The NMDA receptor partial agonist d-cycloserine does not enhance motor learning

Area of Science:

• Neuroscience
• Psychopharmacology
• Cognitive Psychology

Background:

• Increasing interest in pharmacological agents to augment exposure-based cognitive behavioural therapy (CBT) for anxiety disorders.
• D-cycloserine, a partial NMDA agonist, is hypothesized to enhance CBT by accelerating learning.
• Existing human study evidence on d-cycloserine's learning enhancement effects is inconsistent.

Purpose of the Study:

• To investigate the effects of d-cycloserine on human motor learning.
• To determine if d-cycloserine accelerates the learning process in a motor sequence task.

Main Methods:

• A double-blind, placebo-controlled study involving 54 healthy volunteers.
• Random assignment to a single 250mg dose of d-cycloserine or a placebo.
• Performance evaluation using a standardized motor sequence learning task.

Main Results:

• D-cycloserine did not significantly enhance the speed of motor learning.
• No improvement was observed in the overall amount of motor learning.
• Participants receiving d-cycloserine exhibited a trend towards more careful responses, characterized by slower but more accurate movements.

Conclusions:

• D-cycloserine does not appear to benefit psychological treatments through mechanisms related to motor learning.
• Further research is required to explore the influence of d-cycloserine on other cognitive mechanisms relevant to therapy enhancement.