Download Lesson 7: Advances - Raleigh Charter High School

Lesson 7: Advances
Bipolar disorder – a mental disorder in which a person alternates between manic highs and deep
depression; affects 1.2% of AMericans
Treatment – lithium
--anticonvulsants such as carbamazepine and valproate
Epilepsy – recurrent unprovoked seizures; affects 1% of Americans
- Seizures can be generalized (typically result in loss of consciousness, can cause several
behavioral changes, including convulsions or sudden changes in muscle tone, and arise
when there is simultaneous excessive electrical activity over a wide area of the brain) or
partial (maintain consciousness or with altered awareness and behavioral changes. Partial
seizures can produce localized visual, auditory, and skin sensory disturbances; repetitive
uncontrolled movements; or confused, automatic behaviors..)
Treatment – Anti-seizure drugs that target either ions channels or synapses using GABA;
surgery to remove area of brain that starts seizure; electrical-stimulation therapy (pacemakerlike device implanted in the brain)
Depression -- feelings of sadness, hopelessness, pessimism, loss of interest in life, and reduced
emotional well-being; one of the most common and debilitating mental disorders. Depressed
individuals are 18 times more likely to attempt suicide than people with no mental illness; affects 5%
of population.
Affects stress hormones, especially cortisol secretion.
Treatment – antidepressants, psychotherapy, ECT (electroconvulsive therapy)
Antidepressants target serotonin or norepinephrine
Categories of antidepressants: tricyclics (imipramine), MAOIs (isocarboxazid,
phenelzine, and tranylcypromine), SSRIs (selective serotonin reuptake
inhibitors), Prozac or fluoxetine
Pain
1846 – doctors discovered anesthetic properties of ether. Soon after, started using chloroform and
nitrous oxide.
Local anesthesia temporarily interrupts the action of pain-carrying nerve fibers, (Novocain and
lidocaine)
Analgesia refers to loss of pain sensation without loss of sensitivity to touch. The two main types of
analgesics are nonopioids (aspirin and related nonsteroidal anti-inflammatory drugs[NSAIDs] such as
ibuprofen, naproxen, and acetaminophen) and opioids (morphine, codeine). Nonopioid analgesics are
useful for treating mild or moderate pain, such as headache or toothache or arthritis.
Opioids are the most potent painkillers and are used for severe pain, such as that occurring after
major chest or abdominal surgery. Opioids can be injected directly into the spinal cord to block pain
without numbness or paralysis.
Neuropathy – pain that results from damage to the nervous system; not treatable with NSAIDS or
opioids; common in diabetics and stroke patients. There is research on the horizon to block pain
message from nocioceptors.
Parkinson’s disease
- characterized by symptoms of slowness of movement, muscular rigidity, tremor, and
postural instability.
- Decreased dopamine levels; Overactive basal ganglia
- Treated with the drug, levodopa (converted to dopamine in body), and carbidopa (prevents
digestion of L-dopa)
- It is believed that hereditary factors may render some individuals more vulnerable to
environmental factors such as pesticides (MPTP story).
- Surgical destruction of parts of basal ganglia (pallidum and subthalamic nuclei) reduce
Parkinson’s symptoms.
- Stem cell therapy is being explored.
Challenges
Addiction
Drug abuse: harmful drug use
Tolerance: progressive need for higher drug dose to achieve same effect
Drug dependence: a state that results in withdrawal symptoms when drug use stops
Drug addiction: loss of control over drug taking, even in the face of adverse physical, personal or
social consequences.
Drugs activate the “reward system” of the brain which includes the ventral tagmental area, the
nucleus accumbens, and the prefrontal cortex causing a sense of euphoria.
Three classes of drugs:
Stimulants – cause the release of adrenaline from adrenal glands leading to 1)increased arousal (heart
rate, breathing rate, etc) and 2) increased sugar into the blood.
Depressants – lower heart rate and breathing rate, some dull or block pain
Hallucinogens – alter perceptions
Nicotine – Tobacco use is the leading preventable cause of death in the US; Smoking accounts for
7% of total US health care costs
Drug
Nicotine
Cocaine and
amphetamines
Opiates (heroin,
morphine)
Class
Stimulant
Stimulants
Depressant
Affects on brain
Treatment/ Misc
Release of dopamine in Zyban (bupropion)
reward center
Release of dopamine in
reward center
Release of dopamine in o Methadone (longreward center and
acting oral opiate
AMYGDALA
that keeps relieves
cravings and
withdrawal
symptoms)
o LAAM (longeracting version of
methadone)
o Naloxone and
naltrexone – block
opiates; these are
administered to
stop an overdose.
