://doi.org/10.1002/cne.21598

Lienbacher K, Ono S, Fleuriet J, Mustari M, Horn AKE (2018) A subset of palisade endings only in the medial and inferior rectus muscle in monkey contain calretinin. Investigative Ophthalmology & Visual Science 2018;59:2944–2954.

Mayadali ÜS, Fleuriet J, Mustari M, Straka H, Horn AKE (2021) Transmitter and ion channel profiles of neurons in the primate abducens and trochlear nuclei. Brain, Structure and Function 2021: 226:2125-2151. DOI: 10.1007/s00429-021-02315-7

Horn AKE, Straka H (2021) Biochemical and molecular organization of extraocular motoneurons and eye muscles. Annual Review of Vision Science 2021. 7:793–825 doi.org/10.1146/annurev-vision-100119-125043 Book: Büttner-Ennever JA, Horn AKE (2014) Olszewski and Baxter's Cytoarchitecture of the Human Brainstem; Karger, 3rd, revised and extended edition; XII + 290 p., 604 fig., 1 tab., hard cover; ISBN: 978-3-318-02367-1