Ch. 5 - Synapses

Question 1

primary scientist

Answer 1

Otto Loewi, 1936 Nobel Prize winner

Question 2

synapses: general

Answer 2

communication sites between neurons
trillions in the human body
sites for learning, memory, drug action, and neurological disorders.
pre-synaptic terminal: axon terminal or end foot
post-synaptic terminal: dendritic spines

Question 3

chemical synapses vs. electrical synapses

Answer 3

chemical: use neurotransmitters to conduct signals across the cleft, ONE WAY, messenger molecules are released once AIS detects threshold.
electrical: use gap junctions to allow free flow of ions, BOTH WAYS, contact between 2 cells via hemichannels (hexamer connexion)

Question 4

neurotransmitter types

Answer 4

small molecule (COURSE RELEVANT), peptide, lipid, gaseous, ionic

Question 5

small-molecule neurotransmitters

Answer 5

fast-acting and synthesized through dietary supplements
must know: ACh (acetylcholine), DA (dopamine) and 5-HT (serotonin) AMINES, and Glu (glutamate) and GABA (gamma-aminobutyric acid) AMINO ACIDS.

Question 6

ACh - acetylcholine (NT and activation system)

Answer 6

first discovered, involved in neuromuscular function (organs, muscles)
- CHOLINERGIC system: attention, waking EEG and memory
- produced in 2 basal forebrain nuclei and 1 midbrain nucleus
- distributed to amygdala, neocortex, and hippocampus

Question 7

DA - dopamine (NT and activation system)

Answer 7

involved in attention, motivation, and reward pathways. the “pleasure” chemical.
- DOPAMINERGIC system: nigrostriatal pathway (substantia nigra to caudate nucleus) and mesolimbic pathway (ventral tegmentum to hippo/amygdala/prefrontal cortex, nucleus accumbens in basal ganglia)
- connected to Parkinson disease (degeneration of substantia nigra)

Question 8

5-HT - serotonin (NT and activation systems)

Answer 8

involved in mood, aggression, sleep, pain, and the “calming” chemical. synthesized by tryptophan.
SERATONERGIC system: maintains waking EEG, sourced from Raphe nuclei
- connected to depression (low levels of serotonin)

Question 9

GABA & Glu - gamma-aminobutyric acid and glutamate (NTs and activation system)

Answer 9

the work horses of the brain.
located in the cerebellum and forebrain.
GABA: inhibitory
Glu: excitatory

Question 10

types of NT receptors

Answer 10

ionotropic: aka ligand-gated channel; pore opens and promotes ion flow
metabotropic: chemicals and proteins recieve NTs

Question 11

steps of neurotransmission

Answer 11

1. synthesis
2. packaging and storage (in vesicles to await the arrival of action potential)
3. release (action potential triggers NT release (exocytosis))
4. reception (crosses cleft and binds to the post-synaptic receptor)
5. inactivation (NT diffuses away/is disposed of/ taken up by other cells)

** ALL NEUROTRANMISSION IS ANTEROGRADE (pre to post)