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Laczó J, Markova H, Lobellova V, Gazova I, Parizkova M, Cerman J, Nekovarova T, Vales K, Klovrzova S, Harrison J, Windisch M, Vlcek K, Svoboda J, Hort J, Stuchlik A. Scopolamine disrupts place navigation in rats and humans: a translational validation of the Hidden Goal Task in the Morris water maze and a real maze for humans. Psychopharmacology (Berl) 2017; 234:535-547. [PMID: 27885411 DOI: 10.1007/s00213-016-4488-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/11/2016] [Indexed: 12/18/2022]
Abstract
RATIONALE Development of new drugs for treatment of Alzheimer's disease (AD) requires valid paradigms for testing their efficacy and sensitive tests validated in translational research. OBJECTIVES We present validation of a place-navigation task, a Hidden Goal Task (HGT) based on the Morris water maze (MWM), in comparable animal and human protocols. METHODS We used scopolamine to model cognitive dysfunction similar to that seen in AD and donepezil, a symptomatic medication for AD, to assess its potential reversible effect on this scopolamine-induced cognitive dysfunction. We tested the effects of scopolamine and the combination of scopolamine and donepezil on place navigation and compared their effects in human and rat versions of the HGT. Place navigation testing consisted of 4 sessions of HGT performed at baseline, 2, 4, and 8 h after dosing in humans or 1, 2.5, and 5 h in rats. RESULTS Scopolamine worsened performance in both animals and humans. In the animal experiment, co-administration of donepezil alleviated the negative effect of scopolamine. In the human experiment, subjects co-administered with scopolamine and donepezil performed similarly to subjects on placebo and scopolamine, indicating a partial ameliorative effect of donepezil. CONCLUSIONS In the task based on the MWM, scopolamine impaired place navigation, while co-administration of donepezil alleviated this effect in comparable animal and human protocols. Using scopolamine and donepezil to challenge place navigation testing can be studied concurrently in animals and humans and may be a valid and reliable model for translational research, as well as for preclinical and clinical phases of drug trials.
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Affiliation(s)
- Jan Laczó
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic. .,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic.
| | - Hana Markova
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic
| | - Veronika Lobellova
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic
| | - Ivana Gazova
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic
| | - Martina Parizkova
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic
| | - Jiri Cerman
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic
| | - Tereza Nekovarova
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic.,National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Karel Vales
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic.,National Institute of Mental Health, Topolova 748, 250 67, Klecany, Czech Republic
| | - Sylva Klovrzova
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Charles University in Prague, Akademika Heyrovskeho 1203, 500 05, Hradec Králové, Czech Republic
| | - John Harrison
- Metis Cognition Ltd., Park House, Kilmington Common, Warminster, Wiltshire, BA12 6QY, UK.,Imperial College Faculty of Medicine, South Kensington Campus, London, SW7 2AZ, UK
| | - Manfred Windisch
- NeuroScios GmbH, Willersdorferstrasse 6, A-8061, Radegund/Graz, Austria
| | - Kamil Vlcek
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic
| | - Jan Svoboda
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic
| | - Jakub Hort
- Department of Neurology, Second Faculty of Medicine, Charles University and Motol University Hospital, V Uvalu 84, 150 06, Prague, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno, Pekarska 53, 656 91, Brno, Czech Republic
| | - Ales Stuchlik
- Department of Neurophysiology of Memory, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20, Prague, Czech Republic.
