Striatal transcriptome changes linked to drug-induced repetitive behaviors

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• Stereotypies, or repetitive motor patterns, are key symptoms in neuropsychiatric disorders and can be induced by psychomotor stimulants like amphetamine.
• Striatal plasticity and reinforcement-related circuits are implicated in the development of stereotypies.
• Understanding the molecular basis of drug-induced stereotypies may offer insights into shared phenotypes with neuropsychiatric conditions.

Purpose of the Study:

• To identify transcriptomic changes in the striatum associated with the development of amphetamine-induced stereotypic behavior in mice.
• To investigate the role of specific signaling pathways, such as extracellular signal-regulated kinase (ERK) cascades and neuregulin 1 (Nrg1), in drug-induced stereotypies.

Main Methods:

• Mice were subjected to different amphetamine treatment schedules to induce varying degrees of stereotypy.
• Bulk RNA sequencing (RNAseq) was used to compare striatal gene expression between drug-treated and control groups.
• Gene set enrichment analysis was performed to identify enriched biological pathways and gene sets.

Main Results:

• Amphetamine treatment altered the expression of genes in extracellular signal-regulated kinase (ERK) cascades across all treated groups.
• A subset of 20 genes, significantly dysregulated in the sensitized group with prolonged stereotypy, showed high overlap with genes regulated by neuregulin 1 (Nrg1).
• Neuregulin 1 (Nrg1) is a known susceptibility gene for schizophrenia and autism, involved in neuronal development and survival.

Conclusions:

• Drug-induced sensitization of the Nrg1 signaling pathway in the striatum may underlie the shared behavioral stereotypy phenotypes between stimulant abuse and neuropsychiatric disorders like schizophrenia and autism.
• These findings highlight a potential molecular link between stimulant-induced behaviors and the pathophysiology of certain neuropsychiatric conditions.