| Popis: |
Several neurological disorders are characterized by a pathological overexcitation of neurons. However, little is known about the precise mechanisms that underlie inhibition, or the repression of overactivity, which could potentially restore function lost due to overexcitation. One promising area of research is axo-axonic cells in the hippocampus, a class of cells that has been implicated as one of the most important inhibitory circuit elements due to their innervation of axon initial segments of pyramidal cells. As axon initial segments are the site of action potential generation, and pyramidal cells are the primary excitatory unit in the brain, axo-axonic cells and their direct connection to pyramidal cells may play a uniquely important inhibitory role. Previous research has shown variability in activity patterns of axo-axonic cells, suggesting further subtypes within this group, which this study aimed to further investigate. The research discussed in this thesis involved confocal imaging of immunostained axo-axonic cells in mouse hippocampal subsections, followed by recording these cells' location within the hippocampus, bouton connectivity, laminar distribution, and protein expression, attempting to identify trends in variability. We found significant variability, but no evidence of distinct subtypes. This information can be used to contribute to a growing body of work on the role of these cells within healthy neuron networks, and potentially contribute to future research into applications of harnessing axo-axonic cells' natural inhibitory ability in diseases involving overexcitation. |
