Use of calcium imaging for analysis of neuronal gap junction coupling

Abstract

We recently used western blots for connexin 36 and neuronal dye coupling with neurobiotin to measure developmental decrease in neuronal gap junction coupling in cell cultures. To ask whether Ca 2+ imaging also can be used to measure changes in the amount of neuronal gap junction coupling, we defined a Ca 2+ coupling coefficient as the percentage of neurons with bicuculline-induced increases in intracellular Ca 2+ that are suppressed by blocking gap junctions. We demonstrate in rat and mouse hypothalamic neuronal cultures that the Ca 2+ coupling coefficient decreases during culture development, this decrease is prevented by manipulations that also prevent developmental decrease in neuronal gap junction coupling, and the coefficient is low in cultures lacking connexin 36. The results indicate that Ca 2+ imaging is a useful tool to quantify the amount of neuronal gap junction coupling in cultures.

Glutamate- and GABA-mediated neuron–satellite cell interaction in nodose ganglia as revealed by intracellular calcium imaging

“…i increase in neurons has been reported in the central nervous system, and it has been suggested that bicuculline blocks inhibitory inputs from GABAergic synapses via GABA A receptors, thus causing neuronal [Ca 2? ] i to increase (Arumuga et al 2008;Kato-Negishi et al 2003). It is known that GABA is released by two distinct mechanisms: Ca 2?…”