Figure 10. Muscimol injection into the caudal ventrolateral medulla (CVLM) increases the effect of hypercapnia on sSND in vagotomized sino-aortic deafferented rats.
A, effect produced by stepping end-expiratory CO2 from 5 to 10% on sSND and PND in one rat before and after bilateral microinjection of muscimol into CVLM (1.75 mm, 30 nl). B, average results from 9 rats. sSND at rest during the control period was defined as 100 units (*P < 0.05 for effect of hypercapnia relative to baseline). C, effect produced of stepping end-expiratory CO2 from 5 to 10% on sSND before and 5 min after injection of muscimol into CVLM (*P < 0.05 for effect of muscimol). D, effect of muscimol on mvPND elicited by stepping end-expiratory CO2 from 5 to 10% (*P < 0.05). E, injection sites. The two coronal sections represent from top to bottom Bregma −13.3 and −13.6 mm after Paxinos & Watson (1998).