Communication between neurons Flashcards
What is the neurotransmitter used for memory?
NO nitric oxide
What neurotransmitter is responsable for arousal, consciousness, motor functions, learning, memory damage (and in memory problems (alzheimer’s))?
Acetylcholine
Which neurotransmitter prepares the brain to respond to stimuli from the enviroment?
Norepinipherine
Which neurotransmitter has a role in motor functions of basal ganglia, reward pleasure and addiction?
Dopamine
Which neurotransmitter does cocaine inhibit its uptake?
Dopamine
Which neurotransmitter is responsible for pain analgesia in the spinal cord and sense of well being?
Serotonin (5-HT)
What are some inhibitory neurotransmitters?
GABA and glycine
Which neurotransmitter has an excitatory role on the memory?
Glutamate
What are the types of cell surface receptors found?
1, ionotropuc receptors (Ligand gated ion channels, fast (msecs))
2.Metabotropic receptors
(receptors coupled to intracellular signalling, slow (secs))
What is the receptor that GABAA and glycine bind to?
ANionic, ionotropic receptors
What neurotransmitters bind to cationic ionotropic receptors?
Nicotinic acetylcholine
Ionotropic glutamate receptors (AMPA, Kainate, NMDA)
Serotonin (5-HT3)
Define synapses
The site of contact between 2 neurons or 2 cells without protoplasmic continuity
What is the function of synapses?
Transmission of impulses
Convergence (intensification)
Divergence (spread)
Site of action of drugs
What are the type of synapses?
Chemical (chemical transmission)
Electrical (gap junctions)
Conjoint (combined)
What happens when NMDA receptor channels are depolarized?
Mg2+ blocks the channel
What is the mechanism of synaptic transmission ?
- Depolarizatio of the knos, opening of voltage gated Ca2+ channels, Ca2+ influx, vesicle membrane fuses with cell membrane, rupture of the vesicles and release of the neurotransmitter
- cros the cleft
- Combine with specific postsynaptic receptors, change in permeability of postsynaptic membrane to one or more ions
- the transmitter triggers either opening or closure of specific ligand activated ion channels, electrcal changes (either excitatiry ach, or inhibitory as GABA)
Opening of Na+ channels > EPSP
Opening of K+ or cl- channels > IPSP
5.Removal of NT: by diffusion, enzyme, active reuptake of glial cells
What are the functional structures of chemical synapses?
- Presynaptic terminal (contains mitochondria and neurotransmitter vesicles)
- Synaptic cleft (contains ECF, rich in Na+ & Ca++ ions)
- Postsynaptic membrane contains receptor
