Supplementary Figure 3: NAc D1-MSN terminals to the VM innervate selectively neurons with GABA-like properties.
From: Coding the direct/indirect pathways by D1 and D2 receptors is not valid for accumbens projections
(a) Out of 15 neurons (n = 3 mice) tested in the VM 10 neurons exhibited eIPSCs generated by D1-MSN terminals while 5 neurons did not respond. Cell numbers in each group correspond also to the appropriate groups in b-e. (b) The D1-MSN-responding VM neurons did not exhibit significant Ih (-24.1±6.8 pA) while the non-responding VM neurons showed robust Ih (-178.3±35.0 pA, unpaired t-test, t(13)=5.74, p<0.0001). Ih was calculated as the difference between the currents during the first and the last 100 ms of the 2 s long hyperpolarizing step. Bottom – representative Ih recordings for D1-responding (left) and D1 non-responding (right) VM neurons. (c) VM neurons receiving D1-MSN input from the NAc showed higher action potential firing rate compared to VM neurons not receiving D1-MSN input (7.97±1.3 Hz vs. 0.02±0.02 Hz, respectively; unpaired t-test, t(13)=5.05, p=0.0005). (d) VM neurons receiving D1-MSN input from the NAc showed higher sIPSC frequency compared to VM neurons not receiving D1-MSN input (6.65±0.74 Hz and 1.83±0.75 Hz, respectively; unpaired t-test, t(13)=4.20, p=0.0012). (e) VM neurons receiving D1-MSN input from the NAc showed higher sIPSC amplitude compared to VM neurons not receiving D1-MSN input (72.3±7.4 pA and 35.1±2.8 pA, respectively; unpaired t-test, t(13)=3.61, p=0.0036). Results are presented as mean±s.e.m. Error bars represent s.e.m. *, p<0.05.
