Introduction: Neurogenetic events (proliferation, migration, molecular specification, neural aggregation, dendritic differentiation, axonal growth, synaptogenesis and cell death) occur in transient cerebral compartments (ventricular zone -VZ, subventricular zone -SVZ, intermediate zone -IZ, subplate -SP, cortical plate -CP, marginal zone –MZ). In this study we analyzed general patterns of vascularisation in relation to the development of cellular compartments in the human fetal cerebrum.
Methods: Histological sections from fetal brains (http://www.zagrebbraincollection.hr/) ranging from 7,5 PCW until 36 PCW were processed with Stensas modification of Rio del Hortega method, GFAP and vimentin immunohistochemistry.
Results: In the earliest specimen examined blood vessels were present in all existing zones (VZ, SVZ and preplate). After the formation of CP, deep network (VZ, SVZ) shows mesh-like pattern, while cell dense CP shows predominant radial pattern. Parallel with formation of SP, new intermediate network is formed. During mid gestation the cerebral wall shows typical lamination (VZ, SVZ, IZ, SP, CP, MZ). Vascular network in VZ is composed from venula type vessels with big diameter of mesh units. Deep SP zone exhibited radially oriented large vessels with evenly spaced side branches. Superficial SP shows plexiform mesh like pattern similar as deep CP, while radially oriented vessels characterize superficial CP and MZ. After 34 weeks, there is gradual transformation of SP vascularization and diminishment of the ventricular network parallel with thinning of VZ and SVZ.
Conclusions: Characteristic laminar patterns of vascular network are present in the cerebral wall from embryonic to the end of fetal period. We propose that the process of change of transient vascular patterns is accompanied with transformation of radial glia, astrogliogenesis, diminishment of the amount of extracellular matrix as well as changes in axonal and dendritic growth. Identifying spatio-temporal patterns of angiogenesis in telencephalon could shed a new light on pathophysiology of vascular malformations in the brain.
Patient Care: Identifying spatio-temporal patterns of angiogenesis could shed a new light on pathophysiology of vascular malformations in the brain.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe cerebral angiogenesis 2) Discuss, in small groups about angiogenesis patterns and it's connection to pathophysiology of vascular malformations, 3) Identify possible abnormal patterns that could lead to vascular malformation