Figure 5.
Optogenetic activation of RP3VGABA neuron axons excites GnRH neurons. A, B, Example traces and corresponding rate meters below (10 s bins) illustrating the effects of blue-light stimulation trains (300 pulses) on GnRH neuron firing. GnRH neurons increased their action potential firing during the stimulation train (immediate), after the stimulation train (delayed) or both (immediate and delayed) in response to 2 Hz (A) or 10 Hz (B) stimuli. C, The immediate response to the stimulation train was seen in similar proportions of GnRH neurons, but was of larger magnitude at 10 Hz (*p < 0.05; number of cells at base of histograms). D, The delayed response to the stimulation train was evoked in a larger proportion of GnRH neurons and had a larger magnitude at 10 Hz compared with 2 Hz (**p < 0.01). E, The immediate response at both 2 and 10 Hz was abolished by 5 μm gabazine (*p < 0.05), whereas the delayed response (F) was not altered.