Fig. 7.

Microinjection of glutamate into the InM causes respiratory depression, sympathoexcitation and HNA activation. Microinjection of glutamate (40 nl of 100 mM) into the InM (injection sites confirmed histologically using pontamine sky blue) at the time marked by the vertical line evokes tonic activity in HNA and ∫HNA, with underlying inspiratory activity. Following glutamate injection the expiratory period in PNA and ∫PNA was exaggerated and SNA and ∫SNA became more tonic, with a cessation in respiratory related bursts. This is coupled to a small increase in PP with no obvious changes to HR, other than diminished respiratory sinus arrhythmia