Hyperactive mTORC1 in striatum dysregulates dopamine receptor expression and odor preference behavior.

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• The mechanistic target of rapamycin (mTOR) pathway is crucial for brain development and synaptic plasticity.
• Dysregulation of mTOR is implicated in central nervous system diseases like autism spectrum disorder (ASD) and neurodegenerative disorders.
• Previous research primarily focused on mTOR's effects on excitatory neurons, with limited investigation into inhibitory neurons.

Purpose of the Study:

• To investigate the role of mTOR complex 1 (mTORC1) signaling in the development and function of striatal inhibitory neurons.
• To determine the behavioral consequences of hyperactivating mTORC1 specifically in inhibitory neurons of the striatum.

Main Methods:

• Generation of transgenic mice with hyperactivated mTORC1 signaling exclusively in striatal inhibitory neurons.
• Analysis of neuronal populations, dopamine receptor expression (D1 and D2), and behavioral assessments (motor learning, olfactory preference).

Main Results:

• Hyperactivation of mTORC1 in striatal inhibitory neurons led to an increase in GABAergic inhibitory neurons.
• Transgenic mice showed altered dopamine receptor D1 and D2 expression in ventral striatal medium spiny neurons.
• Impaired motor learning and dysregulated olfactory preference behavior were observed, despite preserved basic olfaction.

Conclusions:

• mTORC1 signaling is essential for the development and function of striatal inhibitory neurons.
• Hyperactivation of mTORC1 in these neurons contributes to motor and sensory behavioral deficits.
• These findings highlight the mTORC1 pathway's involvement in neurodevelopmental and neurodegenerative conditions affecting motor and sensory functions.