Dynamic and generalized Wentzell node conditions for network equations

Abstract

Motivated by a neurobiological problem, we discuss a class of diffusion problems on a network. The celebrated Rail lumped soma model for the spread of electrical potential in a dendritical tree prescribes that the common cable equation must be coupled with particular dynamic conditions in some nodes (the cell bodies, or somata). We discuss the extension of this model to the case of a whole network of neurons, where the ramification nodes can be either active (with excitatory time-dependent boundary conditions) or passive (where no dynamics take place, i.e. only Kirchhoff laws are imposed). While well-posedness of the system has already been obtained in previous works, using abstract tools based on variational methods and semigroup theory we are able to prove several qualitative properties, including asymptotic behaviour, regularity of solutions, and monotonicity of the semigroups in dependence on the physical coefficients. Parole chiave cable equations on networks, ultracontractive semigroups of operators, Wentzell and dynamic boundary conditions