Neuronal hyperactivity in a LRRK2-G2019S cellular model of Parkinson’s Disease

Abstract

Monogenic Parkinson's Disease can be caused by a mutation in the leucine-rich repeat kinase 2 (LRRK2) gene, causing a late-onset autosomal dominant inherited form of Parkinson's Disease. The function of the LRRK2 gene is incompletely understood, but several in vitro studies have reported that LRRK2-G2019S mutations affect neurite branching, calcium homeostasis and mitochondrial function, but thus far, there have been no reports of effects on electrophysiological activity. We assessed the neuronal activity of induced pluripotent stem cell derived neurons from Parkinson's Disease patients with LRRK2-G2019S mutations and isogenic controls. Neuronal activity of spontaneously firing neuronal populations was recorded with a fluorescent calcium-sensitive dye (Fluo-4) and analysed with a novel image analysis pipeline that combined semi-automated neuronal segmentation and quantification of calcium transient properties. Compared with controls, LRRK2-G2019S mutants have shortened inter-spike intervals and an increased rate of spontaneous calcium transient induction.

A Quantitative Model of Sporadic Axonal Degeneration in the Drosophila Visual System

“…Recent evidence indicates that synaptic failure in AD is at least partly induced by neuronal hyperactivity in the early stages of the disease, and this mechanism could also be involved in developing a late-onset autosomal dominant inherited form of PD ( Nuriel et al, 2017 ; Hector and Brouillette, 2020 ; Lucumi Moreno et al, 2021 ). We thus tested whether activity of PRCs is linked to the axonal degeneration described in our model.…”

Mechanistic model-driven exometabolomic characterisation of human dopaminergic neuronal metabolism

“…Summary A human neuroepithelial stem cell line from a healthy human donor was maintained and differentiated toward midbrain-specific dopaminergic neurons using an established protocol [70], summarised in Section 1.1.1. Cellular morphology was monitored during differentiation and after sufficient time had elapsed (23 days), calcium imaging and automated image analysis was used to assess electrophysiological activity, using an established pipeline [51], summarised in Section 1.1.2. Immunofluorescent staining was used to identify differentiated cell types (Section 1.1.3).…”

“…Full frame fluorescence images, of size 2560×2160 pixels, were acquired using an epifluorescence microscope (Leica DMI6000 B, Germany) equipped with a cooled sCMOS camera (Neo 5.5, Andor technology, UK) and both were controlled with Micro-manager (version 1.4) [18]. Images were sampled at a rate of approximately 10 Hz for about 2 min, stored as image stacks and analysed off-line using an established pipeline for automated calcium image analyses [51]. For each segmented neuron, we measured fluorescence traces as relative changes in fluorescence intensity over time.…”