Hi again @keun. Could you explain what you mean by “but the ampa, nmda, and gaba all have a negative sign in the constant term” – what is the “constant term” here? In your AMPA equations, w and g_a should be positive, and the (E_\text{AMPA} - v) term will be positive as well, since E_\text{AMPA} > v. In contrast, for an inhibitory synapse, E_\text{GABA} < v (almost always), so I_\text{GABA} will be negative.