Dorsolateral Prefrontal Cortex

Anatomy

• Middle frontal gyrus and the lateral surface of the superior frontal gyrus; Brodmann areas (BA) 9 and 46, partly 8.
• Bounded posteriorly by premotor cortex (BA 6), inferiorly by the inferior frontal sulcus and inferior frontal gyrus, and anteriorly by frontopolar cortex (BA 10).
• Granular (prominent layer IV) association cortex; connected to parietal cortex by long-range white matter tracts (superior longitudinal fasciculus).
• Blood supply: superior branches of the middle cerebral artery (MCA); anterior cerebral artery (ACA) along the dorsomedial edge.
• Boundary in the model: HCP-MMP1.0 areas 46, 9-46 (d, a-v, p-v), 8Av, 8Ad, 8C, 8BL, 9a, 9p, i6-8, s6-8, SFL and the inferior frontal sulcus–junction areas (IFSa, IFSp, IFJa, IFJp). Those falling on the medial surface go to mPFC (Glasser et al., 2016). For students: “DLPFC” is not a single area but a family of areas.

Functions

• Working memory: holding information briefly in mind and operating on it (manipulation).
• Planning, breaking tasks into sequential steps, problem solving and organization.
• Cognitive flexibility (switching rules or strategies) and abstract reasoning.
• Top-down control of attention and suppression of distractors.
• Cognitive reappraisal in emotion regulation.
• Verbal fluency and generativity (left-dominant); visuospatial working memory (right-dominant).
• Neurochemistry of working memory (key to understanding drug effects): Noradrenaline, α2A receptor: closes cAMP–HCN channels on dendritic spines, strengthening prefrontal network connectivity and resistance to distractors. This is how guanfacine works (Wang et al., 2007). B Dopamine, D1 receptor: an inverted-U relationship; too little and too much both impair working memory (Arnsten). Under stress, excess catecholamines take the DLPFC “offline”. B

Connections and chemistry

• Caudate nucleus (cognitive/dorsolateral frontostriatal loop)
• Thalamus — mediodorsal nucleus
• Posterior parietal cortex (frontoparietal control network)
• Anterior cingulate cortex
• Cerebellum (Crus I/II) — cognitive cerebellar loop
• Mesocortical dopamine (VTA), noradrenaline (locus coeruleus)
• Subgenual cingulate (sgACC): anticorrelated (negative) connectivity; the success of the TMS target in depression relates to the strength of this anticorrelation (Fox et al., 2012)

Development

Developmental course through childhood and adolescence.

• One of the latest-maturing regions of the brain; frontal gray matter volume peaks in late childhood, and cortical thinning through synaptic pruning begins in adolescence.
• Myelination and strengthening of frontoparietal connections continue into the mid-20s.
• Its late maturation relative to the reward system in adolescence (the “dual systems / imbalance model”) helps explain risk-taking.
• Sensorimotor → association axis: cortical maturation proceeds from sensory and motor areas toward association cortices. The DLPFC sits at the late end of this axis; prolonged plasticity brings both a learning opportunity and a risk for psychopathology (Sydnor et al., 2021). B
• Maturation of executive function: a shared curve across 10,766 people (ages 8–35). Rapid gains at 10–15, slowing at 15–17, adult levels at 18–20 (Tervo-Clemmens et al., 2023). Clinical implication: expectations of “adult-like” planning in adolescents should be adjusted for age. A

Clinical

• ADHD: hypoactivation of frontostriatal circuits; about a 3-year delay in reaching peak cortical thickness, most marked in prefrontal cortex (Shaw et al., 2007). B ENIGMA cortical analysis (2,246 patients, 1,934 controls): smaller surface area in children, mostly in frontal, cingulate and temporal regions; no difference in adolescents and adults (Hoogman et al., 2019). Consistent with the maturational delay model of Shaw 2007. A Effects are small; MRI cannot diagnose an individual patient.
• Early-onset schizophrenia: DLPFC dysfunction during working memory tasks (hypofrontality).
• Depression: left DLPFC hypoactivity; the rTMS target. FDA clearance (2024) as add-on treatment for major depression at ages 15–21.
• Links with school performance in specific learning disorders and executive function problems.

