Gyrus cinguli

The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe.Medial surface of cerebral hemisphere. Medial view. Deep dissection.Medial surface of cerebral hemisphere. Medial view. Deep dissection.Medial surface of cerebral hemisphere. Medial view. Deep dissection. The cingulate cortex is a part of the brain situated in the medial aspect of the cerebral cortex. The cingulate cortex includes the entire cingulate gyrus, which lies immediately above the corpus callosum, and the continuation of this in the cingulate sulcus. The cingulate cortex is usually considered part of the limbic lobe. It receives inputs from the thalamus and the neocortex, and projects to the entorhinal cortex via the cingulum. It is an integral part of the limbic system, which is involved with emotion formation and processing, learning, and memory. The combination of these three functions makes the cingulate gyrus highly influential in linking motivational outcomes to behavior (e.g. a certain action induced a positive emotional response, which results in learning). This role makes the cingulate cortex highly important in disorders such as depression and schizophrenia. It also plays a role in executive function and respiratory control. From Latin cingulātus (girdled) Based on cerebral cytoarchitectonics it has been divided into the Brodmann areas 23, 24, 26, 29, 30, 31, 32 and 33. The areas 26, 29 and 30 are usually referred to as the retrosplenial areas. This corresponds to areas 24, 32 and 33 of Brodmann and LA of Constantin von Economo and Bailey and von Bonin. It is continued anteriorly by the subgenual area (Brodmann area 25), located below the genu of the corpus callosum).It is cytoarchitectonically agranular. It has a gyral and a sulcal part. Anterior cingulate cortex can further be divided in the perigenual anterior cingulate cortex (near the genu) and midcingulate cortex. The anterior cingulate cortex receives primarily its afferent axons from the intralaminar and midline thalamic nuclei (see thalamus). The nucleus anterior receives mamillo-thalamic afferences. The mamillary neurons receive axons from the subiculum. The whole forms a neural circuit in the limbic system known as the Papez circuit.The anterior cingulate cortex sends axons to the anterior nucleus and through the cingulum to other Broca's limbic areas. The ACC is involved in error and conflict detection processes. This corresponds to areas 23 and 31 of Brodmann LP of von Economo and Bailey and von Bonin. Its cellular structure is granular. It is followed posteriorly by the retrosplenial cortex (area 29).Dorsally is the granular area 31. The posterior cingulate cortex receives a great part of its afferent axons from the superficial nucleus (or nucleus superior- falsely LD-) of the thalamus (see thalamus), which itself receives axons from the subiculum. To some extent it thus duplicates Papez' circuit. It receives also direct afferents from the subiculum of the hippocampus. Posterior cingulate cortex hypometabolism (with 18F-FDG PET) has been defined in Alzheimer's disease. A retrograde tracing experiment on macaque monkeys revealed that the ventral anterior nucleus (VA) and the ventral lateral nucleus (VL) of the thalamus are connected with motor areas of the cingulate sulcus. The retrosplenial region (Brodmann's area 26, 29 and 30) of cingulate gyrus can be divided into three parts: i.e., retrosplenial granular cortex A, retrosplenial granular cortex B and retrosplenial dysgranular cortex. The hippocampal formation sends dense projections to retrosplenial granular cortex A and B and fewer projections to the retrosplenial dysgranular cortex. The postsubiculum sends projections to retrosplenial granular cortex A and B and to the retrosplenial dysgranular cortex. The dorsal subiculum sends projections to retrosplenial granular cortex B, while ventral subiculum sends projections to retrosplenial granular cortex A. Entorhinal cortex – caudal parts – sends projections to the retrosplenial dysgranular cortex. The rostral cingulate gyrus (Brodmanns's area 32) projects to the rostral superior temporal gyrus, midorbitofrontal cortex and lateral prefrontal cortex.The ventral anterior cingulate (Brodmann's area 24) sends projections to the anterior insular cortex, premotor cortex (Brodmann's area 6), Brodmann's area 8, the perirhinal area, the orbitofrontal cortex (Brodmann's area 12), the laterobasal nucleus of amygdala, and the rostral part of the inferior parietal lobule. Injecting wheat germ agglutinin and horseradish peroxidase conjugate into the anterior cingulate gyrus of cats, revealed that the anterior cingulate gyrus has reciprocal connections with the rostral part of the thalamic posterior lateral nucleus and rostral end of the pulvinar.The postsubiculum receives projections from the retrospleinal dysgranular cortex and the retrosplenial granular cortex A and B. The parasubiculum receives projections from the retrosplenial dysgranular cortex and retrosplenial granular cortex A. Caudal and lateral parts of the entorhinal cortex get projections from the retrosplenial dysgranular cortex, while the caudal medial entorhinal cortex receives projections from the retrosplenial granular cortex A. The retrosplenial dysgranular cortex sends projections to the perirhinal cortex. The retrospleinal granular cortex A sends projection to the rostral presubiculum. The posterior cingulate cortex (Brodmann's area 23) sends projections to dorsolateral prefrontal cortex (Brodmann's area 9), anterior prefrontal cortex (Brodmann's area 10), orbitofrontal cortex (Brodmanns’ area 11), the parahippocampal gyrus, posterior part of the inferior parietal lobule, the presubiculum, the superior temporal sulcus and the retrosplenial region.The retrosplenial cortex and caudal part of the cingulate cortex are connected with rostral prefrontal cortex via cingulate fascicule in macaque monkeys Ventral posterior cingulate cortex was found to be reciprocally connected with the caudal part of the posterior parietal lobe in rhesus monkeys. Also the medial posterior parietal cortex is connected with posterior ventral bank of the cingulate sulcus.