Neural Progenitor Cells Rptor Ablation Impairs Development but Benefits to Seizure-Induced Behavioral Abnormalities

Area of Science:

• Neuroscience
• Molecular Biology
• Epilepsy Research

Background:

• The mammalian target of rapamycin (mTOR) signaling pathway is implicated in epileptogenesis.
• Raptor is a key component of the mTOR Complex 1 (mTORC1) signaling pathway.
• The specific role of raptor protein in epilepsy and its associated comorbidities requires further investigation.

Purpose of the Study:

• To investigate the contribution of raptor protein to the development of epilepsy.
• To explore the role of raptor protein in epilepsy-related comorbidities.
• To analyze the impact of raptor deletion on mTORC1 signaling in the context of epilepsy.

Main Methods:

• Generated mice with conditional knockout of raptor protein (Rptor CKO) using Rptor^flox/flox and nestin-CRE mice.
• Analyzed raptor protein expression via Western blotting.
• Assessed neuronal death (FJB staining), mossy fiber sprouting (Timm staining), spontaneous seizures (EEG-video), and behavioral changes (Morris water maze, open field test).

Main Results:

• Rptor deletion partially blocked downstream mTORC1 signaling and led to decreased body/brain weight and cortical thickness in young mice.
• In Rptor CKO mice, kainic acid (KA)-induced mTORC1 overactivation was reversed, and mossy fiber sprouting was attenuated.
• KA seizure-induced cognitive deficits and anxiety-like behaviors were partly reversed in Rptor CKO mice, despite similar spontaneous seizure frequency and neuronal death compared to controls.

Conclusions:

• Loss of the Rptor gene in neural progenitor cells impacts early development but alleviates certain behavioral abnormalities post-seizure.
• Raptor protein plays a significant role in modulating epilepsy-associated comorbidities.
• Targeting raptor-mediated mTORC1 signaling may offer therapeutic potential for epilepsy comorbidities.