This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Molchan, S. E. Articles by Sunderland, T. Search for Related Content PubMed Articles by Molchan, S. E. Articles by Sunderland, T. Social Bookmarking                   What's this?

The effects of thyrotropin-releasing hormone and scopolamine in Alzheimer's disease and normal volunteers

Unit on Geriatric Psychopharmacology, Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD

Alan M. Mellow

Department of Psychiatry, University of Michigan, Ann Arbor, MI

James L. Hill

Unit on Biostatistics, Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD

Herbert Weingartner

Section on Cognitive Neurosciences, National Institute of Alcoholism and Alcohol Abuse, Bethesda, MD, USA

Rick Martinez

Unit on Geriatric Psychopharmacology, Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD

Benedetto Vitiello

Unit on Geriatric Psychopharmacology, Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD

Trey Sunderland

Unit on Geriatric Psychopharmacology, Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, MD

Thyrotropin-releasing hormone (TRH), a neuromodulator and possibly a neurotransmitter in the central nervous system, was shown in a prior study of young normal volunteers to attenuate the memory impairment induced by the anticholinergic drug scopolamine. In the present study, the cognitive, behavioral and physiologic effects of high dose TRH (0.5 mg/kg), both alone and following administration of scopolamine, were examined in 10 Alzheimer's disease (AD) patients (mean age±SD=63.5 years) and 12 older normal volunteers (mean age=64.9±8.8 years). On the day AD subjects received TRH alone, modest but statistically significant improvement from baseline performance was documented on some tests of learning and memory, especially in those with mild dementia severity. In comparing cognitive test performance between the scopolamine alone and scopolamine+TRH conditions, only two test scores were significantly higher in the latter condition. In the group of older volunteers, TRH did not attenuate scopolamine-induced cognitive impairment, contrary to prior findings in a group of younger controls. In fact, older subjects performed worse after receiving scopolamine followed by TRH than after receiving scopolamine alone. In addition, no change from baseline cognitive performance was detected after subjects received TRH alone. These findings raise several questions and speculations on possible age-related changes in the cholinergic system, as well as on the mechanism of the interaction of TRH with the cholinergic system.

Key Words: thyrotropin-releasing hormone (TRH) • neuropeptide • scopolamine • memory • Alzheimer's disease; ageing

Journal of Psychopharmacology, Vol. 6, No. 4, 489-500 (1992)
DOI: 10.1177/026988119200600404


CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				C.D. Watson, M.J. Hewitt, K.C.F. Fone, S.L. Dickinson, and G.W. Bennett Behavioural effects of scopolamine and the TRH analogue RX77368 on radial arm maze performance in the rat J Psychopharmacol, January 1, 1994; 8(2): 88 - 93. [Abstract] [PDF]