Neuronal activity of the anterior cingulate cortex during an observation-based decision making task in monkeys

Preferential Representation of Past Outcome Information and Future Choice Behavior by Putative Inhibitory Interneurons Rather Than Putative Pyramidal Neurons in the Primate Dorsal Anterior Cingulate Cortex

The dorsal anterior cingulate cortex (dACC) plays crucial roles in monitoring the outcome of a choice and adjusting a subsequent choice behavior based on the outcome information. In the present study, we investigated how different types of dACC neurons, that is, putative pyramidal neurons and putative inhibitory interneurons, contribute to these processes. We analyzed single-unit database obtained from the dACC in monkeys performing a reversal learning task. The monkey was required to adjust choice behavior from past outcome experiences. Depending on their action potential waveforms, the recorded neurons were classified into putative pyramidal neurons and putative inhibitory interneurons. We found that these neurons do not equally contribute to outcome monitoring and behavioral adjustment. Although both neuron types evenly responded to the current outcome, a larger proportion of putative inhibitory interneurons than putative pyramidal neurons stored the information about the past outcome. The putative inhibitory interneurons further represented choice-related signals more frequently, such as whether the monkey would shift the last choice to an alternative at the next choice opportunity. Our findings suggest that putative inhibitory interneurons, which are thought not to project to brain areas outside the dACC, preferentially transmit signals that would adjust choice behavior based on past outcome experiences.

Conserved features of anterior cingulate networks support observational learning across species

The ability to observe, interpret, and learn behaviors and emotions from conspecifics is crucial for survival, as it bypasses direct experience to avoid potential dangers and maximize rewards and benefits. The anterior cingulate cortex (ACC) and its extended neural connections are emerging as important networks for the detection, encoding, and interpretation of social signals during observational learning. Evidence from rodents and primates (including humans) suggests that the social interactions that occur while individuals are exposed to important information in their environment lead to transfer of information across individuals that promotes adaptive behaviors in the form of either social affiliation, alertness, or avoidance. In this review, we first showcase anatomical and functional connections of the ACC in primates and rodents that contribute to the perception of social signals. We then discuss species-specific cognitive and social functions of the ACC and differentiate between neural activity related to 'self' and 'other', extending into the difference between social signals received and processed by the self, versus observing social interactions among others. We next describe behavioral and neural events that contribute to social learning via observation. Finally, we discuss some of the neural mechanisms underlying observational learning within the ACC and its extended network.

Anterior cingulate cortex involved in social food-foraging decision-making strategies of rats

INTRODUCTION

Decision making as a complex cognitive process involves assessing risk, reward, and costs. Typically, it has been studied in nonsocial contexts. We have developed a novel laboratory model used with rodents to detect food-foraging decision-making strategies in different social settings. However, the brain regions that mediate these behaviors are not well identified. Substantial evidence shows that the anterior cingulate cortex (ACC) participates in evaluation of social information and in decision making.

METHODS

In this study, we investigated the effect of bilateral lesions in the ACC on established behaviors. Kainic acid (KA) was administered bilaterally to induce ACC lesions, and saline microinjection into the ACC was used in the sham group.

RESULTS

In contrast to the sham-lesioned animals, when faced with the choice of foraging under a social context, rats with ACC lesions preferred foraging for the less desirable food. Moreover, in these situations, the total amount of food foraged by the ACC-lesioned group was less than the amount foraged by the sham group. Notably, neither social interactions nor social agonistic behaviors were affected by ACC lesions.

CONCLUSIONS

These data suggest that the ACC is a key region underlying neural processing of social decision-making, specifically tending to compete for foraging high predictive reward food.

Pregenual Anterior Cingulate Gyrus Involvement in Spontaneous Social Interactions in Primates-Evidence from Behavioral, Pharmacological, Neuropsychiatric, and Neurophysiological Findings

The anterior cingulate cortex (ACC) has been implicated in different aspects of cognition and decision making, including social cognition. Several studies suggest that this region is actually formed by sub-regions concerned with distinct cognitive functions. The ACC is usually divided in its rostro-caudal axis, with the caudal ACC playing a major role in processing own actions, and the rostral ACC being related to social cognition. Recently, it has been suggested that the ACC can also be functionally divided in its dorso-ventral axis into ACC gyrus (ACCg) and ACC sulcus (ACCs), with the ACCg having a central role in processing social information. In this context, we propose that the pregenual ACCg might be especially important for engaging in social interactions. We discuss previous findings that support this hypothesis and present evidence suggesting that the activity of pregenual ACCg neurons is modulated during spontaneous social interactions.

