Mental illness:

Neuroscience and its origin:

• Neuroscience was originally physiological psychology. However, overtime it gradually evolved to become neuroscience. From there, neuroscience further evolved to become multi-disciplinary.

• Neuroscience now is many types of science coming together to ask what leads to mental disorder.

• With further evolution of neuroscience, scientists began to realize that it wasn’t enough to know what’s happening in the brain. This is due to other organs also having an impact on how the brain works. One example of this is microbiota.

• The goal of a neuroscientist is to define a mental illness

Microbiota:

• In humans, there’s microbiota in the gut. These bacteria are important because they help with fermentation, protection against pathogens, stimulating immune response, and vitamin production

• One crucial thing is that microbiota must be balanced.

• Disruption in microbiota balance could affect the brain

• A way that balance of the microbiota could be impacted is diet. the reason why is because food promotes bacterial growth.

• Antibiotics disrupt the microbiota balance because it kill bacteria regardless if beneficial or harmful.

• Another issue with antibiotics is that harmful bacteria can develop a resistance. This is due to natural selection removing bacteria without the resistance gene. Due to this, it promotes increase in bacteria with the resistance gene since they can pass it on and reproduce more.

• An issue with antibacterial resistance is that it will always happen regardless of the antibiotics made. Therefore, companies are hesitant to produce more since it will become pointless in the end

• Example: There’s only one effective type of antibiotic for gonorrhea and that is losing its potency.

Mental illness and issues with it plus social issues related:

• Mental illness is when you express yourself in a way that’s not considered normal

• A social issue is that people don’t care about mental illness so long as it doesn’t affect you or others. The reason why such belief is harmful is because mental illness can sneak up on you, then get worse.

• Mental illness “sneaking up on you” refers to how symptoms tend to be mild and not noticeable at first. However, without treatment, the symptoms will get worse and have more impact on the individual’s life.

• For all mental illnesses, the brain is a crucial feature.

• Another problem is that people with mental illness might dismiss their illness as normal

• Often, a mental illness will be genetic. However, the mental illness won’t develop unless a person undergoes certain experiences

• It is actually very common to have mental illness, approximately every third door has it. I believe that expression is meant to say every third household since it makes sense for families to share a mental illness.

• One issue is Loneliness, it in itself has worse effects that depression. It’s currently considered that loneliness is at an epidemic level. Interestingly, it’s considered worse for your health to be lonely than it is to smoke.

• Another factor that could cause mental illness is the collision of what self wants versus what the family wants of them.

• A reason why mental illness is so deadly is because it actually reduces the lifespan of a person by 10 years on average. Another effect is that health span gets reduced.

• An issue that makes the mental illness issue worse is that mental illness tends to get limited funding. Often this is because mental illness is dismissed as unimportant

• In general, the medical system seems to have a lot of bias. For example, Indigenous people or other people of color do not get the same treatment as a white person

  • Due to Indigenous people being viewed as more “mentally ill” than a white person. Because of this, any illness that an indigenous person experiences could be blamed on mental illness.

• Another issue in the medical system is the stigma against mental illness. It has caused actual diseases to be blamed on mental illness

  • For example, Chronic fatigue syndrome has been considered to be a type of mental illness when it is really a inflammatory immune system issue

• One thing that contributes to the stigma is labels. One reason why is because people are unique when it comes to mental illness. Having labels neglects that uniqueness.

• Labels can still be beneficial since they’re a convenient way to determine the problem. Although, they can’t be relied on too much since people can be given the wrong label and get misdiagnosed. That can occur when symptoms of different disorders overlap.

  • Problematic because this can lead to someone getting the wrong treatment, which can make the mental illness worse.'

  • An example, when someone is first developing BPD their symptoms are similar to depression. This can cause someone to then get misdiagnosed with depression. When given treatment for depression, it can lead to hypermania.

What neuroscientists do to address these issues in mental illness:

• There are different procedures done. Further more, there are different methods.

• It’s possible to try to experimentally determine which drugs work and how effective they are.

• A good experiment should have a group with the drug, a placebo, and one with nothing. Furthermore, it it important to know if different groups of people might react differently to the drug. That is why there should also be different types of people.

  • Examples could be different sex and different age groups.

  • Important not to have past three designs or else the data might become difficult to interpret.

