PTSD

Posttraumatic Stress Disorder or PTSD is a serious psychiatric disorder that can occur after a traumatic experience. It is usually associated with soldiers who have been in military combat, but can also occur after natural disasters, vehicular accidents, sexual assault, terrorist incidents, plane crashes, and a variety of other traumatic incidents. Although most people will experience elevated levels of stress during and after the traumatic incident, they will eventually subside and go away over time. Only a few develop PTSD.

Factors in PTSD development

Development of PTSD involves an array of factors such as:
 ·        Intensity of trauma
·         Duration of trauma
·         Casualties
·         Extent of injury to self
·         Personal reaction
·         Support system available after trauma
·         Ability to cope

Symptoms

·         Flashbacks- bad memories or nightmares can be seen as reliving the traumatic event. Flashbacks may cause the individual to feel scared and helpless.

·         Avoidance- of situations that trigger a memory often changing everyday tasks. It can include everything from sounds and smells to people and places that remind them of a key aspect or element present at the time.  

·         Hyperarousal- individuals with PTSD report feeling jittery, alert, and even paranoid often. This can often cause the individual trouble sleeping and concentrating.

·         Negative feelings- The person may feel guilt, worry, and depression. Some even report a numb feeling and may isolate themselves from other to avoid talking about the traumatic event. 

Other problems

Other conditions such as depression, substance abuse, and depression may also be co-morbid with PTSD. Individuals with PTSD may also have chronic feelings of hopelessness and despair as well as chronic pain. These individuals are also more likely to have marital or relationship problems. 

Treatments

Psychotherapy- there are several different types of psychotherapy available for individuals with PTSD, all involve meeting with a therapist. 

·        Cognitive Behavioral Therapy (CBT) has shown to be the most effective type of counseling. It examines the relationships between thoughts and feelings that influence the individual's behavior and aims to change disturbing thoughts/feelings negatively impacting behavior. There is Exposure therapy and Cognitive Processing therapy. Exposure therapy involves the patient being exposed to the trauma (in a safe way) until it's no longer met with fear. Cognitive processing therapy allows the patient to cope, accept, and understand what has happened. The goal is for you to change the way you think about the traumatic event and help decrease feelings of guilt and blame. 

Medications

·        Antidepressants
SSRIs like Sertraline and Paroxetine more commonly known as Zoloft and Paxil, respectively. 

·         Prazosin
Can reduce nightmares and sleep problems because it blocks the effects of adrenaline released. 

*As with all medications, there are possible side effects that an individual must consider beforehand.  CONSULT WITH A DOCTOR before discontinuing any medications or thinking of taking any medication.

PTSD OVERVIEW

Here is a list of hotlines available if you or someone you know is dealing with PTSD and needs help.
PTSD Hotline:  1-800-273-8255
National Sexual Assault Hotline:  1-800-656-HOPE
National Center for PTSD: 802-296-6300
Safe Helpline: 877-995-5247

References:
http://www.ptsd.va.gov/public/PTSD-overview/basics/what-is-ptsd.asp
http://ww.nimh.nih.gov/health/topics/post-traumatic-stress-disorder-ptsd/index.shtml

What's in a smell?

When you smell the lovely aroma of freshly baked bread you probably don't think "wow those are some good smelling chemicals", but more likely your mouth waters and you might even become hungry. You might also remember a time you were out with friends and had a pastry or a time your mom baked bread. Smell is very important; it can alert us of a fire, prevent us from eating rotten food, and gives food much of its taste.

While we can smell more than 10,000 different smells and have hundreds of olfactory receptors, rodents have thousands of olfactory receptors. So how exactly does smell work? Let's start with some basic anatomy and physiology involved in olfaction, which is the sense of smell. Just as your nervous system uses neurons to function, smell also has specialized neurons for smell called olfactory cells. The special cells line the back of your nasal passages and have tiny threadlike hairs called, cilia. If the olfactory receptor is stimulated an impulse will be sent.

The cilia will then send the impulse (smell) to the olfactory bulb, which then sends it to certain areas in the brain. The brain is then left to interpret the pattern of the molecules or odorants as a specific odor. This takes place in the olfactory area in the cerebral cortex. 

While this explains how we are able to associate a certain chemical trace with a "smell", why is it that certain smells bring back memories? A certain breezy perfume may bring to memory a day at the beach or a certain musty smell may remind you of days spent at grandmas. 

Well as the olfactory bulb sends the odorants to the cerebral cortex, it also sends it to other parts such as the hippocampus, hypothalamus and the amygdala. These structures (including the olfactory bulbs) are part of the limbic system, which deal with memory and emotional behavior. 

