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Loveland JL, Stewart MG, Vallortigara G. Effects of oxytocin‐family peptides and substance P on locomotor activity and filial preferences in visually naïve chicks. Eur J Neurosci 2019; 50:3674-3687. [DOI: 10.1111/ejn.14520] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 07/07/2019] [Accepted: 07/15/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Jasmine L. Loveland
- Center for Mind/Brain Sciences (CIMeC) University of Trento Rovereto Italy
- Behavioural Genetics and Evolutionary Ecology Research Group Max Planck Institute for Ornithology Seewiesen Germany
| | - Michael G. Stewart
- Department of Life, Health and Chemical Sciences The Open University Milton Keynes UK
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Sim YJ, Kim H, Shin MS, Chang HK, Shin MC, Ko IG, Kim KJ, Kim TS, Kim BK, Rhim YT, Kim S, Park HY, Yi JW, Lee SJ, Kim CJ. Effect of postnatal treadmill exercise on c-Fos expression in the hippocampus of rat pups born from the alcohol-intoxicated mothers. Brain Dev 2008; 30:118-25. [PMID: 17723286 DOI: 10.1016/j.braindev.2007.07.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2005] [Revised: 07/04/2007] [Accepted: 07/10/2007] [Indexed: 10/22/2022]
Abstract
Maternal alcohol-intoxication during pregnancy exerts detrimental effects on fetal development and is known to influence learning ability and memory capability by altering neuronal activity in the hippocampus. c-Fos expression represents neuronal activity and plays a crucial role in the brain development. Physical exercise is known to enhance neuronal plasticity and activity. In the present study, we investigated the influence of postnatal treadmill running on the c-Fos expression in the hippocampus of rat pups born from the alcohol-intoxicated mothers. The results obtained show that maternal alcohol-intoxication suppressed c-Fos expression in the hippocampus of rat pups and that postnatal treadmill exercise enhanced c-Fos expression in the hippocampus of these rat pups. The present study suggests that exercise should be considered as a therapeutic means of countering the effects of maternal alcohol-intoxication, and that it may provide a useful strategy for enhancing the neuronal activity of children born from the mothers who abuse alcohol during pregnancy.
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Affiliation(s)
- Young-Je Sim
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
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Lee MH, Kim H, Lim BV, Chang HK, Lee TH, Jang MH, Shin MC, Lee J, Shin MS, Kim CJ. Naloxone potentiates treadmill running-induced increase in c-Fos expression in rat hippocampus. Life Sci 2003; 73:3139-47. [PMID: 14550853 DOI: 10.1016/j.lfs.2003.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The expression of c-Fos is induced by a variety of stimuli and is sometimes used as a marker for increased neuronal activity. In the present study, the effect of treadmill running on c-Fos expression in the hippocampus and the involvement of opioid receptors were investigated via c-Fos immunohistochemistry. It was shown that c-Fos expression in the CA1 region, the CA2 and CA3 regions, and the dentate gyrus of the hippocampus was significantly increased by treadmill running and naloxone, a nonselective opioid receptors antagonist, treatment enhanced treadmill exercise-induced increase of hippocampal c-Fos expression. Base on the present results, it can be suggested that treadmill running increases hippocampal neuronal activity and that endogenous opioids curtail the exercise-induced increase.
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Affiliation(s)
- Myoung-Hwa Lee
- Research Institute of Sports Science, Korea University, #1 5-ga Anam-dong, Sungbuk-gu, Seoul 136-701, South Korea
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Staner L, Duval F, Calvi-Gries F, Mokrani MC, Bailey P, Hode Y, Toussaint M, Luthringer R, Muzet A, Macher JP. Morning and evening TSH response to TRH and sleep EEG disturbances in major depressive disorder. Prog Neuropsychopharmacol Biol Psychiatry 2001; 25:535-47. [PMID: 11370996 DOI: 10.1016/s0278-5846(00)00185-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
1. The aim of this study was to investigate hypothalamo-pituitary-thyroid axis (HPTA) functioning and sleep EEG disturbances in major depressive disorder. 2. Thyroid function was evaluated by determination of TSH levels before and after 8 AM and 11 PM TRH administration on the same day in a sample of 113 consecutively-admitted DSM-IV major depressed inpatients (72 females aged 44.3 +/- 13.0 and 41 males aged 45.7 +/- 10.7) that underwent sleep EEG recordings. 3. A blunted TSH response occurred in 15.9% for 8 AM deltaTSH (maximum increment above baseline at the 8 AM TRH challenge), in 39.8% for 11 PM deltaTSH and in 77% for deltadeltaTSH (difference between 11 PM deltaTSH and 8 AM deltaTSH). A negative correlation between deltadeltaTSH and duration of awakenings after sleep onset, and a shorter sleep onset latency in patients with a blunted 11 PM deltaTSH were found, but these two significant relationships disappeared after controlling for the effects of gender and age. 4. The present findings do not support the hypothesis that, in major depression, HPTA dysfunctioning, as reflected in TSH response to TRH, may be related to sleep EEG disturbances.
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Affiliation(s)
- L Staner
- FORENAP - Institute for Research in Neurosciences, Neuropharmacology and Psychiatry, Centre Hospitalier, Rouffach, France.
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Braszko JJ, Kamiñski KA, Hryszko T, Jedynak W, Brzósko S. Diverse effects of prolonged physical training on learning of the delayed non-matching to sample by rats. Neurosci Res 2001; 39:79-84. [PMID: 11164255 DOI: 10.1016/s0168-0102(00)00207-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The physiological effects of physical exercise have been extensively studied. Nevertheless, its influence on cognitive functioning remains a matter of controversy. In this study we have attempted to assess the effects of repeated exercise (6 weeks of daily treadmill running, meant to resemble human physical training), on parallel learning of a complex task [delayed non matching to sample (DNMS)] by rats. The trained rats appeared to learn the procedure slower and made a significantly lower percentage of correct choices (P<0.01) as compared to those in the non-trained control group. However, when only those rats, from both the groups, which reached the criterion of 80% correct choices in two consecutive sessions were compared, no significant differences were observed. These results suggest an adverse influence of long term physical exercise on rats' ability to learn complex tasks, but only by the 'poor performers'. The 'good performers' were insensitive to the deleterious effects of the exercise.
