6-2 psychoactive drugs
What may provide a small benefit against alzheimer disease?
Acetylcholinesterase inhibitors, such as tacrine (Cognex), raise ACh levels and may provide a small benefit
What can produce e hallucinations and out-of-body experiences?
Antagonists for the NMDA receptor, such as phencyclidine (PCP, or angel dust) and ketamine (Special K)
How is finding g a universally acceptable grouping for... the psychoactive drugs is virtually impossible.?
Any system will have a unique set of limitations because drugs with similar chemical structure can have different effects, while drugs with different structure can have similar effects. Furthermore, a single drug acts on many neurochemical systems and has many effects.
How are Nicotine's mood-altering effects are unusual in comparison to most drugs?
At low doses, nicotine is a stimulant, but at very high doses, it dampens neuronal activity (Wadgave & Nagesh, 2016). Tobacco smokers report feelings of relaxation, sharpness, calmness, and alertness. When smoke from a tobacco cigarette is inhaled, within a few seconds nicotine stimulates acetylcholine nicotinic receptors, which then indirectly causes the release of acetylcholine and several other neurotransmitters, including norepinephrine, epinephrine, arginine vasopressin, serotonin, endorphins, and dopamine.
How does nicotine dependence e involves both psychological and physical aspects
s. Smoking cessation leads to heightened anxiety, irritability, craving, inability to feel pleasure, and tremors.
dopamine hypothesis of schizophrenia
Idea that excess dopamine activity causes symptoms of schizophrenia.
Why should n dopamine antagonists should ameliorate the symptomology?
If excessive dopamine is a consequence of druginduced psychosis and some forms of naturally occurring schizophrenia
Why do some plants incorporate caffeine into their tissues?
Plants face several challenges, such as herbivores, pathogens (like fungi), and attracting pollinators. All of these selective forces, and many others, have shaped plant adaptations; one such adaptation is incorporating toxins such as caffeine into its tissues Caffeine acts as a natural pesticide, discouraging or killing herbivorous insects and inhibiting the invasion and colonization of pathogenic fungi. Nectar containing caffeine may enhance the rewarding properties of pollinators, such as honeybees, and improve distribution of pollen (Wright et al., 2013). We humans have contributed massively to the success of coffee and tea plants by distributing them widely over our planet, at the expense of native plant and animal species and the local ecology
fetal alcohol spectrum disorder
Range of physical and intellectual impairments observed in some children born to alcoholic parents.
what do very high doses of alcohol result in?
stupor, memory loss, unconsciousness, life-threatening respiratory depression, and inhalation of vomit.
alcohol consumption short-term psychological and physiological effects?
t depend on several factors, including the amount and concentration of alcohol, the duration over which it is consumed, the amount of food eaten, and the consumer's weight and experience with alcohol.
How does the chemical name describe a drugs structure?
the generic name is nonproprietary and is spelled lowercase; and the proprietary, or brand, name, given by the pharmaceutical company that sells it, is capitalized
what can change alcohol use by mothers and fathers before conception?
the methylation status of some genes that contribute to disabilities found on the spectrum
three different types of serotonergic agonist drugs are prescribed for depression?
the monoamine oxidase (MAO) inhibitors; the tricyclics, so called because of their three-ring chemical structure; and the selective serotonin reuptake inhibitors (SSRIs).
How is ketamines mechanism of action, as a glutamatergic agonist, is very different from those of most modern drugs prescribed to reduce depression
the others operate on serotonin and norepinephrine targets
what provides the reinforcing aspect of nicotine?
the release of dopamine
Why is e, PCP is also a dopaminergic agonist, which may account for some of its psychoactive effect?
Research indicates that PCP inhibits nicotinic acetylcholine receptors as well as inhibiting dopamine reuptake
behavioral symptoms of children with FASD?
They display varying degrees of learning disabilities and low intelligence test scores, as well as hyperactivity and other social problems. Individuals with FASD are 19 times as likely to be incarcerated as those without i
Advocates for serotonergic agonists?
United States promoted their use for "mind expansion and personal truth." Mescaline, obtained from the peyote cactus, is legal in the United States for use by Native Americans for spiritual practices.
How does repeated daily intake of caffeine produces a mild form of drug dependence.?
