GSK3? Hyperactivity during an Early Critical Period Impairs Prefrontal Synaptic Plasticity and Induces Lasting Deficits in Spine Morphology and Working Memory.

ABSTRACT: Schizophrenia (SZ) is a neurodevelopmental disorder in which the emergence of cognitive symptoms occurs during early adolescence. Glycogen synthase kinase-3? (GSK3?) plays a critical role in synaptic plasticity during development and is highly implicated in the etiology of SZ. However, how GSK3? activity affects synaptic plasticity and working memory function in the prefrontal cortex (PFC) during development remains unknown. Here we show a GSK3? hyperactivity during the early postnatal period in a neurodevelopmental rat SZ model that receives gestational exposure (E17) to the neurotoxin methylazoxymethanol (MAM). Accompanied with this change, adult MAM rats exhibited a significant decrease in spine density as well as impaired working memory, which was rescued by treatment with a GSK3? inhibitor during the juvenile period. Furthermore, the age-dependent hyperactive GSK3? caused a significant deficit in long-term potentiation (LTP) and facilitated long-term depression (LTD) in PFC pyramidal neurons. Notably, these changes in synaptic plasticity occurred only during the late juvenile period and were efficiently reversed by application of GSK3? inhibitors. Because the balance of LTP and LTD plays a critical role in activity-dependent synaptic stabilization and elimination during cortical development, the transient hyperactive GSK3? likely accounts for the cortical spine loss and PFC-dependent cognitive deficits in adulthood. These results highlight the importance of the postnatal trajectory of GSK3? for spine development and PFC function, and may shed light on the prophylactic treatment of cognitive symptoms in the SZ.

SUBMITTER: Xing B 

PROVIDER: S-EPMC5101547 | biostudies-other | 2016 Dec

REPOSITORIES: biostudies-other