A time-delay model of dopamine-modulated prefrontal-limbic interactions in schizophrenia

Eva Kaslik, Maria Roxana Matei, Mihaela Neamțu, Anca Rădulescu

Chaos, Solutions & Fractals

Abstract

We revisit a nonlinear mathematical model of prefrontal–limbic interactions, aimed to capture both healthy and pathological activation patterns in emotion regulatory circuits. The model's parameter space encapsulates the strengths of the projection pathways and of other interactions between the system's neural and dopamine units. These nonlinear parameters can be assigned physiological interpretation (representing, e.g., the control level of arousal, or the vulnerability of the system to elevated stress cortisol). In the current work, we explore the possibility, based on recent literature on the role of midbrain dopamine systems, that dopamine-mediated pathways act not simply as nonlinearities in the system, but also along a different timeline than other interactions, which may explain their specific signature on neural dynamics. We found that dopamine fluctuations can be as impactful on controlling dynamics as changes in strength of synaptic pathways. We also documented that higher dopamine levels allow for complexities of temporal patterns which are not accessible at lower levels. Our conclusions underline the importance of considering the timeline of dopamine contributions to limbic–prefrontal regulation of emotion. More generally, our study supports the value of considering time delays when modeling brain circuits in which timing of interactions is of essence.

BibTeX

@article{KaslikMateiNeamtuRadulescu2026,
  title         = {
    A Time-Delay Model of Dopamine-Modulated Prefrontal–limbic Interactions in
    Schizophrenia
  },
  author        = {Eva Kaslik and Maria Roxana Matei and Mihaela Neamțu and Anca Rǎdulescu},
  year          = 2026,
  month         = jan,
  journal       = {Chaos, Solitons \& Fractals},
  publisher     = {Elsevier {BV}},
  volume        = 202,
  pages         = {117606--117606},
  doi           = {10.1016/j.chaos.2025.117606},
  abstract      = {
    We revisit a nonlinear mathematical model of prefrontal–limbic
    interactions, aimed to capture both healthy and pathological activation
    patterns in emotion regulatory circuits. The model's parameter space
    encapsulates the strengths of the projection pathways and of other
    interactions between the system's neural and dopamine units. These
    nonlinear parameters can be assigned physiological interpretation
    (representing, e.g., the control level of arousal, or the vulnerability of
    the system to elevated stress cortisol). In the current work, we explore
    the possibility, based on recent literature on the role of midbrain
    dopamine systems, that dopamine-mediated pathways act not simply as
    nonlinearities in the system, but also along a different timeline than
    other interactions, which may explain their specific signature on neural
    dynamics. We found that dopamine fluctuations can be as impactful on
    controlling dynamics as changes in strength of synaptic pathways. We also
    documented that higher dopamine levels allow for complexities of temporal
    patterns which are not accessible at lower levels. Our conclusions
    underline the importance of considering the timeline of dopamine
    contributions to limbic–prefrontal regulation of emotion. More generally,
    our study supports the value of considering time delays when modeling brain
    circuits in which timing of interactions is of essence.
  },
}