2026-10-11T06:11:36Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34036028 2026-09-30T17:42:59Z category_7 category_12 category_15 category_16 category_873 category_106 category_734 portal_5 item_type_3 month_year_09_2026

<p>Secretion and plasma model parameters.</p> Duncan J. MacGregor (25145402) Medicine Cell Biology Neuroscience Physiology Chemical Sciences not elsewhere classified Science Policy Biological Sciences not elsewhere classified regulate water loss dynamically heterogeneous patterns complete neural system neuronal cell bodies prolonged osmotic challenge peptide hormone vasopressin hypothalamic vasopressin neurons extracellular fluid osmolarity distributed neuroendocrine system stores gradually decline distant hormone stores detailed neuronal model despite upregulated synthesis turn trigger secretion regulate plasma volume maintain hormone supply div >< p 2 +</ sup modelling vasopressin synthesis synthesis dynamics based activity dependent upregulation plasma volume dependent upregulation sustained challenge storage dynamics recovery based neuroendocrine cells model suggests elevated osmolarity neuronal activity large stores coordinate synthesis timescale memory slow recovery several days salt loading posterior pituitary pituitary terminals physiological input mrna content mrna acts intracellular ca homeostatic systems generate complex form part experimentally tested demand balance coupling spiking axonal terminals <div><p>Hypothalamic vasopressin neurons are neuroendocrine cells which form part of the homeostatic systems that regulate plasma volume and extracellular fluid osmolarity. In response to synaptic inputs encoding osmolarity and changes in plasma volume, they generate complex and dynamically heterogeneous patterns of spikes that in turn trigger secretion of peptide hormone vasopressin from axonal terminals in the posterior pituitary. The thousands of neurons’ secretory signals generate a summed plasma vasopressin signal acting at the kidneys to regulate water loss. Vasopressin is synthesised in the neuronal cell bodies, packaged into vesicles, and transported to large stores at the pituitary terminals. Supported by activity-dependent upregulation of synthesis and transport, these stores can maintain a secretion response for several days of elevated osmolarity, experimentally tested by dehydration or salt loading. However, despite upregulated synthesis, stores gradually decline during sustained challenge, followed by a slow recovery. With no evidence of a store encoding feedback signal, previous simple modelling explained these synthesis dynamics based on activity-dependent upregulation of transcription and mRNA content. Here we integrate this idea into a detailed neuronal model, coupling spiking, secretion, and synthesis to simulate a complete neural system, from physiological input to output, and ask how a distributed neuroendocrine system can maintain hormone supply-demand balance over prolonged challenge without direct feedback from distant hormone stores. The model suggests that mRNA acts as a long-timescale memory of neuronal activity, extending temporal integration beyond spike activity and intracellular Ca²⁺ to coordinate synthesis with sustained demand.</p></div> 2026-09-30T17:55:49Z Dataset Dataset 10.1371/journal.pcbi.1014832.t002 https://figshare.com/articles/dataset/_p_Secretion_and_plasma_model_parameters_p_/34036028 CC BY 4.0