Figure 4.

Generation of Venus-Tagged Arc Knockin Mice

(A) The Venus sequence was inserted before the stop codon of the protein using the TAP vector as template. The cross of both knockin mice with a transgenic Cre-expressing mouse line deleted the neo resistance cassette by recombination between loxP-sites. Asterisk, stop codon (TAA) of the coding sequence; thick black line, TAP and Venus tag sequence, as indicated; triangle, loxP site.

(B) Structure of the Venus-tagged Arc regions as in Figure 1B.

(C) PCR amplification of WT (bottom band) and Arc Venus-targeted alleles (top band). Venus/+, heterozygous for Venus-tagged Arc.

(D) Input-output relationships illustrate averaged field excitatory postsynaptic potential (fEPSP) amplitudes in slices from Arc^Venus/Venus (n = 26, N = 8) and WT mice (n = 22, N = 8) in response to stimulation of Schaffer collaterals. Areas under input-output curves were not significantly different between genotypes (F_(1,13.06) = 0.499; p = 0.493).

(E) Normalized magnitude of LTP 60–65 min after LTP induction did not differ significantly in mutant mice (185% ± 4%; n = 25, N = 8; F_(1,11.64) = 2.92; p = 0.114) relatively to their WT counterparts (174% ± 4%; n = 22, N = 8).

(F) Paired-pulse facilitation was not statistically different (F_(1,11.08) = 1.372, p = 0.266) in Arc^Venus/Venus animals (n = 26, N = 8) compared with their WT littermates (n = 22, N = 8). Data are presented as mean ± SEM, with n = slices and N = mice.

(G) Representative section of Arc^Venus mouse brain crossed with WT (left) and PSD95^−/− (right) mice. Shown is a bar chart of the total cell fluorescence corrected by the area and the background signal. Scale bars, 15 μm.