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Hou XQ, Wu DW, Zhang CX, Yan R, Yang C, Rong CP, Zhang L, Chang X, Su RY, Zhang SJ, He WQ, Qu Z, Li S, Su ZR, Chen YB, Wang Q, Fang SH. Bushen‑Yizhi formula ameliorates cognition deficits and attenuates oxidative stress‑related neuronal apoptosis in scopolamine‑induced senescence in mice. Int J Mol Med 2014; 34:429-39. [PMID: 24919922 PMCID: PMC4094586 DOI: 10.3892/ijmm.2014.1801] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 05/20/2014] [Indexed: 11/06/2022] Open
Abstract
Bushen‑Yizhi formula (BSYZ), a traditional Chinese medicine formula consisting of six herbs has been reported to possess a neuroprotective effect. The present study aimed to investigate the effects of BSYZ on learning and memory abilities, as well as oxidative stress and neuronal apoptosis in the hippocampus of scopolamine (SCOP)‑induced senescence in mice, in order to reveal whether BSYZ is a potential therapeutic agent for Alzheimer's disease (AD). A high‑performance liquid chromatography (HPLC) fingerprint was applied to provide a chemical profile of BSYZ. Extracts of BSYZ were orally administered to mice with SCOP‑induced memory impairment for two weeks. The learning and memory abilities were determined by the Morris water maze test. The oxidant stress‑related indices, such as activity of superoxide dismutase (SOD) and levels of glutathione (GSH) and malondialdehyde (MDA) were examined in hippocampus of SCOP‑treated mice. The cell death ratio was assessed by TUNEL staining, while apoptotic‑related proteins including Bcl‑2 and Bax were determined by immuno-fluorescent staining and western blot analysis. Caspase‑3 was determined by western blot analysis. Consequently, a chromatographic condition, which was conducted at 35˚C with a flow rate of 0.8 ml/min on the Gemini C18 column with mobile phase of acetonitrile and water‑phosphoric acid (100:0.1, v/v), was established to yield common fingerprint chromatography under 203 nm with a similarity index of 0.986 within 10 batches of BSYZ samples. BSYZ at a dose of 2.92 g/kg significantly improved the cognitive ability, restored the abnormal activity of SOD and increased the levels of MDA and GSH induced by SCOP. Moreover, the neural apoptosis in the hippocampus of SCOP‑treated mice was reversed by BSYZ by regulating the expression of Bcl‑2, Bax and caspase‑3. The results demonstrated that BSYZ had neuroprotective effects in SCOP‑induced senescence in mice by ameliorating oxidative stress and neuronal apoptosis in the brain, supporting its potential in AD treatment.
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Affiliation(s)
- Xue-Qin Hou
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Dian-Wei Wu
- Shantou Hospital of Traditional Chinese Medicine, Guangzhou, Guangdong 515031, P.R. China
| | - Chun-Xia Zhang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Rong Yan
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Cong Yang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Cui-Ping Rong
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Lei Zhang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Xiang Chang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Ru-Yu Su
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Shi-Jie Zhang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Wen-Qing He
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Zhao Qu
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Shi Li
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Zi-Ren Su
- School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510006, P.R. China
| | - Yun-Bo Chen
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Qi Wang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
| | - Shu-Huan Fang
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong 510405, P.R. China
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Morain P, Lestage P, De Nanteuil G, Jochemsen R, Robin JL, Guez D, Boyer PA. S 17092: a prolyl endopeptidase inhibitor as a potential therapeutic drug for memory impairment. Preclinical and clinical studies. CNS DRUG REVIEWS 2002; 8:31-52. [PMID: 12070525 PMCID: PMC6741683 DOI: 10.1111/j.1527-3458.2002.tb00214.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Any treatment that could positively modulate central neuropeptides levels would provide a promising therapeutic approach to the treatment of cognitive deficits associated with aging and/or neurodegenerative diseases. Therefore, based on the activity in rodents, S 17092 (2S,3aS,7aS)-1][(R,R)-2-phenylcyclopropyl]carbonyl]-2-[(thiazolidin-3-yl)carbonyl]octahydro-1H-indole) has been selected as a potent inhibitor of cerebral prolyl-endopeptidase (PEP). By retarding the degradation of neuroactive peptides, S 17092 was successfully used in a variety of memory tasks. These tasks explored short-term, long-term, reference and working memory in aged mice, as well as in rodents and monkeys with chemically induced amnesia or spontaneous memory deficits. S 17092 has also been safely administered to humans, and showed a clear peripheral expression of its mechanism of action through its inhibitory effect upon PEP activity in plasma. S 17092 exhibited central effects, as evidenced by EEG recording in healthy volunteers, and could improve a delayed verbal memory task. Collectively, the preclinical and clinical effects of S 17092 have suggested a promising role for this compound as an agent for the treatment of cognitive disorders associated with cerebral aging.
