1. Baxter, M. G., Goff, D., Miller, A. A. and Saunders, I. A. (1977). Br. J.Pharmac., 59, 455–56 P
2. Benjariiin, R. M. (1970). Brain Res., 24, 525–29
3. Bird, S. J. and Kuhar, M. J. (1977). Brain Res., 122, 523–33
4. Bradley, P. B. (1968). In Pain (ed. A. Soulairac, J. Cahn and J. Charpentier ), Academic Press, New York, pp. 411–23
5. Bradley, P. B. and Bramwell, G. J. (1977). Neuropharmacology, 16, 519–26