Figure 3. Dynamic microtubules are required for the development of SHPs upon cLTP.

(A) Dissociated hippocampal cultures were preincubated with nocodazole (200 nM, for 4 h) to block neuronal microtubule dynamics and cLTP was then induced. Column bars show the quantification of SHPs (number/µm) under cLTP and nocodazole+cLTP conditions. Suppressing MT assembly/disassembly with nocodazole significantly reduced SHP density compared with the density measured after 40 min of cLTP. (B) Column bars show the quantification of SHPs (number/µm) in nocodazole washout experiments. The cultures were incubated with 200 nM nocodazole for 4 h, and nocodazole was then washed out. The cultures were kept in culture medium for 3 h, and cLTP was then induced. Blocking dynamic MTs with nocodazole followed by washout restored SHPs and significantly increased SHP density compared with unstimulated controls. The histograms show the mean ± SEM. *p<0.05.