1. The Biology of Behavior
Chapter 2
The Biology of Behavior
PowerPoint® Presentation
by Jim Foley

2. Complete questions on p.58 We’re doing a fun experiment.
Homework this Weekend
Read pp.56-58
Complete questions on p.58
MONDAY
BE ON TIME!!
We’re doing a fun experiment.

3. Searching for the biology of “self”
Is our identity in the heart?
In the brain?
In the whole body?
Biological Psychologists explore the associations between body, mind, and behavior.
No animation.
Lesson to bring out here: the brain is not a computer, or a mind, or identity which is separate from the rest of the body; it is all interconnected, as we soon shall see.

4. Overview: What We Have in Mind
Building blocks of mind: Neurons and how they communicate (neurotransmitters)
Systems that build the mind: Functions of Parts of the Nervous system
Supporting player: the slower-communicating Endocrine system (hormones)
Tools for examining the brain and its activities
More primitive and advanced brain structures
No animation.

5. Neural and Hormonal Systems

6. Neurons and Neuronal Communication: The Structure of a Neuron
No animation.
Most of the neurons are in the brain but there are motor and sensory neurons throughout the body. The message does not travel down the axon in the same way an electrical signal does down a wire; in fact electricity in a wire travels 3 million times faster. In the body, neural signals travel about 2 to 180 miles per hour. However, the chemical signal has an advantage; it does not decrease in intensity as it travels down the axon. No signal is lost.
You could demonstrate speed of signal transmission by having it travel across all the students hand to brain to hand across the room (or hand to shoulder to possibly bypass the brain).
Note the myelin sheath. Multiple sclerosis involves the degeneration of this layer, thus interfering with neural communication with muscles and other areas.
There are billions of neurons
(nerve cells) throughout the body.

7. Action potential: a neural impulse that travels down an axon like a wave
Just as “the wave” can flow to the right in a stadium even though the people only move up and down, a wave moves down an axon although it is only made up of ion exchanges moving in and out.
Automatic animation.
Note: with both the stadium example and the action potential example, no physical object actually flows in any direction when the wave flows.
The action potential is the area that is briefly charged by the net intake of positive ions; this is the traveling “electrical charge” created when channels in the cell membrane quickly allow positive ions in, and then more slowly pump the ions out again as the wave moves on.
The fans in the stadium create the wave by standing up briefly; the cell membrane creates a wave by pumping positive ions in briefly. This could be the subject of a demonstration in class.

8. How neurons communicate (with each other):
When does the cell send the action potential? When it reaches a threshold.
How neurons communicate (with each other):
The neuron receives signals from other neurons; some are telling it to fire and some are telling it not to fire.
When the threshold is reached, the action potential starts moving.
Like a gun, it either fires or it doesn’t; more stimulation does nothing.
This is known as the “all-or-none” response.
The action potential travels down the axon from the cell body to the terminal branches.
The signal is transmitted to another cell. However, the message must find a way to cross a gap between cells. This gap is also called the synapse.
Click to show each stage in the path.
If signals only have one level of intensity, then why does a punch hurt more than a tap? Because in the case of the punch, more neurons are firing.
The threshold is reached when excitatory (“Fire!”) signals outweigh the inhibitory (“Don’t fire!”) signals by a certain amount.

9. The Synapse
The synapse is a junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron.
The synapse is also known as the “synaptic junction” or “synaptic gap.”
No animation.

10. Neural Communication: Between Neurons
Engage Your Students!!
You will find a links to a 1:39 fun and funky student-produced claymation of synaptic transmission on slide number 40 (not embedded into slide, due to instability of links).
Watching Live Brains (icon on left)
For the first time, scientists can watch individual brain cells in living animals for long periods of time.
But, as this ScienCentral News video reports, they've come to different conclusions about what it tells us about our brains.
Alcohol, Neurotransmitters, and Your Brain (icon on right) 
This animation uses the effects of alcohol to provide a tutorial on the electrochemical processes of neural transmission. It then provides an overview of the brain structures that are impacted by alcohol consumption and their behavioral correlates.
WILEY VIDEO
Watching Live Brains
ANIMATION
Neurotrans-mitters
© 2012 John Wiley & Sons, Inc. All rights reserved.

