Does the mutant mouse lurcher have deficits in spatially oriented behaviours?

Area of Science:

• Neuroscience
• Behavioral Genetics

Background:

• Lurcher mutant mice are a model organism used to study cerebellar development and function.
• Previous research suggests cerebellar dysfunction can impact spatial learning and memory.

Purpose of the Study:

• To investigate the spatial learning and memory capabilities of Lurcher mutant mice.
• To assess the impact of Lurcher mutation on different types of spatial tasks, including those involving water and T-mazes.

Main Methods:

• Morris milk tank test to assess spatial learning.
• Water-maze spatial alternation task to evaluate memory and navigation.
• T-maze tasks (swimming and food-rewarded) to assess learning and goal-directed behavior.
• Assessment of motor coordination.

Main Results:

• Lurcher mice demonstrated directional deficits in the Morris milk tank and water-maze alternation tasks.
• They showed impaired spontaneous alternation and difficulty alternating with increased inter-trial intervals.
• Lurcher mice learned T-maze swimming escape tasks slower, despite intact motor coordination.
• Paradoxically, no deficit was observed in a food-rewarded T-maze task, even with ataxic locomotion.

Conclusions:

• Lurcher mutants exhibit specific deficits in spatial orientation and navigation, particularly in aquatic environments.
• The mutation affects the ability to guide locomotion toward visible goals in water.
• Motor coordination does not fully explain the observed spatial learning and memory impairments.