Synaptic Action

Synaptic Potentials:•EPSP•IPSP

Synaptic Potentials

•Excitatory Postsynaptic Potential (EPSP)•triggered by excitatory neurotransmitters•open ligand-gated Na+ channels•allows Na+ to flow inside the cell•causing a slight depolarization of the postsynaptic cell•moves the postsynaptic cell closer to firing an action potential

•Inhibitory Postsynaptic Potential (IPSP)•triggered by inhibitory neurotransmitters•open ligand-gated K+ channels or Cl- channels•allows K+ to flow out of the cell or Cl- to flow inside the cell•causing a slight hyperpolarization of the postsynaptic cell•moves the postsynaptic cell further from firing an action potential

The Battle to -55mV

EPSP

IPSP

Neurotransmitters•Amines

•Quaternary amines•Acetylcholine (ACh)

•Monoamines•Catelcholamines

•Epinephrine (EPI)•Norepinephrine (NE)•Dopamine (DA)

•Indoleamines•Serotonin (5-HT)•Melatonin

•Amino acids•Gamma-aminobutyric acid (GABA)•Glutamate (GLU)•Glycine•Histamine (HIST)

•Neuropeptides•Opioid peptides

•Enkephalins (ENK)•Endorphins (END)

•Peptide Hormones•Oxytocin (Oxy)•Substance P •Cholecystokinin (CCK)•Vasopressin (ADH)•Neuropeptide Y (NPY)

•Hypothalamic Releasing Hormones•GnRH•TRH•CRH

Cholinergic (Ach) System

*

*(PPT)

(BF)

Noradrenergic (NE) System

*

(LC)

Serotoninergic (5-HT) System

Raphe Nuclei *

Dopaminergic (DA) System 1Mesolimbic

Ventral Tegmental Area (VTA)*

Dopaminergic (DA) System 2Mesostriatal

*

Basal Ganglia