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Published on: August 1, 2018
Functional differentiation of memory retrieval network in macaque posterior parietal cortex.
Kentaro Miyamoto1, Takahiro Osada, Yusuke Adachi
1Department of Physiology, The University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Neuron
|February 27, 2013
Summary
This monkey fMRI study identifies two distinct posterior parietal cortex (PPC) regions involved in memory retrieval. These findings suggest functional similarities in PPC memory networks between macaques and humans.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Primate Neuroimaging
Background:
- Human fMRI studies implicate the posterior parietal cortex (PPC) in memory retrieval.
- However, specific memory-related functional regions within the macaque PPC remain unestablished.
- This study aims to bridge this gap by investigating macaque PPC activity during memory tasks.
Purpose of the Study:
- To identify and functionally characterize memory-retrieval-related regions in the macaque posterior parietal cortex (PPC).
- To investigate the differential roles of identified PPC regions using a serial probe recognition paradigm.
- To explore the effective connectivity between the hippocampus and PPC regions during memory retrieval.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was employed in macaques during a recognition memory task.
- A serial probe recognition paradigm was used to differentiate activity related to initial versus later item retrieval.
- Effective connectivity analyses were performed to assess information flow between brain regions.
Main Results:
- Two distinct PPC activation sites were identified: area PG/PGOp and area PEa/DIP.
- Area PG/PGOp, along with the hippocampus, showed higher activity during initial item retrieval.
- Area PEa/DIP was more active for the retrieval of later items in the series.
- Hippocampal connectivity to PG/PGOp increased during initial retrieval, while connectivity to PEa/DIP did not.
Conclusions:
- The macaque PPC contains functionally distinct regions (PG/PGOp and PEa/DIP) involved in different aspects of memory retrieval.
- These regions are integrated into separate brain-wide networks supporting memory retrieval.
- The findings suggest a functional correspondence of PPC memory networks between macaques and humans.
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