Table 1.
Anaesthetic regimens employed
| Anaesthetic and dose | No. of animals |
|---|---|
| Ketamine/xylazine | |
| Induction, i.p., 100 mg kg−1, 10 mg kg−1, respectively, then supplements of ketamine/xylazine (same proportions), i.v., as required. | 6 |
| Urethane | |
| 1.4 g kg−1, i.p. | 3 |
| Ketamine only | |
| 100 mg kg−1, i.p., then supplements, i.v., as required. | 1 |
| Halothane only | |
| Induction 5%, maintenance 1–2% for surgery and 0.4–1% for recording. | 2 |
| Fentanyl and ketamine, then α-chloralose | |
| Induction, fentanyl, 2 mg kg−1, plus ketamine 50 mg kg−1, i.p., maintained with ketamine and fentanyl i.p., then i.v. as required. For recordings, α-chloralose (20 mg kg−1, i.v.). | 1 |
| Halothane then α-chloralose | |
| Halothane: induction 5%, maintenance 1–2% during surgery, titrated to α-chloralose (30–80 mg kg−1, i.v.) for recording. | 12 |
| Ketamine/xylazine then decerebration | |
| As above, until decerebration. | 5 |
| Halothane then decerebration | |
| Induction 5%, maintenance 1–2% during surgery. Lowered to 0.5% at start of decerebration; turned off once decerebration completed. | 21 |
Suppliers: ketamine, Vetalar, Pfizer, UK; xylazine, Rompun, Bayer plc, UK; urethane, Sigma; halothane, Merial Animal Health Ltd, UK; fentanyl, Sublimaze, Janssen-Cilag, UK; α-chloralose; α-Chloralose-HBC complex, Sigma (doses cited above are the equivalent doses of α-chloralose; actual doses of the complex were 10 times higher).