Download NEURAL TRANSMISSION

NEURONS
&
NEURAL TRANSMISSION
NEUROCHEMICAL MECHANISMS OF
DRUG ACTION
Nervous System Divisions

CNS (central nervous
system)



Brain, Spinal Cord
12 pairs of cranial nerves
(originate from cranium)
PNS (peripheral nervous
system)

Somatic nervous system
• 31 pairs of spinal nerves

Autonomic nervous system
CNS ORGANIZATION
Autonomic Nervous System
NEURONS
NEURON MEMBRANE

Membrane Structure


Semipermeable lipid
bilayer
Proteins
• Ion channels
• Transport pumps
• Receptors
MEMBRANE POTENTIAL
ACTION POTENTIAL
ACTION POTENTIAL
CONDUCTION OF A.P.
NEURONAL COMMUNICATION

POSTSYNAPTIC
POTENTIALS


Excitatory PSP
Inhibitory PSP
NEUROCHEMICAL SYNAPSE





Presynaptic
Membrane
Postsynaptic
Membrane
Synaptic Vesicles
Synaptic Cleft
Receptor Sites
SYNAPTIC TRANSMISSION
 Synthesis
 Storage
 Neurotransmitter
Release
 Receptor Activation
 Neurotransmitter
Deactivation


Enzymatic Deactivation
(Metabolism)
Reuptake
SYNTHESIS
NEUROTRANSMITTER FAMILIES

Acetylcholine
 Monoamines




Amino Acid Transmitters





Norepinephrine
Dopamine
Serotonin
Glutamate
GABA
Histamine
Glycine
Neuropeptides


Enkephalins
Endorphins
Receptor Subtypes for
Neurotransmitters







Acetylcholine: nicotinic, muscarinic
Dopamine: D1, D2, D3, D4, D5
Norepinephrine: alpha1, alpha2, beta1, beta2
Serotonin: 5-HT1a,1b,1c,1d; 5-HT2a,2b,2c;; 5-HT3…
GABA: GABAA, GABAB
Glutamate: NMDA, AMPA, mGluR
Endorphins: mu, kappa, delta
NEUROCHEMICAL PATHWAYS
RECEPTOR ACTIVATION

Ligand-gated ion channels
 Ionotropic Receptors
 Metabotropic Receptors


G proteins
Second Messengers
RECEPTOR ACTIVATION
DRUG ACTIONS ON RECEPTOR
ACTIVATION

Agonists



Competitive
Noncompetitive
Antagonists


Competitive
Noncompetitive
PRESYNAPTIC MECHANISMS
POSTSYNAPTIC MECHANISMS
Psychoactive Drug Classes

CNS stimulants


CNS depressants


morphine, methadone
Antipsychotics


LSD, PCP, mescaline, MDMA(?)
Narcotics (Opioids)


alcohol, benzodiazepines, barbiturates, GHB
Hallucinogens


amphetamine, cocaine, caffeine, nicotine
chlorpromazine, haloperidol, clozapine,
risperidone
Antidepressants

SSRIs (e.g., Prozac, Paxil), MAOIs, tricyclics
Pharmacology of Psychoactive Drugs
 Drugs



with cholinergic actions
curare (nicotinic antagonist)
atropine (muscarinic antagonist)
nicotine (nicotinic mixed agonist/antagonist)
 Nonselective




monoamine agonists
reserpine
MAO inhibitors (e.g., deprenyl)
tricyclic antidepressants (e.g., imipramine)
CNS stimulants (e.g., cocaine, amphetamine)
Pharmacology of Psychoactive Drugs
 Other


dopaminergic drugs
antipsychotics (haloperidol, chlorpromazine)
antiparkinson agents (L-DOPA, bromocriptine)
 Serotonergic


SSRIs -- (Prozac, Paxil)
LSD
 GABAergic



drugs
drugs
benzodiazepines (Valium, Xanax)
alcohol
bicuculline (convulsant)
Pharmacology of Psychoactive
Drugs