Table 1.

Effects of chronic 7 d infusion of BDNF (4 μg/d) or vehicle in rat frontoparietal cortex on TrkB protein and mRNA expression

TrkB Protein/mRNA Levels	Vehicle	BDNF	Student's t test (two-tailed)
Trk tyrosine phosphorylation	1.0  ± 0.4	3.3  ± 0.2	t12 = 4.8;p < 0.0005
(Trk P-tyr; fold induction over vehicle)
Full-length TrkB protein	100  ± 3	66  ± 7	t12 = 4.5; p < 0.001
(gp145 TrkB; percent vehicle)
Truncated TrkB protein	100  ± 5	78  ± 9	t6 = 2.1; p < 0.08, NS
(gp95 TrkB; percent vehicle)
TrkB/GAPDH mRNA	100  ± 5	88  ± 6	t8 = 1.6; p = 0.15, NS
(percent vehicle)

At the end of a 7 d intracortical infusion of BDNF (4 μg/d) or vehicle in intact animals, the infused cortex was microdissected, and levels of Trk protein were assayed by immunoblotting (data shown in Fig. 10). TrkB mRNA was analyzed by RNAse protection assay (described in Materials and Methods) using a cDNA probe that recognizes all TrkB isoforms; a GAPDH probe was included in the same reaction mixture to assess relative levels of RNA present in each hybridization (data calculated as the ratio of TrkB to GAPDH). Values shown are means ± SEM for 4–7 rats per group. NS, Not significant at p < 0.05.