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Silic B, Aggarwal M, Liyanagama K, Tripp G, Wickens JR. Conditioned approach behavior of SHR and SD rats during Pavlovian conditioning. Behav Brain Res 2023; 443:114348. [PMID: 36796486 DOI: 10.1016/j.bbr.2023.114348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/04/2023] [Accepted: 02/13/2023] [Indexed: 02/16/2023]
Abstract
Individual differences in reward-related learning are relevant to many behavioral disorders. Sensory cues that predict reward can become incentive stimuli that adaptively support behavior, or alternatively, cause maladaptive behaviors. The spontaneously hypertensive rat (SHR) expresses a genetically determined elevated sensitivity to delay of reward, and has been extensively studied as a behavioral model for attention deficit hyperactivity disorder (ADHD). We investigated reward-related learning in the SHR, comparing them to Sprague-Dawley (SD) rats as a reference strain. A standard Pavlovian conditioned approach task was used, in which a lever cue was followed by reward. Lever presses could occur while the lever was extended, but had no effect on reward delivery. The behavior of both the SHRs and the SD rats showed that they learnt that the lever cue predicted reward. However, the pattern of behavior differed between the strains. During lever cue presentation, SD rats pressed the lever more often and made fewer magazine entries than SHRs. When lever contacts that did not result in lever presses were analyzed, there was no significant difference between SHRs and SDs. These results suggest that the SHRs attributed less incentive value to the conditioned stimulus than the SD rats. During the presentation of the conditioned cue, cue directed responses are called sign tracking responses, whereas responses directed towards the food magazine are called goal tracking responses. Analysis of behavior using a standard Pavlovian conditioned approach index to quantify sign and goal tracking tendencies showed that both strains had a tendency towards goal tracking in this task. However, the SHRs showed a significantly greater goal tracking tendency than the SD rats. Taken together, these findings suggest that attribution of incentive value to reward predicting cues is attenuated in SHRs, which might explain their elevated sensitivity to delay of reward.
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Affiliation(s)
- Bozena Silic
- Neurobiology Research Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Mayank Aggarwal
- Laboratory for Integrated Theoretical Neuroscience, Center for Brain Science, RIKEN, Japan
| | - Kavinda Liyanagama
- Neurobiology Research Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Gail Tripp
- Human Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Jeffery R Wickens
- Neurobiology Research Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
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Spontaneously hypertensive rats manifest deficits in emotional response to 22-kHz and 50-kHz ultrasonic playback. Prog Neuropsychopharmacol Biol Psychiatry 2023; 120:110615. [PMID: 36007820 DOI: 10.1016/j.pnpbp.2022.110615] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/13/2022] [Indexed: 10/15/2022]
Abstract
Many symptoms used routinely for human psychiatric diagnosis cannot be directly observed in animals which cannot describe their internal states. However, the ultrasonic vocalizations (USV) rodents use to communicate their emotional states can be measured. USV have therefore become a particularly useful tool in brain disease models. Spontaneously hypertensive rats (SHR) are considered an animal model of attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, the specifics of SHR's behavior have not been fully described and there is very little data on their USV. Recently, we developed a communication model, in which Wistar rats are exposed to pre-recorded playbacks of aversive (22-kHz) or appetitive (50-kHz) USV, and their vocal responses depend on the extent of prior fear conditioning (0, 1, 6 or 10 shocks). Here, we investigated SHR's behavior and heart rate (HR) in our communication model, in comparison to Wistar rats employed as controls. In general, SHR emitted typical USV categories, however, they contained more short 22-kHz and less 50-kHz USV overall. Moreover, fewer SHR, in comparison with Wistar rats, emitted long 22-kHz USV after fear conditioning. SHR did not show a 50-kHz playback-induced HR increase, while they showed a profound 22-kHz playback-induced HR decrease. Finally, the number of previously delivered conditioning shocks appeared to have no effect on the investigated vocal, locomotor and HR responses of SHR. The phenomena observed in SHR are potentially attributable to deficits in emotional perception and processing. A lower number of 50-kHz USV emitted by SHR may reflect observations of speech impairments in human patients and further supports the usefulness of SHR to model ADHD and schizophrenia.
