Skip to main content


Figure 1 | Fluids and Barriers of the CNS

Figure 1

From: The effects of Beta-Endorphin: state change modification

Figure 1

The Funnel-Model of the sequential organization of the male rat behavior. The model is based on a transition analysis of the behavioral elements of the male rat occurring during a series of experiments, which included feeding behavior, sexual behavior and territorial aggression, combined with the effects of electrical stimulation of the ventromedial hypothalamic nucleus (VMH). Explanation: see text. We have coined this model the ‘Funnel-Model’, because it illustrates clearly that in phase 1 of the behavioral sequence the animal is relatively free to make choices leading to any possible ‘consummatory act’, or in a wider view, to any behavioral state. Phase 1 can be characterized as a transitional situation, from where any behavioral sequence leading to a specific consummatory act can be performed or from where any possible behavioral state can be reached. At the end of phase 2 the situation is completely different: the male is ‘bound to’ perform the consummatory act, (mostly consisting of a series of physiological reflexes) and the opportunity to select other behavioral transitions is temporarily blocked. Only after completing the consummatory behavior, the ‘freedom’ of phase 1 is available again. The ‘Funnel-model’ illustrates on the one hand that physiological and brain mechanisms are working to support behavioral perseverance and to keep behavior directed to a specific goal, while on the other hand, especially in phase 1, the opportunity is raised to choose another strategy, or to pursue another goal or to reach another state.

Back to article page