- #1
garytse86
- 311
- 0
In the lecture handout it says "When cells are hyperpolarised the result is a depolarisation towards threshold." What does this mean?
GABA(A) Receptors: Hyperpolarization & Depolarization
- Thread starter garytse86
- Start date
Click For Summary
SUMMARY
The discussion focuses on the role of GABA(A) receptors in the processes of hyperpolarization and depolarization in neuronal cells. It clarifies that hyperpolarization leads to a decrease in voltage, which inactivates voltage-gated Na+ channels, allowing them to reset. When the cell returns to resting membrane potential, these channels can reopen, resulting in a depolarization towards the threshold for action potential generation. This mechanism highlights the probabilistic nature of ion channel behavior in neuronal excitability.
PREREQUISITES- Understanding of GABA(A) receptor function
- Knowledge of neuronal action potentials
- Familiarity with voltage-gated Na+ channels
- Concept of hyperpolarization and depolarization in cellular physiology
- Study the mechanism of GABA(A) receptor activation and its effects on neuronal excitability
- Learn about the ball and chain mechanism of voltage-gated Na+ channel inactivation
- Research the role of hyperpolarization in action potential threshold modulation
- Explore the probabilistic nature of ion channel gating in neuronal signaling
Neuroscientists, pharmacologists, and students studying neurophysiology who are interested in the mechanisms of neuronal excitability and the role of neurotransmitter receptors.
- #2
DocToxyn
Science Advisor
- 425
- 0
Not quite sure, can you give us some more context from your notes - where do the GABA receptors fit in?
- #3
quasi426
- 207
- 0
garytse86 said:In the lecture handout it says "When cells are hyperpolarised the result is a depolarisation towards threshold." What does this mean?
A voltage gated Na+ channel will transiently open upon depolarization and a rush of Na+ will come into the cell. The channel will then inactivate via the ball and and chain mechanism, (basically the channel is plugged is its in the open conformation but plugged up so no ions can flow through.) In order for the inactivation to go away there must be a decrease in voltage or hyperpolarization. So it turns that channel opening and closing is basically a probability game. At the resting membrane potential some of the Na channels have the inactivation turned on, however upon hyperpolarization these channels will have the inactivation turned off. Now when you put the cell back to the resting potential some of the channels will open and Na will rush in.
Similar threads
- · Replies 4 ·
- · Replies 5 ·
- · Replies 1 ·
- · Replies 1 ·
- · Replies 12 ·
- · Replies 3 ·