Cocaine-induced hyperactivity and sensitization are dependent on GSK3

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Glycogen synthase kinase 3 (GSK3) is a key regulator of intracellular signaling pathways.
• GSK3 activity is modulated by phosphorylation at specific inhibitory serine residues.
• Understanding GSK3's role in drug addiction is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the effect of acute cocaine administration on GSK3 activity in mice.
• To determine if inhibiting GSK3 can attenuate cocaine-induced behavioral responses.
• To assess the impact of GSK3 inhibition on the development of cocaine sensitization.

Main Methods:

• Mice were administered cocaine (20 mg/kg, i.p.) and GSK3 activity was assessed via phosphorylation levels in the caudate putamen.
• Mice were pretreated with valproate or SB 216763 before cocaine administration to evaluate behavioral effects.
• The development of behavioral sensitization was assessed in mice pretreated with SB 216763 and subjected to repeated cocaine dosing.

Main Results:

• Cocaine administration reduced GSK3beta phosphorylation in the caudate putamen, indicating increased GSK3 activity.
• Pretreatment with valproate or SB 216763 dose-dependently reduced cocaine-induced hyperactivity and stereotypic behaviors.
• SB 216763 pretreatment significantly attenuated the development of cocaine-induced behavioral sensitization.

Conclusions:

• Cocaine exposure activates GSK3beta in the mouse caudate putamen.
• Pharmacological inhibition of GSK3 effectively reduces acute cocaine-induced behaviors.
• GSK3 plays a significant role in both the immediate and long-term behavioral effects of cocaine, suggesting it as a potential therapeutic target.