When a pre-synaptic neuron fires at time t = 0, then the postsynaptic neuron receives a stimulus that is often described by the function If you’re not sure what pre-synaptic and post-synaptic neurons are, have a look at Wikipedia. s(t) = Ate−t

.

However, the constant A sometimes isn’t a constant; often A will be a Gaussian function of another variable, a say. In this case, we would have To classify the stationary points, just choose a0 = σa = 1, say (just to keep things simple), and plot the surface. s(t,

a) = e

−(a−a0

)

2

σ2 a te−t

.

Find and classify the stationary points of s(t, a).