Modeling Uncertainty-Seeking Behavior Mediated by Cholinergic Influence on Dopamine

Abstract

Recent findings suggest that acetylcholine mediates uncertainty-seeking behaviors through its projection to dopamine neurons -another neuromodulatory system known for its major implication in reinforcement learning and decision-making. In this paper, we propose a leaky-integrate-and-fire model of this mechanism. It implements a softmax-like selection with an uncertainty bonus by a cholinergic drive to dopaminergic neurons, which in turn influence synaptic currents of downstream neurons. The model is able to reproduce experimental data in two decision-making tasks. It also predicts that i) in the absence of cholinergic input, dopaminergic activity would not correlate with uncertainty, and that ii) the adaptive advantage brought by the implemented uncertainty-seeking mechanism is most useful when sources of reward are not highly uncertain. Moreover, this modeling work allows us to propose novel experiments which might shed new light on the role of acetylcholine in both random and directed exploration. Overall, this study thus contributes to a more comprehensive understanding of the roles of the cholinergic system and its involvement in decision-making in particular.

Aging, uncertainty, and decision making—A review

“…Furthermore, Yu & Dayan (2005) hypothesized that the noradrenergic and cholinergic systems interact during conditions of uncertainty and that acetylcholine might set the threshold for noradrenaline signaling. Other work suggests that acetylcholine may mediate dopamine signaling by increasing firing rates (Naudé et al, 2016;Belkaid & Krichmar, 2020). Thus, the cholinergic system may influence uncertainty in more ways than one, including the modulation of other neuromodulators.…”

Association of Personal Anxiety with Dopamine Receptor D4 (DRD4), DAT Genes Polymorphism

“…Dopamine is a neurotransmitter that provides neurochemical transmission in the nigrostriatal, mesolimbic, mesocortical and tuberoinfundibular dopaminergic systems in mammals. These brain structures play a vital part in the implementation of psychomotor, cognitive, neuroendocrine functions [3]. Relationship between 'novelty seeking' and dopamine system has been found: an association of temperament with genetic polymorphism encoding the fourth type dopamine receptor (DRD4) was established [4].…”