G. Byatt et Jc. Dalrymplealford, BOTH ANTEROMEDIAL AND ANTEROVENTRAL THALAMIC LESIONS IMPAIR RADIAL-MAZE LEARNING IN RATS, Behavioral neuroscience, 110(6), 1996, pp. 1335-1348
Disruption to the anterior thalamus (AT) may be an important factor in
diencephalic amnesia. Rats with small lesions of the anteromedial (AM
) or anteroventral (AV) nucleus showed persistent working-memory and r
eference-memory deficits in a 12-arm radial maze, although they were c
omparable to controls during the early part of training. The only acti
vity difference in the maze was that lesioned rats failed to run more
slowly when revisiting a baited arm. For all groups, both working and
reference memory were impaired after extramaze cues were removed; remo
val of intramaze cues further impaired performance relative to the ori
ginal conditions. These findings suggest the AT makes a distinct contr
ibution to mnemonic functions, probably as part of an integrated syste
m involving limbic cortex and the hippocampal formation, and that AT l
esions produce a general rather than a specific deficit in spatial or
working memory.