11. Neurotransmitters
Neurotransmitters are chemicals used to send a signal across the synaptic gap.
No animation.
Neurotransmitters are released from the sending neuron and stimulate receptor sites on the receiving neuron. These are the signals telling the receiving cell whether or not to fire the next action potential.

12. Reuptake: Recycling Neurotransmitters [NTs]
Reuptake: After the neurotransmitters stimulate the receptors on the receiving neuron, the chemicals are taken back up into the sending neuron to be used again.
No animation.
Reuptake ends the transmission of the signal.
Medications which inhibit this reuptake process help ensure that the signal gets transmitted. SSRIs help reduce depression by increasing serotonin levels at the synapse this way, and most ADHD medications such as Ritalin work by blocking the transport of dopamine back into the sending neuron.

13. Neural Communication: Between Neurons
Engage Your Students!!
You will find a links to a 1:39 fun and funky student-produced claymation of synaptic transmission on slide number 40 (not embedded into slide, due to instability of links).
© 2012 John Wiley & Sons, Inc. All rights reserved.

14. Seeing all the Steps Together
Neural Communication:
Seeing all the Steps Together
No animation.

15. Roles of Different Neurotransmitters
Some Neurotransmitters and Their Functions
Neurotransmitter
Function
Problems Caused by Imbalances
Serotonin
Affects mood, hunger, sleep, and arousal
Undersupply linked to depression; some antidepressant drugs raise serotonin levels
Dopamine
Influences movement, learning, attention, and emotion
Oversupply linked to schizophrenia; undersupply linked to tremors and decreased mobility in Parkinson’s disease and ADHD
Acetylcholine (ACh)
Enables muscle action, learning, and memory
ACh-producing neurons deteriorate as Alzheimer’s disease progresses
Click to reveal each row.
There are some uses/functions that are not mentioned, such as the role of inadequate norepinephrine and dopamine in ADHD.
Note: Some antidepressants, by blocking reuptake of serotonin, raise serotonin levels at the synapse; they don’t add more serotonin to the body.
The problem in schizophrenia may actually be an overabundance of dopamine receptors, not just an oversupply of dopamine itself.
Norepinephrine
Helps control alertness and arousal
Undersupply can depress mood and cause ADHD-like attention problems
GABA gamma-aminobutyric acid
A major inhibitory neurotransmitter
Undersupply linked to seizures, tremors, and insomnia
Glutamate
A major excitatory neurotransmitter; involved in memory
Oversupply can overstimulate the brain, producing migraines or seizures; this is why some people avoid MSG (monosodium glutamate) in food

16. Serotonin pathways Dopamine pathways
Networks of neurons that communicate with serotonin help regulate mood.
Networks of neurons that communicate with dopamine are involved in focusing attention and controlling movement.
No animation.

17. Divisions of the Nervous System
No animation.
Note that the autonomic, somatic, sympathetic, and parasympathetic branches of the nervous system are all part of the PNS.

18. The Inner and Outer Parts of the Nervous System
The Peripheral Nervous System (PNS), gathers information from the body and sends CNS decisions out to the body.
The Central Nervous System (CNS), the brain and spinal cord, is the body’s decisionmaker.
No animation.

19. Types of Neurons
__________________________carry messages IN from the body’s tissues and sensory receptors to the CNS for processing.
Sensory Neurons
____________carry instructions OUT from the CNS out to the body’s tissues.
Motor neurons
_____________ (in the brain and spinal cord) process information between the sensory input and motor output.
Interneurons
Automatic animation.
There are millions of sensory neurons and millions of motor neurons, but BILLIONS of interneurons.

20. The Peripheral Nervous System
No animation.

21. The Autonomic Nervous System:
The sympathetic NS _________ (fight-or-flight) The parasympathetic NS ________ (rest and digest)
arouses
No animation. 1. Question to ask students: Why not just stay aroused all the time?...to allow the body to repair itself and regain energy from food.
2. Comment to students: note the sympathetic nervous system’s effect on the stomach and bladder., This helps us understand why “I was so upset that I wet my pants” or “I was so upset I threw up.” Now you can take these reports as a sign of strong activation of the sympathetic part of the autonomic nervous system.
calms

22. Neural Networks
These complex webs of interconnected neurons form with experience. Remember: “__________________________________.”
No animation.
These neural networks are activated when needed for action.
Neurons that fire together, wire together