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Affiliation(s)
- J J Braszko
- Clinical Pharmacology Unit, Ludwik Zamenhof Children's Hospital, Medical Academy of Białystok, 17 Waszyngton St., 15-274 Białystok, Poland.
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Affiliation(s)
- E A Nillni
- Department of Medicine, Brown University School of Medicine, Rhode Island Hospital, Providence 02903, USA.
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Mason GA, Rezvani AH, Overstreet DH, Garbutt JC. Thyrotropin-releasing hormone analog TA-0910 reduces voluntary alcohol intake of P rats subchronically in a limited scheduled access paradigm. Alcohol Clin Exp Res 1996; 20:1000-3. [PMID: 8892518 DOI: 10.1111/j.1530-0277.1996.tb01937.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We previously reported that single intraperitoneal injections of the thyrotropin-releasing hormone analog TA-0910 dose-dependently reduce alcohol intake in alcohol-preferring (P) rats in a free-choice continuous access protocol. We later showed, using the same protocol, that a transient tolerance develops to this effect after several consecutive, once-daily injections. In the present study, P rats that had been accustomed to continuous access to alcohol were acclimated to a limited scheduled access protocol in which alcohol was available only between 10 and 11 AM. This resulted in an elevated rate of alcohol intake. Rats were then injected once daily with TA-0910 (0.75 mg/kg) or an equal volume of a saline vehicle at 9:45 AM for 12 consecutive days. After 11 days of scheduled access, rats were allowed continuous access to alcohol. Intake of alcohol and water was measured each day at 11:00 AM. Compared with vehicle, TA-0910 reduced alcohol intake on the 11 days of scheduled access and during the first hour of day 12 when continuous access was restored, but did not reduce total (24 hr) alcohol intake on day 12. Data from this experiment show that TA-0910 reduces alcohol intake over a long period of time in a limited scheduled access protocol.
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Affiliation(s)
- G A Mason
- Skipper Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina at Chapel Hill, USA
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Mason GA, Rezvani AH, Grady DR, Garbutt JC. The subchronic effects of the TRH analog TA-0910 and bromocriptine on alcohol preference in alcohol-preferring rats: development of tolerance and cross-tolerance. Alcohol Clin Exp Res 1994; 18:1196-201. [PMID: 7847606 DOI: 10.1111/j.1530-0277.1994.tb00104.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In a previous study, we showed that a single injection of the thyrotropin-releasing hormone analog TA-0910 dose-dependently reduced alcohol intake in alcohol-preferring (P) rats and increased their water intake over a 24-hr period. In the present study, the effects of seven consecutive, once-daily injections of TA-0910 (0.75 mg/kg, ip) on alcohol preference were determined. P rats developed tolerance to the attenuating effects of TA-0910 on alcohol intake within 3-5 days. Following the development of tolerance to TA-0910, rats were injected with the dopamine agonist bromocriptine (0.5 mg/kg, sc). In the presence of tolerance to TA-0910, the attenuating effect of bromocriptine on alcohol intake was reduced. When rats were made tolerant to the attenuating effects of bromocriptine, they exhibited tolerance to the attenuating effects of TA-0910. These findings indicate that tolerance to the effects of TA-0910 on alcohol intake occurs and suggest dopamine involvement in the mechanism of action of TA-0910 in reducing alcohol intake in P rats.
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Affiliation(s)
- G A Mason
- Skipper Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill 27599-7160
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Hasenöhrl RU, Frisch C, Nikolaus S, Huston JP. Chronic administration of neurokinin SP improves maze performance in aged Rattus norvegicus. BEHAVIORAL AND NEURAL BIOLOGY 1994; 62:110-20. [PMID: 7527633 DOI: 10.1016/s0163-1047(05)80032-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Deficits in associative functions seen with senescence may be based, at least in part, on a decreased availability of trophic factors in the CNS. A reduced concentration of neurokinins, including undecapeptide substance P (SP), also accompanies aging. Thus, given the change in SP metabolism and the known mnemogenic as well as neurotrophic/neuroprotective effects of the peptide, it seems possible that age-related deficits in associative processes could be influenced by treatment with exogenous SP. In the present study, 30-month-old Wistar rats were injected daily with SP (50 or 250 micrograms/kg, intraperitoneally) starting 1 week before they were tested on the Morris water maze task and on motor coordination tests. Control groups included vehicle-injected old and adult (3-month-old) rats. Over the days of maze testing, application of the substances was performed 5 h after testing daily for 15 days and after the last drug delivery, maze testing was continued for 4 more days. The main finding of this study is that chronic administration of both dosages of SP (50 and 250 micrograms/kg) improved the maze performance of the old rats. This facilitatory effect of SP on performance was also evident after the drug treatment had been terminated in the course of maze testing. Furthermore, chronic application of SP in a dose range of 50-250 micrograms/kg was found to reduce age-related deficits in motor capacities.
