Network formation and reorganization of the olfactory system of Xenopus laevis

by Sara Joy Hawkins
Cumulative thesis
Date of Examination:2022-02-09
Date of issue:2022-03-03
Advisor:Prof. Dr. Ivan Manzini
Referee:Prof. Dr. Jochen Staiger
Referee:Dr. Camin Dean
Referee:Prof. Dr. Ralf Heinrich
Referee:Prof. Dr. André Fiala
Referee:Prof. Dr. Martin Göpfert
Persistent Address: http://dx.doi.org/10.53846/goediss-9077

 

 

Files in this item

Name:eDiss_SJHawkins_2021.pdf
Size:4.49Mb
Format:PDF

The following license files are associated with this item:

Abstract

English

The olfactory system is a window to the chemical world, that permits each species to adapt to novel spaces and situations. Despite the various phylogenetic adaptations, this sensory system maintains similar functional and structural features (Eisthen, 2002). One of these shared features is the regenerative capability of the olfactory system, due to the maintenance of stem cell niches that replace neurons throughout life and after lesion. The disruption and damage of olfactory systems in different spe-cies allows us to compare these neurogenic processes and potentially find features that are more or less permissive for the recovery of function, potentially providing clin-ical relevance (Lledo and Valley, 2016; Shohayeb et al., 2018). I lesioned the olfactory system of larval Xenopus laevis, by severing the olfactory nerve, causing loss of olfactory function. Over the course of approximately 2 months, distinct populations of ORNs are regenerated, capable of accurately rewiring in the OB, leading to the morphological and functional recovery of second order neurons and consequently to the recovery of odor representations in the brain that allow for odor recognition (Hawkins et al., 2017; Hawkins et al., in prep). I show that odor-guided behavioral changes are lost after ON transection, and recover after a 7 to 9 week period after lesion (Hawkins et al., in prep). My finding show a clear interplay between peripheral and central nervous system trophic support during the process of recovery from damage. Further comparative analyses of recovery from olfactory sys-tem lesion between vertebrate phyla would contribute to the understanding of what factors or mechanisms promote or inhibit the recovery of odor perception.
Keywords: amphibian; aquatic olfaction; de- and regeneration; nerve transection; odor coding/mapping; behavior; functional calcium imaging
 
Statistik