This interdisciplinary project will incorporate the disciplines of Neuroscience and Biology. However, the project is specifically housed within the Hope College Department of Biology.
With this study, we will examine cellular and molecular mechanisms underlying neuronal regeneration and repair following damage in the olfactory system of zebrafish.
The olfactory system is composed of two peripheral olfactory organs located in the nasal cavity, and the olfactory bulb, a brain region that regulates olfactory information. This system allows organisms to detect odor signals and thus interact with their environment. Olfaction mediates behaviors pivotal for survival, such as feeding, mating, social behavior, and danger assessment.
The olfactory system of zebrafish presents a remarkable degree of regeneration and neuroplasticity, making it an ideal model for the study of regeneration, reorganization, and repair mechanisms following injury and disease.
We have discovered that lesions of the olfactory bulb produce neuron loss and degeneration in many components of the olfactory system, including the olfactory bulb and olfactory sensory neurons of the olfactory epithelium. This neuron loss and degeneration is followed by complete neuronal regeneration and repair. Moreover, we have shown that increased and sustained production of new neurons (i.e. neurogenesis) in a neighboring brain region known as the subventricular zone (SVZ), and in the olfactory epithelium following damage to the olfactory bulb.
Our main goal is to answer the following question:
Is neurogenesis a central component of regeneration and repair in the lesioned olfactory bulb?
To answer this, we will study the timeline of neurogenesis and neuronal fate in the olfactory bulb by using different neuronal markers. This will allow us to track newly born neurons on route to the olfactory bulb, as well as the type of neurons they ultimately become (i.e. glutamatergic v dopaminergic).
We will also use a transgenic fish in which neuronal stem cells, which are neuroinflammatory cells (astrocytes) express a green fluorescent protein. This will allow us to track both neuroinflammatory responses in the olfactory bulbs following lesion, as well as activation of neural progenitor cells in the SVZ.
We will employ the following techniques: fluorescent immunohistochemistry, whole-mount 3D preparations of the olfactory bulb, and confocal microscopy.