No abstract

1 Putative receptors for CGRP and adrenomedullin have been investigated in the rat. Calcitonin Receptor-Like Receptor (CRLR), in combination with Receptor Activity Modifying Proteins (RAMPs) is hypothesized to bind either CGRP or adrenomedullin. The receptors known as RDC1 and L1 have also been shown to bind CGRP and adrenomedullin respectively. 2 In this study it is shown that rat CRLR cDNA speci®es a CGRP receptor when co-transfected with RAMP-1 cDNA and an adrenomedullin receptor when co-transfected with either RAMP-2 or RAMP-3 cDNA in human embryonic kidney 293 cells. 3 CRLR, RAMP, RCD1 and L1 mRNA levels and CGRP and adrenomedullin receptor densities have been measured and correlated with each other in eight rat tissues selected for their distinctive patterns of CGRP and adrenomedullin binding. 4 The data are consistent with the predictions of the CRLR/RAMP model. CGRP binding correlates well with RAMP-1 mRNA levels (R=1.0, P=0.007), adrenomedullin binding shows a tendency to vary with RAMP-2 mRNA levels (R=0.85, P=0.14) and total binding is correlated with CRLR mRNA levels (R=0.94, P=0.03). The data do not support the hypothesis that RDC1 and L1 account for the majority of CGRP and adrenomedullin binding respectively.

1. Two rat clones have been isolated which are similar to known calcitonin-receptor sequences. One of these does not have the distribution expected of a calcitonin receptor. It is widely distributed, with extremely high levels of expression in the lung, where it is associated with the blood vessels. 2. This rat sequence may represent the receptor for calcitonin-gene-related peptide or islet amyloid polypeptide. Both have binding activity in the lung and are potent vasodilators. The gene represented by this sequence may therefore play an important role in the maintenance of vascular tone.

SUMMARYThe cognitive drug research computerized assessment system (COGDRAS) was evaluated in 98 unselected Hammersmith Hospital Memory Clinic patients (mean age 64.9, range 28-83 years). They were divided into five groups (worried well, depressed, demented, minimally cognitively impaired and other brain disorders) on clinical assessment, Mini Mental State Examination (MMSE) and Cambridge Cognitive Examination (CAMCOG) scores. All but one patient completed the computer package, confirming its acceptability. The results of the COGDRAS in the five groups were analysed blind to diagnosis. The performance of the demented group was significantly impaired in comparison with the worried well group, showing that the COGDRAS is valid in mild dementia (mean MMSE 21.5, mean CAMCOG 73.9). The depressed group tended to perform slightly less well than the worried well, and the 'other' group showed a wide range of scores consistent with its diversity. The minimally impaired had scores intermediate between the demented and worried well, but an interesting speed/accuracy tradeoff was seenpatients appeared to maintain accuracy by taking longer to perform tasks. The heterogeneity of the minimally impaired group and the role of the measurement of task completion time in the diagnosis of early dementia are discussed.KEY WORDS-MemOry clinic, dementia, age associated memory impairment, computerized assessment of cognitive function.The cognitive drug research computerized assessment system (COGDRAS) was originally designed to evaluate the cognitive effects of drugs (Wesnes et al., 1987). A further version of the system was developed to examine aspects of cognitive perform- ance in people with dementia. In a memory clinic study using this version, the performance of 23 elderly patients with established dementia was compared with that of control subjects. The demented patients showed large and significant impairments in the speed of choice reaction time and the accuracy and speed of all memory tasks (Simpson et af., 1991). There was good correlation with standard diagnostic instruments and good test-retest reliabi-CCC 0885-6230/95