Table 1.
Properties of postsynaptic responses. Values are presented as mean (standard deviation). Parameters from extracellular data were calculated using the CSD signal from the channel that showed the earliest onset of the inward-going current after the light stimulus. Half-widths are width of current sink or EPSP signal at half the maximum amplitude. Comparisons of half-widths of the CSD signal were made within TC* and within CC† groups using a standard one-way analysis of variance; TC matrix responses were longer than TC core responses (*F1,41=19.82, P<0.0001) and CC feedback half-widths were longer than CC feedforward (†F1,34=7.70, P=0.009). CC, cortico-cortical; CSD, current source density; EPSP, excitatory postsynaptic potential; TC, thalamo-cortical.
| Latency (ms) | Half-width (ms) | Paired pulse ratio | ||
|---|---|---|---|---|
| TC core | CSD (n=16) | 4.67 (1.85) | 8.27 (3.06)* | 0.64 (0.23) |
| Intracellular (n=7) | 3.57 (1.01) | 30.00 (15.90) | 0.62 (0.22) | |
| TC matrix | CSD (n=23) | 5.11 (1.69) | 12.13 (2.62)* | 0.72 (0.19) |
| Intracellular (n=10) | 4.63 (1.87) | 26.10 (14.27) | 0.61 (0.16) | |
| CC feedforward | CSD (n=8) | 3.02 (1.01) | 7.81 (1.31)† | 1.17 (0.37) |
| Intracellular (n=4) | 3.63 (0.78) | 32.75 (16.46) | 1.04 (0.13) | |
| CC feedback | CSD (n=21) | 4.15 (1.97) | 9.42 (1.77)† | 0.90 (0.31) |
| Intracellular (n=4) | 3.69 (2.29) | 27.49 (14.31) | 1.04 (0.22) | |