Reliability Architecture and Aging: Degeneration and Robustness in a Low Redundancy Neuronal Control System, VD1 and RPD2 Body Water Homeostasis in Lymnaea stagnalis

Date
2024-01-30
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Abstract
VD1 and RPD2 are two electrotonically coupled, peptidergic neurons that form an essential low redundancy neural control system in the central nervous system of the Great Pond Snail Lymnaea stagnalis. VD1 and RPD2 have been shown to exert a cardioregulatory role fundamental to proper osmoregulatory function. The performance of the electrical synapse between the two neurons has been shown to change dramatically with age. This change in performance between the neurons occurs concurrently with an increase in the mortality rate of the population. Additionally, ablation of one of the neurons exerting control over these functions has extreme consequences to the organism’s survival. This includes other measures of body water homeostasis thus demonstrating how dramatic the consequences of a lack of system redundancy can be. This thesis explores the intersection of reliability architecture and aging in a low redundancy neural control system. I will provide evidence for the following ideas: 1) The VD1/RPD2 system experiences age-associated declines in performance however, this decline is not uniform throughout the population. 2) Aging in VD1 and RPD2 result in a reduced capacity for acute adaptation to osmotic changes in the external environment. 3) Despite its low redundancy and the accumulation of age-related damage, VD1 and RPD2 prove robust over the lifespan and home-osmotic range of L. stagnalis.
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Keywords
Lymnaea stagnalis, gastropod, VD2 and RPD2, aging, reliability theory, body water, homeostasis, osmoregulation, osmotic stimuli, electrophysiology, electrical synapse, gap junction
Citation
McFadden, E. S. P. (2024). Reliability architecture and aging: degeneration and robustness in a low redundancy neuronal control system, VD1 and RPD2 body water homeostasis in Lymnaea stagnalis (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.