TY - JOUR
T1 - The effects of thyrotropin-releasing hormone and scopolamine in Alzheimer's disease and normal volunteers
AU - Molchan, Susan E.
AU - Mellow, Alan M.
AU - Hill, James L.
AU - Weingartner, Herbert
AU - Martinez, Rick
AU - Vitiello, Benedetto
AU - Sunderland, Trey
PY - 1992/7
Y1 - 1992/7
N2 - 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.
AB - 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.
KW - Alzheimer's disease; ageing
KW - memory
KW - neuropeptide
KW - scopolamine
KW - thyrotropin-releasing hormone (TRH)
UR - http://www.scopus.com/inward/record.url?scp=0027081623&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027081623&partnerID=8YFLogxK
U2 - 10.1177/026988119200600404
DO - 10.1177/026988119200600404
M3 - Article
AN - SCOPUS:0027081623
SN - 0269-8811
VL - 6
SP - 489
EP - 500
JO - Journal of Psychopharmacology
JF - Journal of Psychopharmacology
IS - 4
ER -