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Affiliation(s)
- R U Hasenöhrl
- Institute of Physiological Psychology I, Heinrich-Heine-University Düsseldorf, Germany
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Hasenöhrl RU, Schwarting RK, Gerhardt P, Privou C, Huston JP. Comparison of neurokinin substance P with morphine in effects on food-reinforced operant behavior and feeding. Physiol Behav 1994; 55:541-6. [PMID: 7514795 DOI: 10.1016/0031-9384(94)90115-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In the present study, substance P (SP) was injected intraperitoneally (IP), and its effects on operant behavior were assessed in rats, which had been trained to bar press for food reward on a fixed-ratio (FR) 20 schedule. These effects were compared with IP injection of morphine sulfate, which had previously been shown to strongly suppress operant responding on FR schedules. The IP injection of SP resulted in a dose-related decrement in response rates. SP in a dose range of 250-500 micrograms/kg decreased operant responding, whereas SP in a dose range of 5-50 micrograms/kg did not influence response rates. The IP injection of morphine (10 mg/kg) markedly suppressed operant responding. However, in contrast to the rate-decreasing effects of SP, this suppression was not selective for the reinforced lever as responding on the nonreinforced lever, used as a control, was also decreased. Furthermore, both injection of 10 mg/kg morphine and SP in a dose range of 250-500 micrograms/kg was found to reduce food intake when the animals had free access to food subsequent to the operant conditioning session. The present results provide the first evidence that systemically administered neurokinin SP can affect operant responding for food reward. The suppressive effects on operant behavior and feeding obtained with systemic SP or morphine are discussed with respect to recent findings showing that both drugs can modulate mesolimbic dopamine activity after systemic drug injection.
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Affiliation(s)
- R U Hasenöhrl
- Institute of Physiological Psychology I, Heinrich-Heine-University, Düsseldorf, Germany
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Banki CM, Karmacsi L, Bissette G, Nemeroff CB. CSF corticotropin releasing hormone, somatostatin, and thyrotropin releasing hormone in schizophrenia. Psychiatry Res 1992; 43:13-21. [PMID: 1359593 DOI: 10.1016/0165-1781(92)90137-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cerebrospinal fluid (CSF) corticotropin releasing hormone (CRH), somatostatin (SRIF), and thyrotropin releasing hormone (TRH) were measured by specific radioimmunoassay methods in 86 patients who met DSM-III-R criteria for schizophrenia or schizophreniform disorder and in 30 neurologic controls. The multivariate CSF peptide concentration was significantly different in patients compared with controls, but none of the individual variable differences reached statistical significance when analyzed separately. There were no significant CSF neuropeptide differences among patients with various schizophrenic subtypes. Neither global severity of illness nor individual symptoms were correlated with CSF neuropeptide concentrations. Although schizophrenic patients showed a pattern of mildly lower SRIF and TRH levels in their CSF, together with a weak tendency for higher CSF CRH values, these peptide changes did not appear to be specifically related to the core features of schizophrenia.
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Affiliation(s)
- C M Banki
- Department of Psychiatry, Regional Neuropsychiatric Institute, Nagykallo, Hungary
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Rezvani AH, Garbutt JC, Shimoda K, Garges PL, Janowsky DS, Mason GA. Attenuation of alcohol preference in alcohol-preferring rats by a novel TRH analogue, TA-0910. Alcohol Clin Exp Res 1992; 16:326-30. [PMID: 1590553 DOI: 10.1111/j.1530-0277.1992.tb01385.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Experiments were performed to characterize the acute effect of different doses of a novel thyrotropin-releasing hormone (TRH) analogue (TA-0910) on ethanol intake in rats. Selectively bred alcohol-preferring (P) rats received a single intraperitoneal injection of normal saline or 0.083, 0.25 and 0.75 mg/kg of TA-0910 at 9:30 AM, and their consumption of ethanol, water, and food was measured for 24 hr. TA-0910 dose-dependently attenuated ethanol intake and commensurately increased water consumption. Only the highest dose of TA-0910 increased the total caloric intake. TA-0910 did not affect the pharmacokinetics of ethanol. These findings indicate involvement of TRH systems in ethanol preference and suggest that centrally acting TRH analogues may be therapeutic in the treatment of alcoholism.
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Affiliation(s)
- A H Rezvani
- Skipper Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill 27599-7175
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Garbutt JC, Hicks RE, Clayton CJ, Andrews RT, Mason GA. Behavioral and endocrine interactions between thyrotropin-releasing hormone and ethanol in normal human subjects. Alcohol Clin Exp Res 1991; 15:1045-9. [PMID: 1789379 DOI: 10.1111/j.1530-0277.1991.tb05209.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Thyrotropin-releasing hormone (TRH) has been shown to antagonize the depressant effects of ethanol in animals, but conflicting findings have been reported in humans. To test whether TRH counteracts any of a variety of ethanol-sensitive behavioral measures in normal human subjects and for an effect of ethanol on TRH-induced thyrotropin (TSH) and prolactin (PRL) response, we administered TRH (500 micrograms) or placebo over 1 min intravenously, 30 min after subjects had ingested 0.8 g/kg of ethanol or a placebo drink. Blood samples for TSH and PRL were drawn prior to and 15 and 30 min after injection. Eight male subjects were studied in a balanced, crossover design with each subject receiving placebo-placebo, TRH-placebo, placebo-ethanol, and TRH-ethanol. Whereas ethanol had significant and expected effects on subjective measures, memory, disinhibition, reaction time and time perception, TRH failed to counteract any ethanol effect, except for a small effect in one memory task. Similarly, no effect of ethanol on TRH-induced TSH or PRL response was found. Though the behavioral findings could be interpreted to indicate that TRH does not alter ethanol sensitive behaviors in humans it will be necessary to utilize higher dosages of TRH and/or TRH analogues before firmly drawing this conclusion.
