Jen and Jack are seated in the same row in an airplane but across the aisle from each other. If the information they exchange across the aisle represents the neural impulse between neurons, and Jen and Jack represent the neurons, the aisle most likely represents the

The aisle most likely represents the synapse.

Explanation:

Neurons communicate to each other at synapses. Synapses are junctions or connections in which "information" (electrical or chemical signal) travels from one neuron to the other.

In this scenario, Jen would illustrate a presynaptic neuron; while Jack would illustrate a postsynaptic neuron, while the aisle represents a synapse through which they are transmitting information between each other.