Figure 2. Increased excitation during the critical period (CP) preferentially increases the strength of excitatory inputs to anterior corner cell (aCC).

(A) Left: schematic demonstrating the use of optogenetics for testing strength of A18a or A31k synaptic drive on evoked action potential firing in aCC. Right: representative traces illustrating the effect of excitatory or inhibitory input on evoked action potential firing in aCC, respectively. (B, C) Current-clamp recordings wherein current (~10 pA) was injected to evoke action potential firing in aCC, prior to optogenetic stimulation of premotor input. Amplitude of inputs was quantified as change in frequency of action potential firing (ΔAP Freq. (Hz)) following optogenetic stimulation of A18a or A31k. Change in action potential firing frequency in A18a (p=0.04), but not A31k (p=0.15), was significantly potentiated by embryonic exposure to PTX vs. vehicle controls (EtOH).