Figure 2.

PC modifications induced by TTX treatment. Calbindin immunostaining (a–c) and single Lucifer yellow-injected cells (d–f); proximal dendrites of PCs from vehicle-treated cerebella (a and d) appear typically smooth (arrows), whereas after 6 days of TTX treatment (b and e), they are covered with spines (arrows). If TTX is discontinued for 28 days after 14 days of infusion (c and f), the proximal dendrites (arrows) appear smooth again, as in a and d. Spiny branchlets (arrowheads) are consistently studded with numerous spines. (Scale bar = 15 μm.)