Workshop 8 - Nicotine and Caffeine

Acetylcholine

Nicotine and caffeine are both stimulants that have similar activation on what

Cotinine

Active metabolite of nicotine - In the liver, enzymes metabolize 80–90% of nicotine, producing this, which exhibits similar actions to nicotine

Acetylcholine

Nicotine is an agonist for these nicotinic receptors. Cotinine is a weak agonist for these receptors

Nicotinic receptor desensitisation

When bound to by an agonist, nicotinic receptors undergo an active state and then a desensitized state. The receptor cannot be activated during the desensitized state, and the desensitized state is longer than the active state. This is called..

Functional antagonism

An indirect way of inhibiting a receptor’s activity. The net effects of an agonist inactivate receptor state.

Upregulation

Increased production of receptors. During administration, the brain compensates for the repeated closing of receptor channels by increasing nicotinic receptors

MAO

Chemicals in tobacco inhibit this enzyme. This enhances the effects on DA in NAcc

PNS

Nicotinic receptors (ACh) in this are linked to neuromuscular junctions. Causes muscles to contract.

ANS

Activation here due to nicotine increases sympathetic nervous system activity

Adenosine

Caffeine is an antagonist for these receptors. It has inhibitory effects on neurons. Contributes to sleepiness . No discrete circuit, spread throughout body

Heteromer

Combination of several neurotransmitter receptors. Interact and modulate effectiveness of other neurotransmitters. Similar to allosteric modulators. Can be applied to caffeine, adenosine and DA.