Dynamic Connectivity between Brain Networks Supports Working Memory: Relationships to Dopamine Release and Schizophrenia
| Autor: | Holly Moore, Guillermo Horga, Clifford M. Cassidy, Jared X. Van Snellenberg, Mark Slifstein, Anissa Abi-Dargham, Caridad Benavides, Zhishun Wang |
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| Rok vydání: | 2016 |
| Předmět: |
Adult
Male Pyrrolidines Dopamine Individuality 03 medical and health sciences 0302 clinical medicine Parietal Lobe Salicylamides medicine Humans Amphetamine medicine.diagnostic_test Working memory General Neuroscience Psychophysiological Interaction Cognition Articles medicine.disease Network dynamics Magnetic Resonance Imaging Frontal Lobe 030227 psychiatry Memory Short-Term Schizophrenia Positron-Emission Tomography Female Schizophrenic Psychology Nerve Net Radiopharmaceuticals Psychology Functional magnetic resonance imaging Neuroscience Psychomotor Performance 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | The Journal of Neuroscience. 36:4377-4388 |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.3296-15.2016 |
| Popis: | Connectivity between brain networks may adapt flexibly to cognitive demand, a process that could underlie adaptive behaviors and cognitive deficits, such as those observed in neuropsychiatric conditions like schizophrenia. Dopamine signaling is critical for working memory but its influence on internetwork connectivity is relatively unknown. We addressed these questions in healthy humans using functional magnetic resonance imaging (during ann-back working-memory task) and positron emission tomography using the radiotracer [11C]FLB457 before and after amphetamine to measure the capacity for dopamine release in extrastriatal brain regions. Brain networks were defined by spatial independent component analysis (ICA) and working-memory-load-dependent connectivity between task-relevant pairs of networks was determined via a modified psychophysiological interaction analysis. For most pairs of task-relevant networks, connectivity significantly changed as a function of working-memory load. Moreover, load-dependent changes in connectivity between left and right frontoparietal networks (Δ connectivity lFPN-rFPN) predicted interindividual differences in task performance more accurately than other fMRI and PET imaging measures. Δ Connectivity lFPN-rFPN was not related to cortical dopamine release capacity. A second study in unmedicated patients with schizophrenia showed no abnormalities in load-dependent connectivity but showed a weaker relationship between Δ connectivity lFPN-rFPN and working memory performance in patients compared with matched healthy individuals. Poor working memory performance in patients was, in contrast, related to deficient cortical dopamine release. Our findings indicate that interactions between brain networks dynamically adapt to fluctuating environmental demands. These dynamic adaptations underlie successful working memory performance in healthy individuals and are not well predicted by amphetamine-induced dopamine release capacity.SIGNIFICANCE STATEMENTIt is unclear how communication between brain networks responds to changing environmental demands during complex cognitive processes. Also, unknown in regard to these network dynamics is the role of neuromodulators, such as dopamine, and whether their dysregulation could underlie cognitive deficits in neuropsychiatric illness. We found that connectivity between brain networks changes with working-memory load and greater increases predict better working memory performance; however, it was not related to capacity for dopamine release in the cortex. Patients with schizophrenia did show dynamic internetwork connectivity; however, this was more weakly associated with successful performance in patients compared with healthy individuals. Our findings indicate that dynamic interactions between brain networks may support the type of flexible adaptations essential to goal-directed behavior. |
| Databáze: | OpenAIRE |
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