The New Calcium Imaging Trend (Front Cell Neurosci 2015;9:436)

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons. org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Summary Calcium imaging is a technique for intracellular calcium measurement , and it is important to understand the neural and glial functions. Genetically encoded Ca 2+ indicators have been used extensively in many body systems to detect Ca 2+ transients associated with neuronal activity. The aim of this article is to utilize a number of cell-specific promoters that express the Ca 2+ indicator GCaMP3 in different classes of neurons and glia to determine their effectiveness in measuring activity in enteric neural networks during colonic motor behaviors. 1 The authors found that the activity in glial networks appeared to follow neural activity but continued long after neural activity had waned. With these new tools an unprecedented level of detail can be recorded from the enteric nervous system (ENS) with minimal manipulation of tissue. These techniques can be extended in order to better understand the roles of particular enteric neurons and glia during normal and disordered motility. Comments ENS is composed of neurons and glial cells. Enteric glial cells are located in close contact with enteric neurons within the ganglia, along inter-ganglionic connectives of the myenteric and submucosal plexus, and can also be found in the extra-ganglionic layers of the gut wall, 2 glial cells shows dynamic responses to neuronal inputs and have the apparatus to sequester and release the neuro-active factors. Nonetheless, whether these cells indeed regulate synaptic transmission in a physiological context such as gut motility pattern is not well known. 3 The live imaging of neuron-glia interaction is very important in understanding these functions. The measuring of intracellular calcium can be done using fluorescent indicators and it has become the most popular technique. It consists of 2 steps, in the first step primary ENS cultures are loaded with the Ca 2+ indicator dye, Fluo4-AM or Fura-2, and the second step is stimulated by 75 mM K + depolarization. 4 However, traditional Ca 2+ imaging techniques have limitations. Calcium imaging bleaching changed indicators cannot cross the cell membrane, and the intracellular concentration might decrease during the experiment. This means that long-term recording is difficult , and the recording of drug response is also limitated.