Live Imaging Mitochondrial Transport in Neurons

Abstract

Mitochondria are among a cell’s most vital organelles. They not only produce the majority of the cell’s ATP but also play a key role in Ca2+ buffering and apoptotic signaling. While proper allocation of mitochondria is critical to all cells, it is particularly important for the highly polarized neurons. Because mitochondria are mainly synthesized in the soma, they must be transported long distances to be distributed to the far-flung reaches of the neuron—up to 1 m in the case of some human motor neurons. Furthermore, damaged mitochondria can be detrimental to neuronal health, causing oxidative stress and even cell death, therefore the retrograde transport of damaged mitochondria back to the soma for proper disposal, as well as the anterograde transport of fresh mitochondria from the soma to repair damage, are equally critical. Intriguingly, errors in mitochondrial transport have been increasingly implicated in neurological disorders. Here, we describe how to investigate mitochondrial transport in three complementary neuronal systems: cultured induced pluripotent stem cell-derived neurons, cultured rat hippocampal and cortical neurons, and Drosophila larval neurons in vivo. These models allow us to uncover the molecular and cellular mechanisms underlying transport issues that may occur under physiological or pathological conditions.

Superlocalized Three-Dimensional Live Imaging of Mitochondrial Dynamics in Neurons Using Plasmonic Nanohole Arrays

“…, receptor or vesicle protein). The mitochondrial velocity, on the other hand, confirms the range known from the literature, in general, although the range itself may depend on the kind of neurons and experimental conditions under which the mobility studies are conducted. ,− …”

“…Translocation of intracellular organelles or molecules has been studied by taking snap shots in the fixed tissues. − Despite the long history of research, a multitude of issues still remain elusive because of its limitation of static image data. One of the issues of particular interest is mitochondrial movement that takes place in highly polarized cells such as neurons with long axons and dendrites. , Mitochondrial movement is critical to many cellular processes as it reflects nonuniform spatial distribution of energy demands and supplies on a subcellular level, , and more than 30% of mitochondria in a healthy neuron are known to be in motion. − Therefore, live images are necessary to investigate their distribution and dynamic properties. , …”

Strategies for the Treatment of Parkinson’s Disease: Beyond Dopamine

“…For example, each DA neuron must contain highly active axonal transport through microtubules to support metabolic and repair processes, synaptogenesis, removal of cell waste, and communication with other brain cells (Prots et al, 2013(Prots et al, , 2018Lu et al, 2014). In turn, each of these processes requires constant mitochondrial production of adenosine 5'-triphosphate (ATP) to assist the motor proteins dynein, kinesin, myosin, and actin (Course and Wang, 2016;Course et al, 2017;Vanhauwaert et al, 2019). Altogether, this makes the DA neurons in SN especially susceptible to mitochondrial dysfunction, and the resultant energy deficits could contribute mightily to DA-related impairments, such as those occurring in PD (Horowitz et al, 2011;Venkateshappa et al, 2012;Burbulla et al, 2017;Prots et al, 2018).…”

PINK1 Inhibits Local Protein Synthesis to Limit Transmission of Deleterious Mitochondrial DNA Mutations

“…Overlap between mitochondria and ATG8 areas was analyzed with the ''Colocalization'' method. Binary images from mitochondria in egg chambers were generated according to previous description (Course et al, 2017). To quantify the ratio between TMRM and MTgreen, the germ cell area in an egg chamber was outlined and isolated by ''Clear Outside.''…”