The reason smells can trigger a memory is because when you first encounter a new odor you connect it to a certain moment, person, or place unconsciously. For example, if you were to smell minty scent while eating a candy can you would associate a candy cane with the smell of mint. The next time you get a whiff of mint you will (probably) remember that moment and how you felt. So why is it that not everyone likes the same smells? It is because everyone has a different memory and mood attached to different scents; what may have made you happy while smelling mint may have given someone a headache. 

I hope this clarified how olfaction occurs, happy smelling!

References:

Kalat, J. (2012). Biological Psychology. Cengage Learning.

http://health.howstuffworks.com/mental-health/human-nature/perception/smell.htm
http://www.bbc.com/future/story/20120312-why-can-smells-unlock-memories

How to improve your ...um what's the word???? Oh, memory!

Have you guys ever experienced this???

Well if so, you have experienced the 'tip of the tongue' phenomenon (not a very clever name, right?)
Although this may be one of the few times your memory "fails" you, your memory is actually amazing. It may sound silly, but do you know what memory is?? It is the ability to encode, store, and retrieve information and experiences at any given moment. I am sure if I asked you for your birth date you would answer automatically as well as if I asked for your name, age, or mother's name. This information was probably told to you by your parents at one time and you successfully encoded, stored, and can now retrieve it on the spot.

First, there are many different types of memory.

Here is a brief summary in the three main types of memory.

   

  Sensory Memory: This is the shortest type of memory that is detected by the senses (touch, taste, smelling, hearing, and seeing). It only lasts about 1 second!! It can either be ignored or perceived and that is what makes it so short.

     Short-term Memory (STM) or Working Memory (WM): It used to describe events that have just occurred and are currently manipulating or thinking about. While it is short lasting as well, it can last around 30 seconds to a minute, but beware once you stop focusing or become distracted it is gone forever.

     Long-term Memory (LTM): This is typically the type of memory we think of when we remember our 8th birthday party, first kiss, learning to drive, or graduation. It refers to memories that happened further back and have been encoded, stored, and available for recall. We are able to store unlimited amount of information for infinite amount of time. 

Here is a good video summary on the types of memory as well as tips to improving your memory.

 

Easy ways to improve memory

1. Paying attention

       - As obvious as it sounds giving your full attention to a task helps.

2. Coffee

       - helps because as a stimulant drug it increases levels of arousal making it easier to retain the information.

3. Exercise

       - Other than for memory exercise is good for many things (health, mood, alertness...) as well.

4. Sleep

       - Studies have shown if you take a break during studying your brain can consolidate and solidify information. 

Nap anyone?

5. Chewing gum

       - It increases activity in the hippocampus, a very important area for memory.

       - Increases oxygen levels.

6. Meditating

       - It increases the cerebral cortex, the area responsible for concentration.

7. Chunking

       - You have probably used this before such as when you read a phone number or your SSN. It helps because you put the information into more manageable pieces.

8. Use imagery

        - When you're going grocery shopping use imagery when thinking about what you need.

Try these and see what works for you!

References:

Kalat, J. (2012). Biological psychology. Cengage Learning.
http://www.businessinsider.com/research-tested-ways-to-improve-your-memory-2014-3
http://www.human-memory.net/types.html

Cutting the cables: The split brain

Epilepsy is a serious neurological disorder often characterized by recurrent episodes of increased and abnormal activity in the brain. Epilepsy can occur due to gene mutation, trauma, tumors, infections, or even from the brain being exposed to toxic substances however, the cause is usually unknown.

The Surgery

While there are a couple of methods of treatment, the more severe cases of epilepsy in patients can be treated by performing a rare surgery that cuts the corpus callosum called corpus callosotomy.

It is a risky and invasive treatment option because the corpus callosum will not heal therefore is left as last alternative. As you may know, the main responsibility of the corpus callosum  is allowing communication between the two hemispheres. It is the reason why even though each hemisphere is specialized for certain tasks it never feels as if two people are sharing one body. Severing the corpus callosum works because it stops the epileptic seizures from crossing into the other hemisphere and therefore shorten the time the seizures last as well. Sometimes if the surge of electrical activity cannot "ping" back and forth, a seizure will not even develop! 

