Professor Tomas Hokfelt, Karolinska Institutet, Stockholm Correspondence relating to the sending of reprints, preprints and manuscripts. Letters, dated June 1977, relate to Kosterlitz using Hokfelt's slide of his diagramatic presentation of enkephalin and substance P distribution at a meeting of the U.S. Committee on Problems of Drug Dependence, held in Boston, July 1977. Also includes some correspondence with Marianne Schultzberg, Karolinska Institutet. Letter, dated 26 June 1978, from Kosterlitz, asks whether he could use 'Fig. 7' of Hokfelt's and Schultzberg's paper, 'Enkephalin - like immunoreactivity in gland cells and nerve terminals of the adrenal medulla', at the 'satellite symposium on presynaptic receptors', held in Paris, after the Pharmacology Congress. Letter, dated 2 March 1981, from Hokfelt, explaining that he had to cancel his participation at the Pfizer symposium in Edinburgh, held September 1981, as he intends to spend a period at the NIH [National Institutes of Health] with Mike Brownstein. There are a number of gaps in the correspondence; there is only one letter dating from 1976; a gap between June 1977 and June 1978, and August 1978 and March 1981. 1976 - 1981