Anomalous Behavior Biological Therapy Explained

2021-07-14 04:07 PM

Drug therapy is used to change levels of neurotransmitters and emotions and behaviors

Biological explanations and therapies of mental disorders are since behavior and emotions are regulated by brain systems. These systems allow us to take in information, integrate it with memory and other salient factors, and then respond to behavioral and emotional responses. Once these systems are disrupted, psychological processes such as perception, emotion, or behavior will also become inappropriate. Such disturbances may result from structural brain damage or disturbances in chemical compounds such as neurotransmitters responsible for activating different regions of the brain. By the end of the chapter, you should have mastered:

The neuroanatomical basis of mental health disorders.

Neurotransmitter systems and neurotransmitters primarily influence behavior and emotions.

Drug therapy is used to change levels of neurotransmitters and emotions and behaviors.

Two types of physical interventions are used to treat mental health problems: electric shocks and psychiatric surgery.

Brain behavioral anatomy

The brain is a complex assembly of nerve cells. It is divided into 4 anatomical regions: posterior brain, midbrain, forebrain, and cerebellum.

Posterior brain, midbrain, and forebrain.

The hindbrain contains parts of the brain necessary for vital functions: the brainstem, which controls respiratory function, blood pressure, and heart rate, the reticular body that controls sleep, and the pons and cerebellum, which regulate muscles and posture.

Above those organizations is the midbrain. In the midbrain, there is a part of the reticular body and 2 sensory and motor centers. The midbrain is responsible for directing integrated reflexes and automatic responses including the auditory and visual systems involved in muscle movements.

In the forebrain, there are many important organizations that affect behavior and emotions: • The thalamus: is the bridge connecting the basic functions of the hindbrain and midbrain with processing centers located in the cerebral cortex. . Thalamus is also responsible for controlling attention and participating in memory functions. In addition, it joins the limbic system in expressing emotions.

Hypothalamus: Regulates appetite, arousal, and thirst. This region is also involved in emotional control.

The limbic system is a series of structures that connect different regions of the brain such as the Papazian ring: the hippocampus - the brain's triangle (Fonix) - the mammary bodies - the thalamus - cortex - thalamus. The hippocampus - brain triangle - mammary bodies are also involved in memory. The hippocampus is one of the sites of interaction between the perceptual system and the memory system. A little further is the amygdala - the bridge of sensory information to corresponding behaviors, namely fear or anger responses. It is also known as the "emotional computer" because of its role in coordinating the process of assessing the value of sensory information (e.g. threat) and then controlling behavioral and spontaneous responses. owner later.

The cerebrum

Located on these 3 structures is the cerebrum. This is the part of the brain that we are all too familiar with. It includes some of the following structures:

The basal nucleus: this is a dense array of neuronal bodies. It includes the striatum - the part responsible for controlling complex motor blocks.

The cortex: it is the outer folded layer of gray matter made up of cell bodies and their synaptic junctions. This is one of the most highly organized centers of the brain. Most areas of the cerebral cortex are involved to varying degrees in the regulation of complex behaviors, although there are functional control centers in the brain. The cerebrum is divided into two functional halves, connected by the corpus callosum and numerous basal nerve fibers. The brain is also divided into four lobes: the frontal lobe, the temporal lobe, the occipital lobe, and the parietal lobe. Since these lobes are all involved in the etiology of many neurological and psychiatric disorders, the function of each lobe is discussed in more detail.

Forehead lobe

The frontal lobe makes up about one-third of the brain's mass. The frontal cortex has an executive function, coordinating a variety of complex processes including language, motor regulation, and behavioral programming. Loss of executive function, e.g. due to trauma, has a range of consequences: decreased interest, anxiety about the future, impulsivity, poor initiative, reduced current memory, loss of thinking ability abstraction, inability to make and execute action plans as well as to think about the results of actions. Individuals with frontal lobe injuries become less flexible and rigid. They find it difficult to move from one direction of thought or task to another, changing from one habit or behavior to another. Such disturbances can lead to repetition, where a particular behavior is continued despite instructions to change. The frontal lobe is also thought to influence the motor hierarchy. Injury to the frontal lobe can cause states such as depression/exhaustion (adynamia), which manifests as impairments in language or extrinsic behaviors. The prefrontal region is connected to the limbic system via the thalamus and the motor system in the cerebral cortex. The bridge between the prefrontal cortex and the limbic system is activated during reward, which encourages behavior.

The temporal lobe

Although the functions are distributed, there are distinct centers in the temporal lobes. These centers are in different positions depending on the dominant hand.

In right-handed people, the main language center is in the right hemisphere of the brain, and the visual-spatial processing center is in the left hemisphere. For left-handed people, the localization is not as pronounced. The temporal lobes are also closely related to the sensory systems of smell and hearing. It also has the function of integrating visual information with other senses to form meaningful units. Damage to the temporal lobe, because of temporal epilepsy, can cause false perception or visual hallucinations. There are also reports of olfactory hallucinations, but less so. Due to the diverse function of the temporal lobes, misperceptions or hallucinations can be accompanied by persistent emotions, namely fear (Hermann & Chabiria, 1980). The temporal lobes play an important role in memory and storage systems.

Each neuron has its axon and branches. The end of each branch is the presynaptic terminus. The presynaptic terminus is adjacent to the postsynaptic terminal of another neuron. The area between those two ends is called the synaptic cleft. Neurotransmitters are stored in small sacs called synapses. Under the action of electrical stimulation, the substances contained in the synaptic pocket are released into the synaptic cleft. The neurotransmitters are then absorbed by special cells - receptors located in the postsynaptic region. Then the next neuron will be activated. In cases where all neurotransmitters are not absorbed by postsynaptic receptors, activation may be inhibited, or the substances may be reabsorbed back into the vesicle or reduce the activation of the neurotransmitters. other, for example, monoamine oxidase has been released into the synaptic cleft.