Aftermath

You may be thinking, "this sounds great, no more seizures!" however, any surgery has risks associated with it and this is no exception. People who have undergone corpus callosotomy are often referred to as split-brain people who although maintain motor and intellectual abilities have difficulty performing tasks that are not familiar to them. Severing the corpus callosum affects what split -brain people can see; if an object is presented to them in one hemisphere, the other will not see it. One benefit found in split-brain people is they can use their two hands independently in a way non split-brain people cannot. What do I mean by this? They have the ability of simultaneously moving the left hand and right hand in different directions. They are able to do this because they can plan two actions at once since each hemisphere process information independently. Eventually conflicts between the two hemispheres will diminish as the brain begins to adapt and use smaller connections between the hemispheres.

Hemisphere Specialization 

Studies have shown people suffering damage to a certain hemisphere lose specific abilities and functions which leads to the concept of lateralization. Lateralization is division of labor between the two hemispheres such as the left hemisphere to be involved in language and logical thinking with the right mainly specialized in emotions and creative thinking.

Patients with damage to the left hemisphere are more apt at recognizing and understanding gestures and facial expression because the right hemisphere is better at perceiving emotions, recognizing humor and sarcasm, as well as spatial relations. With the left hemisphere "out of the way", the right hemisphere is able to do what it does best, recognizing emotions. Need clarification? Here is a video that further explains the concept of lateralization and split-brain theory.

In conclusion...

References:

Kalat, J. (2012). Biological psychology. Cengage Learning.

http://www.nature.com/news/the-split-brain-a-tale-of-two-halves-1.10213

The Amazing Spider-Man? More like The Amazing Brain

Do you guys remember this movie??                

                  And do you remember Dr. Curt Connors? The scientist who tried to regrow his arm by combining lizard and human genes, "surprisingly" turning into an evil lizard villain?                                      
                                                         

                                      
Well what I want to talk to you guys about today is not that you should watch the movie, but about one of the many amazing things our brain can do, pathfinding by axons. You may be thinking oh come on this is just a movie, but the concept that leads Dr. Connors to try this "serum" is the regenerative ability of axons to find specific pathways to their original connections. Now I am not saying that it is possible in humans (yet??), but that this is true in some amphibians, (salamanders, newts...) and lizards (tails).

How does regeneration work?

Well in a salamander if you cut off a limb the wound will eventually close and regenerate new cells, bone, and muscle. The first thing is new cells being regenerated, join to form what can be referred to as the wound epidermis  relaying messages for nerves to regenerate. After the amputation, many groups of stem cells join at the wound creating what is called a blastema.


<-------  A=mass of cells 

         B=epidermis 

         C=nerve cells

This leads the cells to essentially start dividing and multiplying again to reform the tissue, bones, muscles, and nerves previously found. However, what I found to be the most interesting is that cells can differentiate between whether they need to regenerate an arm, a leg, or a finger. In other words, they know what is missing and regenerate just that.

The reason that salamanders are able to regenerate limbs are because they can generate new axon branches at the new limb and are able find the correct muscle to respond to. The axons are therefore able to find their way to the correct target.

This video below shows a great summary of how regeneration of limbs in salamanders occurs and how they differ from us.

What about in humans?

Obviously this works in some animals, but what about us? When we get a cut our body quickly adds on new cells patching up the wound creating scar tissue which helps stop blood loss and prevents infections however, it is the scar tissue that prevents us from regenerating. Scar tissue is dead tissue which unlike the blastema will not divide and multiply to reform the limb. It is not easy, but scientists are working to find new and innovative ways, one of which is using the patient's own cells to grow new tissue in a scaffold stimulating natural healing rather than scar tissue.
I turns out Dr. Connors wasn't so crazy after all, if you can get over him turning into a lizard mad-scientist guy.

 

References:

Kalat, J. (2012). Biological psychology. Cengage Learning.
http://www.blastr.com/2012/07/researchers_say_the_scien.php

Addicted to _________? It's because of your nucleus accumbens. Wait, what????

You may be thinking, did I read the title right or is she just making up words? No, you’re right; the nucleus accumbens is an actual area in the brain (proof below). 

As you (may) know, last week I talked about how heroin can pass through the blood brain barrier, but what I did not mention is how we can easily become addicted to drugs. You're probably thinking everyone knows that, but today I want to talk about the role the nucleus accumbens and dopamine plays in addiction.

So to begin with, what is addiction? I know when most people hear addiction they think junkies, rehab, habit, druggies, homeless, unstable, etc,. However, addiction is simply the repetition of a behavior despite the potentially harmful consequences. It has to do with intense cravings and even loss of control in the user. It can "rewire" the brain by changing our motivations  and reinforcing drug experiences and decreasing or inhibiting the pleasure of other experiences. Basically it makes the experiences caused by the drug more alluring, leaving other actions unable to compete for the attention. 