    • The more rigor, the less relevance there is

  • Experimenters also needs to understand that experiments done in animals could yield different results than that in humans due to the different biological differences.

    • Schizophrenia is hard to evaluate in animals because it’s difficult to know what it looks like.

  • It should also be acknowledged that mental disorders come with different subtypes.

• Correlation is another method. It is trying to connect certain events to determine if they’re related to the illness.

  • Correlation is centered around cause and effect.

  • For example, events in early childhood such as child-abuse or poverty might have more significant impact later one. The reason why is because the child brain is more vulnerable to events impacting it because that’s when the brain is still developing. Therefore, experiences will impact its development.

  • An issue with correlation is that the suspected events aren’t always connected because it’s different for every person

    • For example, someone might suspect that parents yelling at them is a factor for their mental illness when really it is poverty because poverty causes a low quality of life for everyone.

  • In reality, it is probably a combination of factors that caused the mental illness. That is why Epidemiologists will gather a bunch of information and create a matrix.

    • Instead, uses a variety of information to determine cause and effect.

    • Works by having X factor lead to a Y% risk. The combination of factors will yield greater of risk in developing a disorder

• For a study to be reliable, it should be repeatable.

• For a study to have validity, it means that the measurements are accurate to what you believe is measured.

  • For example, you’re measuring the mental illness you think you’re measuring.

• Another method is through a retrospective study. It is where you take a group of people and ask about events that occurred in their life.

  • The issue is that people currently suffering will have a more negative view about past events in compare to people currently enjoying their life. Therefore, this method is flawed.

• There is a prospective study, which instead had people recall events and determine who is more likely to get an idea of what caused them to become who they are

• One important thing to note about studies and published papers is that there will be differences within them. This is why a Beta analysis exists so that it can identify the key differences in the studies.

• Overall, with so much data it can become difficult to have proper conclusions due to having such variety of potential answers

• Furthermore, genetic mutations could be a factor

• Socially, different groups will have different experiences

Mental health and it’s impact on events in life.

• There are different stages of how good your mental health is. It is a range Listed bellow is from worst to best:

  • Excelling:

    • Cheerful

    • Joyful

    • Energetic

    • High performance

    • Flow

    • Fully realizing potential

  • Thriving:

    • Positive

    • Calm

    • Preforming

    • Sleeping well

    • Eating normally

    • Normal social activity

  • Surviving:

    • Worried

    • Nervous

    • Irritable

    • Sad

    • Trouble sleeping

    • Distracted

    • Withdrawn

    • Note: This is the cutoff range. When it gets worse than this, it starts becoming problematic and it’s very difficult if not impossible for things to get better on their own.

  • Struggling:

    • Anxious

    • Depressed

    • Tired

    • Poor performance

    • Poor sleep

    • Poor appetite

  • In Crisis:

    • Very anxious

    • Very low mood

    • Absenteeism

    • Exhausted

    • Very poor sleep

    • Weight loss

  • Note about Struggling and In Crisis is that people tend not to recognize that it’s a problem when this occurs due to believing this is normal.

• By definition, Mental illness is not functioning at a level you should be functioning at for a prolonged period of time.

  • It creates a reduced benefit from social interactions.

  • All mental illnesses have some of these components:

    • Significant levels of distress

    • Changes in thinking, mood, or behavior.

    • Feeling isolated, lonely, or sad

    • Feeling disconnected from people and activities

  • There are multiple forms mental illness can take one

  • Having an illness can cause someone to be premorbid to another illness

    • This causes comorbid illnesses

• Mental health disorders often begin in early life and can be experienced by anyone.

• DOHaD is a stressor that affects the mother which can affect the receptors of the fetus. This will later have life repercussions by making the child more vulnerable to the mental or physical illnesses and their commodities.

  • Is an example of how things pre-birth can affect you.

  • Despite people thinking they don’t have memory before language, it is actually false. That is the reason why events early on can affect you.

• Ages when mental illnesses tend to develop

  • Anxiety begins around age 7, 8, or 9

  • Depression begins around ages 10, 1, or 12.

  • Schizophrenia begins around 17 or 18 however females are unique because it can peak again around the age of 34 or just in their 30s

• Note that for a mental illness to be a mental illness is has to be long term, not just feeling distressed over a single bad event.

