Individual behavioral responses to hypothalamic stimulation persist despite destruction of tissue surrounding electrode tip

Abstract

Behavior evoked by hypothalamic stimulation differs among animals, although their electrode placements appear histologically to be identical. These differences have been attributed to selective activation of functionally discrete neural circuits that are in close proximity. We report here, however, that in rats initially exhibiting "stimulus-bound" drinking, this behavior persists following either a series of progressively larger lesions, or a single large lesion, around the electrode tips. Similar results were obtained in rats afforded minimal stimulation experience prior to the lesions. These results suggest that individual differences in response to hypothalamic stimulation cannot be attributed solely to variations in the neuroanatomical locus of stimulation.