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Affiliation(s)
- Philippe Morain
- Institut de Recherches Internationales Servier, 6 Place des pleïades, 92415 Courbevoie, France.
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Marighetto A, Touzani K, Etchamendy N, Torrea CC, De Nanteuil G, Guez D, Jaffard R, Morain P. Further evidence for a dissociation between different forms of mnemonic expressions in a mouse model of age-related cognitive decline: effects of tacrine and S 17092, a novel prolyl endopeptidase inhibitor. Learn Mem 2000; 7:159-69. [PMID: 10837505 PMCID: PMC311328 DOI: 10.1101/lm.7.3.159] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
It has been demonstrated previously on the radial maze that the emergence of an age-related mnemonic impairment is critically dependent on the form which the discrimination problems took. Hence, when the arms were presented one by one (i.e., successive go-no-go discrimination), both adult and aged mice learned to distinguish between positive (baited) and negative (unbaited) arms readily, as evidenced by their increased readiness to enter positive relative to negative arms (i.e., by a differential in arm-entry latencies). A selective impairment in the aged mice was seen when these arms were presented subsequently as pairs, such that the mice were confronted with an explicit choice (i.e., simultaneous 2-choice discrimination). When discriminative performance was measured by the differential run speed between positive and negative arms, aged mice were also impaired. This was particularly pronounced in the 2-choice discrimination condition. We examined the effects of tacrine (3mg/kg, subcutaneously) or S 17092 (10mg/kg, orally) in aged mice on the three behavioral indices of this 2-stage spatial discrimination paradigm. The results indicated that: (1) Tacrine, but not S 17092, enhanced the acquisition of go-no-go discrimination as reflected in arm-entry latencies; (2) both drugs improved choice accuracy in simultaneous discrimination, although the effect of tacrine was less striking and, in particular, far from statistical significance in the very first 2-choice responses; and (3) neither drugs significantly affected run-speed performance. We conclude further that the specific patterns of drug effects on the three indices of discriminative performance might suggest that each index is associated with a distinct form of mnemonic expression relying on separate neural systems.
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Affiliation(s)
- A Marighetto
- CNRS - UMR-5106, Laboratoire Neurosciences Comportementales and Cognitives, 33405 Talence Cedex, France.
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Simard M, van Reekum R. Memory assessment in studies of cognition-enhancing drugs for Alzheimer's disease. Drugs Aging 1999; 14:197-230. [PMID: 10220105 DOI: 10.2165/00002512-199914030-00004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
There is an increasing number of cognition-enhancing drugs for Alzheimer's Disease (AD) and, consequently, drug trials represent a growing field of interest in research. As memory dysfunction is generally the first and most severe cognitive impairment in AD, the choice of memory testing to be used in these studies is of great importance. It should reflect an understanding of memory systems being assessed with neuropsychological tests and the fact that some tests can be more appropriate than others to show benefit with certain classes of cognition-enhancing drugs. Severe deterioration of episodic and semantic memory occurs very early in the AD process while working memory shows a gradual deterioration over time. Some aspects of working and implicit memory can be spared in the mild to moderate stages of AD. Tests of working, episodic, semantic and implicit memory are used as outcomes in trials with acetylcholinesterase inhibitors, drugs with other neurotransmitter strategies, metabolic enhancers and drugs which may impact upon a variety of CNS processes. The clinical scales and observational measures are largely used in trials of cognition-enhancing drugs for AD (46.66% of all the studies reviewed). The Digit Span test, the Rey Auditory Verbal Learning Test, the Buschke Selective Reminding Test and the verbal fluency tasks are the most sensitive memory tests, whereas the most sensitive scales are the Sandoz Clinical Assessment-Geriatric, the Gottfried-Bräne-Steel scale and the Blessed Dementia Scale. Finally, we suggest that future investigations should use sensitive memory tests, together with behavioural and psychiatric scales, rather than general observational evaluations.