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Barreto da Silva L, Camargo SB, Moraes RDA, Medeiros CF, Jesus ADM, Evangelista A, Villarreal CF, Quintans-Júnior LJ, Silva DF. Antihypertensive effect of carvacrol is improved after incorporation in β-cyclodextrin as a drug delivery system. Clin Exp Pharmacol Physiol 2020; 47:1798-1807. [PMID: 32568422 DOI: 10.1111/1440-1681.13364] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/20/2020] [Accepted: 06/10/2020] [Indexed: 01/28/2023]
Abstract
Carvacrol (CARV), has been shown to possess various pharmacological properties, especially in the treatment of cardiovascular diseases. We evaluated the antihypertensive effect of the CARV free and encapsulation of CARV in β-cyclodextrin (CARV/β-CD), and whether CARV/β-CD is able to improve the antihypertensive effects of CARV free in spontaneously hypertensive rats (SHR). The rats were randomly divided into four groups, each treated daily for 21 days and the mean arterial pressure and heart rate was measured every 5 days: group 1, Wistar-vehicle solution; group 2, SHR-vehicle; group 3, SHR-CARV 50 mg/kg/d; and group 4, CARV/β-CD 50 mg/kg/d. After 21 days of treatment, the mesenteric artery from treated animals was tested for phenylephrine (Phe) and sodium nitroprusside (SNP) sensitivity. In addition, administration of CARV/β-CD induced important antihypertensive activity when compared with the uncomplexed form, reducing the progression of arterial hypertension in SHR. Moreover, pharmacological potency to Phe in the SHR-CARV and CARV/β-CD groups was increased, approaching values expressed in the Wistar-vehicle. Furthermore, CARV/β-CD reduced the production of the pro-inflammatory mediator, IL-1β, and increased anti-inflammatory cytokine, IL-10. Together, these results produced evidence that the encapsulation of CARV in β-CD can improve cardiovascular activity, showing potential anti-inflammatory and antihypertensive effects.
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Affiliation(s)
- Liliane Barreto da Silva
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
| | - Samuel Barbosa Camargo
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
| | - Raiana Dos Anjos Moraes
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
| | - Carla Fiama Medeiros
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
| | - Anderson de Melo Jesus
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
| | | | | | | | - Darízy Flávia Silva
- Laboratory of Cardiovascular Physiology and Pharmacology, Federal University of Bahia, Salvador, Brazil
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Aparicio CF, Malonson M, Hensley J. Analyzing the magnitude effect in spontaneously hypertensive (SHR) and wistar Kyoto (WKY) rats. Behav Processes 2020; 181:104258. [PMID: 33035639 DOI: 10.1016/j.beproc.2020.104258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/06/2020] [Accepted: 09/22/2020] [Indexed: 01/03/2023]
Abstract
We analyzed the magnitude effect in Spontaneously Hypertensive (SHR) and Wistar Kyoto (WKY) rats choosing between a smaller-sooner (SSF) and a larger-later food (LLF) in the initial link of a concurrent-chains procedure. The SSF was delivered immediately in one terminal link and the LLF delayed 0.01, 5, 10, 20, 40, or 80 s in the other terminal link. An ABABA design varied food amount, 1 vs. 4 and 3 vs. 8 food-pellets in conditions A and B, respectively. The SHRs made more impulsive choices than the WKYs. The hyperbolic-decay model and the Generalized Matching Law fitted the data well. Discounting rate (k) and the area under the discounting curve (AUC) for the choices made by the SHRs in conditions A, were like those in conditions B. For the choices that the individual WKYs made, k was slightly higher and AUC smaller in conditions B than in conditions A. For both strains sensitivity to the immediacy of the LLF (s) was slightly higher in conditions A than in conditions B. Thus, we found no conclusive, compelling evidence either supporting or discarding the magnitude effect in the SHRs and scarce evidence supporting an effect opposite to the magnitude effect in the WKYs.