Alcohol
Depressant
Release of dopamine in
reward center and
AMYGDALA and
HIPPOCAMPUS;
affects GABAreleasing neurons
Fetal alcohol syndrome
– leading preventable
cause of mental
retardation
Marijuana
Hallucinogen
Affects
neurotransmitter,
anandimide; distorts
perceptions, affects
coordination, and
impairs memory
formation
Active ingredient THC
Rohypnol, GHB,
ketamine
Depressants (some
with hallucinogenic
effects)
Hallucinogen and
stimulant
MDMA (Ecstasy)
Can be lethal if mixed
with alcohol; “date
rape drugs”
May cause long-term
brain damage
Attention deficit hyperactivity disorder (ADHD)
- characterized by inattentiveness, hyperactivity, and impulsive behaviors.
- Affects 3-5% of American children
- Treatment: behavioral therapy and stimulants (Ritalyn)
Alzheimer’s
- forgetfulness and memory loss, disorientation, difficulty with concentration, calculation,
language, and judgment.
- No effective treatment; mostly only treat symptoms
- Characterized by accumulation of beta amyloid plaques and a modified form of a protein
(called tau) that builds up and forms tangles in the brain.
- Associated with reduced levels of acetylcholine
- Evidence for genetic susceptibility, especially for early-onset forms (chromosomes 1, 4, 19,
21)
Amyotrophic lateral schlerosis (ALS or Lou Gehrig’s Disease)
- affects neurons that controls voluntary muscle movements (such as walking); muscles
weaken and deteriorate due to disuse.
-
Most cases occur in families with NO history of the disease; only 5-10% are familial
Death within 3-5 years of first symptoms
Anxiety disorders (phobias, social anxiety disorder, OCD, PTSD, panic disorder)
- OCD: repetitive thoughts and behaviors (hand-washing, for instance)
o Treatment – SSRI’s (Prozac and Zoloft) and behavioral therapy such as exposure
and response prevention.
- Panic disorder: overwhelming sense of doom that occurs out of the blue; accompanied by
sweating, heart-pounding, dizziness, and shortness of breath.
- Phobia: intense, irrational fear of a object or situation
- PTSD (post-traumatic stress disorder): severe anxiety following a stressful event
Autism
- characterized by communication difficulties, delayed development of language, impaired
social skills, and narrow, obsessive interests.
Brain tumors
- “malignant” – cancer that spreads to other parts of the body through the blood
- brain tumors are dangerous even if not malignant because they put pressure on the brain if
they grow
- Primary brain tumor – one that arises within the brain; secondary brain tumor – one that
spread from elsewhere in the body
- Symptoms vary on location and size of the tumor
- Diagnosed with a CT scan or an MRI
- Treatment: surgery, radiation, chemotherapy
Down syndrome
- extra 21st chromosome
- more common with older mothers
- characterized by: mental retardation, low muscle tone, upward slant of eyes, flat face,
enlarged tongue, congenital heart defects, respiratory problems, digestive tract obstruction
Huntington’s Disease
- hereditary brain disorder that affects basal ganglia and cortex
- Symptoms appears between age 30 and 50 and progress slowly over about 20 years
- Symptoms: jerkiness, mood swings, slurred speech, clumsiness, unsteady gait, difficulty
swallowing, loss of balance, impaired reasoning, and memory problems.
- Diagnosed with simple genetic test
Learning Disorders
- Dyslexia: specific reading disorder
- Deficiency in converting letters to sound
- Tends to run in families
- Treatment: practice with reading and taught different reading strategies
Multiple Sclerosis
- diagnosed between 20-50 years old
- autoimmune disease; body attacks myelin sheath, affecting transmission of messages
- Symptoms include: blurred vision, awkward gait, numbness, fatigue, loss of coordination,
tremors, paralysis.
- Treated with steroids.
Neurological AIDS
- caused by HIV
- 20-40% of AIDS patients suffer dementia
Neurological Trauma
- Improved imaging techniques (CT scans and MRIs) have allowed doctors to better prevent
secondary injury of brain trauma, such as edema (swelling) or ischemia (reduced blood flow
to the brain).
- Treatment for increased intracranial pressure: removal of cerebrospinal fluid, moderate
hyperventilation, drugs to remove water from injured tissue.
- Methylprednisolone – a steroid that substantially reduces impairment following spinal cord
injury if administered within eight hours of the injury.
- Neurogenesis – birth of new nerve cells
Schizophrenia
- psychotic disorder marked by hallucinations and delusions.
- Associated with increased dopamine levels and enlarged fluid-filled spaces (ventricles) in the
brain.
- Symptoms usually appear between 15-25 years of age
- Treatment – chlorpromazine(first antipsychotic synthesized in 1950’s), clozapine,
risperidone, olanzapine, quetiapine, ziprasadone, and aripiprazole.
Stroke
- impeded blood supply to the brain, may result in brain damage to affected areas
- treatment: tPA (tissue plasminogen activator), a chemical that dissolves clots
- Risk factors for stroke: family history, obesity, high blood pressure, diabetes, and high
cholesterol.
Tourette Syndrome
- inherited disorder, more common in males
- symptoms: vocal and motor tics
- results from hypersensitivity of dopamine receptors
- Treatment: medications- haloperidol and pimozide.
- Most do without medication because there are serious side effects.