Exploring Contributions of Stimulus Modality and Relationship to the Organization of Remote Memory
Mentor 1
Dr. Helmstetter
Location
Union Wisconsin Room
Start Date
29-4-2016 1:30 PM
End Date
29-4-2016 3:30 PM
Description
Long-term memories may undergo systems consolidation, a gradual transition to distributed neocortical memory storage that develops through time-dependent changes in cortico-cortical functional connectivity. How the specific information encoded at the time of learning shapes the organization of this remote form of memory in the brain is not well understood. Here we begin to examine modality-specific and cross-modal involvement of secondary sensory cortices in remote fear memories by manipulating modality of and relationship between multiple sensory cues at the time of learning. Specifically, using second-order fear conditioning with discrete auditory and visual cues, learning-dependent plasticity in secondary auditory (AuV/TeA) and visual (V2L) cortices was examined. Time-dependent increases in the expression of the synaptic marker synaptophysin were observed as a function of conditioning with auditory and visual stimuli in AuV/TeA and V2L, respectively. Functionally, remote retrieval of either the first-order auditory stimulus or the second-order visual stimulus produced significant activation of AuV/TeA. These data suggest that secondary sensory cortices may store modality-specific information at remote time points, but may also exhibit cross-modal recruitment at the time of retrieval if the initial learning events involve the association of multiple cues. Together, these results support an encouraging new approach to understanding the organizational principles of neocortical memory storage.
Exploring Contributions of Stimulus Modality and Relationship to the Organization of Remote Memory
Union Wisconsin Room
Long-term memories may undergo systems consolidation, a gradual transition to distributed neocortical memory storage that develops through time-dependent changes in cortico-cortical functional connectivity. How the specific information encoded at the time of learning shapes the organization of this remote form of memory in the brain is not well understood. Here we begin to examine modality-specific and cross-modal involvement of secondary sensory cortices in remote fear memories by manipulating modality of and relationship between multiple sensory cues at the time of learning. Specifically, using second-order fear conditioning with discrete auditory and visual cues, learning-dependent plasticity in secondary auditory (AuV/TeA) and visual (V2L) cortices was examined. Time-dependent increases in the expression of the synaptic marker synaptophysin were observed as a function of conditioning with auditory and visual stimuli in AuV/TeA and V2L, respectively. Functionally, remote retrieval of either the first-order auditory stimulus or the second-order visual stimulus produced significant activation of AuV/TeA. These data suggest that secondary sensory cortices may store modality-specific information at remote time points, but may also exhibit cross-modal recruitment at the time of retrieval if the initial learning events involve the association of multiple cues. Together, these results support an encouraging new approach to understanding the organizational principles of neocortical memory storage.
