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Cocaine and the AP-1 transcription factor complex
1Molecular Plasticity Section (MPS), National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland 20892-4135, USA. hope@codon.nih.gov
Annals of the New York Academy of Sciences
|July 21, 1998
Summary
Repeated cocaine use alters gene expression in the brain, leading to persistent neuroplasticity. Chronic Fos-related antigens (Fras) replace normal Fos proteins, potentially blocking gene transcription and maintaining addiction long-term.
Area of Science:
- Neuroscience
- Molecular Biology
- Addiction Research
Background:
- Cocaine addiction persists long after drug clearance, indicating lasting neuroplasticity.
- The underlying mechanisms of persistent cocaine-induced neuroplasticity remain largely unknown.
- Altered gene expression and brain signaling are implicated in the long-term effects of cocaine.
Purpose of the Study:
- To investigate the molecular mechanisms of persistent neuroplasticity in cocaine addiction.
- To examine the role of immediate early genes (IEGs) and Fos-related proteins in the brain.
- To test the hypothesis that chronic Fos-related antigens (Fras) disrupt gene transcription.
Main Methods:
- Administered repeated cocaine doses to rats.
- Assessed the induction of immediate early genes (IEGs) after acute cocaine challenge.
- Identified and characterized novel delta FosB-related proteins (Fras) in rat brain.
- Purified Fras for amino acid sequencing.
Main Results:
- Repeated cocaine administration downregulated IEG induction by acute cocaine.
- Novel, persistent Fras were induced in the striatum and nucleus accumbens, replacing downregulated Fos isoforms.
- These Fras persist long after cocaine administration.
Conclusions:
- Persistent cocaine addiction may involve altered gene expression mediated by Fras.
- Fras might block AP-1-dependent transcription due to structural similarities with delta FosB.
- Further research is needed to confirm the functional impact of Fras on gene expression and addiction.