1993; Lee et al. 2009). To quantify changes in the barrel field size, the area of each individual barrel (A1–A4, B1–B4, C1–C4, D1–D4) was measured (Fig. 1B). The ratio of the total adjusted size of the barrels corresponding to the spared whisker (rows C and D) and the deprived whiskers (rows A and B) within the sensory deprived left hemisphere ([C+D]/[A+B]) was calculated (Fig. 1C). A selective sensory deprivation of only some whiskers during the first postnatal week could decrease the size

of the barrel deprived of sensory input similar to that Inhibitors,research,lifescience,medical observed by deafferentation (Schlaggar et al. 1993), and the spared/deprived whisker ratio would thus increase because of the decrease in the size of the deprived A- and B-row barrels. The ratio (Fig. 1C) was indeed the higher for the P0 group compared Inhibitors,research,lifescience,medical with the control (P0: 1.49 ± 0.04, n = 48; control: 1.24 ± 0.04, n = 20; mean ± SEM unpaired t-test,

P = 0.0003). These anatomical data indicate that sensory deprivation starting at P0 has effects on the somatosensory barrel circuitry. Figure 1 Sensory deprivation causes structural changes in the barrel size. (A) In the sensory deprivation Inhibitors,research,lifescience,medical protocol used, the C- and D-row whiskers were spared during different periods of development. (B) Barrels at the level of layer 4 were stained with cytochrome … Altered sensory experience, during different periods of postnatal development, does not affect the maximum gap-distance achieved Inhibitors,research,lifescience,medical The gap-crossing task was used to study how decision

making based on tactile information from the whiskers is affected by sensory deprivation during the first postnatal week of development, a period critical for the formation of thalamocortical connections. In the “P0 group” only the C- and D-row whiskers were spared (Fig. 1A) between postnatal days 0 and 6 (P0–P6). All whiskers were then left intact Inhibitors,research,lifescience,medical from P7 until 2 days before testing (P29–P32), at which time, all whiskers, except the C2 whisker on the right side, were trimmed (cut or plucked). In the littermate controls, all whiskers were left intact until 2 days before testing (P29–P32). almost Both groups were thus Angiogenesis chemical tested with only the C2 whisker on the right-side intact. The gap-crossing task is performed in complete darkness so that the animals can only rely on tactile information to locate a target platform across a gap (Fig. 2A). Animals from the different groups (control and P0) were tested over a 7-day period with the gap-cross distances increasing over time within each session as determined by a pseudorandom protocol (see Methods). There was no consistent difference between the groups in the average maximum gap-distance achieved during the 7-day testing period (P > 0.05, unpaired t-test; Fig. 2B). In both groups, the average number of successful attempts was 6 during days 3–7.