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Affiliation(s)
- M Simard
- Department of Psychiatry, Baycrest Centre for Geriatric Care, North York, Ontario, Canada
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Broocks A, Little JT, Martin A, Minichiello MD, Dubbert B, Mack C, Tune L, Murphy DL, Sunderland T. The influence of ondansetron and m-chlorophenylpiperazine on scopolamine-induced cognitive, behavioral, and physiological responses in young healthy controls. Biol Psychiatry 1998; 43:408-16. [PMID: 9532345 DOI: 10.1016/s0006-3223(97)00388-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND There is evidence from animal and human experiments that learning and memory come under the separate influence of both cholinergic and serotonergic pathways. We were interested in learning whether serotonergic drugs could attenuate or exacerbate the memory-impairing effects of anticholinergic blockade in humans. METHODS The selective serotonin 5-HT3 receptor antagonist ondansetron (0.15 mg/kg i.v.) and the serotonergic agent m-chlorophenylpiperazine (m-CPP; 0.08 mg/kg i.v.) were administered in combination with the anticholinergic agent scopolamine (0.4 mg PO) and compared to scopolamine alone in 10 young, healthy volunteers. Testing occurred on three separate days. RESULTS As expected, i.v. administration of scopolamine induced significant impairments in episodic memory and processing speed; however, these scopolamine-induced cognitive deficits were not attenuated by pretreatment with i.v. ondansetron (0.15 mg/kg), nor were they exacerbated by administration of i.v. m-CPP (0.8 mg/kg) in addition to scopolamine; however, administration of i.v. m-CPP was followed by a significant increase of self-rated functional impairment, altered self-reality, and dysphoria ratings, and scopolamine's effect on pupil size was potentiated. CONCLUSIONS Together, these results suggest that in young, healthy volunteers scopolamine-induced changes of cognitive performance are only minimally modulated by the serotonergic effects on ondansetron and m-CPP. Further studies with older controls are needed to test whether these findings may be influenced by age.
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Affiliation(s)
- A Broocks
- Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Maryland 20892-1264, USA
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Abstract
Recent evidence indicates that, in addition to the involvement of cholinergic and other neurotransmitter systems, various neuropeptides that occur in cortical and subcortical brain regions have a role in cognitive behavior. This evidence results largely from behavioral studies in rodents and other animals, following peptide administration and only in a very few cases from similar studies in human subjects. Several neuropeptides studied appear to enhance or produce changes conducive to improvement in cognitive performance and these include vasopressin, corticotrophin-releasing hormone (CRH), somatostatin, substance P, neuropeptide Y, and thyrotrophin-releasing hormone (TRH), while one peptide, galanin, has been reported to inhibit cognitive processes. Of those neuropeptides that improve performance, only TRH has been shown recently to attenuate the memory impairment of human subjects and Alzheimer patients treated with an anticholinergic drug, and this review describes a series of complimentary studies in adult and aged rodents that contribute to our understanding of the possible mechanisms involved in the role of TRH in cognition.
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Affiliation(s)
- G W Bennett
- Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, United Kingdom
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Martinez R, Molchan SE, Lawlor BA, Thompson K, Martinson H, Latham G, Weingartner H, Sunderland T. Minimal effects of dextroamphetamine on scopolamine-induced cognitive impairments in humans. Biol Psychiatry 1997; 41:50-7. [PMID: 8988795 DOI: 10.1016/0006-3223(95)00674-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The central anticholinergic drug scopolamine has been used to model aspects of the memory impairment that occurs in Alzheimer's disease and in aging. To determine whether nonspecific stimulant effects can attenuate the cognitive impairment induced by scopolamine, we studied the effects of scopolamine and the stimulant dextroamphetamine in 17 young normal volunteers. After a baseline day of cognitive testing, subjects participated in two study days, in which they received dextroamphetamine (d-AMP) (0.25 mg/kg p.o.) + scopolamine (0.5 mg i.v.) and placebo + scopolamine, in randomized order under double-blind conditions. There were no statistically significant differences in cognitive test performance between the two drug conditions with the exception of one of the category retrieval tasks. Stimulant effects were documented to occur by other measures. We conclude that d-AMP at the dose used does not attenuate the memory impairment induced by scopolamine.
