The neurobiological basis of spontaneous alternation.

When placed in a T-maze, rats or mice possess a strong tendency of alternating arm choices on successive trials. The exploration of novel environmental stimuli is dependent on the integrity of limbic and non-limbic pathways, including the basal forebrain, the hippocampus, the thalamus, the prefrontal cortex, and the dorsal striatum, as well as the vestibular system and cerebellum. Neurochemical pathways using acetylcholine, gamma-amino-butyric acid, and dopamine in the septum and hippocampus have been implicated in the exploration of novel maze arms. In addition to the delineation of interactions between neurotransmitters, the spontaneous alternation test is sensitive to the consequences of normal and pathological aging.