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Affiliation(s)
- J C Garbutt
- Center for Alcohol Studies, University of North Carolina, Chapel Hill
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Hasenöhrl RU, Gerhardt P, Huston JP. Naloxone blocks conditioned place preference induced by substance P and [pGlu6]-SP(6-11). REGULATORY PEPTIDES 1991; 35:177-87. [PMID: 1722047 DOI: 10.1016/0167-0115(91)90081-q] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect of prior treatment with the opioid receptor (opioceptor) antagonist naloxone on conditioned place preference produced by the neurotachykinin substance P (SP) and its C-terminal hexapeptide analog [pGlu6]-SP(6-11) (SPC) was investigated in rats. Place conditioning was assessed using a circular open field partitioned into four quadrants that were equally preferred by the rats prior to drug treatment. On three successive days, rats received an intraperitoneal (i.p.) injection of naloxone-HCl (1 mg/kg) or vehicle 15 min before an i.p. injection of either 37 nmol/kg SP, equimolar dosed SPC or corresponding diluent vehicle. After injection the rats were placed into their assigned treatment corral for 15 min. During the test for conditioned corral preference (CCP), when provided a choice between the four quadrants, rats injected with SP or SPC spent more time in the treatment corral compared to vehicle controls, indicative of a positive reinforcing action of these peptides. The pre-treatment with naloxone blocked the positive reinforcing effects of both SP and SPC; when injected alone, naloxone did not influence the preference behavior. Gross locomotor activity was affected by neither treatment. Thus, the positive reinforcing effects of SP and SPC may be mediated via interactions with the endogenous opioid system(s).
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Affiliation(s)
- R U Hasenöhrl
- Institute of Physiological Psychology I, University of Düsseldorf, F.R.G
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Heilig M, Widerlöv E. Neuropeptide Y: an overview of central distribution, functional aspects, and possible involvement in neuropsychiatric illnesses. Acta Psychiatr Scand 1990; 82:95-114. [PMID: 2173355 DOI: 10.1111/j.1600-0447.1990.tb01366.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Neuropeptide Y (NPY) was first discovered and characterized as a 36-amino-acid peptide neurotransmitter in 1982. It is widely distributed in the central nervous system, with particularly high concentrations within several limbic and cortical regions. A number of co-localizations with other neuromessengers such as noradrenaline, somatostatin, and gamma-aminobutyric acid have been demonstrated. A large number of physiological and pharmacological actions of NPY have been suggested. Recent clinical data also suggest the involvement of NPY in several neuropsychiatric illnesses, particularly in depressive and anxiety states. This article gives a comprehensive review of central distribution of NPY and its receptors, co-localizations and interactions with other neuromessengers, genetic aspects, pharmacological and physiological actions, influence on neuroendocrine functions, and possible involvement in various neuropsychiatric illnesses.
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Affiliation(s)
- M Heilig
- Department of Psychiatry and Neurochemistry, University of Lund, Sweden
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Rinaman L, Miselis RR. Thyrotropin-releasing hormone-immunoreactive nerve terminals synapse on the dendrites of gastric vagal motoneurons in the rat. J Comp Neurol 1990; 294:235-51. [PMID: 2110196 DOI: 10.1002/cne.902940208] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Thyrotropin-releasing hormone stimulates vagally mediated gastric acid secretion and motility by an undefined central mechanism in the rat. The present study sought to determine the anatomical basis for this stimulatory effect by examining the ultrastructural relationship of nerve terminals immunoreactive for thyrotropin-releasing hormone with the dendrites of gastric vagal motoneurons. A light and electron microscopic double immunostaining technique was employed using the beta subunit of unconjugated cholera toxin as a neural tracer. Cholera toxin (50 microliters, 0.25%) was injected into the ventral stomach musculature in five rats. After 72 hours' survival, animals were sacrificed by transcardiac perfusion fixation. Retrogradely transported cholera toxin was immunocytochemically localized in vagal gastric motoneurons and their dendrites in the dorsal motor nucleus of the vagus and nucleus of the solitary tract, alone or in combination with the immunocytochemical localization of thyrotropin-releasing hormone. Ultrastructural analysis of double-labeled material revealed thyrotropin-releasing hormone-immunoreactive nerve terminals making asymmetric synaptic contacts on the retrogradely labeled dendrites of vagal gastric motoneurons. Nerve terminals immunoreactive for thyrotropin-releasing hormone also made asymmetric and symmetric synaptic contacts with unlabeled dendrites of undetermined perikaryal origin. In addition, nonsynaptic varicosities immunoreactive for thyrotropin-releasing hormone were frequently observed in the vagal nuclei. The synaptic contacts between thyrotropin-releasing hormone-immunoreactive nerve terminals and vagal gastric motoneuronal dendrites provide one possible basis for the profound stimulatory effect of central thyrotropin-releasing hormone on gastric vagal motor activity.
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Affiliation(s)
- L Rinaman
- Institute of Neurological Sciences, University of Pennsylvania, Philadelphia 19104
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Kreider MS, Winokur A, Pack AI, Fishman AP. Reduction of thyrotropin-releasing hormone concentrations in central nervous system of African lungfish during estivation. Gen Comp Endocrinol 1990; 77:435-41. [PMID: 2110919 DOI: 10.1016/0016-6480(90)90234-d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Thyrotropin-releasing hormone (TRH) has been implicated as an important modulator of arousal state in mammals. Changes in the content of TRH in several brain regions accompany hibernation in the ground squirrel. In the present study, the involvement of TRH in the regulation of arousal was further investigated in the African lungfish, Protopterus annectens, which contain high concentrations of TRH throughout its central nervous system and enter a hibernation-like state, estivation. Lungfish were divided into three groups. Group 1 was fed normally, group 2 was starved while aquatic, and group 3 was allowed to enter into a state of estivation. After 3 months, the lungfish were sacrificed and the concentrations of TRH, norepinephrine, dopamine, and serotonin were determined in the telencephalon, diencephalon, medulla, and spinal cord. In estivation, there was a significant decline in the concentration of TRH in the diencephalon, with no alteration in other regions. Starvation had no effect on regional TRH concentrations. The concentration of norepinephrine, dopamine, and serotonin did not change in estivation; however, a significant elevation of norepinephrine in the diencephalon and dopamine in the telencephalon was observed in starvation. Starvation and estivation were associated with significant declines in the protein content of the diencephalon and medulla. The estivation-linked decline in TRH in the diencephalon of the lungfish is similar to the decrease in TRH content in the hypothalamus in hibernating ground squirrels. These findings lend further support to the importance of TRH in the regulation of arousal state.
