The angioarchitecture of the superficial and basal arterial system of the hypoplastic rat brain caused by the administration of the neurotoxin, methylazoxymethanol acetate (MAMAc), at the time of neuroblast migration was studied. Increased variation of the arterial branching of the basal main stem of arteries and local vessel changes were observed. The findings suggest a close relationship between vascular and neuronal development, showing a generalized disturbance and local adaptation of vasculature to the altered neuronal architecture of the corresponding hypoplastic areas.