Treatment

This region from the perspective of medication, psychotherapy and neuromodulation. Letter badges are evidence levels.

• Stimulants (methylphenidate, amphetamine) and atomoxetine raise prefrontal dopamine and noradrenaline. Guanfacine strengthens the prefrontal network directly via α2A (Wang et al., 2007). B
• rTMS in adolescents: NeuroStar received FDA clearance in March 2024 as add-on to antidepressants for major depression at ages 15–21. The first TMS treatment cleared for adolescents. A (regulatory decision)
• Target selection: sites in the left DLPFC that are anticorrelated with the sgACC work better; the best coordinates lie in BA 46 (Fox et al., 2012). B
• SAINT (accelerated, fMRI-guided iTBS over 5 days): in treatment-resistant depression, remission 78.6% vs 13.3% with sham (Cole et al., 2022; 14 vs 15 patients, adults). FDA clearance 2022. Still investigational in adolescents. B

Assessment

Neuropsychological tasks and measures that probe this region's function.

• N-back and Digit Span Backward
• Wisconsin Card Sorting Test (WCST) — perseverative errors
• Tower of London / Tower of Hanoi — planning
• Trail Making Test B (TMT-B), Stroop (together with the ACC)
• Verbal fluency (letter fluency: F-A-S)

Lesions and damage

Clinical findings expected with damage or dysfunction.

• Dysexecutive syndrome: impaired planning and organization, perseveration.
• Reduced working memory capacity, distractibility.
• Inability to generate strategies; behavior becomes driven by environmental cues.

In the model

How this structure is defined in the 3D model, and the data source.

HCP-MMP1.0 areas (Glasser et al., 2016; MNI volumetric version: Horn, 2016): 46, 9-46d, a9-46v, p9-46v, 8Av, 8Ad, 8C, 8BL, 9a, 9p, i6-8, s6-8, SFL and the inferior frontal sulcus areas (IFSa, IFSp, IFJa, IFJp). Parts falling on the medial surface were given to mPFC. Each vertex of the frontal gyri was labeled by the nearest HCP area just beneath it; because the volumetric version is derived from the surface, borders may be uncertain by 1–2 mm.

References

Full citations for the card; links go to the paper (DOI) or a PubMed search.

1. Cole EJ et al. Stanford Neuromodulation Therapy (SNT): a double-blind randomized controlled trial. Am J Psychiatry 2022. Search PubMed
2. FDA, NeuroStar Advanced Therapy ergen (15–21 yaş) MDD ek tedavi onayı, Mart 2024 (üretici duyurusu and basın). Search PubMed
3. Fox MD et al. Efficacy of TMS targets for depression is related to intrinsic functional connectivity with the subgenual cingulate. Biol Psychiatry 2012. Search PubMed
4. Glasser MF et al. A multi-modal parcellation of human cerebral cortex. Nature 2016. Search PubMed
5. Hoogman M et al. Brain imaging of the cortex in ADHD: a coordinated analysis of large-scale clinical and population-based samples. Am J Psychiatry 2019. Search PubMed
6. Sydnor VJ et al. Neurodevelopment of the association cortices: patterns, mechanisms, and implications for psychopathology. Neuron 2021. Search PubMed
7. Tervo-Clemmens B et al. A canonical trajectory of executive function maturation from adolescence to adulthood. Nat Commun 2023. Search PubMed
8. Wang M et al. α2A-adrenoceptors strengthen working memory networks by inhibiting cAMP-HCN channel signaling in prefrontal cortex. Cell 2007;129(2):397–410. Search PubMed
9. Klasik (yerleşik, ayrıca aranmadı): Arnsten, D1 ters-U ilişkisi (Vijayraghavan et al., 2007, Nat Neurosci); Shaw et al., 2007 (PNAS). Search PubMed