Binding action and emotion in first-episode schizophrenia

BACKGROUND/AIMS

Several components of social cognition are compromised in schizophrenia (SCZ) from the early stage of the illness. In this study we first investigated whether mirror neuron-driven embodied simulation (mnES) is altered in first-episode SCZ. Second, we tested whether emotional cues impact on the mnES in SCZ patients.

METHODS

Twenty-two SCZ patients and 22 healthy controls (HCs) observed goal-related actions in either a neutral or emotional context during functional magnetic resonance imaging scanning.

RESULTS

Observation of neutral action elicited a lower activity in the frontoparietal network in SCZ patients, as compared to HCs. Particularly, activation in the left inferior parietal lobule in response to the same condition negatively correlated with patients' self-experience disturbances. Moreover, observation of an action performed by an angry agent produced poorer neural activity in the right anterior insula in SCZ patients as compared to HCs. This difference was mostly due to the negative β-values shown by SCZ patients, which positively correlated with their empathy scores. No differences were found contingent upon the observation of an action performed by a happy agent.

CONCLUSION

Our results show that emotional cues allow SCZ patients to partially recover mnES. However, their understanding of the emotional components of the actions of others will likely remain deficient.

[Dimensions of Empathy in Ex-Combatants of the Colombian Armed Conflict Using a Standardized Scale]

INTRODUCTION

Empathy is one of the main concepts of in social neurosciences. It is defined as a trait with multiple dimensions allowing individuals to place themselves in the emotional states of others. Colombia has an irregular, internal and long-lasting armed conflict which has been increasing its cruelty levels.

OBJECTIVES

to assess the empathy dimensions of 285 ex-combatants from the internal Colombian conflict, using the Interpersonal Reactivity Index(IRI) in Spanish. METHODOLOGY AND SUBJECTS: a sample of 285 male ex-combatants, 241 (84, 6%) males: 85,3% paramilitaries, and 14,7% guerillas. The 28 Item IRI questionnaires were administered. 3 exploratory factor analyses (EFA) were performed. Confirmatory factor analyses (CFA) were developed using structural equation procedures.

RESULTS

The first EFA obtained 9 factors (KMO=0,74, variance 54,7% and internal consistency (IC): 0,22 - 0,63). The second EFA produced 20 items with burdens above 0,4 and showed a 6-factor structure (KMO=0,70, variance 50,3%, IC: 0,37 - 0,63). The third EFA forced the 4 original IRI dimensions (KMO=0,74, variance 33,77, IC: 0,44 - 0,77. CFAs showed goodness of adjustment indexes adequate for the three models. The 4-factor model obtained the lowest value, while the 6-factor model obtained the highest. The 4- factor model showed the best IC.

CONCLUSION

The Spanish IRI administered to ex-combatants of the Colombian conflict has possible structures of 4, 6 and 9 factors. The best adjustment was for the 6-fctor. The 4-factor model exhibited the best IC.

The Path to microRNA Therapeutics in Psychiatric and Neurodegenerative Disorders

The microRNA (miRNA) class of non-coding RNAs exhibit a diverse range of regulatory roles in neuronal functions that are conserved from lower vertebrates to primates. Disruption of miRNA expression has compellingly been linked to pathogenesis in neuropsychiatric and neurodegenerative disorders, such as schizophrenia, Alzheimer’s disease, and autism. The list of transcript targets governed by a single miRNA provide a molecular paradigm applicable for therapeutic intervention. Indeed, reports have shown that specific manipulation of a miRNA in cell or animal models can significantly alter phenotypes linked with neurological disease. Here, we review how a diverse range of biological systems, including Drosophila, rodents, and primates such as monkeys and humans, can be integrated into the translation of miRNAs as novel clinical targets.