Prefrontal cortex and working memory for spatial response, spatial location, and visual object information in the rat

Area of Science:

• Neuroscience
• Cognitive Psychology
• Animal Behavior

Background:

• Working memory is essential for cognitive functions.
• The medial prefrontal cortex (MPF) is implicated in various cognitive tasks.
• Understanding the specific roles of MPF subregions in working memory is crucial.

Purpose of the Study:

• To investigate the role of the medial prefrontal cortex (MPF) in different types of working memory.
• To determine if specific subregions of the MPF mediate distinct attribute information.
• To compare the effects of MPF lesions with hippocampal lesions on working memory.

Main Methods:

• Rats were trained on three distinct working memory tasks: spatial response, spatial location, and visual object discrimination.
• Lesions were made to the medial prefrontal cortex (MPF), dorsal hippocampus, and specific MPF subregions (prelimbic and infralimbic cortex).
• Performance on delayed matching-to-sample and delayed nonmatching-to-sample procedures was assessed.

Main Results:

• MPF lesions caused profound deficits in spatial response working memory but only mild deficits in spatial location and no deficits in visual object working memory.
• Dorsal hippocampal lesions resulted in profound spatial location working memory deficits.
• Lesions of the prelimbic and infralimbic cortex (MPF subregions) caused profound visual object working memory deficits.

Conclusions:

• Different neural subregions within the medial prefrontal cortex (MPF) are specialized for processing distinct types of working memory information.
• The MPF plays a critical role in spatial response and, to a lesser extent, spatial location working memory.
• The prelimbic and infralimbic cortex are essential for visual object working memory.