Research report The motor and visual networks in preterm infants: An fMRI and DTI study Maya Weinstein a,b , Liat Ben-Sira c,d , Artzi Moran a,d , Irit Berger e , Ronella Marom e , Ronny Geva b , Varda Gross-Tsur f , Yael Leitner g , Dafna Ben Bashat a,d,h,n a The Functional Brain Center, The Wohl Institute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel b Gonda Multidisciplinary Brain Research Center, Bar Ilan University, Ramat-Gan, Israel c Department of Radiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel d Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel e Department of Neonatology, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel f Neuropediatric Unit, Shaare-Zedek Medical Centre, Jerusalem, Israel g Child Development Center, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel h Sagol School of Neuroscience, Tel Aviv University, Israel article info Article history: Received 6 January 2016 Received in revised form 23 March 2016 Accepted 22 April 2016 Available online 23 April 2016 Keywords: Preterm Functional connectivity DTI Resting-state MRI abstract Knowledge regarding the association between functional connectivity and white-matter (WM) ma- turation of motor and visual networks in preterm infants at term equivalent age (TEA) and their asso- ciation with behavioral outcome is currently limited. Thirty-two preterm infants born o34 weeks ge- stational-age without major brain abnormalities were included in this study, underwent resting-state fMRI at TEA. Thirteen infants also underwent diffusion tensor imaging (DTI). Neurobehavioral assess- ments were performed at one and two years corrected age using the Griffiths Mental Developmental Scales. Functional connectivity between homolog motor and visual regions were detected, which may reflect that a level of organization in these domains is present already at TEA. DTI parameters of WM tracts at TEA demonstrated spatial-temporal variability, with the splenium of the corpus-callosum (CC) found to be the most mature fiber bundle. Correlations between DTI parameters, functional connectivity and behavioral outcome were detected, yet did not show the same pattern of diffusivity changes in the different networks. Visual functional connectivity was negatively correlated with radial-diffusivity (RD) in the optic radiation, while motor functional connectivity was positively correlated with RD in the splenium. In addition, axial-diffusivity (AD) and RD in the genu and midbody of the CC were positively correlated with neurobehavioral outcome at one and 2 years of age. This study highlights the importance of understanding the spatial-temporal changes occurring during this sensitive period of development and the potential effect of extrauterine exposure on the microstructural changes as measured by DTI; their correlation with functional connectivity; and their long term relationship with neuro-behavioral development. & 2016 Elsevier B.V. All rights reserved. 1. Introduction Brain development in the third trimester and early neonatal period is a dynamic and complex process (Dubois et al., 2014). During brain development, several mechanisms take place in- cluding the maturation and functional specialization of gray matter (GM) regions along with the formation and myelination of white matter (WM) connections between the different neural re- gions (Dubois et al., 2014, Vasung et al., 2013). Some processes are time dependent with critical times for maturation. Factors such as epigenetic, intrauterine and extrauterine environmental also have major impact on development. Extrauterine exposure to stress, pain, visual input and nutrition may affect brain development (Anjari et al., 2007; Bhutta and Anand, 2002; Keunen et al., 2015; Tsuneishi and Casaer, 2000; Valeri et al., 2015). Magnetic resonance imaging (MRI) enables noninvasive map- ping of both structural and functional networks. This methodology may aid in understanding the complex interplay between anato- mical and functional brain development (Sui et al., 2014), which is Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/brainres Brain Research http://dx.doi.org/10.1016/j.brainres.2016.04.052 0006-8993/& 2016 Elsevier B.V. All rights reserved. n Correspondence to: The Functional Brain Center, The Wohl Institute for Ad- vanced Imaging, Tel Aviv Sourasky Medical Center, 6 Weizman Street, Tel Aviv, 64239, Israel. E-mail address: dafnab@tlvmc.gov.il (D. Ben Bashat). Brain Research 1642 (2016) 603–611