Abstract
In the mammal auditory perception, neural projection from the auditory thalamus to the cortex is known to be important. Some previous studies showed that the electrical stimulation to the thalamus elicited cortical responses, however, its spatial distribution is unrevealed. In this study, we mapped the cortical responses evoked by the electrical stimulations to thalamus. We put surface microelectrode array on the surface of the rat auditory cortex and inserted depth electrode array to the medial geniculate body (MGB) through the holes of the surface array. The constant current stimulations (50 μA, 150 μsec) were applied for 120 times to some pairs of recording sites in MGB. The surface electrode array recorded and mapped the amplitude of the evoked potentials. We found that the evoked potential was mainly derived from the primary auditory cortex and the anterior auditory field, however, the stimulation to the shallow electrodes of the ventral shank of the depth electrode array resulted in the responses from the ventral auditory field. These results indicate that our experimental system enables the investigation of the functional projection from the auditory thalamus to the cortex.
