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Chapter Two Objectives        Biological Bases of Behavior

Creative Brain Activity                  due Oct 12/13

Pages 40-50
1.  Explain the role of receptors, afferent neurons, interneurons, efferent neurons and effectors in the neural chain.  (2-1 p. 40)
2. Diagram a neuron and label and describe the functions of the following components:  dendrites, soma, axon,  terminal buttons, astrocytes, myelin sheath and synaptic cleft.  (2-2p.41)
 3. Explain what neurotrasmitters are (p. 44 table)and describe how they relate to cocaine (dopamine)  and  anxiety attacks (GABA).
4. Explain the similarities and differences between neuromodulater and neurotransmitters. (p.45 table)
5.  Describe the relationship between acupuncture, placebo effects and the opioid peptides.
                    Explain the effects of stress on the immune system.
6. Describe the chemical changes that accompany neural firing:  resting potential, depolarization, action potential, refractory period,  all or none phenomenon--inhibitory or excitatory.  (graph on p. 50 is confusing)

Key People: Paul Broca, Carl Wernicke, Roger Sperry, Phineas Gage, Tom Bouchard
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Brain Function and Organization
     EEG and evoked potential
     Frontal Lobe and Cognition
     Recording Integrated Activity

Divided and Split Brain

Hydrocephalus
Huntington's Disease
Parkinsons
 brain tissue implantation
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October 15, 1996
New Antidepressants Widely Praised, but Some Fear Overuse
* Drugs: More than 20 million people in 100 countries have taken Prozac,  and competitors are on rise.

By JULIE MARQUIS, Times Science Writer

 It's just a little green and white pill, but it's got the name recognition--and some would say the devoted following--of a rock star.   Twice, the antidepressant Prozac has been featured on the cover of Newsweek. It has been the subject of several books, including one bestseller.  But not everyone is an avid fan. Critics say that it is grossly overprescribed and that its long-term effects are unknown. Others say it is no replacement for a stint on the psychotherapist's couch.

Meanwhile, more than 20 million people in 100 countries have partaken of this flagship drug, the first in a new generation of antidepressants called selective serotonin reuptake inhibitors (SSRIs).  Last year, sales climbed 24% to $2 billion.  And the competitors are coming up fast: The makers of another serotonin-enhancer, Zoloft, sold $1.4 billion worth of the drug last year, a 45% rise over 1994. Third-ranked Paxil's manufacturer sold $782 million worth, up 51%.

What accounts for these medication-sensations?  Oddly enough, it isn't so much that they are more effective than their predecessors. About two-thirds of patients respond to any given antidepressant. Eli Lilly, Prozac's manufacturer, puts its effectiveness  at 70%.  These drugs are simply more tolerable. They can be prescribed more widely, for a longer period, with less risk of serious side effects.  Patients are more likely to stick with the program. The drugs are nonaddictive, they don't produce an amphetamine-like "high" and they are nearly impossible to use, by themselves, as a means of committing suicide.  "It is not a happy pill," Dr. Steven Paul, vice president of Lilly Research Laboratories, said of Prozac.

SSRIs, however, are more than just antidepressants. Prozac and Paxil are approved by the Food and Drug Administration to treat obsessive-compulsive disorder, and Zoloft is awaiting the FDA nod. Paxil is also approved for panic disorders.  The drugs are also prescribed legally by physicians for such "off-label" uses as treating bulimia, weight problems, premenstrual syndrome, alcohol and nicotine addictions--even gambling and compulsive shopping.  Although the precise reasons for their widespread powers are not known, UC San Diego researcher Stephen M. Stahl points to activity in four serotonin pathways in the brain--each of which mediates different effects. The drugs prolong the effects by enhancing the neurotransmitter's concentration in the synaptic cleft (the space between brain cells, or neurons).