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Affiliation(s)
- R Martinez
- Section on Geriatric Psychopharmacology, National Institute of Mental Health, Bethesda, Maryland, USA
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Weingartner HJ, Sirocco K, Rawlings R, Joyce E, Hommer D. Dissociations in the expression of the sedative effects of triazolam. Psychopharmacology (Berl) 1995; 119:27-33. [PMID: 7675946 DOI: 10.1007/bf02246050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fifteen normal volunteers were administered 0.250, 0.375, and 0.500 mg of triazolam and placebo in a double-blind repeated measures cross-over design. Subjects demonstrated dose-dependent impairments in free recall, a test of explicit memory requiring awareness and reflection, and sedation as assessed by objective behavioral measures (the digit symbol substitution task) and subjective visual analogue scales. The sedative drug response did not account for the impairment in free recall. Differences in performance of the two tests of sedation indicated that the effect of this drug on reflective processes accounts for impairment in episodic memory and the inability to track the sedative effects of this drug at the higher doses tested in this study.
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Affiliation(s)
- H J Weingartner
- Cognitive Neurosciences Section, LCS, NIAAA, Rockville Pike, Bethesda, MD 20982, USA
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Lexow N, Joyce JN, Kim SJ, Phillips J, Casanova MF, Bird ED, Kleinman JE, Winokur A. Alterations in TRH receptors in temporal lobe of schizophrenics: a quantitative autoradiographic study. Synapse 1994; 18:315-27. [PMID: 7886624 DOI: 10.1002/syn.890180407] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We utilized quantitative autoradiography to determine the distribution of receptors for thyrotropin-releasing hormone (TRH) throughout the human temporal lobe and to examine the distribution of these receptors in discrete subregions of the temporal lobe from patients diagnosed premortem with schizophrenia. When compared to non-neurologic controls, schizophrenic patients demonstrated an increase of 51% in the concentration of TRH receptors in the molecular layer of the dentate gyrus. Within nuclei of the schizophrenic amygdala, marked decreases were found in the central (44%), medial (38%), cortical (36%), accessory cortical (52%), lateral (54%), and medial basal (22%) nuclei. We also examined postmortem brain samples from patients with Huntington's disease, amyotrophic lateral sclerosis, and Alzheimer's disease for alterations in the distribution of TRH receptors. No significant differences from non-neuropsychiatric controls were noted within the hippocampus in any of these disease states; however, slight alterations were noted in the central and medial basal amygdala in Huntington's disease and in the cortical amygdala in Alzheimer's disease. These disease-specific findings suggest that TRH may play a role in the neurochemical dysfunction of schizophrenia.
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Affiliation(s)
- N Lexow
- Department of Psychiatry, University of Pennsylvania, Philadelphia 19104
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Khan A, Lai H, Ukai Y, Mirolo MH. NS-3, a TRH analog, reverses repeated ECS-induced deficits in water maze performance in the rat. Pharmacol Biochem Behav 1994; 47:477-81. [PMID: 8208765 DOI: 10.1016/0091-3057(94)90146-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Rats given five consecutive daily electroconvulsive shock (ECS) treatments and trained to run in the Morris water maze, starting three days posttreatment, showed deficits in learning and memory functions. Treatment before each training session with the thyrotropin-releasing hormone (TRH) analog NS-3 [(CG-3703), (3R),(6R)-6-methyl-5-oxo-3-thiomorphorinyl-l-histidyl-l-prolinamid e tetrahydrate] reversed these behavioral deficits. The possible use of TRH and its analogs as therapeutic treatment for the cognitive dysfunctions resulting from electroconvulsive shock treatment for depression and the possible involvement of central cholinergic systems in the cognitive dysfunctions are discussed.
