Dorsolateral prefrontal cortex memory

Xu et al. (2005) 8 NA 4.1 14.4 N-Back Task-related neural activity in the left DLPFC showed a significant interaction between test session working memory load. When smokers had smoked ad libitum, task-related activity in the left dorsolateral prefrontal cortex was relatively low for an easy task condition (1-back), and increased as task difficulty increased but when smokers were abstinent overnight, activity in the L-DLPFC was approximately as high at low task level as it was at more difficult levels. 

Avery, R., Franowicz, J.C.S., Studholme C., van Dyck C.H., and Arnsten, A.F.T. (2000) The alpha-2A adrenoceptor agonist, guanfacine, increases regional cerebral blood flow in dorsolateral prefrontal cortex and improves accuracy in monkeys performing a spatial working memory task. Neuropsychopharmacology 23 240-249. 

Add to this mix the conspicuous failure of recent memory to keep dream data in mind for more than a very few minutes and we can consider one of the great dream mysteries (amnesia) to be tentatively solved it is the joint product of the global aminergic demodulation that affects the entire brain and the more local disenablement of the dedicated circuitry of the dorsolateral prefrontal cortex that, in waking, allows us to be critical, decisive, and executive. 

When tense, the muscles receive strong excitatory activation from the brain and, in turn, project excitatory activation back to it. When the tension is performance anxiety—as it so often is—the positive feedback loop that perpetuates the excitatory activation of the brain and muscles include the amygdala at the expense of the dorsolateral prefrontal cortex, which is not free to work its executive functions in an adaptive way. Hence memory may be blocked, decisiveness deferred, and creativity crippled. 

List of Abbreviations CKU, chronic ketamine users COMT, catechol-O-methyltransferase DA, dopamine DAT, DA transporters DLPFC, dorsolateral prefrontal cortex EC, entorhinal cortex MPFC, medial prefrontal cortex NET, norepinephrine transporters PFC, prefrontal cortex SN, substantia nigra VTA, ventral tegmental area TH, tyrosine hydroxylase WCST, Wisconsin Cart Sort Task WM, working memory... 

Manoach DS, Gollub RL, Benson ES, Searl MM, Goff DC, et al. 2000. Schizophrenic subjects show aberrant fMRI activation of dorsolateral prefrontal cortex and basal ganglia during working memory performance. Biol Psychiatry... 

Manoach DS, Press DZ, Thangaraj V, Searl MM, Goff DC, et al. 1999. Schizophrenic subjects activate dorsolateral prefrontal cortex during a working memory task, as measured by fMRI. Biol Psychiatry 45 1128-1137. 

Brozoski et al. (1979) performed a landmark study on the role of PFC DA in working memory function in monkeys. These investigators used a delayed response type procedure to show that 6-OHDA-induced depletion of DA in the principal sulcus of the dorsolateral prefrontal cortex in macaques produced an impairment as profound as ablation by aspiration of the region itself. In contrast, depletion of either noradrenaline or 5-HT in the prefrontal cortex had little effect. Convincing evidence for a specific role of DA came from... 

Osmon suggests that the task, requiring the participant to utilize a rule, must be kept in working memory (dorsolateral prefrontal cortex) to respond quickly to a stimulus. 

This localization of working memory was also identified by Kammer et al, (1997). The engagement of working memory in a visual task involving letter detection produced significant activation in the dorsolateral prefrontal cortex in both hemispheres. ... 

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