Neuroscience 2004 Abstract
| Presentation Number: | 81.12 |
|---|---|
| Abstract Title: | Stable and unstable dopamine release control in the prefrontal cortex by the cortico-mesocortical system during the processing of multiple spatial working memory. |
| Authors: |
Tanaka, S.*1
; Yamashita, K.1
; Yata, H.1
1Dept of Electrical & Electronics Engin., Sophia Univ., Tokyo 102-8554, Japan |
| Primary Theme and Topics |
Cognition and Behavior - Human Cognition, Behavior, and Anatomy -- Working memory |
| Secondary Theme and Topics | Cognition and Behavior<br />- Human and Animal Cognition and Behavior<br />-- Learning & memory: Physiology and imaging |
| Session: |
81. Working Memory I Poster |
| Presentation Time: | Saturday, October 23, 2004 4:00 PM-5:00 PM |
| Location: | San Diego Convention Center - Hall A-H, Board # FF10 |
| Keywords: | circuit, computational, dopaminergic, model |
The control of fundamental cognitive operations of working memory has been suggested to require the regulation of dopamine (DA) in the prefrontal cortex (PFC) (Tanaka 2002: Neural Netw). The internal loop between the PFC and the midbrain DA nuclei (the cortico-mesocortical loop) can work as a regulator of DA release in the PFC with peculiar characteristics (Tanaka 2003: SFN Abstr; Yamashita and Tanaka 2003: Neurocomput). We studied how this DA regulator works during the processing of multi-target spatial working memory via computer simulation of our biological model and theoretical analysis of a simplified model. The simulation shows that the time course of the extracellular DA level in the PFC goes up and down during the processing, such as loading and maintenance, of multi-target spatial working memory. It suggests, however, that there is a window of the DA level in which multiple targets are successfully processed. Within this window, the optimum DA level is different for different tasks. The theoretical and numerical stability analyses of our simplified circuit model suggest that the stability critically depends on the loop gain (i.e., the gains of the feedforward dopaminergic modulation and the glutamatergic cortical feedback projections) and that weaker cortical feedback is generally preferable for stable DA release inside this window. Otherwise, most of the hyperdopaminergic states tend to be unstable, causing DA depletion in the PFC. Therefore, the regulation of the loop gain of the cortico-mesocortical circuit would be crucial for the maintenance of the task-specific optimum DA level in the PFC.
Supported by The Japanese Ministry of Education, Science and Technology grants #15016096 and #15500218
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
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