Simple terminology question:
- Is there a hard boundary between in vitro and ex vivo?
- Is there a hard boundary between in vivo and ex vivo?
Suppose a sensory neuron is electrically recorded in the following settings:
- Surgically accessing through the animal's skin, and patch-clamped,
- Tissue surrounding the neuron is almost separated, but still dangling from the larger part of the animal, and patch-clamped,
- Same as above, but the slight dangling connection is cut,
- The sensory neuron is isolated and put in an artificially oxygenated medium
The sensory neuron is assumed to have purely feedforward signal, and is perfectly healthy in all conditions. Which conditions, if any, are in vivo, in vitro, or ex vivo? (Feel free to propose better hypothetical experiments. I know this example is not the best.)
Am I the only one confused about these terminologies?