23. Interneurons in the Spine ______________ made ___________ the brain
Decisions
without
Your spine’s interneurons trigger your hand to pull away from a fire before you can say OUCH!
Sensory neuron
This is an example of a ________________.
reflex action
No animation.
You not only won’t have time to say “ouch,” you won’t even think it. This is because before the brain gets the pain message, the interneurons in the spinal cord are already sending a message back through motor neurons saying, “pull your hand away!”
Motor neuron
The brain finds out about the reflex ____ it happens.
after

24. The Endocrine System The endocrine system:
a set of glands that produce chemical messengers called hormones.
No animation.
Instead of sending messages across the synapse, the endocrine system sends messages through the bloodstream. The nervous system and the endocrine systems are connected and influence each other. Endocrine system messages travel more slowly but also last longer.

25. The Body’s “Slow but Sure” Endocrine Message System
The endocrine system sends molecules as ________, just like the nervous system, but it sends them ____________________ instead of across synapses.
These molecules, called _________, are produced in various glands around the body.
The messages go to the brain and other tissues.
messages
Pituitary gland
through the bloodstream
hormones
Click to reveal bullets.
“Slow but sure” endocrine system messages take longer to get to their location, but then the molecules hang around for a bit, so the effect of the “message” lasts longer. In neural communication, reuptake of the neurotransmitters sometimes prevents effective communication. (This is the real “chemical imbalance” treated by some medication: slowing reuptake.)
pituitary gland
The _______________ is the “master gland” of the endocrine system.
It is controlled through the nervous system by the nearby brain area--the hypothalamus.
The pituitary gland produces hormones that regulate other glands.

26. Tools of Discovery and Brain Structures
What We’ll See:
How we learn about the brain:
Scans and more
The primitive, life- sustaining, inner parts of the brain:
The _________ and ______ system
Higher Brain structure that help us think and act:
The _____________
brainstem
limbic
Click to reveal bullets.
Cerebral Cortex

27. Monitoring activity in the brain
Tools to read electrical, metabolic, and magnetic activity in the brain:
EEG: electroencephalogram
PET: positron emission tomography
Click to show four bubbles.
MRI: magnetic resonance imaging
fMRI: functional MRI

28. EEG: electroencephalogram
An EEG (electroencephalogram) is a recording of the __________ __________ sweeping across the brain’s surface.
Electrical
waves
An EEG is useful in studying seizures and sleep.
No animation.
EEGs use electrodes placed on the scalp.

29. PET: positron emission tomography
The PET scan allows us to see ________________________ by tracing where a radioactive form of glucose goes while the brain performs a given task.
what part of the brain is active
No animation.

30. MRI: magnetic resonance imaging
fMRI: functional MRI
MRI (magnetic resonance imaging) _____________from signals produced by brain tissue after magnets align the spin of atoms.
The arrows below show ventricular enlargement in a schizophrenic patient (right).
Functional MRI reveals brain activity and function rather than structures.
makes images
Functional MRI __________________MRI images taken a split second apart, and shows changes in the level of oxygen in bloodflow in the brain.
compares successive
Click to reveal Functional MRI information.

31. The Brain: Less Complex Brain Structures
Our tour of the brain begins with parts of the human brain found also in simpler animals; these parts generally deal with less complex functions:
Brainstem (Pons and Medulla)
Thalamus
Reticular Formation
Automatic animation.
Cerebellum
Limbic System

32. The Brainstem: Pons and Medulla
Click to “grow” a subsection view of the brainstem.
The brain’s innermost region begins where the spinal cord enters the skull.

33. The Base of the Brainstem: The Medulla
The medulla controls the most _____________ such as __________ and _____________.
Someone with total brain damage above the medulla could still breathe independently, but someone with damage in this area could not.
basic functions
heartbeat
breathing
Click to reveal second bullet.
Christopher Reeve ( ; an image of him here might work well), an actor in Superman movies and Smallville, couldn’t breathe on his own after a horse riding accident broke his spine at the level of the medulla.

34. The Thalamus
The thalamus is the “sensory switchboard” or “________”: All sensory messages, except smell, are routed through the thalamus on the way to the cortex (outer brain).
These messages _________ from one side of the body to the opposite side of the brain.
router
cross over
The crossover
Click to reveal bullets.
The book says “switchboard,” but perhaps it’s time to upgrade the term to “router.”
Damage to the thalamus can cause blindness and other loss of the senses, even if the sensory organ is fine.
However, damage to the thalamus could not hurt your sense of smell, which bypasses the thalamus and goes straight to the olfactory bulb in the brain.

