Neuropharmacology is the study of drugs which affect the central nervous system.  These include psychotropic drugs that affect mood and behavior, anesthetics, sedatives, analgesics, anticonvulsants, narcotics, hypnotics and a variety of other substances.  While the precise mechanism of action is unknown for most of these drugs, a large number of neuropharmacological agents appear to be involved primarily with synaptic events.  The Department of Pharmacology and Experimental Therapeutics (DPET) contains a core group of investigators who study neuroactive compounds at the molecular, cellular and behavioral level.

Psychopharmacology is the study of the effects of drugs on behavior, combining methods of psychology and pharmacology.  Psychopharmacologists carryout their duties within a number of different settings, including academia, government, private research, industry and clinic.  The study of the effects of drugs on behavior has been productively examined in human as well as nonhuman populations, both within and outside the laboratory.  The central theme running through the research in this division is the use of behavioral principles as they interact with the effects of pharmacological agents and environmental events.

Source: Tufts University School of Medicine's Department of Pharmacology and Experimental Therapeutics

Source: American Psychological Association

 

Plants with stimulant effects are among the earliest plants used by humankind for psychoactive effects.  Our interest in them is due to their profound effect on mental functioning, increasing alertness, the ability to sustain effort, and in some cases, the induction of euphoria.  Despite their seclusion to a particular geographic region, stimulant plants are widely used across the planet.  A sizable portion of the world’s population regularly consumes tobacco, coffee, tea, or some other form of stimulant plants on a daily basis.

The stimulant plants are organized here (see the chart below) by their predominant neuro-chemical mechanism: purinergic (coffee, tea, cocoa, mate, guarana, and kola), cholinergic (tobacco, areca, and lobelia), and monoaminergic (ephedra, coca, and khat).  It is worthwhile to note that most of these plant drugs work through neuromodulatory systems.  They mostly create stimulation not through direct neuronal excitation, but rather by a modulation of neuronal activity.  On the other hand, drugs that directly stimulate excitatory amino acids or block inhibitory amino acids more often have excitotoxic or convulsive effects (e.g., strychnine from Strychnos nux-vomica, or ibotenate from Amanita muscaria).  Rather, the stimulant plants generally act through neuromodulatory receptors linked to G-proteins and intracellular messengers.

Several synthetic stimulants have been developed for clinical use or illegal trade.  Amphetamine was synthesized in 1887, but its medical applications were not investigated until the 1920s (Rudgley 1999).  It was first marketed in 1932 as a treatment for asthma and nasal congestion.  Since then, a number of related drugs have been developed.  Methylphenidate (Ritalin) and pemoline (Cylert) have generally replaced amphetamines for treatment of attention disorders.  Methylenedioxymethamphetamine (MDMA, “Ecstasy”) and several other amphetamine derivatives have been labeled “entactogens,” due to their prominent effect of creating feelings of interpersonal warmth and empathy.  They are also highly neurotoxic to serotonin neurons (White et al. 1996).  Amphetamines and related drugs have long been used to reduce appetite and weight, but dependence liability, toxicity, and the tendency for rebound weight gain after drug discontinuation have made them impractical for this purpose.  Despite the development of numerous synthetic stimulants, the use of plants or plant-derived drugs probably still accounts for the majority of human stimulant consumption.

Purinergic Stimulants

The purinergic stimulants are a small group of chemically and pharmacologically related drugs that are found in several different plants but commonly act on purine neurotransmitters such as adenosine.  Namely, the drugs are caffeine, theophylline, and theobromine, collectively referred to as the methylxanthines.  They are among the most commonly used stimulants in the world, and possibly the most commonly consumed of all drugs.  Methylxanthines are found in several plants that are well known across the world, and in others whose use is more regional.  Collectively, these plants include coffee, cocoa, guarana, mate, and kola.

 

Central nervous system stimulants

 

Common

Botanical

Active constituents

Mechanism

Purinergic

 

   

Coffee

Coffea arabica

Methylxanthines

Adenosine antagonism

Tea

Camellia sinensis

   

Cocoa

Theobroma cacao

   

Guarana

Paullinia cupana

   

Maté

Ilex paraguariensis

   

Kola

Cola nitida & acuminata

   
 

 

   

Cholinergic

 

   

Tobacco

Nicotiana tobacum

Nicotine

Nicotinic Ach agonist

Areca

Areca cathechu

Arecoline, arecaidine, guvacoline guvacine

Muscarinic Ach agonist

Lobelia

Lobelia inflata

Lobeline

Nicotinic Ach agonist

 

 

   

Monoaminergic

 

   

Ephedra

Ephedra sinica

Ephedrine

α, β adrenergic agonist Blocks monoamine reuptake Na+ channel antagonist

Khat

Catha edulis

Cathinone

 

 

 Source: The Psychopharmacology of Herbal Medicine, by Marcello Spinella

 

RELATED ORGANIZATIONS

American College of Clinical Pharmacology (ACCP)

3 Ellinwood Ct.

New Hartford NY 13413-1105

Phone: (315) 768-6117

Fax: (315) 768-6119

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http://www.accp1.org/

American College of Neuropharmacology (ACNP)

ACNP Secretariat

320 Centre Building

2014 Broadway

Nashville, TN 37203

Phone: (615) 322-2075

Fax: (615) 343-0662

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http://www.acnp.org/

American Psychological Association

Division of Psychopharmacology and Substance Abuse

750 First Street, NE

Washington, DC 20002-4242

Phone: (800) 374-2721; 202-336-5510

TDD/TTY: 202-336-6123

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http://www.apa.org/divisions/div28/index.html

American Society for Pharmacology and Experimental Therapeutics (ASPET)

9650 Rockville Pike

Bethesda, MD 20814-3995

Phone: (301) 634-7060

Fax: (301) 634-7061

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.aspet.org/

Federation of American Societies for Experimental Biology (FASEB)

9650 Rockville Pike

Bethesda, Maryland  20814-3998

Phone (301) 530-7000

Fax (301) 530-7001

Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.faseb.org

Food and Drug Administration

Center for Drug Evaluation and Research

Program and Speaker Coordination Staff

5600 Fishers Lane, Room 15A-08

Rockville, MD 20857

Phone: (301) 827-4573

Fax: 301-827-2823

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.fda.gov/cder/drug/default.htm

National Clearinghouse for Alcohol and Drug Information

11426-28 Rockville Pike, Suite 200

Rockville, MD 20852

Phone: (800) 729-6686

Fax: (301) 468-6433

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.health.org/

Society for Neuroscience

11 Dupont Circle, N.W., Suite 500

Washington D.C. 20036

Phone: (202) 462-6688

Fax: (202) 462-9740

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.sfn.org/

U.S. National Library of Medicine

8600 Rockville Pike

Bethesda, MD 20894

Phone: (888) 346-3656 or (301) 594-5983 (local and international calls)

Fax: 301-496-4450

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.nlm.nih.gov/

     

 

USEFUL WEBSITES

PubMed, a service of the National Library of Medicine, provides access to over 11 million MEDLINE citations back to the mid-1960's and additional life science journals. PubMed includes links to many sites providing full text articles and other related resources.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi

Neurosciences on the Internet, a searchable and browsable index of neuroscience resources available on the Internet: Neurobiology, neurology, neurosurgery, psychiatry, psychology, cognitive science sites and information on human neurological diseases.

http://www.neuroguide.com/