Long-term functional recovery in the rat auditory system after unilateral auditory cortex ablation.

CONCLUSIONS

An intact bilateral auditory corticofugal projection is necessary for the auditory system, and above all its main targets, to start working correctly after an acoustic stimulation. After restricted unilateral cortical lesions, the auditory system is able to recover its function in adult animals at 90 days after surgery. (Post-lesion plasticity in adults.)

OBJECTIVES

To study the influence of the cortex on the auditory system functionality and to asses its ability for post-lesion recovery.

METHODS

Restricted unilateral lesions were made in the auditory cortex of adult rats. To evaluate the functionality of the auditory pathway after corticofugal deafferentation, the acoustic startle reflex and prepulse inhibition, together with the auditory brainstem response (ABR), were tested along the survival time.

RESULTS

All the three tests showed a decrease in their responses at 15 days post lesion, and a full recovery at 90 days post lesion for the ABR and at 180 days post lesion for the acoustic startle reflex and prepulse inhibition.