eprintid: 1476676 rev_number: 25 eprint_status: archive userid: 608 dir: disk0/01/47/66/76 datestamp: 2016-03-16 12:12:20 lastmod: 2021-09-23 22:22:33 status_changed: 2016-03-16 12:12:20 type: article metadata_visibility: show creators_name: Harrison, IF creators_name: Anis, HK creators_name: Dexter, DT title: Associated degeneration of ventral tegmental area dopaminergic neurons in the rat nigrostriatal lactacystin model of parkinsonism and their neuroprotection by valproate ispublished: pub divisions: UCL divisions: B02 divisions: C10 divisions: D17 divisions: FI6 keywords: Dopamine, Histone deacetylase inhibitor, Lactacystin, Parkinson’s disease, Substantia Nigra pars compacta, Valproate, Ventral tegmental area note: © 2015 The Authors. Published by Elsevier Ireland Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). abstract: Parkinson's disease (PD) manifests clinically as bradykinesia, rigidity, and development of a resting tremor, primarily due to degeneration of dopaminergic nigrostriatal pathways in the brain. Intranigral administration of the irreversible ubiquitin proteasome system inhibitor, lactacystin, has been used extensively to model nigrostriatal degeneration in rats, and study the effects of candidate neuroprotective agents on the integrity of the dopaminergic nigrostriatal system. Recently however, adjacent extra-nigral brain regions such as the ventral tegmental area (VTA) have been noted to also become affected in this model, yet their integrity in studies of candidate neuroprotective agents in the model have largely been overlooked. Here we quantify the extent and distribution of dopaminergic degeneration in the VTA of rats intranigrally lesioned with lactacystin, and quantify the extent of VTA dopaminergic neuroprotection after systemic treatment with an epigenetic therapeutic agent, valproate, shown previously to protect dopaminergic SNpc neurons in this model. We found that unilateral intranigral administration of lactacystin resulted in a 53.81% and 31.72% interhemispheric loss of dopaminergic SNpc and VTA neurons, respectively. Daily systemic treatment of lactacystin lesioned rats with valproate however resulted in dose-dependant neuroprotection of VTA neurons. Our findings demonstrate that not only is the VTA also affected in the intranigral lactacystin rat model of PD, but that this extra-nigral brain region is substrate for neuroprotection by valproate, an agent shown previously to induce neuroprotection and neurorestoration of SNpc dopaminergic neurons in this model. Our results therefore suggest that valproate is a candidate for extra-nigral as well as intra-nigral neuroprotection. date: 2016-02-12 date_type: published official_url: http://dx.doi.org/10.1016/j.neulet.2015.12.052 oa_status: green full_text_type: pub pmcid: PMC4756273 language: eng primo: open primo_central: open_green article_type_text: Journal Article verified: verified_manual elements_id: 1098643 doi: 10.1016/j.neulet.2015.12.052 pii: S0304-3940(15)30343-8 language_elements: eng lyricists_name: Harrison, Ian lyricists_id: IHARR57 actors_name: Barczynska, Patrycja actors_id: PBARC91 actors_role: owner full_text_status: public publication: Neuroscience Letters volume: 614 pagerange: 16-23 event_location: Ireland issn: 1872-7972 citation: Harrison, IF; Anis, HK; Dexter, DT; (2016) Associated degeneration of ventral tegmental area dopaminergic neurons in the rat nigrostriatal lactacystin model of parkinsonism and their neuroprotection by valproate. Neuroscience Letters , 614 pp. 16-23. 10.1016/j.neulet.2015.12.052 <https://doi.org/10.1016/j.neulet.2015.12.052>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1476676/1/1-s2.0-S0304394015303438-main.pdf