High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons
- Oregon Health and Science University, United States
- Howard Hughes Medical Institute, University of Washington, United States
- Oregon National Primate Research Center, Oregon Health and Science University, United States
Figures
Figure 1
High fidelity response to light (470 nm) stimulation of ARH Kiss1 ChR2-expressing neurons.
(A–B) Examples of evoked inward currents in voltage-clamp (A) and depolarization in current-clamp (B) with varied light intensity (33–330 µW). (C) Trains of light pulses (0.9 mW, 10 ms pulse-width) …
Figure 2
Slow excitatory postsynaptic potential (slow EPSP) is frequency and duration dependent.
(A) Illustration of experimental approach. (B–C), Overlay of epifluorescence (YFP) and differential interference contrast (DIC) images during whole-cell recording (pipette tip can be seen) from …
Figure 3
Slow EPSP is dependent on direct synaptic input from neighboring Kiss1 neurons.
(A) To reduce the variability between Kiss1 neurons from different animals, a response ratio (R2/R1) protocol was used in which the magnitude of second light response (A2) was compared to first …
Figure 4
The slow EPSP is dependent upon G-protein activation.
(A) Intracellular dialysis with low concentrations of QX-314 (0.5 mM) in the internal solution (IS) blocked Na+ channels, but the slow EPSP induced by light stimulation was not blocked. (B) Slow …
Figure 5
Tacr3 agonist mediates the slow EPSP.
(A–C) The slow EPSP was abrogated by an NKB receptor (Tacr3) antagonist SB222,200 (A) and the NKB receptor antagonist cocktail SDZ-NKT 343 (1 µM), GR94,800 (1 µM) and SB222,200 (3 µM) (Tacr1, 2 and …
Figure 6
The κ-opioid receptor agonist blocks the slow EPSP.
(A–B) The κ-opioid receptor antagonist nor-BNI (1 μM) potentiated the slow EPSP (A) and the agonist U69,593 (1 µM) attenuated the slow EPSP (B2 versus B1). However, the Tacr3 agonist senktide is …
Figure 7
Kiss1ARH neurons send contralateral projections to Kiss1ARH neurons inducing circuit excitation.
(A) Confocal image of a coronal section through ARH from a Kiss1-Cre mouse following a unilateral ARH injection of AAV-DIO-ChR2:mCherry. Kiss1 neurons expressing ChR2-mCherry were observed on the …
Figure 8
Dual patch recording reveal that high-frequency auto-excitation of ipsilateral Kiss1ARH neurons recruit contralateral Kiss1ARH neurons.
(A) Image of a coronal section through the ARH from Kiss1-Cre mouse that received dual injection of AAV-DIO-ChR2:mCherry (left side, red) and AAV-DIO-YFP (right side, yellow). Scale bar = 200 µm. (B)…
Figure 9
Tacr3 agonist senktide excites GnRH neurons indirectly through ARH Kiss1 neurons, and a slow EPSP in GnRH neurons is evoked with photoactivation of ChR2 Kiss1ARH neurons.
(A) Schematic drawing of the Kiss1ARH, Kiss1AVPV/PeN and GnRH neuronal circuit (A1) and a high power image (A2) of a parahorizontal slice from a GnRH-EGFP mouse illustrating whole-cell recording of …
Figure 10
Photoactivation of Kiss1ARH fibers excites Kiss1AVPV/PeN neurons via glutamate release.
(A) Schematic drawing of a coronal section showing the bilateral viral injections in the ARH with AAV-DIO-ChR2:mCherry. (B) Sagittal brain slice (B1) and confocal images from the slice (B2, 3) of …
Figure 11
High-frequency photoactivation of Kiss1AVPV/PeN neurons excites GnRH neurons via kisspeptin release.
(A) Schematic drawing of coronal section showing bilateral viral injections in the AVPV with AAV-DIO-ChR2:mCherry. (B) Parahorizontal brain slice of mouse bilaterally injected with a …
Figure 12
Proposed model by which activation of Kiss1 neurons governs GnRH neuronal excitability.
High-frequency photostimulation of Kiss1 neurons in the ARH releases NKB that depolarizes and recruits other Kiss1ARH neurons. Dynorphin is co-released and acts presynaptically to modulate (inhibit) …
