Lecture 3: Synaptic Process

Where are sodium and potassium more concentrated?

Sodium - inside the Cell

Potassium - Outside the Cell

Ionic permeability is ____ dependent.

voltage

fill in the chart

The ____ axon terminal connects with the _____ dendrite spines to create a synapse.

The presynaptic axon terminal connects with the postsynaptic dendrite spines to create a synapse.

What is the difference between electrical and chemical synapse

Electrical Synapse: The cell bodies are directly connected through connexons, allowing for ions to directly flow from cell to cell, rarer

Chemical Synapse: AP travels to axon terminal and causes the release of chemicals called neurotransmitters which bind with receptors on post synaptic cell which can cause depolarization/repolarization

what is the connection point of electrical synapses called?

gap junctions

What is the function of gap junctions at electrical synapses?

transmission of ions at quick speeds

What are the advantages of electrical synapses?

transmission is extraordinarily fast, transmission can be bidirectional

1. Transmitter is synthesized and then stored in ____

2. An Action Potential invades the ____ terminal

3. ____ of presynaptic terminal causes opening of voltage-gated __ channels

4. ___ of ___ through channels

5. Ca2+ causes vesicles to ____ with presynaptic membrane

6. ____ is released into synaptic cleft via exocytosis

7. Transmitter binds to receptor molecules in the ____ membrane

8. Opening or Closing of ____ ____

9. Postsynaptic current causes ___ or ___ PSPs that changes the ____ of the postsynaptic cell

10. Removal of Neurotransmitter by ____ ____ or ____ ___

11. Retrieval of ____ membrane from Plasma Membrane

1. Transmitter is synthesized and then stored in vesicles

2. An Action Potential invades the presynaptic terminal

3. Depolarization of presynaptic terminal causes opening of voltage-gated Ca2+ channels

4. Influx of Ca2+ through channels

5. Ca2+ causes vesicles to fuse with postsynaptic membrane

6. Transmitter is released into synaptic cleft via exocytosis

7. Transmitter binds to receptor molecules in the presynaptic membrane

8. Opening or Closing of postsynaptic channels

9. Postsynaptic current causes Excitatory or Inhibitory PSPs that changes the excitability of the postsynaptic cell

10. Removal of Neurotransmitter by glial uptake or enzymatic degradation

11. Retrieval of vesicular membrane from Plasma Membrane

What are MEPPs

Miniatur EPPs

EPPs represent the ____ ____ of many MEPP-like units

EPPs represent the simultaneous release of many MEPP-like units

How do Synaptic Vesicles get recycled?

What is the role of Calcium in Transmitter Secretion?

Entry of Ca2+ through presynaptic voltage-gated calcium channels causes transmitter release

What is Reversal Potential?

the voltage at which the direction of the current changes from inward to outward

If the reversal potential is more ____ than threshold, excitation results;

inhibition occurs if the reversal potential is more _____ than threshold

If the reversal potential is more positive than threshold, excitation results;

inhibition occurs if the reversal potential is more negative than threshold

What causes action potential in Postsynaptic neuron?

Summation of EPSPs and IPSPs

What are the types of Summation?

Spatial summation (Many PSPs in different locations of dendrites summing up)

Temporal Summation (Many PSPs in the same location at a high frequency, leading to summation)

Electrical Properties of Neurons

What is the Single-Compartmet Neuron Model?