Award Date


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Life Sciences

First Committee Member

J. Steven de Belle

Number of Pages



Animal models have been used for centuries to study learning and memory in simple systems with many applications to humans (Chapter 1). The fruit fly Drosophila melanogaster has added greatly to our current understanding of learning and memory and its underlying biology (Chapter 2). The research described here focuses on the relationship between learning and memory and the brain using three mutant strains of flies: mushroom body miniature B (mbmB), small mushroom bodies (smu), and mushroom bodies reduced (mbr). Mushroom bodies are paired neuronal structures found in most invertebrate brains involved in learning and memory consolidation. All three mutations studied were initially isolated based on a reduced dendritic volume in the mushroom body calyx; In chapter 3, GAL4 driven membrane bound and nuclear localized GFP expression revealed that adult mbmB and smu flies had intact gamma lobes with the rest severely reduced in size; while mbr flies had severe disruption in all lobes. A beta lobe midline fusion is seen in mbmB flies. Adults of all three mutants have a reduction in Kenyon cell number. They all show normal bifurcation and pathfinding of MB gamma neurons in wandering third instar larvae; while cell counts of mbmB and smu Kenyon cell bodies during development show cell number is consistent with wild type until approximately mid-third instar; I have shown that both mbmB and smu have impaired learning scores consistent with other fly mutations causing mushroom body calyx volume reductions. Both have reduced long term memory (LTM) and anesthesia resistant memory (ARM) as well. LTM and ARM are generated using two distinct training protocols, massed for ARM and spaced for LTM. Some reports state that these are additive processes while others say ARM is disrupted by spaced training. My studies support the hypothesis that ARM is disrupted by spaced training.


Body; Disruption; Effects; Learning; Lobe; Lobe Disruption; Memory; Mushroom; Mushroom Body Calyx

Controlled Subject

Neurosciences; Genetics

File Format


File Size

2088.96 KB

Degree Grantor

University of Nevada, Las Vegas




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