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Affiliation(s)
- M S Kreider
- Department of Psychiatry, University of Pennsylvania, Philadelphia 19104
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Abstract
1. Effects of inhibition of angiotensin converting enzyme (ACE, EC 3.4.15.1) in brain on psychomotor, exploratory, stereotyped and cognitive behaviour in rats were investigated. To inhibit brain ACE captopril (D-3-mercaptopropanoyl-L-proline) was given orally (p.o., 50 mg/kg) or intracerebroventricularly (i.c.v., 5 micrograms/rat). 3. Captopril given p.o. but not i.c.v. significantly enhanced stereotypy, overall number of conditioned avoidance responses, and decreased blood pressure. 4. No statistically significant influence of captopril given by either route on the number of crossings, rearings and bar approaches in the open field, performance of passive avoidance and number of correct choices as well as the speed of running for food in the T-maze was observed. 5. In conclusion, a small decrease of the activity of nigrostriatal dopaminergic system caused by the decrease of AII and/or increase of bradykinin, substance P, enkephalins and neurotensin in brain resulting from ACE inhibition is postulated.
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Affiliation(s)
- J J Braszko
- Department of Pharmacology, Medical Academy, Białystok, Poland
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Martínez-Gómez M, Pacheco P, Aréchiga H. Behavioral and electrophysiological effects of crustacean neurohormone on freely moving cats. Physiol Behav 1989; 46:983-92. [PMID: 2634264 DOI: 10.1016/0031-9384(89)90202-3] [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: 01/01/2023]
Abstract
The behavior of freely moving cats was assessed in an observation chamber during prolonged periods of time. Four patterns of behavior were consistently scored during the mid-day period: a) exploration, b) attention, c) grooming and d) drowsiness. Intracerebroventricular injections of crustacean neurodepressing hormone (NDH) greatly extended the time spent in drowsiness. The threshold dose of NDH for this effect was 300 units. The effect was established a few minutes after the injections and lasted for several hours. During this time the animals sat quietly and showed complete or semicomplete closure of the eyelids. Conspicuous changes in brain electrical activity were also observed under NDH. At low doses, the predominant electrophysiological pattern matches the activity recorded under spontaneous lapses of drowsiness, i.e., spindle bursts in trains of 8-16 Hz in cortical areas and mesencephalic reticular formation. At higher doses, the brain electrical activity changes into a nonconvulsive spiking activity in limbic areas. The time course of the effects differs in the various structures recorded. These results suggest a multiple substrate of NDH activity.
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Affiliation(s)
- M Martínez-Gómez
- Laboratorio de Neurofisiología, CIRA Universidad Autónoma de Tlaxcala, México
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21
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Kentroti S, Vernadakis A. Growth hormone-releasing hormone influences neuronal expression in the developing chick brain. I. Catecholaminergic neurons. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1989; 49:275-80. [PMID: 2572359 DOI: 10.1016/0165-3806(89)90028-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have examined catecholaminergic expression during development in the chick embryonic brain using tyrosine hydroxylase (TH) activity as a biochemical marker for catecholaminergic neurons. TH activity was detectable as early as after 4 days of incubation in whole brain homogenates and increased throughout embryonic development. The greatest increase in enzyme activity was observed between embryonic days 8 and 15, a period of active neuronal maturation and synaptogenesis. Growth hormone-releasing hormone (GHRH) was tested for its influence on TH activity during embryonic development. Eight-day-old embryos that received GHRH (50 ng/50 microliters) in ovo on days 1, 3, 5 and 7 exhibited a significant (P less than 0.001) increase in TH activity. Similar results were obtained when GHRH was administered in a single 50 ng/50 microliter dose on day 1 or day 3 of development. However, embryos receiving the same dose of GHRH on day 5 exhibited no significant difference in TH activity as compared to controls. When growth hormone (GH, 100 ng/50 microliters) was administered during the same critical period (day 3) no difference was observed in TH activity as compared to controls. Thus, the effects of GHRH on TH activity do not appear to be mediated through GH. We interpret these data to mean that GHRH can enhance catecholaminergic phenotypic expression in the chick embryonic brain when administered during a discrete critical period of development from days 1 to 3 of embryonic age.
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Affiliation(s)
- S Kentroti
- Department of Pharmacology, University of Colorado School of Medicine, Denver 80262
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22
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de Wied D, van Ree JM. Neuropeptides: animal behaviour and human psychopathology. EUROPEAN ARCHIVES OF PSYCHIATRY AND NEUROLOGICAL SCIENCES 1989; 238:323-31. [PMID: 2670577 DOI: 10.1007/bf00449813] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Animal studies have demonstrated that neuropeptides modulate nervous system functions. It has been postulated that disturbances in neuropeptide systems may be aetiological factors in psychiatric and neurological disorders. Neuropeptides related to ACTH/MSH, including ORG 2766, increase motivation and attention and facilitate recovery processes after nerve damage. These peptides may be effective during the early stage of dementia. Vasopressin and related peptides improve memory processes in animals and humans. In addition, these peptides influence social behaviour, mood and addictive behaviour. The non-opioid gamma-type endorphins have neuroleptic-like activities in animals and antipsychotic effects in a category of schizophrenic patients. Peptides related to CCK have also been found to be effective in these patients. Some neuropeptides, e.g. TRH and PLG, have been reported to exert antidepressant effects. Further research may eventually produce neuropeptides with therapeutic action in psychiatric and neurological diseases.
