Table 1. Systemic and electrophysiological parameters.
| Systemic physiology | CSD electrophysiology | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Experimental groups | N | pH | pCO2 (mmHg) | pO2 (mmHg) | BP (mmHg) | Amp (mV) | Dur (seconds) | Speed (mm/min) | Propagation failure (1−E2/E1, %) | Electrical threshold (μC (25–75%)) |
| SAL 2.5 ml/kg, i.v. | 11 | 7.43±0.04 | 38±3 | 144±29 | 114±13 | 15±4 | 21±5 | 3.7±0.3 | 33±14 | 300 (150–500) |
| GPT 100 mg/kg, i.v. | 7 | 7.44±0.03 | 35±2 | 141±17 | 102±8 | 17±5 | 21±3 | 3.4±0.6 | 35±26 | 1600 (1000–1800)* |
| GPT 200 mg/kg, i.v. | 14 | 7.41±0.03 | 37±4 | 133±14 | 94±6* | 15±5 | 20±6 | 3.7±0.4 | 33±22 | 800 (600–1200)* |
Amp, DC shift amplitude; CSD, cortical spreading depression; Dur, DC shift duration at half amplitude; E1 and E2, electrodes 1 (proximal) and 2 (distal; see Materials and methods); GPT, gabapentin; SAL, saline control.
The systemic physiological parameters for each rat were calculated by averaging all measurements throughout an experiment. CSD amplitudes are the average amplitude of all CSDs evoked during 1 hour topical KCl application. As CSD duration and propagation speed tended to differ between the first and subsequent CSDs, we measured the duration and propagation speed of only the first CSD after topical KCl application. Propagation failure was assessed during topical KCl-induced repetitive CSDs.
*P<0.05 versus saline.