Lecture 3 Flashcards
To prevent transmission at a synapse you could: (choose all that apply)
A. Prevent neurotransmitter exocytosis with a drug
B. Block post-synaptic receptors with a drug
C. Destroy post-synaptic receptors via an autoimmune reaction
D. Block voltaged-gated Ca2+ channels with a drug
All of the above
Which way do ions move during an EPSP?
+ ions enter the cell
Which way do ions move during an IPSP?
+ moves out of the cell, - ions move into the cell
What is summation?
All of the synapses (EPSPs + IPSPs) added together
Would an action potential be generated in the following scenario?
500 EPSP
100 IPSP
Yes, because there is an overall positive charge (+400) and therefore it is stimulating and an AP would be generated
Would an action be generated in the following scenario?
250 EPSP
250 IPSP
No, because the overall charge is 0
T/F Overall when we have a correctly functioning nervous system, the charges are in balance
True
What determines if its an EPSP or IPSP?
The receptor
Neurotransmitter receptors are either _______ or _______
Stimulatory (+ ions enter cell) or Inhibitory (+ ions leave cell, - ions enter cell)
What are the two structure types of neurotransmitter receptors?
- Directed-gated ion channel
- Indirect-gated/second messenger
Where is the receptor located in a direct-gated ion channel?
Directly on the ion channel
What is the sequence of events for a direct-gated ion channel?
Binding –> channel opens –> ions flow
Where does a neurotransmitter bind on an indirect-gated ion channel?
It binds to a receptor that has a G-protein on it.
Once the neurotransmitter binds, part of the G-protein breaks off (2nd messenger) and binds to a different receptor that is attached to a ion channel.
What is the sequence of events for a indirect-gated ion channel?
Neurotransmitter binds –> changes G-protein, subunit detaches –> subunit binds to ion channel –> channel opens –> ions flow
How is the brain able to change based on experience?
Neural plasticity
What happens when a neurotransmitter disengages from a receptor?
- It is dissolved by enzymes OR
2. Pre-synaptic re-uptake (it gets reused in the same process, some drugs can inhibit this)
What happens when if a drug increases the number of neurotransmitters? What is this called?
- The nervous system pulls receptors in –> less receptors = decreases effect
- Receptor Down Regulation
What happens if a drug decreases the amount of neurotransmitters? What is this call?
- The nervous system increases the number of receptors to increases the likelihood of a NT binding –> supersensitization
- Receptor Up Regulation
What are the 5 different types of Glial Cells?
- Astrocytes
- Oligodendroglial cells
- Microglia
- Ependymal cells
- Schwann cells
Which glial cells are part of the CNS? PNS?
CNS = astrocytes, oligodendroglial cells, microglia and ependymal cells PNS = schwann cells
Which cells impair axon regeneration?
Oligodendroglial cells (CNS unable to repair axons)
Which cells promote axon regenerations?
Schwann cells (PNS able to repair axons)
What is the role of the myelin sheath? What cells make it up?
- Insultes axons
- Saltatory conduction (speeds AP transmission)
- Schwann cells
