title: The effects of selective lesions within the anterior thalamic nuclei on spatial memory in the rat.
abstract: Groups of rats received cytotoxic lesions centred in either the anterior thalamic nucleus (AM), the anterior ventral and anterior dorsal thalamic nuclei (AV/AD), or all three nuclei combined (ANT.T). These lesions were made by injecting N-methyl-D-aspartate acid (NMDA). These rats, and a group of surgical controls (SHAM), were trained on a rewarded forced-alternation task in a T-maze. While the selective AM and AV/AD lesions produced an initial acquisition impairment, only the animals with combined lesions (ANT.T) showed a persistent deficit throughout the 16 acquisition sessions. Subsequent testing with a cross-maze confirmed that the SHAM, AV/AD, and AM groups were able to use allocentric cues, while the ANT.T group were impaired. In contrast none of the three anterior groups were impaired on a subsequent egocentric discrimination and reversal task run in the same apparatus. A final test using the eight arm radial-maze, revealed marked deficits in the ANT.T group as well as milder deficits in the AV/AD group. The results from these experiments help to confirm the importance of the anterior thalamic nuclei for allocentric tasks, but suggest that no region is pre-eminently important. The findings also help to account for other studies which have reported that anterior thalamic lesions have seemingly mild effects on tests of spatial memory.
authors.affiliation: School of Psychology, University of Wales, College of Cardiff, UK. aggleton@cardiff.ac.uk
authors.forename: J P
authors.initials: JP
authors.lastname: Aggleton
authors.forename: P R
authors.initials: PR
authors.lastname: Hunt
authors.forename: S
authors.initials: S
authors.lastname: Nagle
authors.forename: N
authors.initials: N
authors.lastname: Neave
mesh_terms: D000818:Animals; D004193:Discrimination Learning / Q000502:physiology; D008297:Male; D008326:Mammillary Bodies / Q000033:anatomy & histology / Q000502:physiology; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D051381:Rats; D013028:Space Perception / Q000502:physiology*; D013787:Thalamic Nuclei / Q000033:anatomy & histology / Q000502:physiology*