Fig. 3From: Analytical Insights on Theta-Gamma Coupled Neural OscillatorsExcitatory regime—phase plane. Phase portrait of system (1) for I E =−0.5, λ=1, ε Θ =0.01, ω=4. The blue line represents the trajectory of the system when starting from initial conditions ( θ 0 ,−π): it passes along the nullcline d θ E d t =φ( θ E ,Θ)=0 (in red) and then quickly escapes to (π, Θ 1 ) once past the singular point (0, Θ 0 ). The dotted purple line shows that, for any starting point (Θ, θ E ) where Θ< Θ 0 and θ E < θ 0 , the trajectory converges to the blue lineBack to article page