PERINATAL METHADONE ADDICTION AFFECTS BRAIN SYNAPTIC DEVELOPMENT OF BIOGENIC-AMINE SYSTEMS IN THE RAT

Administration of methodone to pregnant and nursing rats or direct treatment of developing pups with methadone resulted in deficits of development of body weight, brain weight and synaptosomal uptake of 5-hydroxytryptamine, dopamine and norepinephrine. Defective synaptic development was most apparent immediately after birth in pups whose mothers received methadone; while some recovery occurred by 3 weeks of age, there was a subsequent deficit in synaptosomal uptake post-weaning. A similar pattern also was seen in development of synaptic vesicle amine uptake. Direct treatment of neonates with methadone also caused reductions in development of synaptosomal and vesicular uptake mechanisms, but the patterns of alteration were different from those in the maternal treatment group. These studies show that the adverse effect of opiates on general brain growth are accompanied by a slowing of synaptic development of biogenic amine systems. © 1979.