Endogenous opioids and brain development

Several reports have recently shown that molecules such as gangliosldes are capable to affect neuronal development by enhancing neuritogenesis and axonal sprouting in vivo and in vitro. We have tested the activity of such molecules on neuronal plasticity during CNS development by treating with GM1 (monosialoganglioside) monocularly deprived kittens and newborn rats injected at birth with either 5,7-HT or 6-ORDA. The data obtained after neurotoxic lesion Indicate that GM1 strongly protect neurons from retrograde degeneration allowing a fast regrowth of the degenerated distal axonal portion in the cortex and spinal cord. In the developing visual system GM1 treatment weakens the effect of monocular deprivation both in primary visual cortex, reducing the shift of the ocular dominance distribution, and in the Lateral Geniculate Nucleus, ensuring a normal development of identified relay neurons. Karpiak et al. have recently shown that GM1 enhances learning in newborn animals. These data indicate that Q41 modulate neuronal plasticity at various level of complexity in newborn animals.