Morphological changes in dendritic spines of Purkinje cells associated with motor learning

Experience-dependent changes of spine structure and number may contribute to long-term memory storage. Although several studies demonstrated structural spine plasticity following associative learning, there is limited evidence associating motor learning with alteration of spine morphology. Here, we investigated this issue in the cerebellar Purkinje cells using high voltage electron microscopy (HVEM). Adult rats were trained in an obstacle course, demanding significant motor coordination to complete. Control animals either traversed an obstacle-free runway or remained sedentary. Quantitative analysis of spine morphology showed that the density and length of dendritic spines along the distal dendrites of Purkinje cells were significantly increased in the rats that learned complex motor skills compared to active or inactive controls. Classification of spines into shape categories indicated that the increased spine density and length after motor learning was mainly attributable to an increase in thin spines. These findings suggest that motor learning induces structural spine plasticity in the cerebellar Purkinje neurons, which may play a crucial role in acquiring complex motor skills.     

From Victim to Perpetrator of Trauma: Lived Experiences of Gang-Involved Urban Refugee Youth in Kenya

Somali children and youth in displacement are exposed to prolonged trauma and chronic violence. In spite of a striking link among trauma, gang activities, victimization, and perpetration of violence, however, few studies have been conducted with Somali refugee youth in low-resource urban settings. This qualitative study demonstrates how prolonged trauma shapes ecological conditions of refugee life that induce vulnerable youth to forge support systems through gang membership and violence. The accession of the challenges, from loss of family, to discrimination and police brutality, and to chronic impoverishment, forces the high-risk refugee youth to replicate the various forms of violence to which they have been exposed to survive. Undergoing such chronic and cumulated trauma, these youth continue to normalize and become further desensitized to violence. The systems perspective of this study expands understanding of the intersection of trauma and gang membership and implies the need for an expanded approach to trauma and understanding of the complexities of gang involvement, beyond posttraumatic stress disorder treatment and clinical intervention.     

Unequal Division of Child Care between Korean Spouses and Children’s Self-Regulation: The Mediating Roles of Parental Mental Health,Marital Conflict,and Parental Warmth

Journal of Child and Family Studies - This longitudinal study examined associations between parents’ unequal division of child care when children were 5 years of age and children’s...