Genetic ablation of the mammillary bodies in the Foxb1 mutant mouse leads to selective deficit of spatial working memory.
Mammillary bodies and the mammillothalamic tract are parts of a classic neural circuitry that has been implicated in severe memory disturbances accompanying Korsakoff's syndrome. However, the specific role of mammillary bodies in memory functions remains controversial, often being considered as just an extension of the hippocampal memory system. To study this issue we used mutant mice with a targeted mutation in the transcription factor gene Foxb1. These mice suffer perinatal degeneration of the medial and most of the lateral mammillary nuclei, as well as of the mammillothalamic bundle. Foxb1 mutant mice showed no deficits in such hippocampal-dependent tasks as contextual fear conditioning and social transmission of food preference. They were also not impaired in the spatial reference memory test in the radial arm maze. However, Foxb1 mutants showed deficits in the task for spatial navigation within the Barnes maze. Furthermore, they showed impairments in spatial working memory tasks such as the spontaneous alternation and the working memory test in the radial arm maze. Thus, our behavioural analysis of Foxb1 mutants suggests that the medial mammillary nuclei and mammillothalamic tract play a role in a specific subset of spatial tasks, which require combined use of both spatial and working memory functions. Therefore, the mammillary bodies and the mammillothalamic tract may form an important route through which the working memory circuitry receives spatial information from the hippocampus.
Radyushkin
Konstantin
K
Max-Plank Institute of Biophysical Chemistry, Department of Molecular Cell Biology, Am Fassberg 11, Göttingen 37077, Germany.
Anokhin
Konstantin
K
Meyer
Barbara I
BI
Jiang
Qiuhong
Q
Alvarez-Bolado
Gonzalo
G
Gruss
Peter
P
D000818:Animals; D001522:Behavior, Animal; D003214:Conditioning, Classical / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D003463:Cues; D004268:DNA-Binding Proteins / Q000172:deficiency* / Q000235:genetics; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D051858:Forkhead Transcription Factors; D008297:Male; D008326:Mammillary Bodies / Q000033:anatomy & histology / Q000502:physiology*; D018782:Maze Learning / Q000502:physiology; D008569:Memory Disorders / Q000235:genetics*; D008570:Memory, Short-Term / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout / Q000502:physiology*; D012919:Social Behavior; D013037:Spatial Behavior / Q000502:physiology; D014157:Transcription Factors / Q000172:deficiency* / Q000235:genetics
D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; C491332:Foxb1 protein, mouse; D014157:Transcription Factors