Mesencephalic representations of recent experience influence decision making

Abstract

Decisions are influenced by recent experience, but the neural basis for this phenomenon is not well understood. Here, we address this question in the context of action selection. We focused on activity in the pedunculopontine tegmental nucleus (PPTg), a mesencephalic region that provides input to several nuclei in the action selection network, in well-trained mice selecting actions based on sensory cues and recent trial history. We found that, at the time of action selection, the activity of many PPTg neurons reflected the action on the previous trial and its outcome, and the strength of this activity predicted the upcoming choice. Further, inactivating the PPTg predictably decreased the influence of recent experience on action selection. These findings suggest that PPTg input to downstream motor regions, where it can be integrated with other relevant information, provides a simple mechanism for incorporating recent experience into the computations underlying action selection.DOI: http://dx.doi.org/10.7554/eLife.16572.001

The Cellular Diversity of the Pedunculopontine Nucleus: Relevance to Behavior in Health and Aspects of Parkinson’s Disease

“…Later work from the same group (Redila and others 2015) showed that neurons in the LDT were also responsive to movement and reward but were less influenced by current sensory input. Similarly, Thompson and others (2016) showed that PPN neuronal activity related to decision making. In particular, at the point of action selection, mouse PPN neuronal activity related to the previous choice and its outcome, with the strength of this response that predicted the next decision.…”

Control of adaptive action selection by secondary motor cortex during flexible visual categorization

“…In flexible sound categorization task, the performance of rodents could be accounted for by a distance-to-boundary model, in which the animal compared the current stimulus with an internal categorical boundary ( Jaramillo et al, 2014 ). Previous works showed that perceptual decisions are influenced not only by sensory input but also trial history, which includes history of past stimuli and choice outcome ( Akrami et al, 2018 ; Busse et al, 2011 ; Hwang et al, 2017 ; Lak et al, 2020 ; Thompson et al, 2016 ). During flexible stimulus categorization task, it is unclear how different aspects of trial history influence the internal categorical boundary and the action selection after boundary switch.…”

Pedunculopontine nucleus: An integrative view with implications on Deep Brain Stimulation

“…Additionally, several lines of evidence indicate the PPN to play a role in dopamine mediated behaviours such as motivational behaviour, reinforcement and learning(Okada et al, 2009;Pan and Hyland, 2005). For instance, distinct subpopulations of PPN neurons in monkeys have been demonstrated to respond differentially to predicted and actual reward values and further experiments in rats point towards a role of PPN neurons in detecting reward-prediction errors and in signalling action-outcome associations(Leblond et al, 2014;Okada et al, 2009;Thompson et al, 2016;Tian et al, 2016).Thus, several lines of evidence based on electrophysiological studies and behavioural tasks suggest that the PPN is involved in reinforcement learning and reward circuits. By its modulatory effect on mesencephalic dopaminergic neurons, the PPN is believed to influence behavioural decision-making by direct and indirect regulation of striatal activity(Mena-Segovia and Bolam, 2017).…”