The Physiology and epigenetics of Methamphetamine

• Thomas Crawford• Thomas Jefferson Classical Academy

• Avondale NC

Types of Neurons

• Sensory neurons (Skin and internal organs)• Motor Neurons (locomotion of muscles)• Interneurons (neuron to neuron

communication that routes and distributes signals.

Neural junctions

Reflex

What is a synapse or synaptic gap?

Ways that drugs can interfere with synaptic activity.

• Interfere with neurotransmitter synthesis• Alter the rate of neurotransmitter release

(Botulism prevents ACh from releasing)• Prevent neurotransmitter inactivation (Sarin

gas) (Cocaine dopamine re-uptake inhibitor)• Prevents neurotransmitter from binding to

receptors. (Nicotine)

Some synapses are electrical.

• In fact, at first, all were thought to be electrical. Electrical synapses are difficult to regulate and control.

Neurotransmitter defined

acetylcholine (ACh)-found in great concentrations where neurons act upon muscles.

Curare• norepinephrine and epinephrine-(biogenic amines) generate

action potentials in the CNS, smooth and cardiac muscles. • dopamine-(biogenic amine) stimulates neurons and is involved in

memory, mood and motor cooridnatonCocaine inhibits dopamine removal from synapse

Meth increases dopamine release from neurons

• serotonin-(biogenic amine) involved in mood, rhythms. Inadequate production involved in depression.

•

Crawford W. Long 1842 or so

AMINO ACID NEUROTRANSMITTES

• Glutamate Excitatory in invertebrate neuromuscular junction.

• Aspartate Excitatory CNS• Glycine inhibitory CNS• GABA (gamma aminobutyric acid) inhibitory

in invertebrate neuromuscular junction.

Gaseous Signals of the Nervous System

• NO nitric oxide (signals walls of blood vessels of relax and dilate.

• Nitroglycerin with enzymes convert nitroglycerin to NO which dilate the blood vessels that supply the cardiac muscle.

endorphins

• Are neuropeptides (short chains of amino acids) that serve as neurotransmitters and decrease the perception of pain by the CNS.

• Endorphins may decrease urine output, depress respiration, produce euphoria…

Morphine and heroinOpiate-like polypeptides in the brain

Candace Pert Solomon Snyder

Blood Brain Barrier

Inhibitory neurotransmitters

• Suppress nerve action

Comparison of Mechanisms of Meth and Nicotine

NICOTINE• Mimics and thus replaces

acetylcholine causing “pleasure center” in the brain to release dopamine.

METH• Floods nerve cell internally

causing release of dopamine into the neural synapse.

EFFECTS OF METH

Short term• Increased attention/activity• Decreased fatigue• Euphoria and rush• Increased autonomic

activities (heart rate/respiratory rate)

Long term• Addiction• Paranoia• Hallucinations• Mood swings• Repetitive motor activity• Weight loss

• Long term animal research (20 years) shows that high doses of meth damage the cell ending (synaptic terminals) of dopamine and serotonin receptive neurons.

• Meth backpack and Laurens County Meth bust.

Howard Hughes Medical InstituteHoliday Lecture Series

• Exploring biodiversity: The Search For New Medicines.

• Viral Outbreak: The Science of Emerging Diseases. Free on DVD April 11th

• www.biointeractive.org