There is a downside. The SSRIs have their own set of side effects: occasional nausea and vomiting, anxiety, insomnia, headaches and sexual dysfunction.  "The reality is they are pretty damn good," said Stahl, an adjunct professor of psychiatry at UC San Diego. "But they aren't as good as some people say." Critics' concerns range from the physical to the philosophical.  Shortly after Prozac rose to prominence in the early 1990s, allegations surfaced, in lawsuits and anecdotes, that it prompted violence and suicide.  But the drug companies, along with other clinicians and researchers, have fairly successfully dismissed these as unproven.  "There is no credible, objective evidence," Paul said.  Dr. Peter Breggin, a Maryland psychiatrist who has made a side career out of lambasting what he considers "toxic" psychiatric drug treatments, laments that Prozac may have become "our national prescription drug."

"In less than a generation, we have rejected the motto, 'Just say no to drugs,' and adopted the motto, 'Take this drug to improve your life,' " Breggin writes in his 1994 book, "Talking Back to Prozac." "It is time for opposing voices. It is time to talk back to Prozac."  Breggin also was talking back to Peter Kramer, a psychiatrist who in 1993 published a provocative, sometimes whimsical bestseller,"Listening to Prozac." The book is an exploration of the author's experience treating patients who may not meet the definition of clinical depression, yet find themselves positively transformed by the drug.  After the Kramer book, even Eli Lilly felt the need to stress Prozac's primary mission as an antidepressant. In advertisements two  years ago, the company warned that it ought to be prescribed only "where a clear medical need exists."

In reality, however, Prozac and other SSRIs are prescribed for a variety of purposes, often by general practitioners not necessarily well-schooled in the intricacies of mental illness.  Some mental health experts believe the drugs are overprescribed without a good understanding of whether side effects will emerge, say, 20 years from now.    "Unfortunately, we've got an experiment going on right now with . . . millions of people," said David Antonuccio, a psychology professor at the University of Nevada School of Medicine.  SSRI proponents point out that diabetics take insulin for life and patients with high blood pressure take anti-hypertensives without  drawing the same outcry. And Prozac's maker says the drug, approved by the FDA eight years ago, shows no signs of trouble. "It's not 20 years, but things look good," Paul said.

It is always useful to consider non-drug treatments, says National Institute of Mental Health Director Steven Hyman. But "if somebody is suffering a depression-like distress, and they take a medication and they get a lot better, who could rightly tell them to stop it?"  Some clinicians warn that a drugs-only approach to treatment assigns minimal importance to such intangibles as human will and courage.

"We know that Winston Churchill had manic-depressive illness--but he had a country to run; he had a war to fight. There are people who would be totally incapacitated by that," said UCLA psychiatrist Jeffrey Schwartz. "Am I saying they are weak? No. Am I saying that Churchill was heroic? Yes, I am. "The [strictly] biological people are making an egregious error by removing the heroic struggle of some people against their illness. It's not all about chemicals . . . not all left to doctors."

Psychotherapy, as traditionally practiced, is under enormous pressure. Many patients don't bother with therapy anymore, relying on their general practitioner to dash off a prescription instead.  For patients, drug treatment often is less expensive. A visit to a medical doctor is often reimbursed more fully than one to a counselor.  The very nature of psychotherapy is changing, largely because of the pressures of managed care. But Prozac and drugs like it often are seen by employers and insurers as better investments than long-term therapy.  Psychotherapists are under pressure to prove that their techniques work as well--and as fast. Hence the push toward "time-limited" sessions and by-the-book approaches that are easier to monitor.  The issue isn't simply effectiveness, but cost-effectiveness. For psychotherapists, this is a sore point because they see what they offer as more than time-limited relief.

Economics aside, researchers sometimes disagree on what works best- -psychotherapy, drugs or a combination. Concerning depression, studies comparing older antidepressants to therapy have reached conflicting conclusions.
The point, say mental health advocates, is to expand treatment options, not to lop them off in the name of short-run savings. Therapy and drugs should not be either-or propositions, they say.  "For our population, a pill is often necessary," said Laura Lee Hall, a neuroscientist and deputy director at the National Alliance for the Mentally Ill. "But a pill alone is usually not enough."
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"How is a flushing toilet like a neuron firing?".