Neuron activation is mediated by weak electrical impulses that travel along axons to nerve endings. When the neuron is in a resting state, the outside of the neuron wall has the ion Na and the inside are the ion K. When the neuron is stimulated by information from the receptor site, the ion Na will move. move from the outside of the cell membrane to the inside. Thus began to appear electrochemical waves traveling along the axon and "warming" the cell. Immediately, the ion K will move from the inside to the outside of the neuron, and the original quiet state is repeated.

Neurotransmitters

There are several neurotransmitters involved in the etiology of most common psychiatric disorders. The effects of these substances are presented in Table 3.1 and are discussed in detail in later chapters of the book.

Serotonin

Serotonin was first discovered in the 1950s. It is an amino acid synthesized from L-Tryptophan. Serotonin is found in the striatum, midbrain, forebrain, cerebral cortex, hippocampus, thalamus, and hypothalamus. It is thought that serotonin is involved in emotional regulation. If it is low, it can lead to depressive states and obsessive-compulsive disorders.

Norepinephrine

Norepinephrine is the second neurotransmitter involved in depression and many other anxiety disorders. It is found in the hypothalamus, cerebellum, and hippocampus. Norepinephrine belongs to the catecholamine family.

Dopamine

Dopamine is one of the major neurotransmitters involved in schizophrenia. Dopamine-releasing neurons are found in the midbrain, in an area of ​​the brain designated as A10, connected to the thalamus, hippocampus, prefrontal cortex, and striatum. High levels of dopamine activation are associated with schizophrenia.

GABA

The effectiveness of benzodiazepines in the treatment of anxiety was known before their mode of action was understood. So far it has been found that they act in association with a neurotransmitter called gamma-aminobutyric acid (GABA). GABA contains inhibitory information: when the postsynaptic receptor receives it, it prevents the neuron from activating. Sites that contain GABA include the brain stem, cerebellum, and limbic system.

Vegetative nervous system

Although most explanations of mental health problems focus on neurotransmitters and nerve processes, another system, the autonomic nervous system, is also involved in some states. , namely engaging in stress or anxiety. The autonomic nervous system connects the gyrus to many organs of the body, including the heart, intestines, and smooth muscle system. Its job is to control the functioning of these organs in response to various demands, for example, increased heart rate, breathing rate, and blood pressure during exercise. The complete control of the autonomic nervous system is that of the thalamus. It receives signals about the state of hematopoiesis and the nervous system that informs the body's situation, such as the concentration of oxygen and acid in the blood. On the other hand, it also receives signals from the cerebral cortex and limbic system related to behavioral and emotional factors.

Vegetative process

The autonomic nervous system is divided into two subsystems: sympathetic and parasympathetic. They arise from the medulla oblongata in the brain stem and descend into the spinal cord. At different points in the spinal cord they connect with other nerves to go to the organs they innervate, such as the heart, arteries, skeletal muscles, and intestines. The sympathetic system has an excitatory function, its activation in the brain and spinal cord is controlled by norepinephrine. Elevated levels of norepinephrine lead to increased stimulation and activity of the target organ. The parasympathetic system, on the other hand, reduces arousal. Its activity is controlled by a neurotransmitter called acetylcholine. These two systems operate in opposition to each other, and the body's situation at any given time is related to the predominance of either of these systems.

Endocrine response

Neurotransmitters act very quickly but do not last long. In order to be able to respond to stress for a long time, another system is activated by the sympathetic nervous system… The increased sympathetic system will increase the activity of the adrenal glands. This gland is responsible for secreting into the bloodstream additional hormones for the neurotransmitter’s norepinephrine and epinephrine. These substances are circulated to the required organ and there, they are absorbed by the receptors and maintain the activity initiated by the neurotransmitters.

When emotions or stress are present, the sympathetic nervous system takes over. Then the body's activities lead to the risk of possible damage. At this point, that response is called a fight-flight response. Sympathetic nervous system activity predominates so the heart beats faster and stronger, blood is pumped vigorously to the muscles and withdrawn from the intestinal system, skeletal muscles are stretched to prepare for action. The individual may shiver, speed up, or get ready for action. That archaic response clearly prevails when the stressor is acute and life-threatening. Chronic activation in response to chronic stress or short-term activation at inappropriate times, such as in a supermarket or in a bus queue, is problematic.

Drug therapy

Activation of brain systems depends on the activity of individual neurons. In turn, the activity of each neuron depends on the neurotransmitter that the postsynaptic receptor receives. If it's too much, the system is overworked, and if it's too little, the system is underperforming. The aim of drug therapy is to maintain neurotransmitters at compatible levels. Their impact occurs in one of two ways:

Increases neurotransmitter availability by preventing synaptic reuptake, preventing a breakdown in the synaptic cleft or replacing a low concentration neurotransmitter with a corresponding drug. Drugs that increase the activity of neurotransmitters are called agonists.

Reducing neurotransmitter capacity by reducing neurotransmitter levels or replacing highly active neurotransmitters with less active pharmaceuticals… Drugs that inhibit neurotransmitter activity called an antagonist. The drug is usually given orally or intramuscularly and through it into the bloodstream. The drug enters the brain through the capillaries. Drugs invented to control brain activity are also not easy. The brain is protected by the blood-brain barrier to prevent bacteria and foreign substances from entering the bloodstream. In other parts of the body, the drug can easily reach its target by passing through small holes in the walls of blood vessels. However, the blood vessels in the brain do not have such holes. To reach its destination, the drug must penetrate the vascular wall cells themselves.