Parafascicular Thalamic and Orbitofrontal Cortical Inputs to Striatum Represent States for Goal-Directed Action Selection

Abstract

Several lines of evidence accrued over the last 5–10 years have converged to suggest that the parafascicular nucleus of the thalamus and the lateral orbitofrontal cortex each represent or contribute to internal state/context representations that guide action selection in partially observable task situations. In rodents, inactivations of each structure have been found to selectively impair performance in paradigms testing goal-directed action selection, but only when that action selection relies on state representations. Electrophysiological evidence has suggested that each structure achieves this function via inputs onto cholinergic interneurons (CINs) in the dorsomedial striatum. Here, we briefly review these studies, then point to anatomical evidence regarding the afferents of each structure and what they suggest about the specific features that each contribute to internal state representations. Finally, we speculate as to whether this role might be achieved interdependently through direct PF→OFC projections, or through the convergence of independent direct orbitofrontal cortex (OFC) and parafascicular nucleus of the thalamus (PF) inputs onto striatal targets.

Distinct Medial Orbitofrontal–Striatal Circuits Support Dissociable Component Processes of Risk/Reward Decision-Making

“…Thus, although it is apparent that DMS circuits are incorporating signals from both the mOFC and prelimbic PFC, clarifying the distinct functional contribution of these different corticostriatal pathways remains an important question for future studies. This being said, an important consideration is that the effects of the pharmacological disconnections used here may reflect not only disruption of direct pathways between the mOFC and striatal targets but also through intermediary regions that share projections with these circuits, such as the basolateral amygdala or the parafascicular thalamus (Stayte et al, 2021).…”

The ventrolateral prefrontal cortex is part of the modular working memory system: A functional neuroanatomical perspective

“…However, it is difficult to clearly distinguish between selection functions and the other more integrative perceptual processes needed for the goal-directed guidance in which this subarea is involved. For example, recent studies have indicated that the lateral OFC is involved in the updating of outcome values and integrating specific external and internal perceptual presentations to achieve a goal (Baltz et al, 2018;Stayte et al, 2021). These studies lend weight to its putative perceptual role but do not differentiate the lateral and medial parts with respect to the integrative role that was suggested to be under the control of the medial areas in Ben Shalom's model.…”

Functional Interactions Between the Parafascicular Thalamic Nucleus and Motor Cortex Are Altered in Hemiparkinsonian Rat

“…Numerous primate and rodent studies have shown that CM/PF or PF neurons consist of large anatomically and physiologically distinct neuronal populations that extend topographically organized projections to the striatum and provide relatively minor anatomically collaterals to and from the cerebral cortex ( Sadikot and Rymar, 2009 ; Mandelbaum et al, 2019 ; Stayte et al, 2021 ). The PF is well-positioned to reciprocally modulate information flow between the cerebral cortex and the thalamus to a certain extent ( Sherman, 2017 ; Halassa and Sherman, 2019 ).…”