• One interesting thing is that people can take memories and create their own. This is due to people taking different events, then merging it into a memory

• The neurons in a person can remember early events before language:

  • This means that neurons will be more reactive. When a neuron is active, it will activate a receptor which will excite the next neuron. This network of neurons will then get more active with experience. Therefore, when another event occurs, the neurons will be active in the same way.

  • When pregnant, it a parent experiences experiences a emotion such as stress, it can then affect the fetus.

    • Those who have encountered a stressor are more likely to be impacted by drugs such as cocaine or amphetamine. The same occurs in reverse.

  • The younger the person, the more impactful the events will be.

• Genetics can also influence if a person will develop a mental disorder because they impact phenotypes. The phenotype could be behavior.

  • Note that it’s rare for a single gene to cause an illness. Rather, it’s a combination.

• Note that often these factors will combine and cause a disease

Biophysical mode:

• Meant to acknowledge that different components contribute to a mental illness. It is a venn diagram of the factors: Biological components, Psychological components, and Social components.

• Should note that having a single factor doesn’t guarantee developing mental illness

These factors can influence genes. That is called epigenetics where the genes can activate or disactivate based on environmental stimuli.

Epigenetics:

• When the way the gene expresses itself changes. Could be expressed or suppressed.

• If a gene gets suppressed, it’s more likely to be passed on without necessarily noticing. Therefore, later on it could lead to a more significant impact.

• Its theoretically possible to undo bad epigenetic changes but there’s not many studies to support that.

• Methylation is changes that shouldn’t be there

Stigma:

• statistics are often based on the number of people who use mental health services. Therefore in reality there’s more people who suffer from mental illness than statistics tell us.

• Treatment has been portrayed as barbaric through portrayals of past treatment methods. Unintended consequences of this is that it makes people more afraid to seek out treatment.

Currently, drugs are used as treatment for mental illnesses.

• One issue is that they may seem to have good effects first but it can be later be shown to have consequences. Most often, the positive effects will be apparent first.

• Because we do animal testing, we don’t necessarily know the effects on humans. This is because there are aspects in animals which may differ from humans. For example, mice are often used because they’re cheap but their pregnancy term is shorter and the way they develop cancer is different.

• Ignorance is often what leads to negative affects of drugs occuring.

Diagnosis:

• Currently the biopsychosocial model is used as it views mental illness as coming from those causes. Because of this, psychological issue are viewed as symptoms of a biological disease.

• Often, to diagnose symptoms are identified. With the cluster of symptoms, an illness can get associated with it. The medical approach can be used to determine treatment:

  • Etiology: What caused it?

  • Prognosis: What are the consequences?

  • Epidemiology/Prevalence: How common is it?

• A tool used is the Diagnostic & Statistical Manual of Mental Disorders (DSM):

  • It lists the mental disorders and their symptoms. There are also descriptions of the disorder provided.

  • It has evolved a lot over time as views changed

• Issues with these methods of diagnosis:

  • There is often overlaps of different mental illnesses, which will lead to a misdiagnosis. Furthermore some illnesses are comorbid.

  • Simply knowing the symptoms doesn’t state what can be used as treatment. Most often, there’s a high uncertainty on whether or not the drugs will work.

  • Factors would probably be easier to predict based on traits like age, sex, and other things.

• Research Domain Criteria Initiative (RDoC):

  • It works as a matrix where the symptoms and molecules are listed. As a result, a matrix is created of biological and behavioral features.

  • The goal is to diagnose characteristics so that you can treat the symptoms directly rather than treat the disorder.

  • Overall it is much more a successful method for selecting an effective treatment

  • Eidiosim gives hints on the best strategies based on illness cause

  • Pleiotropy is a set of genes with multiple actions and they tend to have more effects.

Anatomy:

Organization of the Nervous System: Is based on the body axis.

• Dorsal: Top of the brain

• Ventral: Bottom of the brain

• Anterior: Front of the brain

• Posterior: Back of the brain

• Lateral: Outsides of the brain towards the sides

• Medial: Middle of the brain

Directional terminology:

• Coronal section: Front part of brain if you were to cut there

• Horizonal section: If you were to cut off the top part of the brain

• Sagittal section: If cutting results in left and right sections of the brain.

Nervous system::

• Two separate parts of the nervous system

• Central Nervous System (CNS): In the brain and spinal cord

  • Encases for portection

• Peripheral Nervous System (PNS): Has two types

  • Somatic Nervous System:

    • Has Efferent nerves which connect the CNS to the skeletal muscles. Signal goes from brain to skeletal muscles

    • Has Afferent nerves which are sensory nerves that carry information from sense organs to the CNS.

