Dissertation committee:
Μαρία Πιάγκου, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Γεώργιος Στράντζαλης, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Θεόδωρος Τρουπής, Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Βασίλειος Πρωτογέρου, Αναπληρωτής Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Θεανώ Δεμέστιχα, Αναπληρώτρια Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Δημήτριος Φιλίππου, Επίκουρος Καθηγητής, Ιατρική Σχολή, ΕΚΠΑ
Ευθυμία Μπάσδρα, Καθηγήτρια, Ιατρική Σχολή, ΕΚΠΑ
Summary:
OBJECTIVE: To elucidate the anatomy of the white matter fiber tracts implicated in the connectivity of the temporal pole (TP). METHODS: Thirty normal, adult, formalin-fixed cerebral hemispheres were investigated via the white matter dissection technique. Lateral to medial and medial to lateral dissections were performed in tandem using the surgical microscope. RESULTS: The trajectory, morphology and connectivity of all fiber tracts terminating to/arising from the temporal pole was revealed and disclosed. Their temporopolar terminations were delineated. The middle longitudinal fasciculus (MdLF) was consistently recorded to connect the dorsolateral TP to the Parietal and occipital lobes, through the auditory cortex. Within the inferior arm of the cingulum, the Cingulum bundle V (CB- V) was recorded to link the medial TP to the precuneus. The Uncinate fasciculus (UF) was seen to connect the dorsal TP to the posterior orbital gyrus and pars orbitalis, posterior two thirds of the gyrus rectus and posterior one third of the paraolfactory gyrus. CONCLUSIONS: Our results support the hypothesis that distinct subregions of the TP are subcortically connected to different cortical areas subserving various cognitive networks. The essential relationship of the MdLF with the auditory cortex and the functional role of the temporopolar area implicated in its connectivity tend to shift the paradigm of its function towards high-order auditory function. In view of its subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial and mnemonic information. The UF is involved in the connectivity of temporopolar areas implicated in encoding and storing mnemonic and emotionally colored representations to areas of the orbitofrontal cortex that underlie executive functions and behavioral shaping, in a way that memory-based representations alter our behavior.
Keywords:
Brain connectivity, White matter tracts anatomy, Middle longitudinal fasciculus, Cingulum, Uncinate fasciculus