When the individual stops using caffeine, he or she experiences sleepiness, headache, and irritability. These withdrawal symptoms are avoided by continuing to consume caffeine daily but will fade with time (about 4 to 7 days) if the individual gives up caffeine altogether
What do small amount of alcohol cause?
an overall improvement in mood and possible euphoria, increased self-confidence and sociability, decreased anxiety, impaired judgment and fine muscle coordination, and a flushing of the face.
Why do changes in dopamine synapses not completely explain the disorder or the effects of dopaminergic antagonists?
because schizophrenia involves more than just D receptors
How do FGA's act (antipsychotics)
blocking the dopamine D receptor, which immediately reduces motor activity, and alleviates the excessive agitation of some people with schizophrenia
How have humans taken zoopharmacognosy a step further?
by cultivating particular plants and fungi, then extracting, purifying, studying, and synthesizing their psychoactive ingredients—and making a great deal of profit from the enterprise.
What are benzodiazepines used for?
by people who are having trouble coping with significant physical or mental stress, such as a traumatic accident or a death in the family. They are also used as presurgical relaxation agents and can terminate seizures
How does amphetamine prevent dopamine reuptake?
by reversing the direction of the transporter, allowing dopamine to continue to interact with postsynaptic D2 receptors
How are Respiratory diseases, lung cancer, and related negative effects are caused?
by the harmful chemicals found in tobacco smoke rather than in nicotine itself
agonists that are mentally presribed?
dextroamphetamine (Adderall), methylphenidate (Ritalin), and L-dopa.
What does benzodiazepines include?
diazepam (Valium), alprozolam (Xanax), and clonazepam (Klonopin)
How is amphetamine disovered?
in attempts to synthesize the CNS neurotransmitter epinephrine, which also acts as a hormone to mobilize the body for fight or flight in times of stress (
Where is nicotine found?
in the leaves of the tobacco plant, Nicotiana tabacum. Nicotine is also found in small amounts in potatoes, tomatoes, and eggplant.
Parhamcological approaches to depression?
include normalizing stress hormones, modifying neuronal responses, and stimulating neuronal repair.
What do long term and frequent consumption of alcohol lead to?
increased risk of alcoholism, a condition ruinous to individuals and families, as well as an enormous economic burden
How may factors such as Inadequate nutrition, stress from difficult life conditions, acute changes in neuronal function, and damage to brain neurons be related to depression?
nutritional deficiencies may increase vulnerability to stress; stress may change neuronal function; and if unrelieved, altered neuronal function may lead to neuron damage
How is cocaine the origin of the trade name coca-cola?
once contained cocaine (Figure 6-9). Its addictive properties soon became apparent, however, and it was replaced in these products with caffeine.
What has improved the functioning of people with schizophrenia?
, the use of dopamine antagonist drugs that preferentially bind to D
What is the conseuqence of that repeated doses of benzodiazepine drugs lead to tolerance for them?
A larger dose is then required to attain the drug's initial effect. Cross-tolerance results when the tolerance for one drug, like benzodiazepines, is carried over to a different member of the drug group. Cross-tolerance also suggests that benzodiazepines and alcohol act on the nervous system in similar ways.
What is medically prescribed to treat ADHD?
A mphe tamin e (Adderall) and methylphenidate (Ritalin)
Why should alcohol and benzodiazepine drugs not be consumed together?
Because the GABA receptor has different binding sites for GABA, alcohol, and benzodiazepines, activation of each site promotes an influx of Cl , but in different ways. The effects of actions at these three sites summate
zoopharmacognosy
Behavior in which non-human animals self-medicate
difference betwen amphetamine and cocaine?
Both leave more dopamine available in the synaptic cleft, but amphetamine also reverses the transporter that typically packages dopamine into vesicles, thus removing dopamine that was already packaged and increasing its abundance in the synaptic terminal. The transporter found on the synaptic terminal then pumps the dopamine previously packaged in vesicles into the synaptic cleft
How does caffeine block the effect of adenosine and thus acting as an adenosine antagonist?
Caffeine has a very similar structure to adenosine and binds to adenosine receptors without activating them
Why did freud recommend that cocaine be used as a local anesthetic.?
