The role of ras signaling associative learning and memory in Drosophila

Ras is an evolutionally conserved signaling molecule that has been implicated in a variety of cellular events, such as cell proliferation, differentiation, and survival. Recent studies also suggest roles of Ras in neuronal plasticity. I investigated the role of Ras in associative learning and memory in Drosophila. Flies carrying hypomorphic ras mutations were impaired in memory, with normal learning performance. The severity of the memory impairment correlated with molecular lesions in the ras gene. Studies on synaptic morphology at larval neuromuscular junctions revealed an increased number of presynaptic varicosities in the ras mutants. Flies carrying a dominant-negative or -active form of a ras transgene showed a learning impairment, when expression of the transgene occurred in the mushroom bodies (MBs), the center for the associative learning and memory. Acute induction of dominant-active ras expression also resulted in a learning impairment. Simple sensorimotor functions and overall MB morphology were normal in all the flies that showed learning or memory impairments. These results collectively suggest a direct role of Ras signaling in associative learning and memory in Drosophila.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Brain and Cognitive Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Sakamoto, Toshimasa

Advisor dc:contributor.advisor

• William G. Quinn.

• Brain and Cognitive Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34483

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34483