title: Midline thalamic reuniens lesions improve executive behaviors.
abstract: The role of the thalamus in complex cognitive behavior is a topic of increasing interest. Here we demonstrate that lesions of the nucleus reuniens (NRe), a midline thalamic nucleus interconnected with both hippocampal and prefrontal circuitry, lead to enhancement of executive behaviors typically associated with the prefrontal cortex. Rats were tested on four behavioral tasks: (1) the combined attention-memory (CAM) task, which simultaneously assessed attention to a visual target and memory for that target over a variable delay; (2) spatial memory using a radial arm maze, (3) discrimination and reversal learning using a touchscreen operant platform, and (4) decision-making with delayed outcomes. Following NRe lesions, the animals became more efficient in their performance, responding with shorter reaction times but also less impulsively than controls. This change, combined with a decrease in perseverative responses, led to focused attention in the CAM task and accelerated learning in the visual discrimination task. There were no observed changes in tasks involving either spatial memory or value-based decision making. These data complement ongoing efforts to understand the role of midline thalamic structures in human cognition, including the development of thalamic stimulation as a therapeutic strategy for acquired cognitive disabilities (Schiff, 2008; Mair et al., 2011), and point to the NRe as a potential target for clinical intervention.
authors: Department of Psychology, McGill University, Montreal, QC, H3A 1B1, Canada.
authors: J A
authors: JA
authors: Prasad
authors: Department of Psychology, McGill University, Montreal, QC, H3A 1B1, Canada.
authors: A R
authors: AR
authors: Abela
authors: Department of Psychology, McGill University, Montreal, QC, H3A 1B1, Canada. Electronic address: yogita.chudasama@nih.gov.
authors: Y
authors: Y
authors: Chudasama
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology; D001288:Attention / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D056344:Executive Function / Q000502:physiology*; D007175:Impulsive Behavior / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D020644:Midline Thalamic Nuclei / Q000187:drug effects / Q000503:physiopathology*; D023421:Models, Animal; D016202:N-Methylaspartate / Q000633:toxicity; D009483:Neuropsychological Tests; D020318:Rats, Long-Evans; D011930:Reaction Time; D012193:Reversal Learning / Q000502:physiology; D012201:Reward; D065852:Spatial Memory / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
chemical_list: D016202:N-Methylaspartate
keywords: arousal; cognition; hippocampus; prefrontal; thalamocortical