Back to the nucleus accumbens

It is an area rich in dopamine, which is one neurotransmitter responsible for stimulating pleasure centers in the brain and transmitting impulses from neurons to the brain. The nucleus accumbens is also responsible for reinforcing all kinds of experiences we find rewarding as well as in learning new behaviors. It is why it is so“addicting” or rewarding to get high. All drugs  of abuse stimulate the nucleus accumbens by releasing dopamine in the nucleus accumbens. Therefore, when the brain releases this neurotransmitter the "high" felt becomes associated with the drug, reinforcing the usage.  Once the user experiences this high, this memory becomes imprinted as a memory in the hippocampus and is brought back to "memory" every time someone craves, thinks, or takes the drug. Whether the drug usage will lead to addiction depends on many factors such as:

Dopamine

• speed of release
• amount released  
• intensity of release

Drug

• route of administration (injection, inhalation, intranasal, ingestion...)
• dosage
• genetic susceptibility
• frequency of usage

Here is a video explaining the pathology of addiction (it is a little lengthy so I recommend starting at 2:43). I think this video does a good job in explaining how the nucleus accumbens, dopamine, and serotonin play a role in addiction. 

A quick word about tolerance

Tolerance is when more of the drug is needed for the user to experience the same effects and happens when the user habitually uses. Habitual use of the drug leads our brain to adapt and make the effects of the drug less pleasurable or stimulating. When our brain adapts, dopamine has less effect on the nucleus accumbens and we need more and more every time. 

Disclosure

Do not think that drugs are the only thing you can become addicted or that stimulate the pleasure centers in the brain!

References:

Kalat, James. Biolgical Psychology: Eleventh Edition

http://www.wisegeek.com/what-is-the-nucleus-accumbens.htm

http://addiction-dirkh.blogspot.com/2010/02/nucleus-accumbens.html

http://www.helpguide.org/harvard/addiction_hijacks_brain.htm

Blame it on the BBB: The blood-brain barrier

As you may or may not know, actor Philip Seymour Hoffman recently passed away from a heroin overdose. Now you may be wondering, what does this have to do with physiological psychology or more importantly  the blood-brain barrier? Well, I am here to tell you, but first let me explain what the BBB is, how it works, and why we definitely need it.

THE BBB...
The blood-brain barrier is a semi-permeable wall, that runs along the sides of the blood vessels in the brain, in the sense that it allows some materials to cross such as oxygen and carbon dioxide and keeps harmful ones away. You can think of it as your personal Border Customs Agent telling you what you can and cannot pass through the "border" (aka brain).

HOW DOES IT DO IT???
The BBB works by tightly joining endothelial cells to one another so almost nothing can get through. There are several molecules and chemicals that can pass through.

• Small uncharged molecules

• These include the essential elements, oxygen and carbon dioxide. Water is able to cross through the walls of the endothelial cells that make up the BBB through protein channels.

• Lipid soluble molecules

• This refers to the molecules that are able to dissolved in fats such as Vitamins A and D as well as psychoactive drugs. Ex., antidepressants, sleeping aids, and even drugs like heroin.

• Some chemicals
• These are transported to the brain by active transport and include chemicals such as glucose (fuel), certain hormones, and amino acids among a few others.

WHY???
The BBB is needed to keep the brain protected from harmful and toxic substances that can cause damage. Since neurons are hardly ever repaired or replaced the brain needs a "gatekeeper" controlling the entrance to viruses, harmful chemicals, and bacteria. 

THE BBB AND HEROIN
Heroin crosses through the blood brain barrier approximately 100 times faster than morphine! The reason is because it is highly soluble in lipids and therefore passes easily as mentioned above.  As it passes through the BBB it is turned into morphine and the user then feels this intense "euphoric" feeling pass through them. A heroin overdose is caused by the chemicals in the drug altering the brain's neurons oppositely. What do I mean by oppositely? Although you may know it is wrong and your brain is "telling" you not to do it, the pleasure centers in your body are telling you "YES!!" With each use tolerance builds and leads the user to need more. Excess use of heroin stops many automatic process including breathing and beating (heart) which eventually may lead to death.

Below is a video describing the death of the actor, Philip Seymour Hoffman as explained by a drug addiction expert.


Hopefully I have enlightened you, dear reader, on the blood-brain barrier and how important it is for our health.


References
Kalat, James. Biological Psychology:Eleventh Edition
http://news.nationalgeographic.com/news/2014/02/140204-philip-seymour-hoffman-actor-heroin-overdose/
http://www.howitworksdaily.com/science/the-blood-brain-barrier-explained/
http://faculty.washington.edu/chudler/hero.html