Table 1.
Effects of KYNA on nicotinic sensitivity of cultured hippocampal neurons
| Type IA currents | Non-type IA currents | |||
|---|---|---|---|---|
| Peak amplitude (pA) | % Neurons1-a | Peak amplitude (pA) | % Neurons1-a | |
| Control | 374 ± 114 | 53 (16/30) | 87 ± 20 | 43 (13/30) |
| KYNA (1 μm) | 189 ± 38 | 56 (17/30) | 52 ± 7 | 53 (16/30) |
| Control | 221 ± 50 | 67 (27/40) | 61 ± 9 | 20 (8/40) |
| KYNA (10 μm) | 180 ± 31 | 62 (25/40) | 47 ± 9 | 45 (18/40)1-b |
ACh (1 mm)-evoked currents were recorded from neurons sampled from untreated cultures and from cultures that were exposed for 3 d to KYNA (1 or 10 μm). Results obtained from treated neurons were always compared with results obtained from untreated neurons of the same batch of cultures. For each experimental group, results represent the mean ± SEM of data obtained from three to four different cultures. The number of neurons in each experimental group showing type IA and non-type IA currents was expressed as the percentage of the total number of neurons sampled in each group.
Numbers in parentheses indicate number of neurons showing a given response/total number of sampled neurons. (See Results for details on the characterization of the currents as type IA and non-type IA.) According to the unpaired Student's t test, the peak amplitudes of type IA currents and non-type IA currents recorded from neurons treated with KYNA (1 or 10 μm) were not significantly different from those of currents recorded from neurons in the respective control groups.
According to the χ2test, the number of neurons responding with non-type IA currents in KYNA (10 μm)-treated cultures was significantly different from that in control cultures (χ = 4.62 at 95% confidence interval).