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Affiliation(s)
- A Khan
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle 98195
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Molchan SE, Hill JL, Minichiello M, Vitiello B, Sunderland T. Scopolamine effects on the pressor response to thyrotropin-releasing hormone in humans. Life Sci 1994; 54:933-8. [PMID: 8139380 DOI: 10.1016/0024-3205(94)00629-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Thyrotropin-releasing hormone (TRH) produces a marked pressor effect, which may be mediated by central cholinergic neurons, which in turn enhance sympathetic nervous system activity. In this study, 22 subjects (10 patients with Alzheimer's disease and 12 elderly controls) were administered IV scopolamine or placebo prior to administration of IV high-dose TRH (0.5 mg/kg). Systolic blood pressure was less on the day scopolamine was administered prior to TRH administration, as compared with placebo (F[1,20] = 6.12, p < 0.02). Results indicate that the pressor effect of TRH is attenuated by scopolamine, indicating a role of the cholinergic system in this response in humans.
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Affiliation(s)
- S E Molchan
- Section on Geriatric Psychopharmacology, National Institute of Mental Health, Bethesda, MD 20892
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13
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Watson CD, Hewitt MJ, Fone KC, Dickinson SL, Bennett GW. Behavioural effects of scopolamine and the TRH analogue RX77368 on radial arm maze performance in the rat. J Psychopharmacol 1994; 8:88-93. [PMID: 22298534 DOI: 10.1177/026988119400800203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Effects of repeated intracerebroventricular administration of the thyrotrophin-releasing hormone (TRH) analogue, RX77368 (3,3'-dimethyl-TRH, 2 μg, once daily), on a scopolamine-induced performance deficit in an eight-arm radial maze were evaluated in adult rats. Scopolamine (0.3 mg/kg i.p.-30 min) pre-treatment produced a significant deficit in the number of unrepeated arm entries and total arm entries and increased the percentage of incorrect arm entries and the total time on the maze, compared with saline-treated controls. Prior treatment with RX77368 (40 min before maze testing) produced a partial but significant attenuation of the scopolamine-induced performance deficit on the maze during the first five trials but RX77368 also enhanced maze performance during the same period when given alone. These results suggest that the observed scopolamine-induced performance deficit on the radial arm maze partly results from a reduction in locomotion and maze exploration rather than solely impairment of memory, and that RX77368 treatment may improve radial maze performance by increasing arousal and exploratory behaviour in rats rather than directly enhancing cognition.
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Affiliation(s)
- C D Watson
- Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham University, Nottingham NG7 2UH
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14
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POSTER COMMUNICATIONS. Br J Pharmacol 1993; 110:81P-184P. [DOI: 10.1111/j.1476-5381.1993.tb16292.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Duthie SM, Taylor PL, Anderson L, Cook J, Eidne KA. Cloning and functional characterisation of the human TRH receptor. Mol Cell Endocrinol 1993; 95:R11-5. [PMID: 8243797 DOI: 10.1016/0303-7207(93)90043-j] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Thyrotrophin-releasing hormone (TRH) is a hypothalamic tripeptide known to act via its receptor in the anterior pituitary gland to stimulate the release of thyrotrophin (TSH) from thyrotrophs and prolactin (PRL) from lactotrophs. It is also thought to act as a neurotransmitter/neuromodulator in the central and peripheral nervous systems. We have isolated a cDNA encoding the human pituitary TRH receptor (TRH-R) protein with a predicted amino acid sequence of 398 amino acids. Comparison of the amino acid sequences of the human TRH-R with the previously published rodent TRH-Rs showed that it is similar to both the rat and mouse TRH-Rs, except that each species has variant amino acids at the carboxy (COOH) terminus. The human TRH-R belongs to the family of seven transmembrane domain, G-protein-coupled receptors, and it is believed that the COOH terminal region of this family of receptors may play an important role in receptor downregulation/internalisation, and possibly G-protein coupling. COS-1 cells expressing the human TRH-R showed high affinity receptor binding. Stimulation of these cells with TRH produced a typical phosphoinositide response and mobilisation of intracellular calcium [Ca2+]i.
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Affiliation(s)
- S M Duthie
- MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, UK
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