A time-dependent effect of caffeine upon lesion-induced plasticity

► Retinal lesions induce axonal sprouting of intact axons within superior colliculus. ► Caffeine treatment has opposite effects depending on the developmental time window. ► This drug may interfere with natural plasticity during brain development. ► Caffeine emerges as a facilitatory agent for neuronal plasticity in adulthood. During a critical period, unilateral retinal lesions induce rapid axonal sprouting of intact axons into denervated territories within the collicular visual layers. We investigated the effect of caffeine, a non-selective A 1 and A 2a antagonist, upon the lesion-induced plasticity of retinotectal axons. Pigmented rats submitted to a temporal retinal lesion received either caffeine (30 mg/kg, ip) or saline treatment. The anterograde tracing revealed that caffeine treatment during the critical period resulted in a clear reduction on the sprouting of ipsilateral fibers but to an amplification of the plasticity after PND21, thus revealing opposite effects depending on the developmental time window.