  • Autonomic Nervous System:

    • Regulates homeostasis.

    • Also divided into two types:

      • Sympathetic nervous system (SNS): Associated with arousing or fight and flight. It is what gets activated with stress

        • Dilates pupils to enhance vision

        • Relaxes bronchi for more air

        • Accelerates and strengthens heartbeat

        • Inhibits stomach activity and blood is sent to muscles

        • contracts vessels for increased blood pressure

      • Parasympathetic nervous system (PNS): Rest, digestion, overall calmer

        • Contracts pupils

        • Constricts bronchi

        • Slows heart beat

        • Stimulates digestion

        • Dilates vessels

      • The SNS activating causes a feedback loop which inhibits PNS

External features of the brain:

• Cerebrum:

  • major structure of the brain which contains two identical left and right hemispheres. It’s the main part of the brain

• Cerebellum

  • Involved with motor coordination. That is why size is dependent on need for moto coordination. It is the thingy under the main part of the brain (brown thingy in diagrams)

• Brainstem:

  • Has the deep structures of the brain and connects the brain to the spinal cord. It is critical for sustaining life.

The Cerebral Cortex:

• The outer later of grey matter. It’s the one with the wrinkles

  • The wrinkles are meant to save space and fit in more grey matter

  • Gyrus is the bump between grooves

  • Sulcus is the groove between the bumps

• It is part of the cerebrum

• Is the site for higher level functions such as consciousness

Lobes of the brain:

• The cerebral cortex is divided into different lobes

• Frontal lobe: responsible for motor control and executive functions

• Occipital lobe: Is located at the back of the skull and is responsible for vision.

• Parietal lobe: is responsible for touch sensations and sense of self in space

• Temporal lobe: Located at the bottom. Is responsible for auditory sensation, language perception, and gustatory (taste) functions.

Corpus callosum:

• Made up of white matter and connects the two hemispheres of the brain

• It’s important since the right and left hemispheres of the brain work independently.

Hemispheres of the brain:

• Structurally and visually, they’re similar. However, functions differ

  • Visual system is different for the two hemispheres

  • Eye connections cross over

  • Other functions are wired to same side

• Due to the different functions in the brain, it is crucial that there is connection aka corpus callosum.

  • Enables for each side of the brain to know what the other is doing.

Terminology:

• Contralateral: Opposite side

• Ipsilateral: Same side

Lower range of brain:

• Begins development when a fetus is 6 weeks old

• In it, there are hollow regions which connect to the spinal cord

• Spinal fluid can provide a rough index of what occurs in the brain because those fluids are similar to brain fluids.

• Hollows are called ventricles.

Durometer:

• Located at the top of the brain. Its function is the protect the brain.

• It’s a thin sleeve in the form of fluid.

Blood-Brain-Barrier::

• Due to there being a lot of blood flow to the brain, there needs to be a way to prevent toxins from entering. That is the role of the Blood-Brain-Barrier.

• It works by having cells be tightly packed or tightly woven together. Because of this, it prevents larger molecules from entering the brain.

• With the Blood-Brain-Barrier, chemicals can still be transported to the brain through the periphery and is able to go through Blood-Brain-Barrier

  • Same mechanism Import for certain treatments

• Still, there are parts of the brain where the Blood-Brain-Barrier is weaker. Due to cells not being as tightly packed, larger molecules can get in. This is bad since it risks brain diseases and viral infections.

• Furthermore, the blood brain barrier is weaker when you’re young and a fetus. This is due to cell not being as tightly packed.

  • This is why it’s crucial that parent makes healthy choices when pregnant

• Stress can cause the blood brain barrier to open up, causing you to be at greater risk of toxins getting in your brain.

Immune system fact: Killer cells require T-regulatory cells to make them calm down. Otherwise, it risks an autoimmune disorder if they don’t do their role.

More on specific brain anatomy:

Cerebrum is the outer area of the brain:

• The reason why there’s a lot of wrinkles is for increased area

Cerebellum:

• Plays a role in motor function and mood.

• It’s the brown mini-brain

The brainstem:

• Located in the medulla, there’s different section where it’s divided into different sections. These play roles in connecting to other brain regions. They’re also controlled through connections to the spinal cord.