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Affiliation(s)
- D de Wied
- Rudolf Magnus Institute for Pharmacology, Medical Faculty, University of Utrecht, The Netherlands
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23
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24
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Sharif NA. Quantitative autoradiography of TRH receptors in discrete brain regions of different mammalian species. Ann N Y Acad Sci 1989; 553:147-75. [PMID: 2541648 DOI: 10.1111/j.1749-6632.1989.tb46638.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The results clearly show marked heterogeneity and ubiquity of the CNS distribution of TRH receptors across several mammalian species including man. The use of high resolution autoradiography coupled with image analysis has permitted the visualization and quantification of TRH receptor density in even very small regions and nuclei of the CNS. This technique will undoubtedly help elucidate the other areas of TRH receptor localization that have thus far escaped detection in mammals and that are yet to be studied in lower vertebrates. Although an attempt has been made to correlate the presence of the peptide, its receptors, and its possible physiological functions, only further detailed physiological/behavioral investigations will ultimately unravel and support the diverse neurotransmitter and trophic roles of TRH in CNS and endocrine function.
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Affiliation(s)
- N A Sharif
- Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201
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25
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NEMEROFF CHARLESB, EVANS DWIGHTL. Thyrotropin-Releasing Hormone (TRH), the Thyroid Axis, and Affective Disorder. Ann N Y Acad Sci 1989. [DOI: 10.1111/j.1749-6632.1989.tb54497.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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26
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Nemeroff CB, Evans DL. Thyrotropin-releasing hormone (TRH), the thyroid axis, and affective disorder. Ann N Y Acad Sci 1989; 553:304-10. [PMID: 2497676 DOI: 10.1111/j.1749-6632.1989.tb46651.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- C B Nemeroff
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina 27710
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27
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Schaefer CF, Brackett DJ, Biber B, Lerner MR, Holaday JW, Wilson MF, Fagraeus L. Respiratory and cardiovascular effects of thyrotropin-releasing hormone as modified by isoflurane, enflurane, pentobarbital and ketamine. REGULATORY PEPTIDES 1989; 24:269-82. [PMID: 2496439 DOI: 10.1016/0167-0115(89)90223-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Thyrotropin-releasing hormone (TRH) possesses significant arousing and cardio-respiratory stimulant actions. The effects of a 2 mg/kg i.v. bolus dose of TRH on respiration and systemic hemodynamics were compared in conscious, freely-moving rats and during anesthesia with 4 different anesthetics. Fifty-four male Sprague-Dawley rats weighing 285 +/- 4 g (mean +/- S.E.M.) were divided into 5 groups: conscious, enflurane (2%), isoflurane (1.4%), pentobarbital (8 mg/kg/h i.v.), and ketamine (60 mg/kg/h i.v.). Anesthetized rats were intubated and breathed oxygen or anesthetic/oxygen spontaneously. Aortic blood pressure, heart rate, cardiac output, respiratory rate, arterial blood pH, blood gases, lactate and glucose were measured, and data were collected over a 20 min baseline period and for 130 min post-TRH. TRH increased respiratory rate in all groups; concomitant changes in arterial PCO2 indicated increased minute ventilation in the inhalation agent groups but not in the i.v. anesthetic groups or in the awake group. Significant respiratory depression in the enflurane group was rapidly reversed by TRH. The respiratory stimulant and arousing effects of TRH were smallest with ketamine anesthesia. The hemodynamic responses to TRH were consistent with a pattern of sympathoadrenalmedullary activation and were relatively uniform across groups despite anesthetic-induced alterations in baseline values. TRH or its analogues may prove useful as an analeptic in clinical anesthesia.
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Affiliation(s)
- C F Schaefer
- Department of Anesthesiology, University of Oklahoma Health Sciences Center, Oklahoma City 73190
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28
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SHARIF NA. Quantitative Autoradiography of TRH Receptors in Discrete Brain Regions of Different Mammalian Species. Ann N Y Acad Sci 1989. [DOI: 10.1111/j.1749-6632.1989.tb54484.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Abstract
The intracerebroventricular (i.c.v.) administration of substance P elicits in rats an excessive grooming that is characterized by body grooming, anogenital grooming and scratching. The total grooming scores displayed by rats treated with substance P hardly exceeded 23% of the theoretical maximal grooming score. Substance P-induced excessive grooming was suppressed by pretreatment with naloxone, haloperidol on neurotensin. It is concluded that substance P induces excessive grooming with a pattern different from that of grooming elicited by other peptides.
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30
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Van Wimersma Greidanus TB, Maigret C, Rinkel GJ, Metzger P, Panis M, Van Zinnicq Bergmann FE, Poelman PJ, Colbern DL. Some characteristics of TRH-induced grooming behavior in rats. Peptides 1988; 9:283-8. [PMID: 3131746 DOI: 10.1016/0196-9781(88)90261-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Intracerebroventricular administration of TRH induces excessive grooming behavior that is characterized by an important contribution of the elements scratching and paw licking. As compared with other grooming inducing peptides, the pattern of TRH-induced grooming resembles that induced by beta-endorphin rather than those elicited by ACTH or bombesin. TRH-induced excessive grooming is suppressed by pretreatment with haloperidol, naloxone or neurotensin. Haloperidol suppresses TRH-induced grooming in a general way, whereas the suppressive effect of the other drugs is mainly due to a selective reduction of TRH-induced excessive scratching. Combined treatments of rats with TRH and a submaximal dose of ACTH, bombesin or beta-endorphin do not result in higher grooming scores than with single peptide treatment. Excessive grooming elicited by water immersion is not affected by TRH. It is concluded that TRH is undoubtedly an excessive grooming inducing peptide. In situations where excessive grooming is elicited by other peptides or by water immersion, TRH does not further activate the operating systems involved in the existing excessive grooming.
