BMS 439 — Neurotransmitters

For Exam 4

6 Types of CNS Chemical Mediators

1. Small molecules

2. Neuropeptides

3. Lipid mediators

4. Gaseous mediators

5. Neurotrophins & Cytokines

6. Steroids

Neurotransmitters

Fast-acting

Act on ligand-gated ion-channels

Examples: glutamate, GABA

Neuromodulators

Slower-acting (seconds)

Act via G-protein coupled receptors

Examples: dopamine, neuropeptides, prostanoids

Neurotrophic Factors

Slowest-acting

Regulate gene expression & control neural growth through tyrosine kinases

Major Dopaminergic (DA) Pathways in the Brain

1. Nigrostriatal (substantia nigra to striatum)

   • Extrapyramidal motor control

2. Mesolimbic/mesocortical (ventral tegmental midbrain to N. Accumbens, hippocampus, and cortex)

   • Emotion and cognition

3. Tuberoinfundibular (arcuate nucleus of hypothalamus to median eminence then anterior pituitary)

   • Prolactin release