A report from the National Institute of Mental Health says a gene variant that reduces dopamine activity in the prefrontal cortex is related to poorer performance and inefficient functioning of that brain region during working memory tasks, and to slightly increased risk for schizophrenia.
Dopamine-sensitive neurons in the cerebral cortex are found primarily in the frontal lobes. The dopamine system is associated with pleasure, long-term memory, planning and drive. Dopamine tends to limit and select sensory information arriving from the thalamus to the fore-brain. Poor regulation of dopamine pathways has been associated with schizophrenia.
The so-called executive functions of the frontal lobes involve the ability to recognize future consequences resulting from current actions, to choose between good and bad actions (or better and best), override and suppress unacceptable social responses, and determine similarities and differences between things or events.
The frontal lobes also play an important part in retaining longer term memories which are not task-based. These are often memories with associated emotions, derived from input from the brain's limbic system, and modified by the higher frontal lobe centers to generally fit socially acceptable norms (see executive functions above). The frontal lobes have rich neuronal input from both the alert centers in the brain-stem, and from the limbic regions.
