Hemispheric specialization in mood regulation, cerebral dominance for language, and handedness

COSTANZO, ELSA; VILLARREAL, MIRTA; DRUCAROFF, LUCAS JAVIER; ORTIZ VILLAFAÑE, MANUEL; CASTRO, MARIANA NAIR; GOLDSCHMIDT, MICAELA; WAINSZTEIN, AGUSTINA; LADRÓN-DE-GUEVARA, MARÍA SOLEDAD; ROMERO, CARLOS; BRUSCO, LUIS IGNACIO; CAMPRODON, JOAN; NEMEROFF, CHARLES; GUINJOAN, SALVADOR

Buenos Aires

Conferencia; Schizophrenia International Research Society (SIRS) - South American Conference - 2014; 2014

Schizophrenia International Research Society (SIRS).

Hemispheric specialization in the processing and regulation of mood is a fundamental variable to understand circuit dynamics of networks subserving such functions, and to define pathophysiological mechanisms of mood dysregulation across the neuropsychiatric spectrum. From a therapeutic perspective, brain stimulation treatments depend on the precise definition of disease-relevant networks, and lateralized processing is a key factor that influences both efficacy and safety.Objective: To study the lateralized processing of induced sadness and happiness in healthy individuals and examine its relationship with language lateralization and handedness. In 20 right-handed healthy individuals (11 females, age 25.9±5.6 years) and 20 nonright-handed healthy subjects (12 females, age 29.2±9.7 years), we used two functional MRI paradigms: one of mood induction and the other of language activation. Hemispherical language and mood laterality indexes were calculated for each subject.Emotional processing in relevant regions of interest (amygdala, subgenual cingulate or insula) showed different hemispheric dominance patterns, sometimes equal and sometimes opposite to language dominance (Figure 2). These ROIs also showed consistent (amygdala) or opposite (insula) dominance when processing sad or happy mood states in right-handed subjects, but no significant pattern was observed for nonright-handed individuals.This study describes hemispheric differences in mood processing as a function of handedness and language dominance, highlighting intrinsic structure-specific differences within limbic networks. The clinical relevance of these patterns needs to be addressed in order to develop better biomarkers, identify appropriate therapeutic targets, and improve individualized targeting strategies for brain stimulation.