LEARNING AUDITORY ODDBALL PARADIGMS IN RATS USING HUMAN-RELEVANT FREQUENCIES: BEHAVIORAL PERFORMANCE AND THALAMIC ERPS

Rodent models are used to study auditory processing in neuropsychiatric disorders and test new treatments like targeted brain stimulation. However, rats have a different hearing range than humans and require extensive training for complex tasks. This study examined how rats learn an auditory oddball paradigm, whether they can be trained with human-relevant auditory stimuli and if their thalamic event-related potentials (ERPs) are similar to those of humans.
Sprague-Dawley rats (n=10) were trained in a three-class oddball paradigm, responding to a rare Target tone (5 kHz or 1.5 kHz), while ignoring a rare Distractor (1.5 kHz or 5 kHz) and a frequent Standard tone (3 kHz). We measured learning progress, response accuracy, and reaction times. After stereotaxic implantation of electrodes into the thalamus, ERPs were recorded during behavioral testing.
Rats learned the task in 6-7 weeks with no significant difference between the high and low target frequency subgroups. Initially, rats responded randomly but showed improved accuracy and faster reaction times as training progressed (p<0.05). Early in training, rats responded to Standard and Distractor tones similarly to Targets, but later ignored them. Thalamic ERPs showed the highest amplitude following Target compared to Distractor and Standard tones (p<0.05), with no difference between the high or low Target frequencies.
Rats can be trained with auditory paradigms using same frequencies as in human research. Initial confusion with non-Target tones resolved with training, and thalamic ERP responses were similar to those of humans. This approach provides a model for studying auditory attention deficits in neuropsychiatric conditions.