Working memory training decreases hippocampal neurogenesis

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Behavioral Neuroscience

Background:

• Adult hippocampal neurogenesis is linked to cognition, but its regulation by learning is complex.
• Early studies suggested a straightforward relationship, but recent findings indicate a more nuanced interaction.

Purpose of the Study:

• To investigate how the duration and task demands of spatial memory training impact adult hippocampal neurogenesis.
• To determine if prolonged working memory training affects neurogenesis differently than reference memory training or shorter durations.

Main Methods:

• Adult male rats were trained in the Morris water maze using either reference memory (4 days) or working memory (4 or 14 days) paradigms.
• Neurogenesis was assessed by counting newborn hippocampal neurons.
• Circulating corticosterone levels were measured to assess stress responses.

Main Results:

• Four days of spatial training (reference or working memory) did not alter hippocampal neurogenesis.
• Two weeks of working memory training significantly reduced the number of newborn hippocampal neurons compared to controls.
• Maze training, especially working memory tasks, elevated corticosterone levels, suggesting increased stress.

Conclusions:

• Prolonged spatial working memory training reduces adult hippocampal neurogenesis in rats.
• This reduction may be partly mediated by stress-induced elevations in corticosterone.
• The duration and type of spatial memory task are critical factors influencing hippocampal neurogenesis.