Figure 2.

Knockdown of BDNF expression within the DLS increases ethanol self-administration. a, Rats were stereotaxically infused with siBDNF-1 (10¹⁰ TU/ml) into the DLS. Fifteen days after the microinjection, striatal slices were prepared and stained for virus-expressed GFP (green) along with either NeuN (top panel, red), or GFAP (bottom panel, red). The scale bar represents 100 μm. b, siBDNF-1 or siCT were stereotaxically injected into the DLS of rats. Five, 15, and 25 d after the microinjection, DLS were collected for RT-PCR analysis. siBDNF-1 time-dependently decreased BDNF expression in the DLS. Histograms depict the mean ratios of BDNF/GAPDH ± SEM normalized to BDNF levels obtained from control animals. The insert is a representative image of BDNF mRNA levels from samples collected 15 d after infection by the siCT- or siBDNF-1-expressing virus. (n = 7), *p < 0.05, **p < 0.01. c, Rats were treated as described in b and brain samples were collected, 5, 15, or 25 d after injection, and analyzed by Western blot to determine BDNF protein levels. The samples from the three different time points were separated on three different gels to ensure comparison between siBDNF-1 and siCT injections within each time points. The insert is a representative image of BDNF protein levels from samples collected 15 d after infection by the siCT- or siBDNF-1-expressing virus. (n = 3–4), ***p < 0.001. d, e, Rats were stereotaxically infused with siBDNF-1 or siCT (10¹⁰ TU/ml) into the DLS 2 months after the beginning of ethanol self-administration training. d, Injection of siBDNF-1 increases ethanol self-administration 15–16 d after infusion. Results are expressed as mean ± SEM ethanol consumed in grams per kilogram. siBDNF-1: n = 12; siCT: n = 11; *p < 0.05. e, BDNF knockdown in the DLS increases the number of ethanol deliveries. The results are expressed as mean ± SEM ethanol deliveries by blocks of 2 d. siBDNF-1: n = 12; siCT: n = 11; *p < 0.05.