Figure 3.

DDNs Receive Glutamatergic and GABAergic Inputs

(A) Addition of picrotoxin (PIC) during whole-cell DDN recordings of TTX-treated fish isolated a population of events (left) that were abolished by application of kynurenic acid (KYN; right).

(B) Addition of KYN isolated a second population of events (left) that were abolished by addition of PIC (right).

(C) Overlays of glutamatergic currents isolated with picrotoxin and GABAergic currents isolated with kynurenic acid (gray traces). Black traces represent current averages.

(D–F) Box-and-whisker plots of glutamatergic and GABAergic mPSC amplitudes (D), rise times (E), and half-widths (F). In (D)–(F), filled circles depict raw data points; upper and lower hinges of the box correspond to the first and third quartiles; whiskers extend to 1.5× the interquartile range; and lines within boxes represent median.

(G and H) Whole-cell voltage clamp recordings of endogenous synaptic currents recorded from a QX-314-dialyzed DDN of awake, paralyzed larvae clamped at the reversal potential for chloride (G) or cationic (H) currents.

(I) Voltage recording derived from the same cell depicting tonic and burst activity. Note that action potentials were blocked in the recorded cell by addition of QX-314 to the pipette solution.

Right panels in (G)–(I) are excerpts (dashed boxes) of activity shown on an expanded timescale. Scale bars for time in (G)–(I) are shown in (I).