BIO1022 Lecture Notes - Lecture 6: Medulla Oblongata, Electric Field, Hypothalamus
6 Jun 2018
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Lecture 6 (12/8): Nervous System “Systems and Senses”
Chemical synapse in crucial processing point
· Calcium floods in and interacts with the presynaptic membrane and then interacts with ligand-
gland ion channels
· Integration of information is excitatory or inhibitory
· Its chemically driven therefore it can be affected by toxins and disease
· It is modifiable chemically and structurally
Neurotransmitters (1)
· Many types of neurotransmitters
o Have different effects on different cell types
o Excitatory/inhibitory
o It depends on the receptor
Acetylcholine
· One of the most popular neurotransmitter
· Main excitatory
· Excitatory to skeletal muscle
· It is also inhibitory to the vertebrate heart
· Broken down rapidly after use
· Botox – a toxin that comes from a bacteria (botulism)
o Injected into faces
o It blocks Acetylcholine release
o It interacts with muscles and contractions
o Inhibiting muscle movement
o If it is blocked, muscles don’t contract – no wrinkles
· Nicotine
o Binds to acetylcholine receptor
o It is excitatory
o It doesn’t block the release, it goes in and blocks the action of the release
Neurotransmitters (2)
Amino acids
Gamma-aminobutyric acid (GABA)
· Bases of life and DNA
· Important in hormonal reactions
· Mainly inhibitory roles
· Increasing permeability to Chloride
Glutamate
· Always excitatory
· Most common neurotransmitter in the brain
· Is often found in MSG
o It excites the receptors around taste buds and enhances flavour and taste
o Doesn’t change actual flavour but our perception of the flavour
o Very salty and thus very thirsty
Biogenic amines
· Norepinephrine, Dopamine and adrenaline
o Excitatory to the vertebrate heart
o Linked to flight or fight responses
o Very rapid responses
o Changes the way we respond very quickly
o Links to mood, sleep and learning
o A lack of Dopamine: associated with Parkinson’s
o LSD (hallucinatory): binds to dopamine and serotonin (adrenaline) receptors
o Prozac: depression and anxiety
Addictive drugs (Dopamine and drugs)
· Affects neurotransmission
· Affect ‘reward system’
o Nicotine stimulates dopamine-releasing neuron
Document Summary
Lecture 6 (12/8): nervous system systems and senses . Calcium floods in and interacts with the presynaptic membrane and then interacts with ligand- gland ion channels. Integration of information is excitatory or inhibitory. Its chemically driven therefore it can be affected by toxins and disease. Many types of neurotransmitters: have different effects on different cell types, excitatory/inhibitory, it depends on the receptor. It is also inhibitory to the vertebrate heart. Botox a toxin that comes from a bacteria (botulism: injected into faces, it blocks acetylcholine release, it interacts with muscles and contractions, inhibiting muscle movement, if it is blocked, muscles don"t contract no wrinkles. Nicotine: binds to acetylcholine receptor, it is excitatory, it doesn"t block the release, it goes in and blocks the action of the release. Is often found in msg: it excites the receptors around taste buds and enhances flavour and taste, doesn"t change actual flavour but our perception of the flavour, very salty and thus very thirsty.