• List of brainstem regions:

  • Diencephalon: has two parts listed bellow

    • Thalamus: is a waste station

    • Hypothalamus: contains different groups of cells which have different functions. Those cells will be in different regions. Furthermore, it’s the location of the reptilian brain

      • When the hypothalamus develops, there’s two bumps where the larger part of the brain is wrapped around it. The bigger bump is the new brain

      • A role of the hypothalamus is to prepare the immune system if it senses danger.

The ventricular system:

• cushions the brain by having hollow regions called ventricles

Meninges and cerebrospinal fluid (CSF):

• meninges protect the brain and spinal fluid. It is a special membrane.

  • An issue when meninges are infected is that is causes meningitis

• Cerebrospinal fluid (CSF) is what fills the ventricles and circulates around the brain and spinal cord. Similarly to plasma, it contains glucose, salts, and minerals. However it has very little protein. Another trait is that the density is similar to the brain. That way the brain can float comfortably in the skull.

Characteristics of neurons:

• Neurons send messages to each other

• Over time, neurons are lost since they don’t replicate more as a person matures

• The main chord thingy is an axon

• Dendrites have small spicules on. They disappear when disorder appears. It was found that the loss of spicules leads to a lost of brain function.

• It is possible to grow neurons but it doesn’t happen often.

• Arborization: when the amount of Dendrites increases

• When an experience happens, cells will connects by releasing chemicals which go across the gap between them.

In the brain there’s also Glial cells:

• They support and modulate neurons. They also create the myelin sheath.

Neuron parts and functions:

• Dendrites: gather information from other neurons

• Cell body: Core region where the nucleus and DNA is contained

• Axon hillock: Where cell body and axon is joined

• Axon: Carries information which is to be passed to other cells

• Terminal button: At the tip of the axon which conveys information which connects to the dendrites of other neurons.

Moderation: Important for transmission between neurons to be regulated:

• Messages gets sent to presynaptic neuron as a method to regulate transmission.

• Neurons use a self-regulating system

• Auto receptors will get stimulated so that neurotransmitters are only sent when needed.

• Enzymes can modify to the characteristics of another chemical:

  • This can happen inside or outside the neuron

  • Are picky and prefer fresh neurotransmitter. There’s 20% of neurotransmitters that doesn’t get taken and is reabsorbed. Those neurotransmitters can then be broken down and reused

Myelin:

• Generally information is transferred through impulses from the change of electrical potential in the axon. This takes a while on its own.

• Myelin covers the axon everywhere except for the nodes of Ranvier. That way, the impulse only must travel through the nodes of Ranvier and it’s faster.

• Disorder called MS where myelin gets broken down.

• Structurally, myelin is a fatty substance which insulates the axon.

Tract:

• Tracts are large collections of axons in the CNS. They connect nuclei to each other. White matter mostly consists of tracts.

Nerve:

• Large collection of axons forming connections in the PNS.

Nuclei is the grouping of cell bodies:

• Nuclei connect to different parts of the brain and cause functional differences

• They can be recognized from their structure, chemical composition, and function

• White areas is where the spinal fluid is situated

Note: No such thing as specific in the brain since everything is integrated so the different parts of the brain know what’s happening.

Neuron networks:

• Neurons in the cortex will have a uniform grid-like organization

• Neurons in the subcortex and brainstem are more irregular

Methods to keep us young:

• Synapsis will often form, however, with too many there’ll be inefficiency. This is because too many messages get sent. It leads to a loss of specificity with too much useless neurons. To solve this, synaptic pruning occurs to remove inactive neurons.

Subcortical Network

• Limbic system is important for emotions and memories. However, it can be affects by psychological disorders and drug addiction. There are three major parts:

  • Circulate cortex: Does emotional processing and memory

  • Amygdala: Associated with fear, aggression, and emotionally charged memories

  • Hippocampus: Forms long-term memories

• Basal ganglia controls movement and are crucial for learning and memory. Specifically, the play a role in learning habits. Three main parts are:

  • The caudate nucleus

  • The globus pallidus

  • The substantia nigra: Part of midbrain and contains dopaminergic neurons which project into the basal ganglia

Communication of the Brain:

Gluttons:

• Are located at the end of the axons. Their role is to release the chemical when a neuron is excited. This action will excite the receptors of the next neuron.

