What resolves this contention: {'position': 'PNNs primarily close plasticity by…

What resolves this contention: {'position': 'PNNs primarily close plasticity by physically stabilizing PV synapses', 'evidence_description': 'ChABC restores OD plasticity; PNN formation correlates with critical period closure; structural stabilization of perisomatic synapses'} / {'position': 'PNNs close plasticity primarily through Otx2 accumulation in PV cells', 'evidence_description': 'Otx2 binds PNN sugars and accumulates in PV neurons; blocking Otx2-PNN interaction reopens plasticity; Otx2 conditional knockout prevents critical period closure'}