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Aqueous Fraction from Hibiscus sabdariffa Relaxes Mesenteric Arteries of Normotensive and Hypertensive Rats through Calcium Current Reduction and Possibly Potassium Channels Modulation. Nutrients 2020; 12:nu12061782. [PMID: 32549326 PMCID: PMC7353181 DOI: 10.3390/nu12061782] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND/OBJECTIVES Hibiscus sabdariffa L. (H. sabdariffa (HS)) extract has a vascular relaxant effect on isolated rat thoracic aorta, but data on small resistance arteries, which play an important role on the development of hypertension, are still missing. The purposes of this study were (1) to assess the effect on isolated mesenteric arteries (MA) from normotensive (Wistar and Wistar-Kyoto (WKY)) and spontaneous hypertensive rats (SHR); (2) to elucidate the mechanism(s) of action underling the relaxant effect in light of bioactive components. METHODS Vascular effects of HS aqueous fraction (AF) on isolated MA rings, as well as its mechanisms of action, were assessed using the contractility and intracellular microelectrode technique. The patch clamp technique was used to evaluate the effect of HS AF on the L-type calcium current. Extraction and enrichment of AF were carried out using liquid-liquid extraction, and the yield was analyzed using HPLC. RESULTS The HS AF induced a concentration-dependent relaxant effect on MA rings of SHR (EC50 = 0.83 ± 0.08 mg/mL), WKY (EC50 = 0.46 ± 0.04 mg/mL), and Wistar rats (EC50 = 0.44 ± 0.08 mg/mL) pre-contracted with phenylephrine (10 µM). In Wistar rats, the HS AF maximum relaxant effect was not modified after endothelium removal or when a guanylate cyclase inhibitor (ODQ, 10 µM) and a selective β2-adrenergic receptor antagonist (ICI-118551, 1 µM) were incubated with the preparation. Otherwise, it was reduced by 34.57 ± 10.66% when vascular rings were pre-contracted with an 80 mM [K+] solution (p < 0.001), which suggests an effect on ionic channels. HS AF 2 mg/mL significantly decreased the peak of the L-type calcium current observed in cardiac myocytes by 24.4%. Moreover, though the vasorelaxant effect of HS, AF was reduced by 27% when the nonselective potassium channels blocker (tetraethylammonium (TEA) 20 mM) was added to the bath (p < 0.01). The extract did not induce a membrane hyperpolarization of smooth muscle cells, which might suggest an absence of a direct effect on background potassium current. CONCLUSION These results highlight that the antihypertensive effect of HS probably involves a vasorelaxant effect on small resistance arteries, which is endothelium independent. L-type calcium current reduction contributes to this effect. The results could also provide a link between the vasorelaxant effect and the bioactive compounds, especially anthocyanins.
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Ju DT, K AK, Kuo WW, Ho TJ, Chang RL, Lin WT, Day CH, Viswanadha VVP, Liao PH, Huang CY. Bioactive Peptide VHVV Upregulates the Long-Term Memory-Related Biomarkers in Adult Spontaneously Hypertensive Rats. Int J Mol Sci 2019; 20:E3069. [PMID: 31234585 PMCID: PMC6627188 DOI: 10.3390/ijms20123069] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 12/19/2022] Open
Abstract
Hypertension is one of the growing risk factors for the progression of long-term memory loss. Hypertension-mediated memory loss and treatment remain not thoroughly elucidated to date. Plant-based natural compounds are an alternative solution to treating human diseases without side effects associated with commercial drugs. This study reveals that bioactive peptides extracted from soy hydrolysates mimic hypertension-mediated memory loss and neuronal degeneration and alters the memory molecular pathway in spontaneously hypertensive rats (SHR). The SHR animal model was treated with bioactive peptide VHVV (10 mg/kg/oral administration) and angiotensin-converting-enzyme (ACE) inhibitors (5 mg/kg/oral administration) for 24 weeks. We evaluated molecular level expression of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and survival markers phospho-protein kinase B (P-AKT) and phosphoinositide 3-kinase (PI3K) after 24 weeks of treatment for SHR in this study. Western blotting, hematoxylin and eosin (H&E) staining, and immunohistochemistry showed long-term memory loss and neuronal degeneration in SHR animals. Bioactive peptide VHVV-treated animals upregulated the expression of long-term memory-relate proteins and neuronal survival. Spontaneously hypertensive rats treated with oral administration of bioactive peptide VHVV had activated CREB-mediated downstream proteins which may reduce hypertension-mediated long-term memory loss and maintain neuronal survival.
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Affiliation(s)
- Da-Tong Ju
- Department of Neurological Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan.
| | - Ashok Kumar K
- Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan.
| | - Wei-Wen Kuo
- Department of Biological Science and Technology, China Medical University, Taichung 404, Taiwan.
| | - Tsung-Jung Ho
- Department of Chinese Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien 970, Taiwan.
| | - Ruey-Lin Chang
- School of Post-Baccalaureate Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung 404, Taiwan.
| | - Wan-Teng Lin
- Department of Hospitality Management, College of Agriculture, Tunghai University, Taichung 407, Taiwan.
| | | | | | - Po-Hsiang Liao
- Graduate Institute of Basic Medical Science, China Medical University, Taichung 404, Taiwan.
- Holistic Education Center, Tzu Chi University of Science and Technology, Hualien 970, Taiwan.
- Cardiovascular research center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan.
| | - Chih-Yang Huang
- Holistic Education Center, Tzu Chi University of Science and Technology, Hualien 970, Taiwan.
