Cingulate Cortex

Introduction

The cingulate cortex is located in the middle portion of the cerebral cortex and is considered part of the limbic lobe (comprising the frontal, parietal, and the temporal lobes of the brain).

 

The cingulate cortex is the largest structure of the brain associated with memory and emotions.

 

What Is the Main Function of the Cingulate Cortex?

The cingulate cortex is connected to the other brain structures by numerous neuron fibers. Its connections to the amygdala and hypothalamus are especially strong.

 

Due to this, the functions of this area of the brain are varied and complex. They include the control and regulation of processes related to emotion, action, learning, sleep, behavior, and memory. Examples include error detection, social evaluation, consciousness, the registration and emotional association of pain, learning new skills, etc.

 

 

What Is the Structure of the Cingulate Cortex?

The cingulate cortex is made up of the cingulate gyrus, located above the corpus callosum and the cingulate sulcus next to it. This brain structure is made of gray matter and can be divided into anterior and posterior regions.

 

What Is the Anatomy and Function of the Anterior Cingulate Cortex?

 

The anterior cingulate cortex (ACC) is located at the front of the cingulate cortex. It has numerous connections that support diverse functions such as autonomic and endocrine responses, pain perception, initiation of motor movements, cognitive decision-making, anticipation, and management of social behavior, etc.

 

Located partly in the cingulate gyrus and partly in the cingulate sulcus, the anterior cingulate cortex comprises the Brodmann areas 24, 33, and 34.

 

Also, a particular type of neuron labeled as spindle cells is present in the brain’s structure. The spindle cells are individual spindle-shaped projection neurons whose function is to regulate the neurons’ global firing rate and the emotional state.

 

Brodmann Area 24

This Brodmann area is located in the ventral anterior part of the cingulate cortex. It also includes portions of the cingulate gyrus and the frontal lobe.

 

BA 24 is referred to as the awareness center of the brain. It involves olfaction, i.e., recognizing familiar odors, emotional processing cues, inductive/deductive reasoning, taste, auditory attention, visuospatial attention, etc.

 

Brodmann Area 33

The Brodmann area 33 is located in the anterior cingulate gyrus and involves motor preparation/planning, motor imagery, response to vestibular and ocular motor stimulation, pain, etc.

 

Brodmann Area 34

The dorsal entorhinal cortex (on the parahippocampal gyrus) is the location of the Brodmann area 34. It participates in the process of cognitive/motor inhibition, object-naming, semantic and phonological verbal fluency, working memory, memory encoding, time-based memory, etc.

 

What Is the Anatomy and Function of the Posterior Cingulate Cortex?

 

The posterior cingulate cortex (PCC) is located at the back of the cingulate cortex. Anatomically, the PCC is surrounded by the cingulate sulcus, corpus callosum, parieto-occipital sulcus, and the Brodmann area 24 mid-cingulate region.

 

This brain structure houses the Brodmann areas 23 and 31. It’s also made up of granular cells and has numerous reciprocal connections with the anterior cingulate cortex that support emotional and motivational information flow. It’s also actively involved in retrieving autobiographical memory, emotional stimuli, and the regulation of internal/external attention.

 

Brodmann Area 23

The ventral posterior cingulate cortex is the location of the Brodmann area 23. This area participates in the lexico-semantic processing, semantic emotional information processing, selective attention to speech, word and face encoding, response to thermal stimuli, fear conditioning, etc.

 

Brodmann Area 31

This Brodmann area is a dorsal posterior subdivision of the cingulate context, occupying a medial parietal lobe area. It supports the control and regulation of temperature, response to thermal stimuli, pain, touch stimuli, etc.

 

What Happens if the Cingulate Cortex Is Dysfunctional?

When any portion or structure of the cingulate cortex suffers damage, it becomes dysfunctional and may lose its ability to respond to conditioned stimuli. This can result in behaviors such as aggression and shyness.

 

The dysfunctionality of the cingulate cortex is related to the following medical conditions and diseases:

 

  • Schizophrenia
  • Depression

 

Early Alzheimer’s Disease

Inflicted damage or lesion to the posterior cingulate cortex leads to impairment of learning and memory, which are the key features of the early stages of Alzheimer’s disease.

 

Alzheimer’s disease is the most common form of declination of mental functions and processes. It’s a condition that destroys the synapses between neuron cells in the brain over time.

 

The dysfunction of the posterior cingulate gyri and the other structures of the cingulate cortex also lead to disorientation of the affected individual, which is another early symptom of this disease.

 

Obsessive-compulsive Disorder

When some of the behaviors a person learns become a habit that is often repeated in order to relieve the affected individual from anxiety or stress, we refer to them as obsessions (obsessive thoughts that cannot be controlled) and compulsions (uncontrolled behaviors). This kind of behavior can occur due to the dysfunctionality of the cortical structures or psychological/psychiatric comorbidities.

What Are the Symptoms of Obsessive-Compulsive Disorder?

The list of main symptoms that the individuals affected by the obsessive-compulsive disorder experience includes:

  • Fear of accidentally hurting others or themselves;
  • Obsessive (dark) thoughts, often including contemplation of committing suicide;
  • Obsessive religious or ideological thoughts that the affected person feels obliged to bring to fruition;
  • Debilitating anxiety;
  • Debilitating fear of losing a possession or a person;
  • Fear of contamination with virus, germs, or filth;
  • Obsession with geometric arrangements in the surroundings of the affected person;
  • Obsessive-compulsive ordering or cleaning (an affected person can spend most of their awake time cleaning).

