Table 1.

Proportions and type of firing modulations by region

Modulated (fraction)Increased (fraction)Decreased (fraction)Multiphasic (fraction)χ2dfp
Supragranular
    Control0.810.410.260.34
    Saline0.650.480.260.261.6320.4426 (n.s.)
    Muscimol0.670.460.200.340.8420.657 (n.s.)
Granular
    Control0.830.640.110.25
    Saline0.770.520.170.322.6320.2685 (n.s.)
    Muscimol0.690.610.170.221.2920.5247 (n.s.)
Infragranular
    Control0.820.270.270.46
    Saline0.830.470.180.354.0220.134 (n.s.)
    Muscimol0.750.560.050.3918.92<0.0001***
POM
    Control0.780.470.210.32
    Saline0.740.510.210.280.5620.7558 (n.s.)
    Muscimol0.730.540.150.311.9120.3848 (n.s.)
VPM
    Control0.820.290.210.50
    Saline0.740.330.290.383.7920.1503 (n.s.)
    Muscimol0.720.470.300.2221.422<0.0001***
  • Supragranular, granular, and infragranular refer to firing modulations recorded from depths corresponding to the layers II/III, layer IV, and layers V/VI, respectively. Active tactile discrimination was characterized by increases and decreases in neural activity that were region and layer specific. Characteristic patterns of neuronal firing were found in different areas and layers. Significant differences in the type of modulations found were clearer in infragranular layers of S1 and in VPM. Inactivation of M1 induced an increase in the number of neurons exhibiting exclusive increased firing modulations. In VPM, the inactivation of M1 reduced the number of cells with multiphasic patterns of activity, increasing the number of neurons with exclusive excitatory activity.

  • ***p < 0.001.