Lecture 5 Flashcards
Monoamines
refer to the particular neurotransmitters dopamine, noradrenaline and serotonin.
How is serotonin synthesized?
L-Tryptophan →5-HTP → 5-HT = serotonin).
Tryptophan
- Dietary precursor.
- Competes with other amino acids at BBB.
Tryptophan Hydroxylase
- Rate-limiting enzyme.
- Neural stimulation regulates.
- Autoreceptors.
5-HTP
- People take this with In combo with taking MDMA to help prevent neurotoxicity.
- Skips rate limiting step, because 5-HTP can pass the brain blood barrier when serotonin can’t.
Storage, Release & Inactivation of 5-HT
- 5-HT is packaged into vesicles by VMAT2.
- Reserpine blocks storage of serotonin.
- Released by vesicular release.
MDMA
- 5-HT and DA, NE
- Toxicity & memory deficits
- Long term and psychiatric effects controversial.
- Adjunct to psychotherapy.
Therapy: adjunct to psychotherapy.
MAIO
a class of drugs that inhibit the activity of one or both monoamine oxidase enzymes.
- powerful antidepressant.
5-HT1A
- Limbic areas
- Postsynaptic
- Autoreceptor
Serotonin Syndrome
High 1A agonist action
Symptoms:
- Repetitive muscle spasms.
- Resting tremor.
- Restlessness, agitation.
- Disorientation.
- Sympathetic activation.
5-HT13
- Ligand-gated ion channel.
- Pain, eating, hyperactivity.
- Vomiting reflex.
- Accompany chemotherapy.
Triptans
cause consecration of blood vessels in the brain, which eases pain.
Serotonin on Cognition & Behavior
States of consciousness: Enhance repetitive motor activity while suppressing sensory processing.
Plays a role in sleep regulation, hunger, mood states & sexual behaviour.
5-HT plays a role in the processing of pain signals at the level of the spinal cord.
SSRIs are the most common treatment for several anxiety disorders.
Low serotonergic activity = increased aggressive behavior.
Learning & Memory: Contextual fear conditioning (used to investigate the role of 5-HT in learning and memory).
Blood Brain Barrier (BBB).
the frontier that isolates brain tissues from the substances circulating in the blood vascular system.