Table 3.

Percentage of striatonigral versus striato-GP neuron spines, as identified by dopamine receptor immunolabeling, receiving axospinous synaptic contact from BDA-labeled IT-type versus PT-type terminals

Type of spine targeted by BDA + synaptic terminal	Percentage of spines with IT-type axospinous synaptic terminal	Percentage of spines with PT-type axospinous synaptic terminal	Significance of IT versus PT frequency difference on spine type by t test
D1 + (striatonigral)	23.7% (based on 75 BDA + IT-type synaptic terminals on D1 + spines in six striata)	12.4% (based on 39 BDA + PT-type synaptic terminals on D1 + spines in seven striata)	IT versus PT frequency on D1 + spines not significantly different; p = 0.06
D2 + (striato-GP)	10.2% (based on 29 BDA + IT-type synaptic terminals on D2 + spines in five striata)	40.1% (based on 68 BDA + PT-type synaptic terminals on D2 + spines in five striata)	IT versus PT frequency on D2 + spines significantly different at p = 0.0003
Significance of D1 versus D2 difference in corticostriatal input type by t test	Frequency of IT input significantly different on D1 versus D2 spines at p = 0.05	Frequency of PT input significantly different on D1 versus D2 spines at p = 0.0003