Summary
Working memory is a fundamental cognitive ability, allowing us to keep information in memory for the time needed to perform a given task. A complex neural circuit fulfills these functions, among which is the anterior cingulate cortex (CG). Functionally and anatomically connected to the medial prefrontal, retrosplenial, midcingulate and hippocampus, as well as motor cortices, CG has been implicated in retrieving appropriate information when needed to select and control appropriate behavior. The role of cingulate cortex in working memory-guided behaviors remains unclear due to the lack of studies reversibly interfering with its activity during specific epochs of working memory. We used light to activate eNpHR3.0 and thus silence cingulate neurons while animals perform a standard delayed non-match to trajectory task. We found that, while not causing an impairment in eNpHR3.0+ animals when compared to eNpHR3.0-CTRL animals, silencing cingulate neurons during retrieval decreases the mean performance if compared to silencing during encoding. Such retrieval-associated changes are accompanied by longer delays in control animals, consistent with an adaptive recruitment of additional cognitive resources.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
We do not see a performance diference between eNpHR3.0+ and CTRL groups, only performance diferences within the former group depending on when light is delivered, and equivalent differences in the dynamic of behaviour. As such, rather than evidence of an absolute impairment in performance, we now see this as suggesting an interference with more subtle aspects of the neural mechanisms supporting memory-based decision, warranting further studies rather than an explicit conclusion. For this reason, we changed our title, abstract, main conclusions, and discussion to reflect this different view. The same principle applies to the latency observations.