Synapse:

• The space between the axon and the dendrites.

• Role is to transfer chemicals between neurons

• The synaptic clef is the area chemicals will go across and are present in

Gabba:

• An issue is that neurons can get over or under stimulated. For this reason, chemicals are required to promote and inhibit excitation.

• Gabba is an inhibitory chemical for the neurons.

• Glutamate is an excitatory chemical for neurons

Neuron self-regulation:

• Having a greater amount of chemicals excites neurons. As a mechanism to prevent neurons from getting too excited, chemicals hitting the pre-synaptic clef indicate that the neuron needs to stop releasing chemical.

For a message to be sent, the cell body must send a signal to its axon and an electrical signal can be sent to release neurotransmitter.

If a certain chemical causes a disorder, these are possible treatments:

• Can block the receptors in the receiving neuron so that why chemical release can’t occur.

• Could manipulate the second messenger so that no signal can be sent even when it receives the neurotransmitter.

Electricity:

• Due to there being the charged particles sodium and potassium.

• Inside the axon, the resting potential is around -70 mV. Meanwhile outside has an equal opposite charge.

  • Note: It’s possible to be less then -70 mV. It just means that more work is required to send a signal

• When charge changes, the new charge will spread throughout the rest of the axon.

• Charge can change quickly due to the myelin coating, having previously caused pressure, disappearing. This is why voltage can change quickly.

• Action potential: The entire neuron has is activated at once so that a signal can be sent to the next neuron.

• Once signal has been sent, ions will be pumped back into their regular status

Multiple Sclerosis:

• Disease that destroys myelin sheaf. Because of this, there’s nothing to prevent charge from getting in and out. Therefore, signals are sent significantly slower.

Action Potentials:

• By definition, it is the change of charge in a neuron that must reach a threshold of approximately -60 mV to -50 mV.

Depolarization:

• When the charge reduces and returns back to normal

Synaptic transmission:

• First, neurotransmitters get synthesized and are stored in the presynaptic axon terminal

• Second, an Action potential must stimulate a release of neurotransmitters into the synaptic cleft.

• Third, the Neurotransmitters must bind to receptors

  • It’s important to note that the chemical structure of the neurotransmitter must fit that of the receptor for the binding to occur. The specialized proteins are embedded in the post-synaptic membrane.

  • There are 21 different forms and per form there’s 5 receptors

• Fourth, the ligand-gated receptors coupled to ion channels will the cause the channels to open once bound to a neurotransmitter. This will cause an influx of ions to change potential of the post-synaptic neuron. This is called post-synaptic potential (PSP).

Reason why glutamate and GABA work:

• glutamate is excitatory because its receptor enables the influx of cations. This then depolarizes the post-synaptic membrane therefore increasing likelihood of another action potential.

• GABA and glycine are inhibitory because their receptors enables the influx of anions such as Cl^-. As a result, the post-synaptic membrane is hyperpolarized and the likelihood of an action potential is decreased.

Ageing and neurons:

• As you age, there’s a reduction in number of neurons of present. As a result, diseases such as Parkinson’s are caused.

• It’s possible to manipulate the synapse but there will be an associated risk due to brain regions interacting with each other

SRRI’s and how they work:

• Instead of giving a person more serotonin, they actually enable serotonin to be brought back in and be reused

• It not very effective since it typically take 2-3 weeks to feel any effect and their effectiveness is dependent on the amount of BDNF and requires a specific receptor to be effective.

Triggering action potential:

• EPSP: brings a neuron closer to the threshold potential. To do this they can summate to increase likelihood of an action potential. For summation, they must be close together since if they’re far the neuron will have enough time to regulate resting membrane potential hence no action potential gets triggered.

• EPSP must happen close together in time and space for action potential to be triggered.

• axon hillock: where the sufficient depolarization must occur.

Neural signaling:

• PSP get elicited on the cell body and dendrites

• PSP is conducted decrementally to the axon hillock

• threshold potential gets reached at the axon hillock and an action potential is triggered

• action potential the gets conducted down the axon

• when the action potential arrives at the terminal buttons, it triggers to release of neurotransmitters into the synapse.