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31
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Abstract
Intrathecal (i.t.) injection of substance P (SP) results in a behavioral syndrome characterized by caudally directed biting and scratching. The present results indicate that repeated injections of 10 ng of SP, administered at 60 sec intervals, result in the rapid development of tachyphylaxis to this SP-induced behavioral phenomenon. Three injections of SP produced a greatly attenuated behavioral response compared to that of a single injection of SP. Mice injected with Freund's adjuvant in the hind foot pads to produce an arthritic-like condition exhibited significantly less desensitization to SP after repeated i.t. injection compared to that in saline-injected control mice. While large doses of naloxone (5 mg/kg s.c. or 1 microgram i.t.) combined with each injection of SP completely blocked the desensitization to the effect of SP in naive mice, a smaller dose of naloxone (0.5 mg/kg administered s.c.) failed to alter the apparent tachyphylaxis to SP similar to that seen in saline-treated control mice. Pretreatment with 0.5 micrograms i.t. of beta-funaltrexamine (beta-FNA) also failed to alter the degree of apparent tachyphylaxis to SP. Co-administration of 1 microgram of fluoxetine, a serotonin reuptake inhibitor, or 1 microgram of phentolamine, an alpha-adrenergic antagonist, completely blocked the development of tachyphylaxis to i.t. SP. These results indicate that tachyphylaxis to SP appears to involve activation of the endogenous opioid system. Desensitization also appears to involve activation and inhibition of the descending adrenergic and serotonergic systems respectively.
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Affiliation(s)
- Alice A Larson
- Department of Veterinary Biology, 295 Animal Science/Veterinary Medicine Building, University of Minnesota, St. Paul, MN 55108 U.S.A
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32
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33
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Griffiths EC, Rothwell NJ, Stock MJ. Thermogenic effects of thyrotrophin-releasing hormone and its analogues in the rat. EXPERIENTIA 1988; 44:40-2. [PMID: 3127235 DOI: 10.1007/bf01960238] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Acute or chronic injection of RX 77,368 (a TRH analogue; 1 mg/kg s.c.) stimulated oxygen consumption (VO2) and brown adipose tissue activity in the rat, and decreased weight gain. Other TRH analogues (CG 3509, RGH 2202) and TRH itself also stimulated VO2. These thermogenic actions are probably mediated centrally by stimulation of sympathetic outflow to brown fat.
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Affiliation(s)
- E C Griffiths
- Department of Physiological Sciences, University of Manchester Medical School, England
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34
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Lamour Y, Epelbaum J. Interactions between cholinergic and peptidergic systems in the cerebral cortex and hippocampus. Prog Neurobiol 1988; 31:109-48. [PMID: 2840687 DOI: 10.1016/0301-0082(88)90029-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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35
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Abstract
1. The tripeptide TRH exerts a spectrum of biological activities in both animals and man. Some of these activities have been extensively studied, particularly in psychiatric patients. 2. Behaviorally, TRH appears to increase the sense of well-being, motivation, relaxation, and coping capacity in both normal subjects and patients with psychiatric and neurologic disease. These effects are not disease-specific; attempts to use TRH as a treatment tool have thus been disappointing. 3. Endocrinologically, administration of TRH stimulates the response of TSH; this response has been reported to be blunted in approximately 30% of patients with major depression. However, TSH blunting is not specific for depression, it has also been observed in a variety of other psychiatric conditions. 4. The relevance of these effects for psychiatry in general, and for psychoneuroendocrinology especially, is discussed in this review.
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Affiliation(s)
- P T Loosen
- Vanderbilt University Medical Center, Nashville, Tennessee
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36
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Papir-Kricheli D, Frey J, Laufer R, Gilon C, Chorev M, Selinger Z, Devor M. Behavioural effects of receptor-specific substance P agonists. Pain 1987; 31:263-276. [PMID: 2448728 DOI: 10.1016/0304-3959(87)90041-8] [Citation(s) in RCA: 103] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Septide and senktide are synthetic substance P (SP) agonists with extremely high selectivity for 1 of the 3 known SP receptor subtypes. When injected intrathecally, they produced dramatically different behavioural effects. Septide, the selective SP-P receptor agonist, evoked intense, compulsive scratching, biting and licking of the hind limb, with no sign of motor flaccidity, and without measurable effect on responses to noxious thermal or mechanical stimulation of the foot or tail. In contrast, senktide, the selective SP-N receptor agonist, produced profound, but transient, motor flaccidity, reduced response to noxious stimuli and, at low doses, 'wet-dog shakes.' These various symptoms, all previously associated with SP and/or synthetic SP analogues, appear therefore to derive from activation of distinct SP receptor subtypes.
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Affiliation(s)
- Dalia Papir-Kricheli
- Life Sciences Institute, Hebrew University of Jerusalem, Jerusalem 91904 Israel Institute of Chemistry, Hebrew University of Jerusalem, Jerusalem 91904 Israel School of Pharmacy, Hebrew University of Jerusalem, Jerusalem 91904 Israel
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37
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Kanba KS, Richelson E. Comparison of the stimulation of inositol phospholipid hydrolysis and of cyclic GMP formation by neurotensin, some of its analogs, and neuromedin N in neuroblastoma clone N1E-115. Biochem Pharmacol 1987; 36:869-74. [PMID: 3032199 DOI: 10.1016/0006-2952(87)90178-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Neurotensin, some of its analogs, and neuromedin N were examined for comparison of their potencies at stimulating inositol phospholipid hydrolysis and cyclic GMP synthesis in intact murine neuroblastoma cells (clone N1E-115). Neurotensin(8-13) and acetylneurotensin(8-13) had the highest potencies for the stimulation of the hydrolysis of inositol phospholipid, which were about three times as potent as neurotensin (EC50 = 0.9 nM). On the other hand, fragments of the amino-terminal portion of neurotensin, such as neurotensin(1-6), neurotensin(1-8) and neurotensin(1-11), showed no ability to stimulate this hydrolysis. Neuromedin N, which is similar in structure to neurotensin(8-13) and which has been demonstrated to stimulate cyclic GMP formation [J.A. Gilbert and E. Richelson, Eur. J. Pharmac. 129, 379 (1986)], had EC50 values of 2.5 and 4.5 nM for release of [3H]inositol phosphates and stimulation of cyclic [3H]GMP respectively. A strong correlation was obtained between the EC50 values for neurotensin and several analogs in the stimulation of the release of inositol phosphates and the EC50 values for these peptides in the stimulation of cyclic GMP formation in neuroblastoma clone N1E-115 cells under similar experimental conditions. Thus, these two different biochemical effects of neurotensin and its analogs appear to be mediated by the same receptor site, which may also have been the site of action of neuromedin N in these cells.