35. Reticular (“net-like”) Formation
The reticular formation is a nerve network in the brainstem.
It enables alertness (arousal); stimulating this makes us wide awake.
It also filters incoming sensory information and relays it to other brain areas.
Click to reveal bullets.
Additional information/lecture material:
The structure of the reticular formation: this network of neurons branches from the spinal cord up into the thalamus. I have added two lines to the picture to indicate this.
How do we know about arousal? In the cat experiments, researchers stimulated the reticular formation in order to make a sleeping cat pop awake. Similarly, cutting the reticular formation made a cat lapse into a permanent coma.
About the filtering: it could be said that the reticular formation controls selective awareness; it ‘selects’ which incoming information to send to other brain areas. This enables us to follow a conversation in a crowd, i.e. to select a “signal” out of sensory “noise.”

36. Cerebellum (“little brain”)
The cerebellum helps _______________ _______________ such as playing a sport.
coordinate voluntary movement
Click to reveal bullets.
The cerebellum is located in two parts, behind the pons and below the back of the brain.
The cerebellum also is the area where implicit memories and conditioning are stored. It also helps us judge time, modulate emotions, and integrate multiple sources of sensory input.
The cerebellum has many other functions, including enabling nonverbal learning and memory.

37. The Limbic (“Border”) System
The limbic system coordinates:
emotions such as fear and aggression.
basic drives such as hunger and sex.
the formation of episodic memories.
The hippocampus (“seahorse”)
processes conscious, episodic memories.
works with the amygdala to form emotionally charged memories.
The Amygdala (“almond”)
consists of two lima bean- sized neural clusters.
helps process emotions, especially fear and aggression.
Click to reveal bullets.
The limbic system is located on the “border”/limbus between the brainstem and cortex; it is between the least complex and most advanced brain structures and between the cerebral hemispheres.
The hippocampus is one of the few places in the brain in which neurogenesis is known to take place.
Stimulating different parts of the amygdala triggers different versions of the defensive, self-protective emotions; one part increases aggressive reactions, while another increases fearful withdrawal. Destruction of part of the amygdala can apparently eliminate both emotions.
Note: aggression and fear reactions involve networks across the brain, and these reactions can be stimulated elsewhere.
The pituitary gland is in the text image, but I faded and shrank the label because it is not really part of the limbic system; I’ll restore it when talking about the hypothalamus.

38. The Amygdala: Enabling two different responses to threat
Electrical stimulation of one area of a cat’s amygdala provokes aggressive reactions.
If you stimulate a different part of the amygdala and put the cat in a cage with a mouse, the cat will cower in terror.
Click to reveal bullets.

39. In what region would damage most likely: Disrupt your ability to skip?
Disrupt your ability to hear and taste?
Perhaps leave you in a coma?
Cut off your breath and heartbeat?
Cerebellum

40. The Hypothalamus: The Hypothalamus as a Reward Center
lies below (“hypo”) the thalamus.
regulates body temperature and ensures adequate food and water intake (homeostasis), and is involved in sex drive.
directs the endocrine system via messages to the pituitary gland.
Thalamus
The Hypothalamus as a Reward Center
Riddle: Why did the rat cross the grid?
Why did the rat want to get to the other side?
Click to reveal bullets.
If you lesion one part of the hypothalamus of a rat, it stops eating; lesion another part and it hardly stops eating.
Click to reveal ‘Hypothalamus Reward Center’ riddle. Click again for answer.
Instructor: After addressing the riddle on the slide, but before adding the additional lecture material below, consider throwing out a question, “So where on this screen is the reward center?. Is it here, (point to the cage), the place to go to get rewards? Oh, it’s up here? (point to the hypothalamus).” [This is where you could note, as below, that there are other reward centers…]
Additional lecture material:
There are other reward centers, including an area near the hypothalamus, the nucleus accumbens.
Many of these areas rely on dopamine, which may be why people with low dopamine (ADHD) don’t learn well from rewards, and why people who crave dopamine (ADHD, addicts, young teens, and those with reward deficiency syndrome) are reckless in their search for it, maybe even crossing an electrified grid like the rat in the illustration.
Pushing the pedal that stimulated the electrode placed in the hypothalamus was much more rewarding than food pellets.