Involvement Of Anterior Cingulate Cortex Research Articles

A circuit from the locus coeruleus to the anterior cingulate cortex modulates offspring interactions in mice

Social sensitivity to other individuals in distress is crucial for survival. The anterior cingulate cortex (ACC) is a structure involved in making behavioral choices and is influenced by observed pain or distress. Nevertheless, our understanding of the neural circuitry underlying this sensitivity is incomplete. Here, we reveal unexpected sex-dependent activation of ACC when parental mice respond to distressed pups by returning them to the nest ("pup retrieval"). We observe sex differences in the interactions between excitatory and inhibitory ACC neurons during parental care, and inactivation of ACC excitatory neurons increased pup neglect. Locus coeruleus (LC) releases noradrenaline in ACC during pup retrieval, and inactivation of the LC-ACC pathway disrupts parental care. We conclude that ACC maintains sex-dependent sensitivity to pup distress under LC modulation. We propose that ACC's involvement in parenting presents an opportunity to identify neural circuits that support sensitivity to the emotional distress of others.

Elucidating medial temporal and frontal lobe contributions to approach-avoidance conflict decision-making using functional MRI and the hierarchical drift diffusion model.

The prefrontal cortex (PFC) has long been associated with arbitrating between approach and avoidance in the face of conflicting and uncertain motivational information, but recent work has also highlighted medial temporal lobe (MTL) involvement. It remains unclear, however, how the contributions of these regions differ in their resolution of conflict information and uncertainty. We designed an fMRI paradigm in which participants approached or avoided object pairs that differed by motivational conflict and outcome uncertainty (complete certainty vs. complete uncertainty). Behavioral data and decision-making parameters estimated using the hierarchical drift diffusion model revealed that participants' responding was driven by conflict rather than uncertainty. Our neural data suggest that PFC areas contribute to cognitive control during approach-avoidance conflict by potentially adjusting response caution and the strength of evidence generated towards either choice, with differential involvement of anterior cingulate cortex and dorsolateral prefrontal cortex. The MTL, on the other hand, appears to contribute to evidence generation, with the hippocampus linked to evidence accumulation for stimuli. Although findings within perirhinal cortex were comparatively equivocal, some evidence suggests contributions to perceptual representations, particularly under conditions of threat. Our findings provide evidence that MTL and PFC regions may contribute uniquely to arbitrating approach-avoidance conflict.

Pupil-Linked Arousal Responds to Unconscious Surprisal.

Pupil size under constant illumination reflects brain arousal state, and dilates in response to novel information, or surprisal. Whether this response can be observed regardless of conscious perception is still unknown. In the present study, male and female adult humans performed an implicit learning task across a series of three experiments. We measured pupil and brain-evoked potentials to stimuli that violated transition statistics but were not relevant to the task. We found that pupil size dilated following these surprising events, in the absence of awareness of transition statistics, and only when attention was allocated to the stimulus. These pupil responses correlated with central potentials, evoking an anterior cingulate origin. Arousal response to surprisal outside the scope of conscious perception points to the fundamental relationship between arousal and information processing and indicates that pupil size can be used to track the progression of implicit learning.SIGNIFICANCE STATEMENT Pupil size dilates following increase in mental effort, surprise, or more generally global arousal. However, whether this response arises as a conscious response or reflects a more fundamental mechanism outside the scrutiny of awareness is still unknown. Here, we demonstrate that unexpected changes in the environment, even when processed unconsciously and without being relevant to the task, lead to an increase in arousal levels as reflected by the pupillary response. Further, we show that the concurrent electrophysiological response shares similarities with mismatch negativity, suggesting the involvement of anterior cingulate cortex. All in all, our results establish novel insights about the mechanisms driving global arousal levels, and it provides new possibilities for reliably measuring unconscious processes.

Adenosine A2A receptor deletion affects social behaviors and anxiety in mice: Involvement of anterior cingulate cortex and amygdala

Blockade of adenosine A2A receptors can potentiate motivation to work for natural reinforcers such as food. Conspecific interaction is a potent natural reinforcer in social animals that can be manifested as preference for social exploration versus other sources of novel stimulation. Deficiencies in this type of motivated behavior (social withdrawal) have been seen in several pathologies such as autism and depression. However, the role of A2A receptors in motivation for social interaction has not been widely explored. Social interaction paradigms evaluate the natural preference of animals for exploring other conspecifics, and the ability to differentiate between familiar versus novel ones. Anxiety is one of the factors that can induce avoidance of social interaction. In the present study, adenosine A2A knockout (A2AKO) and wild-type (WT) mice were assessed for social and anxiety-related behaviors. c-Fos immunoreactivity was evaluated as a measure of neuronal activation in brain areas involved in different aspects of motivation and emotional processes. Although A2AKO mice showed an anxious profile, they displayed higher levels of sociability and were less sensitive to social novelty. WT mice displayed a typical pattern of social recognition 24h later, but not A2AKO mice, which explored equally both conspecifics. There were no differences between strains in aggressiveness, perseverance or social odor preferences. c-Fos immunoreactivity in A2AKO mice was higher in anterior cingulate and amygdala compared to WT mice. Thus, A2A receptors appear to be potential targets for the improvement of pathologies related to social function.

Anterior cingulate cortex involvement in subclinical social anxiety

We demonstrated differential activation in the anterior cingulate cortex (ACC) between subjects with high and low social anxiety in response to angry versus neutral faces. Activation in the ACC distinguished between facial expressions in the low, but not the high, anxious group. The ACC's role in threat processing is discussed.

To Cross or Not To Cross

Different theoretical accounts have attempted to integrate anterior cingulate cortex involvement in relation to conflict detection, error-likelihood predictions, and error monitoring. Regarding the latter, event-related potential studies have identified the feedback-related negativity (FRN) component in relation to processing feedback which indicates that a particular outcome was worse than expected. According to the conflict-monitoring theory the stimulus-locked N2 reflects pre-response conflict. Assumptions of these theories have been made on the basis of relatively simple response-mapping tasks, rather than more complex decision-making processes associated with everyday situations. The question remains whether expectancies and conflicts induced by everyday knowledge similarly affect decision-making processes. To answer this question, electroencephalogram and behavioral measurements were obtained while participants performed a simulated traffic task that varied high and low ambiguous situations at an intersection by presenting multiple varying traffic light combinations. Although feedback was kept constant for the different conditions, the tendency to cross was more pronounced for traffic light combinations that in reallife are associated with proceeding, as opposed to more ambiguous traffic light combinations not uniquely associated with a specific response. On a neurophysiological level, the stimulus-locked N2 was enhanced on trials that induced experience-based conflict and the FRN was more pronounced for negative as compared to positive feedback, but did not differ as a function of everyday expectancies related to traffic rules. The current study shows that well-learned everyday rules may influence decision-making processes in situations that are associated with the application of these rules, even if responding accordingly does not lead to the intended outcomes.

Evidence for Anterior Cingulate Cortex Involvement in Monitoring Preparatory Attentional Set

Evidence for Anterior Cingulate Cortex Involvement in Monitoring Preparatory Attentional Set