Article

Previous work demonstrates that spatial (explicit) and nonspatial (implicit)
elements of place learning in the Morris water maze (MWM) task can be dissociated
and examined in the context of experimental traumatic brain injury (TBI).
Providing nonspatial cognitive training (CT) after injury can improve place
learning compared with untrained controls. In the present study, we hypothesized
that brief exposure to extra-maze cues, in conjunction with CT, may further
improve MWM performance and extra-maze cue utilization compared with CT alone.
Adult male Sprague-Dawley rats (n = 66) received controlled cortical impact (CCI)
injury or sham surgery. Beginning day 8 postsurgery, CCI and sham rats received 6
days of no training (NT) or CT with/without brief, noncontextualized exposure to
extra-maze cues (BE and CT, respectively). Acquisition (days 14-18), visible
platform (VP; day 19), carryover (CO; days 20-26), and periodic probe trials were
performed. Platform latencies, peripheral and target zone time allocation, and
search strategies were assessed. CCI/BE rats had shorter acquisition trial
latencies than CCI/NT (P < .001) and tended to have shorter latencies than CCI/CT
rats (P < .10). Both BE and CT reduced peripheral zone swimming for CCI rats
versus CCI/NT. CCI/BE animals increased spatial swim strategies from day 14 to
day 18 relative to CCI/CT and showed similar swim strategy selection to the
Sham/NT group. These data suggest that visual priming improves initial place
learning in the MWM. These results support the visual priming response as another
clinically relevant experimental rehabilitation construct, to use when assessing
injury and treatment effects of behavioral and pharmacological therapies on cognition after TBI.
CI - (c) The Author(s) 2015.

Langue : ANGLAIS