Table 1.
Effects of i.c.v. injection of different doses of GABA, GABAA/GABAB agonist/antagonists on RT and EcoG spectrum power in conscious rabbbits
| Compound | Dose (n) | ΔRtmax (°C) | ECoG power spectra |
|---|---|---|---|
| Vehicle | −−−(6) | +0.3±0.1 | |
| GABA | 48 μmol (6) | −1.7±0.1** | ↑ δ, θ |
| Nipecotic acid (GABA uptake inhibitor) | 5 nmol (4) | −0.2±0.2 NS | |
| 50 nmol (6) | −1.4±0.2**# | ↑ δ, θ | |
| THIP (GABAA agonist) | 10 nmol (4) | −0.3±0.1 NS | |
| 30 nmol (4) | −0.6±0.2** | ||
| 60 nmol (4) | −1.0±0.4**# | ↑ δ | |
| Muscimol (GABAA agonist) | 18 nmol (5) | −1.0±0.3**# | ↑ δ, θ |
| R(−)baclofen (GABAB agonist) | 1 nmol (4) | −0.6±0.2** | |
| 8 nmol (6) | −1.2±0.3**# | ↑ δ, θ | |
| CGP35348 (GABAB antagonist) | 12 μmol (4) | +0.1±0.2 NS | n.e. |
| Bicuculline (GABAA antagonist) | 1.8 nmol (4) | 1.1±0.5* | n.e. |
| CGP35348+muscimol GABAB antagonist+GABAA agonist | 0.4 μmol+18 nmol (4) | −0.4±0.2* | |
| 1.2 μmol+18 nmol (4) | −0.1±0.3 NS† | n.e. | |
| Bicuculline+muscimol (GABAA antagonist+GABAA agonist) | 0.2 nmol+18 nmol (4) | −1.2±0.3**,§ | |
| 1.8 nmol+18 nmol (4) | −1.8±0.2**,† | ↑ δ, θ**,↑ δ † |
n.e.: no effect. ↑: increase. δ: 1.1–3.3 Hz frequency band. θ: 4.6–9.2 Hz frequency band. RT data are reported as mean±s.e.m. The comparison between AUC(0–24 h) obtained after different treatments was performed using ANOVA followed by post hoc Dunnett's test.
*
P<0.05 vs vehicle;
**
P<0.001 vs vehicle;
#
NS vs 48 μmol GABA,
§
NS vs 18 nmol muscimol,
†
P<0.05 vs 18 nmol muscimol.