PMC

Circuit diagrams. (a) A superconducting circuit in which a single-Josephson-junction flux qubit and an LC oscillator are inductively coupled to each other by a shared inductor. (b) Equivalent circuit obtained by applying the so-called Y- transformation to the inductor network in circuit (a). (c) The outer loop of circuit (a), which forms an LC oscillator. (d) The inner loop of circuit (a), which forms a single-Josephson-junction flux qubit.

Prediction of the signaling time of the feedforward loop. (A) Circuit diagram of the incoherent feedforward loop. (B) Simplified circuit schematic highlighting the signaling time of interest (in gray). This signaling time, T_TOT, is the summation of the time for AraC to activate lacI and the time for LacI to repress yfp. (C) Histogram of the experimentally measured T_TOT of the two-step cascade (blue bars). Red curve is the predicted signaling time, which was convolved from the experimental measurements of the three sub-circuits (below). (D) Circuit schematic of the modified activation circuit. (E) The modified activation circuit was used to measure the signaling time T₁, which is the time for AraC to activate LacI, plus the YFP observation time. (F) Histogram of the measured T₁ of the modified activation circuit. (G) Circuit schematic of the repression circuit. (H) The repression circuit was used to measure the signaling time T₂, which is the time for LacI to repress YFP. (I) Histogram of the measured T₂ of the repression circuit (from ). (J) Circuit schematic of the reporter only circuit. (K) The P_BAD reporter only circuit was used to measure YFP observation time, T_y. (L) Histogram of the measured T_y of the reporter only circuit (from ).

Shown are the excitatory and inhibitory connections in the egg-laying circuit inferred from these studies. Both the HSNs and VCs excite the vulval muscles, and the HSNs excite the VCs, generating a feed-forward circuit exciting the vulval muscles. The VCs also inhibit the HSNs, creating a negative feedback loop between the HSNs and VCs. The PLMs inhibit the HSNs to mediate touch inhibition of egg-laying.

a ∣ Simple cortico-thalamo-cortical (CTC) loops involve direct connections between TC and PT or CT neurons. Such loops are relatively uncommon. b ∣ Complex loops involve IT neurons closing the cortical end of the loop. Complex loops, particularly of the matrix-type, appear to be ubiquitous. The smaller ‘cyclo-plots’ (circular circuit plots with coloured arrows) are included as concise representations of the basic cellular connectivity in each type of loop.