One trial conditioning with apomorphine is blocked by cycloheximide

Area of Science:

• Neuroscience
• Pharmacology
• Behavioral Science

Background:

• Unilateral 6-hydroxydopamine lesions in rats create an animal model for Parkinson's disease, inducing circling behavior.
• Apomorphine is a dopamine agonist used to study motor control and behavioral responses in lesioned animals.
• Protein synthesis is crucial for long-term memory consolidation.

Purpose of the Study:

• To investigate the role of protein synthesis in the formation of long-term memory for conditioned rotation.
• To determine if cycloheximide, a protein synthesis inhibitor, affects the consolidation of learned motor behaviors.

Main Methods:

• Rats with unilateral substantia nigra lesions were administered apomorphine to induce circling behavior.
• Cycloheximide or saline was administered after apomorphine to assess its effect on memory formation.
• Conditioned rotation behavior was tested after a two-week period and again after a second apomorphine administration.

Main Results:

• Animals treated with cycloheximide did not exhibit conditioned rotation two weeks after the initial treatment.
• Control animals (saline-treated) showed significant conditioned rotation.
• Both groups displayed conditioned rotation after a second apomorphine administration, indicating memory recovery.

Conclusions:

• Protein synthesis is essential for the long-term consolidation of conditioned motor behaviors.
• Inhibition of protein synthesis by cycloheximide temporarily disrupts memory formation for learned behaviors.
• The findings highlight the dynamic nature of memory consolidation and potential for recovery.