Pt. 4 Serotonin

What does the media focus on surrounding serotonin?

Anxiety, obesity, and aggression

Are the 5-HT receptors Metabotropic or ionotropic?

There are 14 5-HT receptors

13 are Metabotropic, one (HT3 are ionotropic)

This ionotropic are excitatory

Where are these 5-HT1A receptors and what do they do

There are increased levels of this receptor in the hippocampus, amygdala & dorsal raphe nuclei

These receptors are mostly autotrophic

Also found on post-synaptic neurons by decreases cAMP or increase K channels opening

Where is the 5-HT2A receptor found and what does it do

Are found in the neocortex, striatum, and nucleus accumbens

This activates 2nd messenger system increasing Ca in the cell and protein kinases C

What do changes in the serotonergic neurons do

Changes in the system relate to SIDS, OCD, tics, depression

How can we determine the function of serotonergic system?

• compare serotonin levels between neurotypical and psych patients

• look at SSRIs response

• look at genes for serotonin transports (SERT) and how they differ with psych patients

What are the 2 defects that mice w/o serotonergic neurons

• thermoregulation patterns

• apnea episodes

What is the function of the 5-HT 1B, 2C, 6

Hunger and eating

5-HT1b, 2C Apply agonists which decrease food intake

For 5-HT6 food intake decreases with applying antagonists

What is hypophagia vs hyperphagia

Hypophagia: reduce food intake vs hyperphagia: increasing food intake

What does the 5-HT6 receptor do?

The activation of 5-HT6 has been found to improve memory in lab animals

What is the novel object recognition task?

A lab animal is given several minutes to explore 2 objects, then 1 objects is replaced with a new object.

The time the animal explores a new object vs the known object is measured.

What do 5-HT6 antagonists do

They improve performance on novel object recognition task

• under development to treat schiz or Alzheimer’s