Most people might not get the connection immediately, but should you read through this it will hopefully create a mnemonic connection which will make it easier for you to recall the information.

depolarization - represented by the toilet flushing

all-or-none principle - the toilet either flushes completely or not at all;it doesn't flush a little or a lot

direction of impulse - the toilet only flushes one way, the impulse can't come the other direction (you hope!)

refractory period - after you flush the toilet, it won't flush again for a certain period of time, even if you push the handle repeatedly

threshold - you can push the handle a little bit, but it won't flush until you push the handle past a certain critical point this corresponds to the level of excitatoryneurotransmitters that a neuron must absorb before it will fire

resting potential -  The toilet is"waiting"to fire, and the water in the tank represents the over all negative charge inside the neuron waiting for depolarization

action potential - the action potential is represented by opening the flap in the tank and the water suddenly flowing into the urinal.

sodium potassium pump:  at resting potential, the water is a combination of negatively charged chloride and positively charged potassium.  When the toilet is flushed, rapidly sodium which has not been able to enter the urinal comes flowing in and pushes the potassium out.  During the refractory period, the potassium reenters and the sodium is pushed back in and balance and repolarization occurs.
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Question #2: The somatic system is to the sense organs and skeletal muscles as the autonomic system is to
thebrain.     internal organs and glands.              spinal cord.               extremities and senses.

Question #3: The fatty material which insulates axons and speeds conduction of neural impulses is called the
nerve tract.  myelin sheath.  axon terminal  cranial tissue.

Question #4: Two chemical elements involved in action potential are
sodium and potassium.  iron and sodium.  sodium and nickel.  iron and potassium.

Question #5: Which of the following statements is true of neurotransmitters?
They prevent neurons from exciting or inhibiting each other.
They bind to any receptor site that is available.
They exist in the brain, spinal cord, peripheral nerves, and certain glands.
 They affect mood only in a negative direction.

Question #6: The neurotransmitter associated with sleep, mood, appetite, pain suppression, and temperature regulation is
serotonin.            acetylcholine.                 GABA.                  endorphin.

Question #7: Hormones originate primarily in the
brain and spinal cord.            endocrine glands.                  somatic nervous system.
neurons and glial cells.

Question #8: Which method has been used when a part of the brain is removed for study?
lesion method           PET scan                  MRI             EEG

Question #9: The area of the brain that arouses the higher centers in a demanding situation is the
thalamus            hypothalamus.              reticular activating system.          cerebellum.

Question #10: The hypothalamus controls the operations of the _____nervous system.
central           autonomic                  somatic            total

Question #11: Which lobes of the brain receive information on pressure, pain, and temperature?
temporal           frontal                occipital                      parietal

Question #12: The lobe of the brain associated with vision is the _____ lobe.
frontal              occipital                parietal                     temporal

Question #13: Which of the following is the female chromosome pattern?
YY            XY            XX                      YX

Question #14: If an individual has one dominant and one recessive gene in a pair, he or she will show _______________________
the trait corresponding to the dominant gene.
either trait, depending on the environment in which he or she lives.
the trait corresponding to the recessive gene.
a mix of the traits corresponding to both the dominant and recessive gene.

Question #15: Twins who develop from two separate eggs are called
monozygotic.       identical.       fraternal.          conjoined.
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Quiz #2

The correct answer is: The outside.

2. What causes diffusion?
The need of atoms to move to more empty areas
Atoms are pushed to more empty areas
Random movements of atoms and molecules

The correct answer is: Random movements of atoms and molecules

3. Which pair of charges will attract each other?
+/+
-/-
+/-

The correct answer is: +/-

4. If the inside of the neurons is -30mV relative to the outside and the K+ ion channel is open, what will the K+ ion tend to do?
these ions will tend to exit, drawn by the like charges outside the neuron..
these ions will tend to exit because of the greater concentration of K+ on the inside of the axon.
they will tend to stay in the axon because the positive K+ ions will be drawn to the more negative inside of the axon.

The correct answer is: they will tend to stay in the axon because the positive K+ ions will be drawn to the more negative inside of the axon.
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