Cellular and Molecular Biology

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Gap Junctions: Sensory Neuron Connectivity


In an experiment (illustrated below) yellow dye was injected into a mature olfactory neuron and red dye was injected into an immature olfactory neuron. You observe that the yellow dye spreads to several other mature neurons.

Only the one immature neuron is labeled. The dye does not leak into the extracellular space. Following this experiment you conduct another identical experiment, except you incubate the tissue in carbenoxolone (which blocks connexin function) before injecting the dyes. In this second experiment, one mature and one immature neuron are labeled.

Einstein - Created for Albert.io. Copyright 2016. All rights reserved.

What is the most likely explanation for these observations?

Select ALL that apply.


Only mature neurons are capable of secreting and taking up the dye. Carbenoxolone prevents the neurons from taking up the dye.


Only mature neurons have gap junctions.


The mature neurons that you have observed have gap junctions which are incapacitated with the application of carbenoxolone; the immature neuron that was injected does not have functioning gap junctions, but more experiments would need to be conducted to determine whether some immature neurons may have gap junctions.


Carbenoxolone kills the cells that have taken up the dye.


The mature and immature neurons that you observe in the second experiment are not communicating with one another through gap junctions.