Table 1.

Basic membrane properties from the NAc shell (MSNs) and OFC (pyramidal neurons) after Pavlovian approach test

	NAc shell				OFC
	Unpaired		Paired		Unpaired		Paired
	GFP−	GFP+	GFP−	GFP+	GFP−	GFP+	GFP−	GFP+
Resting Vm (mV)	−80.43 ± 0.47	−79.00 ± 1.05	−79.94 ± 0.64	−76.77 ± 1.14	−77.08 ± 1.49	−77.92 ± 1.28	−77.33 ± 1.20	−76.05 ± 1.16
Rheobase (pA)	52.43 ± 4.39	52.00 ± 4.76	51.79 ± 3.41	39.38 ± 3.24	108.54 ± 16.81	120.71 ± 13.75	107.08 ± 23.72	106.46 ± 13.75
Ri (mΩ)	387.60 ± 24.17	385.52 ± 46.69	351.23 ± 14.77	498.15 ± 39.64***,#	158.36 ± 15.63	162.74 ± 15.29	227.21 ± 26.90†	186.79 ± 18.19†
AP peak (mV)	60.8 ± 2.36	61.62 ± 4.37	71.05 ± 2.00	67.40 ± 3.24	82.19 ± 2.01	77.34 ± 2.43	78.53 ± 2.28	79.50 ± 1.73
AP half-width (ms)	1.78 ± 0.04	1.79 ± 0.12	1.62 ± 0.09	1.67 ± 0.10	1.22 ± 0.03	1.33 ± 0.5	1.25 ± 0.03	1.18 ± 0.04
fAHP (mV)	−9.66 ± 0.60	−10.15 ± 0.76	−10.95 ± 0.54	−9.86 ± 0.79	−7.21 ± 1.37	−9.10 ± 0.67	−10.47 ± 0.95†	−10.27 ± 0.62†
mAHP (mV)	−8.08 ± 0.44	−8.20 ± 0.52	−9.64 ± 0.47	−8.57 ± 0.67	−8.10 ± 0.87	−8.79 ± 0.82	−7.20 ± 1.19	−8.31 ± 1.23

Data are expressed as mean ± SEM (***p < 0.001, †p < 0.05, #p < 0.05).

#Significant interaction of Condition × GFP;

***significant differences between Paired GFP + compared with Paired GFP−;

†main effect of Condition. Liquid junction potential was −11.1 mV and was not adjusted for. Spike characteristics were determined from the first action potential (AP) of spike runs consisting of 6–8 spikes. Input resistance was calculated from slope of the I/V curve measured in response to 2 pA (NAc shell) or 5 pA (OFC) current steps. The AP threshold was calculated by the third-order derivative method (Cotel et al., 2013) using Mini Analysis software. (In this method, the maximum value of the third derivative of the AP trace (d3Vm/dt3) was utilized to determine onset time of the AP and then the critical membrane voltage that was required to elicit an AP (AP threshold) was determined.) The AP peak was calculated as the difference between the AP peak and the AP threshold. Half-width was measured as the AP width at half-maximal spike. Postspike fAHPs and mAHPs were measured 3 and 30 ms after the AP threshold, respectively, similar to Ishikawa et al. (2009).

V_m, Resting membrane potential; R_i, input resistance; fAHP, fast AHP; mAHP, medium AHP.