2026 ECNP Congress

PS02-2011

Touchscreen-based assessment of cognitive flexibility and motivation in mice lacking beta2 nicotinic acetylcholine receptors in cholinergic neurons

Cristóbal Estepa Castillo — K. Baranova, A. Alves Barboza, H. Janickova · The Institute of Physiology of the Czech Academy of Sciences, Cholinergic Signaling, Prague, Czech Republic

2026 ECNP Congress

Introduction

The striatum and its cholinergic interneurons (CINs) are critical regulators of cognitive flexibility and motivation — key behavioral domains whose disruption underlies major neuropsychiatric disorders, including addiction, eating disorders, and depression [3]. CINs exert powerful modulatory control over striatal output, and their dysfunction has been consistently linked to impaired goal-directed behavior and cognitive rigidity across multiple clinical conditions. Our previous work demonstrated that striatal CINs specifically express β2-containing nicotinic acetylcholine receptors (β2* nAChRs), and that conditional deletion of the β2 subunit in cholinergic neurons produces significant behavioral alterations in mice, encompassing social interaction, and exploratory behavior, as well as increased sensitivity to the pro-locomotor effects of stimulants [4]. However, the contribution of this receptor system to cognitive flexibility and motivated behavior had not been directly examined.

Aims

Given the clinical significance of cognitive flexibility and motivation — and their disruption in neuropsychiatric conditions such as addiction and depression — we aimed to determine whether selective deletion of β2* nAChRs in striatal CINs alters cognitive functions. We employed a behavioral platform directly translatable to human clinical assessments to minimize experimenter bias and maximize translational validity.

Methods

ChAT(IRES)-Cre::β2-flox/flox mice were generated to selectively delete β2* nAChRs in cholinergic neurons. We first validated that Cre insertion near the ChAT promoter does not produce confounding behavioral effects. Mutant mice and Cre-negative littermate controls were assessed using touchscreen-equipped operant chambers (Bussey–Saksida platform) — a fully automated, experimenter-independent system with strong translational validity to human neuropsychological tests. Cognitive flexibility was evaluated through a Pairwise Discrimination paradigm followed by Reversal Learning and Extinction, while motivated behavior was assessed using Fixed Ratio and Progressive Ratio schedules.

Results

WT and MT mice learned the Pairwise Discrimination task, both Acquisition and Reversal, within a similar number of days. However, during Acquisition, accuracy was significantly higher in MT mice in the early sessions, whereas WT mice reached a similar performance level by the final sessions. MT mice also spent significantly more time in the reward delivery area during the early sessions of Acquisition, possibly indicating a stronger goal-directed bias toward the reward location. Additionally, MT mice displayed a significantly elevated number of inter-trial interval touches at the beginning of both Acquisition and Reversal, which progressively decreased, reaching levels comparable to those observed in WT mice. So far, no significant differences were found between WT and MT mice in motivational behavior, in the number of emitted touches and beam break points.

Conclusions

Our results suggest that touchscreen operant chambers are a valuable approach to assess cognitive flexibility and motivation, as demonstrated by the successful completion of Pairwise Discrimination and Motivation tasks, by WT and MT mice. These results indicate a possible role of β2* nAChRs expressed by striatal CINs in the modulation of associative learning, positioning them as a promising therapeutic target for neuropsychiatric disorders such as addiction or depression [1,2].

References

  1. Yu LF; Zhang HK; Caldarone BJ; Eaton JB; Lukas RJ; Kozikowski AP. Recent developments in novel antidepressants targeting α4β2-nicotinic acetylcholine receptors. Journal of Medicinal Chemistry. 2014; 57(20); 8204–8223.
  2. Pitchers KK; Kane LF; Kim Y; Robinson TE; Sarter M. ‘Hot’ vs. ‘cold’ behavioural-cognitive styles: motivational-dopaminergic vs. cognitive-cholinergic processing of a Pavlovian cocaine cue in sign- and goal-tracking rats. European Journal of Neuroscience. 2017; 46(11); 2768–2781.
  3. Chantranupong L; Beron CC; Zimmer JA; Wen MJ; Wang W; Sabatini BL. Dopamine and glutamate regulate striatal acetylcholine in decision-making. Nature. 2023; 621(7979); 577–585.
  4. Abbondanza A; Bas IR; Modrák M; Čapek M; Minich J; Tyshkevich A; Naser S; Rangotis R; Houdek P; Sumová A; Dumas S; Bernard V; Janíčková H. Nicotinic acetylcholine receptors expressed by striatal interneurons inhibit striatal activity and control striatal-dependent behaviors. Journal of Neuroscience. 2022; 42(13); 2786–2803.