Memory functions in prednisone-treated kidney transplant patients Corticosteroid hormones pass the blood brain barrier, and corticosteroid receptors are abundant in the brain especially the hippocampus, where they have their highest density (1). Glucocorticoid binding appears to be involved in a variety of neurochemical effects, ranging from control of certain structural and metabolic features of glia cells to the modulation of certain types of neuro- transmitter interactions and thus indirectly modify chemical communication within the brain (2). It is well known that information has to pass the hippocampus in order to be incorporated into the verbal declarative memory system (3). It is further known that the hippocampus is active during retrieval of such information (4). Two types of corticosteroid receptors are described: the type II or glucocorticoid receptors (GRs) and type I or mineral-corticoid receptors (MRs). Although the names suggest otherwise, both types of receptors do bind glucocorticosteroid hormones. The MRs are concentrated in a few subcortical neural structures, among the hippo- campus, which has the highest level of MRs. The GRs are more equally distributed (1, 2, 5). In the hippocampus MR occupation maintains or sti- mulates neural excitability, while GR occupation suppresses neural excitability (1, 6, 7). There will, therefore, be an inverted U-shaped relationship between hippocampus excitability and cortico- steroid concentrations (1). Moreover, there are indications that a comparable inverted U-shaped curve represents the relationship between corti- costeroid levels and memory capacity, which could explain reports of both facilitating and detrimental effects on memory of acute glucocor- ticosteroid treatment (8). Bermond B, Surachno S, Lok A, ten Berge IJM, Plasmans B, Kox C, Schuller E, Schellekens PTA, Hamel R. Memory functions in prednisone- treated kidney transplant patients. Clin Transplant 2005: 19: 512–517. ª Blackwell Munksgaard, 2005 Abstract: The literature indicates that high daily doses of gluco-cortico- steroids have a degenerating effect upon the hippocampus and thus result in reduced declarative memory capacities. In order to prevent rejection, renal transplant recipients are treated with moderate daily doses of gluco-corti- costeroids and, if necessary, with high pulse-doses during a few days. The question, therefore, arises as to whether or not such standard treatments result in memory impairments. For this reason, declarative memory capa- cities were measured, by means of a Dutch version of Rey’s 15 Words Test, in a group of 52 renal transplant recipients. Results clearly indicated severe reductions in declarative memory capacities in these patients. Bob Bermond a , Sugianto Surachno b , Anja Lok a , Ineke JM ten Berge b , Barbara Plasmans a , Cornelis Kox b , Esther Schuller a , Peter TA Schellekens b and Ronald Hamel a a Department of Psychology, Faculty of Social and Behavioural Sciences and b Divisions of Nephrology and Clinical Immunology & Rheumatology, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands Key words: memory functions – prednisone – renal transplant recipients Corresponding author: Dr Ronald Hamel, Department of Psychology, Faculty of Social and Behavioural Sciences, University of Amsterdam, Roetersstraat 15, 1018 WB Amsterdam, The Netherlands. Tel.: +31 20 525 6854; fax: +31 20 639 1656; e-mail: r.hamel@uva.nl Accepted for publication 25 March 2005 Clin Transplant 2005: 19: 512–517 DOI: 10.1111/j.1399-0012.2005.00376.x Copyright ª Blackwell Munksgaard 2005 512