Pattern Separation: A Potential Marker of Impaired Hippocampal Adult Neurogenesis in Major Depressive Disorder

Frontiers in Neuroscience

Mirjana Maletic-Savatic¹  Chadi Calarge³  Sohye Kim³  Carla Sharp⁴  Lilian Dindo⁵  Kellen Gandy⁵ 

[1] Dan and Jan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, United States;Department of Obstetrics and Gynecology, Baylor College of Medicine and Center for Reproductive Psychiatry, Pavilion for Women, Texas Children's Hospital, Houston, TX, United States;Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX, United States;Department of Psychology, University of Houston, Houston, TX, United States;Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States;

关键词: neurogenesis;    pattern separation;    major depressive disorder;    dentate gyrus;    RDoC matrix;    psychological inflexibility;   

DOI  :  10.3389/fnins.2017.00571

来源: DOAJ

【 摘 要 】

Adult neurogenesis involves the generation of new neurons, particularly in the dentate gyrus of the hippocampus. Decreased hippocampal neurogenesis has been implicated in both animal models of depression and in patients with major depressive disorder (MDD), despite some inconsistency in the literature. Here, we build upon current models to generate a new testable hypothesis, linking impaired neurogenesis to downstream psychological outcomes commonly observed in MDD. We contend that disruption in adult neurogenesis impairs pattern separation, a hippocampus-dependent function requiring the careful discrimination and storage of highly similar, but not identical, sensory inputs. This, in turn, can affect downstream processing and response selection, of relevance to emotional wellbeing. Specifically, disrupted pattern separation leads to misperceived stimuli (i.e., stimulus confusion), triggering the selection and deployment of established responses inappropriate for the actual stimuli. We speculate that this may be akin to activation of automatic thoughts, described in the Cognitive Behavior Theory of MDD. Similarly, this impaired ability to discriminate information at a fundamental sensory processing level (e.g., impaired pattern separation) could underlie impaired psychological flexibility, a core component of Acceptance and Commitment Therapy of MDD. We propose that research is needed to test this model by examining the relationship between cognitive functioning (e.g., pattern separation ability), psychological processes (e.g., perseveration and psychological inflexibility), and neurogenesis, taking advantage of emerging magnetic resonance spectroscopy-based imaging that measures neurogenesis in-vivo.

【 授权许可】

Unknown