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38
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Biologischer Hintergrund. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/978-3-642-71819-9_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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39
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Suemaru S, Hashimoto K, Hattori T, Inoue H, Kageyama J, Ota Z. Starvation-induced changes in rat brain corticotropin-releasing factor (CRF) and pituitary-adrenocortical response. Life Sci 1986; 39:1161-6. [PMID: 3018413 DOI: 10.1016/0024-3205(86)90347-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Starvation-induced changes in CRF concentration in major brain regions and abnormalities in the pituitary-adrenal axis were examined in rats using rat CRF radioimmunoassay. The CRF concentrations in the hypothalamus and cerebellum were significantly reduced in the completely starved rats, while those in the midbrain, thalamus and neurointermediate lobe of the pituitary were significantly increased in the semi-starved or completely starved rats. No significant changes in the CRF concentrations were found in the pons, medulla oblongata and cerebral cortex. In the completely starved rats, the serum ACTH level was significantly reduced, whereas the serum corticosterone level was markedly elevated. These observations suggest that starvation may stimulate the CRF-ACTH-corticosterone system and that not only hypothalamic CRF but also extrahypothalamic CRF may be discretely related to feeding behavior or starvation. The reduced serum ACTH level in starved rats may be ascribed to the negative feedback effect of the elevated serum corticosterone.
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40
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Kanba KS, Kanba S, Okazaki H, Richelson E. Binding of [3H]neurotensin in human brain: properties and distribution. J Neurochem 1986; 46:946-52. [PMID: 3950614 DOI: 10.1111/j.1471-4159.1986.tb13061.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The binding of [3H]neurotensin to membranes from human brain at 0 degrees C was specific, saturable, and reversible. In the frontal cortex, the equilibrium dissociation constant (KD) for [3H]neurotensin determined from the ratio of rate constants (k-1/k1), saturation isotherms, and inhibition binding experiments was 0.80, 2.0, and 2.0 nM, respectively, and the maximum number of binding sites (Bmax) from the saturation isotherms and the competitive binding experiments was 2.4 and 2.2 pmol/g of tissue, respectively. Hill coefficients for binding were equal to 1, indicating the presence of single, noncooperative binding sites. Inhibition of specific binding of [3H]-neurotensin by several analogs of neurotensin showed that [Gln4]neurotensin and neurotensin(8-13) had the highest affinities for these binding sites in human frontal cortex, with each analog being approximately 13-fold more potent than neurotensin. In addition, these data showed that the carboxy-terminal portion of neurotensin played an important part in the binding of this neuropeptide in human brain, a result described for other species. Regional distribution of binding sites was different from that reported for animal brains. Of the 33 different regions investigated, the uncus and substantia nigra showed the highest specific binding of [3H]neurotensin, whereas such areas as the pineal body, medulla, and corpus callosum had few binding sites.
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41
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Watkins LR, Suberg SN, Thurston CL, Culhane ES. Role of spinal cord neuropeptides in pain sensitivity and analgesia: thyrotropin releasing hormone and vasopressin. Brain Res 1986; 362:308-17. [PMID: 3080201 DOI: 10.1016/0006-8993(86)90455-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The existence of a wide variety of neuropeptides within the spinal cord dorsal horn raises the question of their possible roles in sensory processing. The present series of behavioral experiments examined the effects of intrathecal (IT) administration of two such neuropeptides, thyrotropin-releasing hormone (TRH) and vasopressin (VAS), on pain sensitivity and antinociception. TRH exerted no marked effect on basal pain sensitivity over the dose range examined (0.25 ng-2.5 micrograms). However, a U-shaped dose-response effect on morphine antinociception (3 micrograms, IT) was observed, wherein potent attenuation, moderate attenuation, or enhancement of morphine-induced antinociception was observed following the various doses tested. In contrast, VAS produced non-opiate antinociception at the highest doses tested (25 ng and 250 ng) and none of the VAS doses (0.25 ng-250 ng) appeared to interact with IT morphine (3 micrograms) antinociception. Lastly, IT TRH was not observed to interact with IT VAS antinociception. These data provide evidence that these neuropeptides exert strikingly different effects on pain sensitivity and opiate antinociception, and provide initial evidence that TRH may be included in the growing list of neuropeptides that can act like endogenous opiate antagonists within the central nervous system.
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42
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Kragh-Sørensen P, Olsen RB, Lund S, Van Riezen H, Steffensen K. Neuropeptides: ACTH-peptides in dementia. Prog Neuropsychopharmacol Biol Psychiatry 1986; 10:479-92. [PMID: 3025927 DOI: 10.1016/0278-5846(86)90019-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Studies on the treatment of demented patients with ACTH neuropeptides are reviewed. The discussion is restricted to ACTH4-10 and an orally active peptide, the modified ACTH4-9 fragment: H-Met (O2)-Glu-His-Phe-D-Lys-Phe-O (Org 2766). The first part of the review concentrates on data from animal pharmacology and basic and human studies which have relevance for the clinical effects shown in demented patients. The second part concerns clinical studies in man. Own results from a placebo-controlled dose finding study on the treatment of 156 PDSD patients with Org 2766 are presented. Org 2766 was in this study found to have a significant therapeutic effect in patients with PDSD measured mainly on the basis of SCAG total, although the effect was found to be rather small (average 4 points improvement on SCAG total). Post hoc analyses demonstrated that effects were clinically relevant for only 25 per cent of the patients. Analyses of SCAG factor scores indicated an effect on cognitive function and somatic function. The study failed to show clear dose-response relationship. However, before a final conclusion on the efficacy of Org 2766 can be reached the results must be confirmed by others.
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