Deficient experience-dependent plasticity in the visual cortex of Arc null mice

Within the visual cortex a vast assortment of molecules work in concert to sharpen and refine neuronal circuits throughout development. With the advent of genetic mouse models it is now possible to probe the individual contributions of single molecules implicated in this process. The Arc (activity-regulated cytoskeletal associated) gene is an effector immediate early gene that has been suggested to play a critical role in synaptic plasticity. The goal of this thesis is to understand the workings of Arc within the visual cortex. Specifically, we ask how genetic deletion of Arc influences plasticity, and how visual response properties differ between cells types containing, and not containing Arc. To elucidate a role for Arc in visual cortical plasticity we took advantage of knockin mice expressing GFP in place of Arc protein (referred to as KO mice for simplicity). We combined intrinsic signal imaging, visually evoked potentials, and two-photon in vivo calcium imaging to assess plasticity in juvenile and adult wild-type (WT), heterozygote, and KO mice. We find that plasticity is disrupted in the visual cortex of Arc KO mice in the absence of obvious deficits at the level of basal response properties. In addition, this work has revealed that: 1) Arc is necessary for the establishment of normal ocular dominance during development and critical for deprived eye depression in the visual cortex of juvenile animals 2) Loss of Arc impairs AMPA receptor internalization in visual cortex- a necessary requirement for synaptic weakening after lid suture.

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

2009

Author dc:creator

• McCurry, Cortina (Cortina Luann)

Advisor dc:contributor.advisor

• Mriganka Sur.

• 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/1721.1/49738

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/49738