Learning efficiency: The influence of cue salience during spatial navigation

Behavioural Brain Research

2016

Self Cite

The objective of this study was to examine the effects of NMDAR and AMPAR antagonism on the expression of Zif268 and c-Fos in the hippocampus and medial prefrontal cortex during spatial memory encoding in rats trained in the Morris water maze. NMDAR inhibition impaired navigation and significantly attenuated expression of Zif268, but not c-Fos, in area CA1. AMPAR channel blockade had little effect on learning or IEG expression. Overall, Zif268 and c-Fos displayed markedly different patterns of hippocampal and prefrontal expression, with Zif268 being more closely linked to spatial learning.

mentioning

confidence: 99%

Differential expression of immediate early genes Zif268 and c-Fos in the hippocampus and prefrontal cortex following spatial learning and glutamate receptor antagonism

Farina

Behavioural Brain Research

2016

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“…Animals can employ a range of navigational strategies to reach a goal, from simple stimulus–response associations, such as approaching a prominent beacon, to the use of more complex representations based on spatial relationships between available cues in the environment (Farina et al., 2015; Rodrigo, 2002; Whitlock, Sutherland, Witter, Moser, & Moser, 2008). Evidence from existing literature strongly indicates that response and place strategies are supported by distinct neural substrates.…”

Section: Introductionmentioning

confidence: 99%

Hippocampal and prefrontal contributions to memory retrieval: Examination of immediate early gene, NMDA receptor and environmental interactions

Farina

2020

Eur J of Neuroscience

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Animals can use a range of strategies to recall important locations. These include simple stimulus–response strategies and more complex spatial (place) strategies, which are thought to have distinct neural substrates. The hippocampus—and NMDA receptor activation therein—is considered to be crucial for spatial, but not response strategies. The medial prefrontal cortex has also been implicated in memory retrieval; however, evidence concerning its specific role is equivocal. Both hippocampal and prefrontal regions have been associated with flexible behavioural responding (e.g. when task demands change). Here, we investigated the use of spatial and non‐spatial strategies in the Morris water maze and their associated brain areas in rats using immediate early gene (IEG) imaging of Zif268 and c‐Fos. Specifically, we charted the involvement of hippocampal and prefrontal subregions during retrieval of spatial and non‐spatial memories. Behavioural flexibility was also examined using intact and partial cue configurations during recall. Results indicated that regions of both the hippocampus (area CA3) and prefrontal cortex (anterior cingulate cortex) were preferentially engaged in spatial memory recall compared to response learning. In addition, both spatial and non‐spatial memories were dependent on NMDA receptor activation. MK801 impaired recall performance across all groups and reduced IEG activation across hippocampal and prefrontal regions. Finally, IEG results revealed divergent patterns of Zif268 and c‐Fos activity and support the suggestion that Zif268 plays a functional role in the recall of long‐term memories.

“…13 demonstrated poor water maze performance using a small cue located further away from a goal but good learning with a near, big landmark. Indeed, cues that are located close to the goal gain more control over an animal’s performance compared to cues located further away 14,15 (although see 16 ). A recent operant model of spatial learning 2 , based on the general associative model of Rescorla and Wagner 17 , allows participants to learn about multiple cues when they encounter success or failure at a given location.…”

Section: Introductionmentioning

confidence: 99%

“…During learning, some features, including independent distance and directional components, may be used while others not. Indeed, evidence for separate distance and directional components has been observed with bees 19 , pigeons 20 , Clark’s nutcrackers 21–23 and rats 9,16 . Here we present an associative model of landmark learning, based on Rescorla & Wagner 17 , and combine this with an autoregressive random walk model of goal-directed swimming behavior 24 .…”

Section: Introductionmentioning

confidence: 99%

Understanding the role of distance, direction and cue salience in an associative model of landmark learning

Fey

2019

Sci Rep

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Navigation and spatial memory relies on the ability to use and recall environmental landmarks relative to important locations. Such learning is thought to result from the strengthening of associations between the goal location and environmental cues. Factors that contribute to the strength of this association include cue stability, saliency and cue location. Here we combine an autoregressive random walk model, that describes goal-directed swimming behaviour, with an associative learning model to provide an integrated model of landmark learning, using the water maze task. The model allows for the contribution of each cue, the salience and the vector information provided (both distance and directional) to be separately analysed. The model suggests that direction and distance information are independent components and can influence searching patterns. Importantly, the model can also be used to simulate various experimental scenarios to understand what has been learnt in relation to the cues, thereby offering new insights into how animals navigate.