Evidence of a third branch in the uncinate fasciculus and possible implications

The uncinate fasciculus (UF) is a ventral, anterior, associative C-shaped white matter bundle that connects the temporo-amygdala-orbitofrontal network, which is functionally dedicated to the integration of visceral and emotional states, cognition and behaviour.1 Issues in that network are shown with cognitive and behavioural symptoms characteristic of temporal lobe epilepsy, mood disorders and neurodegenerative dementias, including Alzheimer's disease and semantic dementia. In animal studies, the disconnection of the UF causes impairment of object-reward association and learning temporally complex visual information.2 The Orbito Frontal Cortex (OFC) and other regions of the Prefrontal Cortex gained interest following the reported changes in Phineas Gage's behaviour ( € acquired sociopathy') due to a brain frontal pole injury34 and have since been considered important for personality and social behaviour.5 Furthermore, it has also been reported that violent personality disordered offenders have reduced prefrontal cortex grey matter volume and glucose metabolism and impaired OFC activation during adversative conditioning.