7 Channels Regulate Firing during Synaptic Integration in GABAergic Striatal Neurons

Figure 10

Sequential actions of muscarine and XE991. (a) After XE991 (20 μM) increased control synaptically evoked depolarization in a dSPN, muscarine (1 μM) had an additional action, as expected, due to the presence of M₄ receptors [24]. (b) This additional action does not happen in iSPNs since they lack M₄-receptors. (c) After muscarine, XE991 only provoked a small additional depolarization, since it is rare that a receptor action saturates completely a given effector. However, comparing (a) and (c) shows that additional action in (a) suggests that it is not due to M₁-receptors [24]. (d) Additional action of XE991 is due to an autorregenerative response, which can also appear without it (cf. (b)).

(a)

(b)

(c)

(d)