A Focus on the Functions of Area 25 (original) (raw)
Related papers
Cortical connections position primate area 25 as a keystone for interoception, emotion, and memory
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2018
The structural and functional integrity of subgenual cingulate area 25 (A25) is crucial for emotional expression and equilibrium. A25 has a key role in affective networks, and its disruption has been linked to mood disorders, but its cortical connections have yet to be systematically or fully studied. Using neural tracers in rhesus monkeys, we found that A25 was densely connected with other ventromedial and posterior orbitofrontal areas associated with emotions and homeostasis. A moderate pathway linked A25 with frontopolar area 10, an area associated with complex cognition, which may regulate emotions and dampen negative affect. Beyond the frontal lobe, A25 was connected with auditory association areas and memory-related medial temporal cortices, and with the interoceptive-related anterior insula. A25 mostly targeted the superficial cortical layers of other areas, where broadly dispersed terminations comingled with modulatory inhibitory or disinhibitory microsystems, suggesting a d...
The Subgenual Anterior Cingulate Cortex in Mood Disorders
CNS Spectrums, 2008
ABSTRACTThe anterior cingulate cortex (ACC) ventral to the genu of the corpus callosum has been implicated in the modulation of emotional behavior on the basis of neuroimaging studies in humans and lesion analyses in experimental animals. In a combined positron emission tomography/magnetic resonance imaging study of mood disorders, we demonstrated that the mean gray matter volume of this “subgenual” ACC (sgACC) cortex is abnormally reduced in subjects with major depressive disorder (MDD) and bipolar disorder, irrespective of mood state. Neuropathological assessments of sgACC tissue acquired postmortem from subjects with MDD or bipolar disorder confirmed the decrement in gray matter volume, and revealed that this abnormality was associated with a reduction in glia, with no equivalent loss of neurons. In positron emission tomography studies, the metabolic activity was elevated in this region in the depressed relative to the remitted phases of the same MDD subjects, and effective antid...
Proceedings of the National Academy of Sciences of the United States of America, 2017
Disorders of dysregulated negative emotion such as depression and anxiety also feature increased cardiovascular mortality and decreased heart-rate variability (HRV). These disorders are correlated with dysfunction within areas 25 and 32 of the ventromedial prefrontal cortex (vmPFC), but a causal relationship between dysregulation of these areas and such symptoms has not been demonstrated. Furthermore, cross-species translation is limited by inconsistent findings between rodent fear extinction and human neuroimaging studies of negative emotion. To reconcile these literatures, we applied an investigative approach to the brain-body interactions at the core of negative emotional dysregulation. We show that, in marmoset monkeys (a nonhuman primate that has far greater vmPFC homology to humans than rodents), areas 25 and 32 have causal yet opposing roles in regulating the cardiovascular and behavioral correlates of negative emotion. In novel Pavlovian fear conditioning and extinction para...
Anterior Cingulate Pathways May Affect Emotions Through Orbitofrontal Cortex
Cerebral Cortex, 2016
The anterior cingulate cortex (ACC) and posterior orbitofrontal cortex (pOFC) are associated with emotional regulation. These regions are old in phylogeny and have widespread connections with eulaminate neocortices, intricately linking areas associated with emotion and cognition. The ACC and pOFC have distinct cortical and subcortical connections and are also interlinked, but the pattern of their connections-which may be used to infer the flow of information between them-is not well understood. Here we found that pathways from ACC area 32 innervated all pOFC areas with a significant proportion of large and efficient terminals, seen at the level of the system and the synapse. The pathway from area 32 targeted overwhelmingly elements of excitatory neurons in pOFC, with few postsynaptic sites found on presumed inhibitory neurons. Moreover, pathways from area 32 originated mostly in the upper layers and innervated preferentially the middledeep layers of the least differentiated pOFC areas, in a pattern reminiscent of feedforward communication. Pathway terminations from area 32 overlapped in the deep layers of pOFC with output pathways that project to the thalamus and the amygdala, and may have cascading downstream effects on emotional and cognitive processes and their disruption in psychiatric disorders.
