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Experimental neurobiology in monkeys has provided evidence that neuronal activity in prefrontal cortex is related to working memory (WM) functions (Goldman-Rakic). Cortical networks are based on modules composed of interconnected excitatory glutamate and inhibitory GABA circuits. Also other transmitters such as dopamine (DA) influence the processing properties of these networks.
Clincial ob servations and studies in human subjects have shown that bad WM functions (high distractibility) can be caused by cocaine that elevates DA concentration. Also too low DA concentration, as it seems to be the case in schizophrenia, weakens WM (low persistence of information; Winterer).
Hypothetical exploratory computational modleing was proposed by Durstewitz et al. who showed in line with neurobiological experiments that that the ratio of DA D1 / D2 receptors could be critical for proper functioning of WM. Persistence of information depends on high D1 receptor activation.
Some strategies of modeling and implications for theoretical psychiatry are discussed in the presentation.
Source: Tretter & Müller (2007)Pharmacopsychiatry Supplement S 1 |
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