Human iPSC-Derived Neurons with Reliable Synapses and Large Presynaptic Action Potentials.
J Neurosci
; 44(24)2024 Jun 12.
Article
in En
| MEDLINE
| ID: mdl-38724283
ABSTRACT
Understanding the function of the human brain requires determining basic properties of synaptic transmission in human neurons. One of the most fundamental parameters controlling neurotransmitter release is the presynaptic action potential, but its amplitude and duration remain controversial. Presynaptic action potentials have so far been measured with high temporal resolution only in a limited number of vertebrate but not in human neurons. To uncover properties of human presynaptic action potentials, we exploited recently developed tools to generate human glutamatergic neurons by transient expression of Neurogenin 2 (Ngn2) in pluripotent stem cells. During maturation for 3 to 9â
weeks of culturing in different established media, the proportion of cells with multiple axon initial segments decreased, while the amount of axonal tau protein and neuronal excitability increased. Super-resolution microscopy revealed the alignment of the pre- and postsynaptic proteins, Bassoon and Homer. Synaptic transmission was surprisingly reliable at frequencies of 20, 50, and 100â
Hz. The synchronicity of synaptic transmission during high-frequency transmission increased during 9â
weeks of neuronal maturation. To analyze the mechanisms of synchronous high-frequency glutamate release, we developed direct presynaptic patch-clamp recordings from human neurons. The presynaptic action potentials had large overshoots to â¼25â
mV and short durations of â¼0.5â
ms. Our findings show that Ngn2-induced neurons represent an elegant model system allowing for functional, structural, and molecular analyses of glutamatergic synaptic transmission with high spatiotemporal resolution in human neurons. Furthermore, our data predict that glutamatergic transmission is mediated by large and rapid presynaptic action potentials in the human brain.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Synapses
/
Action Potentials
/
Presynaptic Terminals
/
Induced Pluripotent Stem Cells
/
Neurons
Limits:
Humans
Language:
En
Journal:
J Neurosci
Year:
2024
Type:
Article
Affiliation country:
Germany