Cocaine did prove valuable for this purpose, and many derivatives, such as xylocaine (often called Novocain), are used today. These local anesthetic agents reduce a cell's permeability to sodium ions and so reduce nerve conduction
difference between cocaine and amphetamine and methamphetamine?
Cocaine is purified from leaves of the coca plant (Figure 6-8), whereas amphetamine and methamphetamine are synthetically produced
selective serotonin reuptake inhibitors (SSRIS)
Drug that blocks 5-HT reuptake into the presynaptic terminal and most commonly used to treat depression.
monoamine oxidase (MAO) inhibitors
Drug that blocks the enzyme monoamine oxidase from degrading such neurotransmitters as 5-HT, NE, and DA.
tricyclics?
Drug, characterized by its three-ring chemical structure, that blocks 5-HT reuptake transporter proteins.
How does GABA produces its inhibitory effect by decreasing a neuron's firing rate?
Excitation of the GABA receptor produces an influx of Cl through its pore. An influx of Cl increases the concentration of negative charges inside the cell membrane, hyper-polarizing it and making it less likely to propagate an action potential.
similiarty nicotine and caffeine?
Like caffeine, it functions as an antiherbivore chemical and was at one time widely used as an insecticide
major depression?
Mood disorder characterized by prolonged feelings of worthlessness and guilt, disruption of normal eating habits, insomnia, a general slowing of behavior, and frequent thoughts of suicide
Where are serotenergic agonists found?
Some, such as mescaline (peyote; 3,4,5- trimethoxyphenethylamine), DMT (N, N-Dimethyltryptamine), and psilocybin, are found in plants and mushrooms, while others, such as lysergic acid diethylamide (LSD) and MDMA (Ecstasy, XTC; 3,4- Methylenedioxymethamphetamine), are produced synthetically
amphetamine?
Synthetic compound that increases the neurotransmitter dopamine in the synaptic cleft by reversing the dopamine transporter
How do GABAergic agonists work?
The GABA receptor, illustrated in Figure 6-7, contains a site where GABA binds, another separate site where alcohol binds, and still another site where benzodiazepines bind, as well as a chloride ion (Cl ) channel.
What makes it difficult to draw conclusions about the effects of methamphetamines compared to the effects of legally synthesized amphetamines?
The process of illicit manufacture
symptoms of children with FASD?
abnormal facial features, such as unusually wide spacing between the eyes. Their brains display a range of abnormalities, from small size with abnormal gyri to abnormal clusters of cells and misaligned cells in the cortex
Why does using dopamine antagonists to treat psychosis makes these mental disorders manageable, it does not constitute a cure.?
according to the National Institute on Disability, Independent Living, and Rehabilitation Research, although the number of people in mental institutions remains relatively low, as many as 75 percent of those who are homeless and 50 percent of incarcerated people have mental health issues. According to Human Rights Watch, in 2015 in the United States, 10 times as many mentally ill people were incarcerated as resided in mental institutions.
Difference between endogenous adenosine and caffeine?
adenosine induces drowsiness, and caffeine works in opposition to this, making us feel more alert and peppy
What are serotenergic agonists well known for?
altering perceptions of one's surroundings, feelings, sensations, and images (visual hallucinations), producing what are known as "trips."
Good trips on serotonergic agonists?
can be pleasurable and are associated with feelings of joy or euphoria (referred to as a "rush"), disconnection from reality, decreased inhibitions, and the belief that one has extreme mental clarity or superpowers
figure 6.8 behavioral stimulant
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see 6-6 behavioral continuum of sedation
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see 6-9 warning label
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see figure 6-10
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see table 6-1 psychoactive drugs
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What three names have most psychoactive drugs?
chemical, generic, and branded.
dopamine antagonists that are medically prescribed for schizophrenia and druginduced psychosis?
chlorpromazine (Thorazine), haloperidol (Haldol), clozapine (Clozaril), and aripiprazole (Abilify, Aripiprex)
dopamine agonists that are used recreationally?
cocaine, amphetamine, and methamphetamine
Source of caffeine
coffee seed (not a bean) of Coffea plants. But caffeine is also found in the seeds, nuts, leaves, and nectar of a number of other plants native to East Asia and South America
What does alcoholism result in?
damage to the central and peripheral nervous systems, as well as nearly every other system and organ in the body.
