Nervous system compensation following tail loss and regeneration in the leopard gecko (Eublepharis macularius)


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


S5-12  Tue Jan 5 18:30 – 19:00  Nervous system compensation following tail loss and regeneration in the leopard gecko (Eublepharis macularius) Bradley, S*; Bailey, CDC; Bent, L; Howe, E; Vickaryous, MK; University of Guelph, ON, CAN; UofG, ON, CAN; UofG, ON, CAN; UofG, ON, CAN; UofG, ON, CAN sbradl01@uoguelph.ca

As for many lizards, leopard geckos (Eublepharis macularius) can voluntary self-amputate (autotomize) a portion of their tails in response to threatening stimuli. Tail loss results in a sudden reduction of body mass, changes in posture, and a shift of the center of mass. Over time a new tail is regenerated, but the position of the center of mass is never fully restored. As a result, lizards present a unique opportunity to investigate how the nervous system compensates when faced with mass-related perturbations. Here, we performed a spatiotemporal examination (before, during, and after tail regeneration) of cutaneous tactile sensitivity (mediated via the peripheral nervous system; PNS) and Purkinje cell neuromorphology (a key cell type of the central nervous system; CNS). We hypothesized that following tail loss and regeneration, the PNS and CNS would demonstrate evidence of somatosensory and neuromorphological changes to compensate for the alterations in mass. Using Semmes-Weinstein monofilaments, we identified regional differences in tactile sensitivity across the ventral surface of the original tail; the tail base is more sensitive than the tail tip. Within 30 days of tail loss, the tail is fully regenerated and tactile sensitivity restored. Using a modified Golgi-Cox staining method, we characterized and quantified the neuromorphology of Purkinje cells, the sole output cells of the cerebellum. We found there were localized changes to the dendritic arbor of Purkinje cells following tail regeneration. These data suggest that neuroplasticity may play a role in long-term compensation following tail regeneration. Together, these findings represent the first evidence of compensatory roles of both the PNS and CNS in a tail regenerating species.

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