Figure 6.

Changes in environmental conditions induce a reversible plasticity of whisker-evoked electrical brain responses. A, Environmental enrichment paradigm. In one group, mice were housed alone in a standard cage for 3 weeks, after which the first SEP was recorded; mice were then housed in enriched cages for another 3 weeks, and the second SEP was recorded. In another group, mice were housed first in the rich and then in the poor environment. B, Examples of SEP waveforms recorded over the barrel cortex in mice housed first in poor environment (solid trace) and then in a rich environment (dotted trace). C, Examples of SEP waveforms in mice housed first in a rich environment (solid trace) and then in a poor environment (dotted trace). D, Averages of the SEP amplitudes of the first and second recordings for the four experimental groups. E, Examples of SEP waveforms recorded over the barrel cortex at baseline and after rhythmic 8 Hz whisker stimulation in mice previously housed in a poor environment (left; same dataset as in Fig. 1) or a rich environment (right). F, Pooled averages of the SEP amplitudes from the three baseline recordings and the recordings made between 20 and 50 min after a 10 min period of 8 Hz whisker stimulation in mice previously housed in a poor or a rich environment.