 

What Are the Types of Obsessive-Compulsive Disorder?

This disorder can be observed through many different forms in which it occurs. However, there are 4 main subdivisions of obsessive-compulsive disorder:

  • Cleaning and contamination;
  • Ordering and symmetry;
  • Intrusive (taboo) thoughts;
  • Hoarding of objects.

 

Cleaning and Contamination

This type of obsessive-compulsive disorder is characterized by obsessive cleaning of the living environment, frequent washing of hands, disinfection of everything the affected individual comes into contact with, avoiding people and public places in fear that they can spread a virus or infection, etc.

 

Ordering and Symmetry

The individuals affected by this type of obsessive-compulsive disorder are preoccupied with perfection. They have an uncontrollable urge to order things and objects and arrange and rearrange them multiple times in a day in order to satisfy their compulsion to make things in their surroundings look perfectly lined up.

 

Intrusive (Taboo) Thoughts

The symptoms that occur in this sub-type of the obsessive-compulsive disorder include unwanted thoughts or mental representations that continuously disturb the affected individual, triggering psychological restlessness and severe forms of anxiety. These intrusive images and ideas usually occur after a traumatic experience or a stressful situation.

 

Hoarding of Objects

The persistent desire to purchase various items, despite having no reasonable need for them, is the main symptom of this type of obsessive-compulsive disorder. These patients face severe anxiety when they need to discard some of the hoarded objects. Very often, they sacrifice all the living space in order to make room for the piles of items they compulsively hoard.

 

Schizophrenia

This severe psychiatric disorder is characterized by a combination of hallucinations, delusions, tremors, extremely disordered thinking and behavior, and a lack of emotional intelligence.

 

Other symptoms of schizophrenia include:

 

  • The illusion of hearing voices or noises;
  • The illusion of seeing visions or shadows;
  • Paranoid behavior (suspicion and distrust);
  • The affected individuals may believe in having unusual powers;
  • The affected individuals may believe that others control their thoughts.

 

The triggers for this abnormal activity of neurons have been found in the cingulate cortex, specifically in its posterior part. Since it disturbs the rational thinking and perception of life, the affected individuals oddly interpret reality.

 

How Many Types of Schizophrenia Are There?

There are four main types of this disorder:

 

  • Paranoid schizophrenia – Characterized by extreme paranoid behavior and inappropriate emotional responses. The affected individuals show little pleasure for life at this stage of this disorder.
  • Catatonic schizophrenia – The emotional shutdown is typical for this type of schizophrenia. The affected individuals appear to be paralyzed, both mentally and physically. They can stand still with no facial expressions for an extended period, with no drive to eat, drink, or urinate.
  • Undifferentiated schizophrenia – This classification is relevant for the individuals who exhibit behaviors and symptoms related to two or more other types of schizophrenia.
  • Schizoaffective disorder – The affected individual is delusional and suffers from depression, mania, and hypomania.

 

Almost 90% of the affected patients need lifelong treatment with the administration of antipsychotic drugs, counseling, and social rehabilitation to reduce schizophrenia symptoms.

 

 

Depression

Depression is a mood disorder characterized by a long-lasting feeling of sadness, which inhibits the progress of the affected individual. This emotional state gives rise to the sense of low self-worth and guilt, thus reducing the ability of the individual to live life to the fullest.

 

It typically starts by failing to achieve a plan, after which the emotional needs of the individual fail to be met, after a severely traumatic experience, or after medical conditions that can change the functionality of the brain.

 

Fun Facts

Did you know?

 

  1. The word cingulate originates from the Latin language, meaning ‘belt.’
  2. The corpus callosum is the most massive white matter structure, comprising more than 200 million axonal projections.
  3. Granular cells are located in various brain regions, including the cerebellum, cerebral cortex, hippocampus, and the olfactory bulb. They produce structural proteins (keratins, loricrin, profilaggrin, and others) and lipids (ceramides, free fatty acids, etc.).
  4. The Brodmann areas of the cerebral cortex were distinguished by Korbinian Brodmann in the early 1900s. This German anatomist identified a total of 52 Brodmann areas.
  5. The cingulate cortex also gives us the ability to vocalize our emotions, i.e., to express our feelings aloud.
  6. The sulci of the cerebral cortex can be complete or incomplete. The gyri, on the other hand, increase the gray matter. By this, they also increase the quantity of information which is processed in the brain.
  7. Most of the blood supply of the cingulate cortex comes from branches of the anterior cerebral artery.
  8. The anterior cingulate cortex has neuron fiber connections with the speech and vocalization areas in the frontal lobes. These areas also include the Broca’s area, which is responsible for controlling the motor functions involved with speech production.
  9. The anterior cingulate gyrus participates in forming emotional bonding and attachment, particularly between a mother and a child. The frequent vocalization between the mothers and their infants is the trigger of emotional bonding.
  10. Individuals with a dysfunctional cingulate cortex often have problems communicating and dealing with changing situations.