Receptors What!! There’s More??

Receptors are a very important part of Neurotransmission

• What we know….(or think we know)– The number of receptors and the ratio of

inhibitory and excitatory receptors are primarily determined by genetics (from DNA), but can be influenced by stress, drugs, and other Environmental factors

– NTs, hormones and drugs can all bind to receptors

There are two types of receptors we will discuss. Depending on the type AND location they perform differently.

• Metabolic Receptors- Activate G protein binds to receptor inside the cell

• Ionic Receptors-These open and close ion channels

Receptors are affected by:

• Full Agonists– Turn on the synthesis of the second messenger or

fully open ion channel• Antagonists

– Block natural antagonist NT, which must be present or they do nothing

• Partial agonists and antagonists– Act as net

• Inverse Agonists– Closes ion channels or Turns off synthesis of 2nd mes.ANDAllosteric Modulation: What is this?

Neurotransmitters

The Main Six

• Serotonin

• Dopamine

• Norepinephrine

• Acetylcholine

• GABA

• Glutamate

SerotoninRegulates:

Body temperatureHunger and thirstSexual behaviorSleep & ArousalAggression

Play a role in:Mania Depression & AnxietySchizophrenia (moderate role)OCDFood Craving & BulimiaPhobia & PanicMigraine Headaches

Dopamine

• Involved in – Voluntary Movement– Parkinson’s Disease and Huntington’s Chorea

(moderate in HC)– Tourette’s– Mania– Depression– Schizophrenia

Norepinephrine

• Flight or Fight

• Mania

• Depression (esp. fatigue, apathy, concentration)

• Schizophrenia

• Panic Attacks

Acetylcholine (ACH)

• Parasympathetic Nervous System

• Regulation of Voluntary Movement

• Memory

• Associated with decline in normal aging and Alzheimer's

GABA

• Inhibition

• Sleep

• Hunington’s Chorea

Glutamate

• Learning and Memory- excitatory NTs allow messages to pass more efficiently in the hippocampus