Synaptic Transmission Flashcards
How are NT stored?
In synaptic vesicles
What are the two types of synaptic vesicles?
Small clear (40-60nm) and large dense (90-250nm)
What are the differences between chemical and electrical NT?
Electrical- quicker and less flexible, 3.5nm.
Chemical- slower, more flexible, delay of 3-5ms, uses a NT, unidirectional, 30-50nm.
Why does synaptic release occur?
Due to increase in intracellular calcium
How it the NT removed from the synaptic cleft?
Either by breakdown, reuptake into the terminal or it diffuses away
Where are amino acids, amine and peptide NT formed?
Amino acids and amines in the axon terminal but peptides are formed in the soma and transported to the terminal via axoplasmic transport
What is electrical transmission?
Direct flow of ions form one neurone to another, hence the direct influence of electric current from one to another.
Describe a gap junction?
Two very close membranes which have a hemichannel for transmission. 3.5nm gap and a brief 0.1ms delay, they are modulated by pH, NT and the concentration of calcium
Describe chemical neurotransmission?
NT substance is released from pre-synaptic cell, it diffuses across the cleft and effects the post-synaptic cell.
What are the 2 SNARE proteins and what do they do?
Synaptobreuin- binds with SNAP -25 on the membrane
Synaptotagmin- is a calcium sensor
What are the two types of post-synaptic receptors?
Metabotropic and ionotropic
