| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
|---|
| Research Abstract |
The aim of this study was to elucidate, at neuronal level, the role of the insular cortex for the expression of emotional behaviors in monkeys and rats. In the first fiscal year (2002), single neuron activity was recorded from the monkey insular cortex during performance of a delayed-response delayed-reward go/nogo task ; and responsiveness to the task was analyzed. As a result, we found that there are neurons related to attention, reward anticipation or behavioral decision making in the insular cortex ; we also found that there are functional topography in the insula. In the second fiscal year (2003), we recorded single neuron activity in the gustatory insular cortex of alert rats, and analyzed responses to rewarding or aversive taste stimuli. As a result, we found that some insular neurons responded differentially to the 4 standard taste stimuli (sweet, salty, sour and bitter). In addition to these taste cells, we found some neurons specifically responding to water or rinse. The cells best responding to salty or bitter tended not to respond to other taste stimuli but their own best stimulus, while for the sweet-best cells, the responses to sweet were almost similar to those to sour ; for the sour-best cells, the responses to sweet, sour and bitter were considerably similar. When considering the fact that sweet has innately hedonic while sour or bitter has an aversive property, the present results suggested that the insular neurons play an important role in the coding of taste quality. In the final fiscal year (2004), neural activity was recorded from the rat insular cortex during performance of a stimulus-reward/aversion association task, and responsiveness to the task was analyzed. As a result, we found that some insular neurons specifically code tones with biological significance.
|
