<p>Single neuron and homogeneous population basal activity and prolonged osmotic challenge and recovery.</p>

The transcription rate mostly tracks the osmotic stimulus with some drop off due to non-linearities in the spiking response. The mRNA content rises non-linearly as the balance shifts between transcription, and depletion due to synthesis (translation). The synthesis rate increases but fails to track the increasing secretion rate.

The reserve store is gradually depleted to ~27%. Plasma vasopressin increases initially linearly but then slows as the neurons shift from phasic to continuous spiking. Following the ramped challenge, secretion falls to basal rates, but elevated synthesis is sustained by the increased mRNA content, depleting this to recharge the reserve store.

A 100 neuron homogeneous population produces the same response with less noise.</p>