Polyhomeostatic adaption occurs when evolving systems try to achieve a target
distribution function for certain dynamical parameters, a generalization of the notion
of homeostasis. Here we consider a single rate-encoding leaky integrator
neuron model driven by white noise, adapting slowly its internal parameters,
threshold and gain, in order to achieve a given target distribution for its
time-averaged firing rate. For the case of sparse encoding, when the target
firing-rate distribution is bimodal, we observe the occurrence of spontaneous
quasiperiodic adaptive oscillations resulting from fast transition between
two quasistationary attractors. We interpret this behavior as self-organized
stochastic tipping, with noise driving the escape from the quasistationary
attractors.