title: Stimulus-specific adaptation: can it be a neural correlate of behavioral habituation?
abstract: Habituation is the most basic form of learning, yet many gaps remain in our understanding of its underlying neural mechanisms. We demonstrate that in the owl's optic tectum (OT), a single, low-level, relatively short auditory stimulus is sufficient to induce a significant reduction in the neural response to a stimulus presented up to 60 s later. This type of neural adaptation was absent in neurons from the central nucleus of the inferior colliculus and from the auditory thalamus; however, it was apparent in the OT and the forebrain entopallium. By presenting sequences that alternate between two different auditory stimuli, we show that this long-lasting adaptation is stimulus specific. The response to an odd stimulus in the sequence was not smaller than the response to the same stimulus when it was first in the sequence. Finally, we measured the habituation of reflexive eye movements and show that the behavioral habituation is correlated with the neural adaptation. The finding of a long-lasting specific adaptation in areas related to the gaze control system and not elsewhere suggests its involvement in habituation processes and opens new directions for research on mechanisms of habituation.
authors.affiliation: The Department of Physiology and Biophysics, The Ruth & Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel.
authors.forename: Shai
authors.initials: S
authors.lastname: Netser
authors.forename: Yael
authors.initials: Y
authors.lastname: Zahar
authors.forename: Yoram
authors.initials: Y
authors.lastname: Gutfreund
mesh_terms: D000161:Acoustic Stimulation; D000200:Action Potentials / Q000502:physiology; D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D009949:Orientation; D011571:Psychoacoustics; D013018:Sound Spectrography; D020305:Strigiformes; D013477:Superior Colliculi / Q000166:cytology; D013997:Time Factors