Figure 1.

Timeline comparison of cortical activity development in A1, V1, and S1. Development of cortical activity in mice from P0 to P40 in A1, V1, and S1. In the three areas, synchronized spontaneous activity is present during the first postnatal week, but it desynchronizes through the second postnatal week in A1 (Babola et al., 2018; Meng et al., 2020); V1 (Rochefort et al., 2009; Ackman et al., 2012; Siegel et al., 2012), and S1 (Golshani et al., 2009; Che et al., 2018). In A1 (top panel), the onset of evoked sensory activity takes place by the end of the first postnatal week and it becomes more prominent upon ear opening at P11 (Anthwal and Thompson, 2016; Makarov et al., 2021). Two auditory critical periods for pure tones (PT CP; Barkat et al., 2011) and Frequency modulated sweeps (FMS CP; Bhumika et al., 2020) take place shortly after, P12–15 and P31–38 respectively. In V1 (middle panel), evoked visual responses start by the end of the first postnatal week and become more reliable by the second postnatal week (Colonnese et al., 2010), around the time of eye opening (~P14). The critical period for ocular dominance (ODP CP) takes place between P21 and P35 (Hensch, 2005; Espinosa and Stryker, 2012) and an orientation selectivity (OS) CP has been shown in google-reared mice between P28 and P49 (Yoshida et al., 2012). In S1 (bottom panel), passive whisker stimulation can trigger evoked responses from birth (Anton-Bolanos et al., 2019), but these responses become more reliable around P6–8 (Colonnese et al., 2010) and active whisking onset occurs around P14 (Landers and Philip Zeigler, 2006). An early anatomical CP is observed in S1 from P0 to P4, capable of altering barrel formation and thalamocortical innervation (Durham and Woolsey, 1984; Lee et al., 2009). While throughout life, different paradigms of sensory deprivation can induce discrete forms experience-dependent plasticity in particular layers/synapses (Nowicka et al., 2009; Wen and Barth, 2011; Gainey et al., 2018).