3: Nicotine

How does inhalation of nictoine compare to IV

Inhalation allows it to reach the brain 2x as fast as IV (in as little as 7 seconds)

How does nicotine enter lungs

Nicotine enters lungs on particles called tar: a complex mix of H-C some are carcinogenic which contributes to taste and smell

What method of nicotine inhalation gets the fastest effects

Cigarettes gets the effects the fastest, but are not the longest lasting

Average smoker takes 10 puffs

So 30 cigs a day. = 300 hits

Cigarette half life

2 hrs

Nicotinic cholinergic receptors

A subtype of Ach ionotropic receptors with 5 subunits

2 alpha and 3 beta with different configurations

Acute tolerance

Takes place over the day as the 1st cig is the best

Mechanism of receptor

Increasing doses may lead to receptor desensitization

• continuous depolarization, depolarization block must remove an agonist or cell won’t fire again

What is the alpha 7 subunit

It is important in nicotinic receptors to novel object recognition test

Drugs that are agonists for this are in works for improving memory