Neurotransmitters classes:

• This includes class and examples

• Amino acids: Glutamate (Glu), Glycine (Gly), y-aminobutyric acid (GABA)

• Monoamines: Dopamine (Do), Norepinephrine (NE), Epinephrine (EP), Serotonin (5-HT)

• Peptides: Vasopressin, Oxytocin, Neuropeptide Y

• Other: Acetylcholine (Ach), Adenosine, Anandamide, Nitric Oxide.

Receptors and ligands:

• Ligands: Molecules which bind and activate receptors. Neurotransmitters and hormones are ligands

• Receptor: is a protein shaped in a way so that it can only accept binding from certain ligands

• Drugs and poisons will interact with receptors in a way that’s similar to ligands

Deactivating Neurotransmitters:

• Neurotransmitters can diffuse from the synaptic cleft

• Degradation: where enzymes break down neurotransmitters into inactive molecules.

• Glial cells and uptake stay neurotransmitters

Cingulate cortex:

• Role is to take the variety of sensory information in order to create proper appraisals of what’s occurring. It is also the center place to coordinate things

Hypothalamus:

• One role is to enable survival functions such as eating, drinking, and mating.

Dendrites and synapses:

• Over time, dendrites gain synapses since experiences and doing something connects synapses. It is important to enable identification of things regardless of similarities.

Synaptic pruning:

• a process that occurs when there’s too many synapses

In the ventricle (hollow part of brain)

• Neurotrophins are located here, which are growth factors. Due to synaptic plasticity, it’s possible to grow new neurons since the brain is malleable

• This doesn’t occur much after birth however it is a form of treatment for conditions that cause people to lose too many neurons.

Glial cells:

• Less permanent than neurons.

• Originally, they were thought of as only helpers to the neurons. However, it has been later found that there’s different types which have different functions. These types are listed bellow:

  • Astral glia: They have tentacles and play a role in development

  • Micro glia: provide cytrophins to the brain which otherwise wouldn’t be there. Play role of immune cells in the brain and cause the inflammatory response. Regulation of them may be needed if there’s too much and they get too excited.

• Events can influence glial cells. For instance, positive events increase activity and negative events decrease activity. Trauma influxes glial activity in attempt to help you however this is excitotoxic therefore harmful.

Influence while pregnant increases the chance of developing schizophrenia.

Stress:

Stressors:

• Negative experiences are considered stressors.

• Different types of stressors listed bellow:

  • Psychogenic stressor: psychological

  • Neurogenic stressor: physical

  • Systemic stressor: bodily systemic events

Appraisal:

• Are what you do when exposed to a stressor to determine if something is dangerous

• Secondary appraisal: After something is determined to be dangerous, questions are made on how to deal with the danger.

• Note: incorrect appraisals can be made

Kahneman and Tversky:

• suspected the appraisal process since people make too many errors

• Came of with Heuristics, which is the shortcuts people make in thinking to choose convenience and comfort

Priming:

• when people are primed to think in a certain away

• It is how the placebo effect is effective and the autonomous nervous system still acts due to conditioning.

Conforming:

• Due to people believing groups give strength. This will cause people to try and fit into a group even though it’s illogical

• Note: there can be exceptions which is often dependent on biological factors.

Coping mechanisms:

• Three main categories are:

  • Problem Solving

  • Avoidance

  • Emotional Response

• Different methods can be ideal depending on situation and can even be combined

Rumination:

• How people reflect on a situation after it occurs. The type can tell you about the type of person you are since depressive types tend to do negative rumination

• Negative rumination: Reflecting on how you should’ve been more aggressive

• Positive rumination: Analysis and problem solving

Psychological factors to stress:

• Feeling a lack of control over stressors can create more stress than if you have control over what will happen.

• The lack of control causes an animal to learn helplessness and changes neurochemistry

Physiological response to stress:

• General adaptation syndrome: is a way to respond to stress though three steps:

  • Alarm: Reaction to stressor

  • Resistance: cope with stressor. uses cortisol and HPA axis

  • Exhaustion: when Physiological factors are depleted

• Two pathways

  • Sympatho-adrenomedullary axis (SAM). It’s faster:

    • Hypothalamus projects into the spinal cord where they synapse with neurons in sympathetic nervous system. SNS then projects into the adrenal medulla which releases catecholamine and epinephrine and norepinephrine into circulation

    • Catecholamine epinephrine and norepinephrine binds to adrenergic receptors in the body which increase heart rate and other stuff

  • Hypothalamic-pituitary-adrenal axis (HPA). It’s slower:

    • Releases corticotropin-releasing hormone (CRH) into the anterior pituitary which stimulates release of adrenocorticotropic hormone into general circulation which simulates release of cortisol from the adrenal cortex

    • Cortisol is a steroid and has two receptors mineralocorticoid receptor and glucocorticoid receptor

Hormone:

• In the periphery and the brain. They’re secreted form different organ glands so they must travel longer to activate receptors

Hormones working together:

• Several processes that work in conjunction with each other. For example, eating is in conjunction with stress since eating isn’t needed when your life is in danger

• An unusual response is increases appetite when exposed to stress

Autonomic nervous system:

• Sympathetic: prepares for action. Can release norepinephrine to stimulate response in organs like the heart.

• Parasympathetic: Slows things down. The opposite to norepinephrine is acetylcholine, which is an inhibitor. Too much causes a coma

Depression:

• Has different types as listed

  • Neurovegetative: typical depression symptoms

  • Atypical depression: when people eat and sleep more

• Each type requires a different treatment

Amygdala:

• Hormone in this region creates anxiety

• On it there’s the extended amygdala

  • Creates anxiety about the future and tricks you into not being worried for a while

Ambiguous stressor:

• When there’s uncertainty if the stressor will occur. Lack of knowledge is what creates stress and increases brain activity so that you can know what’s happen. Because of the uncertainty, incorrect conclusions can be made

Systemic stressors:

• Changes in the immune system can be interpreted as a stressor and cause the body to get defensive.

Allostasis:

• Occurs if there’s danger and can be repeated when exposed to a situation multiple times

• Allostatic overload happens when it’s been activated too much and the system crashes and cells begin to die.

Hippocampus and aging:

• Hippocampus is related to memory and is thought to be related to dementia and Alzheimer. Specifically, it’s also related to stress responses

• In elders, these cells die and cortisol levels rise. This is bad since it increases cell loss and limits inflammation.

Sensitization:

• Neuro responses tend to be greater with another encounter since receptors are hit again.

• It can also make people more prone to drug reaction due to similarities.

• Childhood increases these effects since brain is still developing.

Prefrontal cortex:

• Involved with concertation, planning, decision making, insight, judgment, error detection, and memory retrieval. Functions get impaired with stress since it’s stimulated by DA and NE but stress shuts those down

Immunity:

Two types of immune system:

• Innate immune system: what you’re born with

• Adaptive immune system: acquired

Innate:

• Rudimentary immune cells will determine which cells are part of the body when you’re a fetus.

• That way, it can differentiate between self and pathogen.

Neutrophile:

• Cells that surround and kill a pathogen. To do this, they must sacrifice themself.

Macrophage:

• When identifying a pathogen, it will use its tentacle to bring the pathogen into itself where it gets ground up so that a piece may be taken up to the surface.

• Note: Because a piece is brought to the surface, the T-helper cell can then identify it and alert the rest of the immune system

Antigen presenting cells:

• Present a pathogen to the T-helper cells

Virus:

• Infiltrate a cell to reproduce. They do this until their population is so high the cell burst

Natural killer cells:

• Innate cells which are best at killing cancer cells and viruses

Cytotoxic T-cells:

• can kill a cell infected by a virus and inject it so that the cell dies, therefore killing all viruses inside.

B-cell:

• Uses antibodies which have chemical compositions. When there’re a match with the receptor then it’s identified as a foreigner and killed

• T-helper cells will then remember the foreigner

It takes about 4-6 days for the immune system to be fully ready

Memory cells:

• Crucial to remember a pathogen so that the next time the immune system can be ready more quickly and stronger

• Both B-cells and T-cells play this role.

Change in environment:

• Exposure can happen because there’s different animals which carry different viruses.

Cancer cells:

• They multiply fast. These are usually complicated to deal with since they can evade the immune system by attaching self to the immune system

Stressor impact on immune system:

• Allostatic overload occurs and the immune system crashes

• Mild stressors tend to enhance immune system while chronic stressors worsen it

Cytokines:

• Located in the periphery. They’re involved in the transmission of information. Often named IL-number. These promote inflammation and fever

• Not good if too much inflammation and fever since cells could get killed. That’s why inflammatory ones like Il-4 and Il-10 exist.

Microbiota:

• works in harmony with the immune system and is formed by acquired bacteria over time.