Similiarty amphetamine and cocaine?
dopaine agonists
by what is adhd characterized?
excessive activity and difficulty controlling behavior or paying attention, though many people with ADHD have very long attention spans for tasks they find interesting.
When are the effects of alcohol worse for FASD?
f alcohol is consumed in the first trimester, a time of organogenesis and the highest levels of DNA synthesis
How is ketamine currently medically prescribed?
for starting and maintaining anesthesia. It induces a trance-like state while providing pain relief, sedation, and memory loss Ketamine is being tested as a rapid-acting antidepressant and is in phase III clinical trials for use in 659 treating major depressive disorder
What are the symptoms of psychosis also observed in?
individuals diagnosed with schizophrenia.
bad trips on serotenergic agonists?
irrational fears, panic attacks, paranoia, rapid mood swings, intrusive thoughts of hopelessness, wanting to harm others, and suicidal ideation
other mechanisms of action of caffeine?
it inhibits an enzyme that ordinarily breaks down the second messenger, cyclic adenosine monophosphate (cAMP). The resulting increase in cAMP leads to increased glucose production, making more energy available and allowing higher rates of cellular activity
What do GABAergic agonists do at very high doses?
kill
similiarty between PCP and ketamine?
known as dissociative anesthetics, compounds that produce feelings of detachment—dissociation—from the environment and self because they distort perceptions of sight and sound
what do medium doses of alcohol result in?
lethargy, sedation, balance problems, and blurred vision
What can long-term use of D2 antagonists lead to?
many unwanted side effects, including tardive dyskinesia (TD).
How is amphetamine used nowadays?
popular weight-loss aid. Many over-the-counter compounds marketed as stimulants or weight-loss aids have amphetaminelike pharmacological actions
repeated use of serotonergic agonists?
problems with sleep, mood, memory, and attention
what do high doses of alcohol result in?
profound confusion, slurred speech ("wats da proplem, ossifer?"), staggering, dizziness, and vomiting—an adaptive response to poisoning
What can chronical recreation use of adderall and ritalin lead to?
psychosis, a term applied to behavioral disorders characterized by hallucinations (false sensory perceptions), delusions (false beliefs), paranoia, and disordered thoughts, among a host of other symptoms.
Why were the majority of medically prescribed drugs were not created to act on specific neurotransmitter systems?
rather, drugs were tested on different patient groups, and specific uses in medical treatments were approved based on analysis of their effectiveness
What do GABAergic agonists do at low doses?
reduce anxiety
what is lifetime prevalence of methamphetamine used for?
related to its ease of manufacture in illicit laboratories and to its potency, thus making it a relatively inexpensive yet potentially devastating drug
tardive dyskinesia?
s a movement disorder that results in involuntary, repetitive body movements such as grimacing, sticking out the tongue, or smacking the lips, as well as rapid jerking movements or slow writhing movements.
What does Widespread reduction of neuronal firing underlies?
s the behavioral effects of drugs that affect the GABA synapse.
how does dopamine plays a central role in normal movement and mental health?
s. Recall that dopamine agonists, such as L-dopa, boost dopamine levels to restore movements in people with Parkinson disease
How is nicotine a potentially lethal poison?
the total amount of nicotine in one cigarette, if injected, can be lethal to an inexperienced person.
What do GABAergic agonists do at high doses?
they aneshetize / induce coma
What do GABAergic agonists do at medium doses?
they sedate;
Why was amphetamine widely used in World War II?
to help troops and pilots stay alert, increase confidence and aggression, and boost morale—a practice that continues today
How is mematine (Namenda) and NMDA antoganist presribed in treatment of alzheimer?
to prevent neuronal loss
what is amphetamine based drugs prescribed for?
to treat adhd
What Benzedrine (form of amphetamine) originally used for?
to treat asthma and sold in inhalers as a nonprescription drug through the 1940s
When are cholinergic agonists are medically prescribed to treat alzheimer disease?
when smoking is a risk benefit
What is the severity of effects of FASD related to?
when, how much, and how frequently alcohol is consumed over the course of pregnancy
What are the effects that caffeine promotes the release of other neurotransmitters, such as dopamine and acetylcholine?
which endows caffeine with its stimulant effects that improve reaction time, wakefulness, concentration, and motor coordination
