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Strong Support
mechanistic
Analysis v3
History

When CaV3.1 T-type calcium channels are overexpressed in specific hypothalamic neurons, these neurons become more active at rest and fail to respond to leptin, even though the leptin receptors and...

17
Pro
0
Against

Mechanism

Synthesis from 1 study

How it works

Too many CaV3.1 calcium channels in hunger-control brain cells make them fire nonstop at rest, so they can't respond to the fullness signal from leptin. Turning down these channels brings back the response to leptin.

Most probable mechanism

In Simple Terms

When too many CaV3.1 calcium channels are present in hunger-regulating brain cells, these cells fire constantly at rest, so they cannot respond to the fullness signal from leptin—even though the signal is received normally. Blocking these extra channels restores the cells' ability to react to leptin.

Causal chain
1

CaV3.1 T-type calcium channel expression increases in hypothalamic POMC neurons

Verified by multiple studies
which leads to
2

Increased CaV3.1 expression enhances T-type current density and shifts voltage dependence of activation and inactivation toward resting membrane potential

Verified by multiple studies
which leads to
3

Biophysical shifts expand the window current at resting membrane potential, causing sustained calcium influx and depolarization

Verified by multiple studies
which leads to
4

Elevated basal excitability and spontaneous burst firing raise membrane potential to a plateau that prevents further depolarization by leptin-activated TRPC1/5 channels

Verified by multiple studies
which leads to
5

Leptin receptor and downstream signaling pathways remain fully functional but cannot alter neuronal firing due to pre-existing depolarization

Verified by multiple studies
which leads to
6

Partial inhibition of CaV3.1 channels reduces basal excitability below the firing threshold, restoring leptin-induced depolarization and electrical responsiveness

Verified by multiple studies

Evidence from Studies

Supporting (1)

17

Community contributions welcome

17

Genetic Deletion of KLHL1 Leads to Hyperexcitability in Hypothalamic POMC Neurons and Lack of Electrical Responses to Leptin

Case-Control Study
Animal & In Vitro
2021

Contradicting (0)

0

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

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Source Study

Genetic Deletion of KLHL1 Leads to Hyperexcitability in Hypothalamic POMC Neurons and Lack of Electrical Responses to Leptin

Score: 17
DOI: 10.3389/fnins.2021.718464

Similar Assertions

In mouse brain cells called POMC neurons, the hormone leptin triggers a sequence of ion channel activations that increases calcium influx and makes the cells fire electrical signals more readily.

12
0
87%

In mice lacking the KLHL1 gene, increased levels of CaV3.1 calcium channels in specific brain neurons lead to a 40% higher baseline calcium current, a shift in channel activation to more negative voltages, and a 2.3-fold increase in calcium entry at rest.

17
0
84%

Cav3.1 channels control the entry of calcium ions into specific brain cells called POMC neurons, which are involved in signaling fullness after eating.

17
0
79%

In mouse brain cells called POMC neurons, leptin does not directly change how T-type calcium channels open or close; instead, it affects these channels indirectly by causing the cell membrane to depolarize through activation of TRPC channels.

12
0
79%

In mouse brain cells called POMC neurons, blocking TRPC or T-type calcium channels stops leptin from making the cells more active, including preventing the decrease in the minimum current needed to trigger firing and the increase in firing rate.

12
0
77%