Neurocircuitry of mood disorders
This review begins with a brief historical overview of attempts in the first half of the 20th century to discern brain systems that underlie emotion and emotional behavior. These early studies identified the amygdala, hippocampus, and other parts of what was termed the ‘limbic’ system as central parts of the emotional brain. Detailed connectional data on this system began to be obtained in the 1970s and 1980s, as more effective neuroanatomical techniques based on axonal transport became available. In the last 15 years these methods have been applied extensively to the limbic system and prefrontal cortex of monkeys, and much more specific circuits have been defined. In particular, a system has been described that links the medial prefrontal cortex and a few related cortical areas to the amygdala, the ventral striatum and pallidum, the medial thalamus, the hypothalamus, and the periaqueductal gray and other parts of the brainstem. A large body of human data from functional and structural imaging, as well as analysis of lesions and histological material indicates that this system is centrally involved in mood disorders
Brain Structure and Function, 2008
The neural networks that putatively modulate aspects of normal emotional behavior have been implicated in the pathophysiology of mood disorders by converging evidence from neuroimaging, neuropathological and lesion analysis studies. These networks involve the medial prefrontal cortex (MPFC) and closely related areas in the medial and caudolateral orbital cortex (medial prefrontal network), amygdala, hippocampus, and ventromedial parts of the basal ganglia, where alterations in grey matter volume and neurophysiological activity are found in cases with recurrent depressive episodes. Such findings hold major implications for models of the neurocircuits that underlie depression. In particular evidence from lesion analysis studies suggests that the MPFC and related limbic and striato-pallido-thalamic structures organize emotional expression. The MPFC is part of a larger ''default system'' of cortical areas that include the dorsal PFC, mid-and posterior cingulate cortex, anterior temporal cortex, and entorhinal and parahippocampal cortex, which has been implicated in self-referential functions. Dysfunction within and between structures in this circuit may induce disturbances in emotional behavior and other cognitive aspects of depressive syndromes in humans. Further, because the W. C. Drevets (&) Á M. L. Furey Section on Neuroimaging in Mood and Anxiety Disorders,
Subgenual anterior cingulate activation to valenced emotional stimuli in major depression
NeuroReport, 2005
Major depression has been associated with anomalous activation in the subgenual anterior cingulate cortex, but its response to emotional stimuli is poorly understood. The primary goal of this study was to compare levels of activation in the subgenual anterior cingulate cortex of diagnosed depressed and nondepressed participants in response to happy and sad facial expressions of a¡ect. Whereas cognitive theories of depression predict increased activation to negative stimuli, depressed participants were found to exhibit increased activation to both types of stimuli in the subgenual anterior cingulate cortex. Importantly, the loci were in di¡erent regions of the subgenual anterior cingulate cortex, suggesting that there is functional specialization in the processing of negatively and positively valenced stimuli. NeuroReport 16:1731^1734 c 2005 Lippincott Williams & Wilkins.
Subgenual Cingulate Cortex Activity in Predicting Risk Factor and Treatment-Response in Depression
WMJ (Warmadewa Medical Journal), 2018
Major depressive disorder (MDD) contributes significantly to morbidity, disability, and decreased quality of life, despite the expansion of treatment options. This, in part, is caused by a lack of valid, applicable, and reliable biomarkers to predict the risk, treatment response, and prognosis of depression. In recent years, the anterior cingulate cortex, in particular pars subgenual (sgACC), has received much attention due to its potential utilization as a neural endophenotype for depression. This essay discusses the functional activity of sgACC, mostly by functional magnetic resonance imaging, in relation to predicting risk for developing depression, predicting patient response-to-treatment, and eventually, to creating a platform for the personalized psychiatric approach to each patient. The caveats and conditions need to be met are also discussed, in order to firmly establish sgACC activity as a valid biomarker for depression. Keywords: depression, anterior cingulate cortex, subgenual, biomarker, fMRI
Behavioural brain research, 2006
A growing body of functional imaging studies suggests that human depression and anxiety symptoms are associated with functional abnormalities in the circuitry formed by the rostral anterior cingulate cortex (rACC) and its direct limbic and paralimbic connections. In rodents however, the role of the rACC (rCG1/rCG2) remains unknown in depression-related behaviours and elusive in acute anxiety. In order to address this, we specifically lesioned the rat rCG1/rCG2, and assessed the behavioural outcome using a modified forced swim test (FST) and the elevated plus maze (EPM), tests for depression and anxiety related behaviours respectively. Lesions of the rostral anterior cingulate cortex significantly increased the time spent immobile in the FST without affecting climbing or swimming performances, suggesting a pro-depressant effect. On the contrary, none of the parameters measured in the EPM was affected by the lesion. These data point to an involvement of the rCG1/rCG2 in depression-rel...
Dorsal peduncular cortex activity modulates affective behaviors in mice
The medial prefrontal cortex (mPFC) is critically involved in cognitive and emotional function and underlies many neuropsychiatric disorders, including mood, fear and anxiety disorders. In rodents, disruption of mPFC activity affects anxiety- and depression-like behavior, with evidence supporting specialized contributions from its subdivisions. The rodent mPFC is often subdivided into the anterior cingular cortex (ACC), prelimbic cortex (PL), and the infralimbic cortex (IL), and broken down into the dorsomedial prefrontal cortex (dmPFC), spanning ACC and dorsal PL, and the ventromedial prefrontal cortex (vmPFC), which includes the ventral PL, IL, and in some studies the dorsal peduncular cortex (DP) and dorsal tenia tecta (DTT). The DP/DTT have recently been implicated in the regulation of stress-induced sympathetic responses via projections to the hypothalamus. While many studies implicate the PL and IL in anxiety-, depression-like and fear behavior, the contribution of the DP/DTT ...