Neurons

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-small/nonpolar/fat soluble (hydrophobic): intercellular mechanism

*polar bears are big and like water

- bind on surface (response happens immediately)

- inside cell (takes a delayed amount of time)

What is the first step in the action of a ligand on a cell?

- binding of that ligand to a specific receptor either within the cell or on the cell membrane of its target cell

- receptors on the cell membrane are typically proteins

Endogenous ligands and their corresponding exogenous ligands

1. Acetylcholine-Nicotine

2. Dopamine-Methamphetamine

3. Epinephrine-Albuterol

4. Cortisol-Methylprednisoline

5. Testosterone-Oxandrolone

[Glial cells]: support cells for neurons

[Neurons]

- Input region (dendrites), location of where stimulus comes

- The endogenous ligand which does the communication between two cells of the nervous system is called a neurotransmitter

*The movement of Na+ and K+ is due to voltage gated ion channels and it's a cascade of ions pouring through ion pores

- Positive on outside of the cell and more negative on inside of the cell

- Resting potential is -70V and when sodium rushes in (depolarization), cell becomes more +

- When K+ rushes out of cell, the cell becomes more - (depolarization)

- After action potential, it overcorrects and becomes more negative than it needs to be (hyperpolarization) (cell can't respond to stimulus at this stage)

Ex: cocaine- their neurons are becoming more positive and stimulates it

Ex: Novocaine- hyperpolarized from dentist

Novo