- Cardiovascular research center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970, Taiwan.
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 404, Taiwan.
- Department of Biotechnology, Asia University, Taichung 413, Taiwan.
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Cerebral Blood Flow in SHR Rats after Transplantation of Mesenchymal Stem Cells. Bull Exp Biol Med 2019; 166:586-590. [PMID: 30783841 DOI: 10.1007/s10517-019-04396-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Indexed: 10/27/2022]
Abstract
Intracerebral transplantation of mesenchymal stem cells to 6- and 12-month-old SHR rats induced angiogenesis in the pia mater. In 6-months-old SHR rats, perfusion in the brain tissue after cell transplantation considerably increased, while in 12-month-old rats it remained practically unchanged. We also observed marked activation of regulatory processes in the cerebral vascular system, most pronounced in 12-month-old rats. Neurogenic and myogenic tone of cerebral vessels increased significantly, while endothelium-dependent tone slightly decreased. The increase in neurogenic and myogenic tone of blood vessels in SHR rats at the age of 6 and 12 months after transplantation of stem cells can be explained by the formation of new smooth muscle cells in the pre-existing arteries walls. Greater muscle mass developed stronger force and contributed to narrowing of the arterial lumen, as a result, there was no increase in blood flow despite the downstream angiogenesis. A slight decrease in endothelium-dependent tone can be explained by increased production of vasodilators by newly formed endothelial cells.
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Aparicio CF, Hennigan PJ, Mulligan LJ, Alonso-Alvarez B. Spontaneously hypertensive (SHR) rats choose more impulsively than Wistar-Kyoto (WKY) rats on a delay discounting task. Behav Brain Res 2017; 364:480-493. [PMID: 28963043 DOI: 10.1016/j.bbr.2017.09.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/19/2017] [Accepted: 09/25/2017] [Indexed: 11/29/2022]
Abstract
Indications of Attention Deficit Hyperactivity Disorder (ADHD) in the spontaneously hypertensive rat (SHR) are not consistent across different tests of impulsivity, questioning the SHR's validity as a rodent model of ADHD. This study used a concurrent-chains procedure to examine possible differences in impulsive choice between SHRs and control-normotensive Wistar Kyoto (WKY) rats. The aim was to extend the generality of findings showing regularities between the hyperbolic-decay model and the generalized matching law fitting delay discounting data from nonhuman animals. The objectives were to: (1) examine differences in impulsive choice between SHRs and WKYs; (2) add evidence suggesting that the SHR is a suitable model of ADHD; (3) demonstrate that concurrent-chains procedures requiring locomotion detect differences in impulsive choice between SHRs and WKYs; (4) support the idea that impulsivity in nonhuman animals increases with training. The initial link used two non-independent random interval schedules arranging entries to the terminal links, where one fixed-time (FT) schedule delayed 1-food pellet and the other FT 4-food pellets. The FT delaying the former was kept constant at 0.1s and that delaying the latter changed after every 10 food deliveries, defining six delay components (0.1, 5, 10, 20, 40, and 80s) presented in random order each session. Results showed that the SHRs choose more impulsively than the WKYs, adding to the body of evidence suggesting that the SHR may be a suitable model of ADHD. Both models of choice fitted the impulsive choices of the SHRs and WKYs well; positive correlations between estimates of parameters k and s suggested compatibility between models of choice showing that impulsivity increases with training.
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Höfler RU, Channa ML, Nadar A. The effect of multivitamin-multimineral supplementation on the health status of inbred Wistar and spontaneously hypertensive rat strains. J S Afr Vet Assoc 2016; 87:1324. [PMID: 27381881 PMCID: PMC6138154 DOI: 10.4102/jsava.v87i1.1324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/22/2015] [Accepted: 12/09/2015] [Indexed: 11/22/2022] Open
Abstract
The nutraceutical industry has proliferated in recent years, with the most popular form of supplementation being the multivitamin-multimineral (MVMM) supplement. In the animal health sector, supplement use has also expanded. The objective of this study was to determine the effects of MVMM supplementation, beneficial or otherwise, on the general health status of the spontaneously hypertensive rat (SHR) strain, an animal model used in hypertension research. A commercially prepared MVMM supplement was given tri-weekly via oral dosing for 8 weeks to two groups of seven adult female SHR and Wistar rats. Their corresponding control groups were dosed with deionised water only. Systolic and diastolic blood pressure, fasting blood glucose, growth rate and food and water intake were measured weekly. At the end of 8 weeks, the animals were euthanased and a full blood profile, urine sodium to potassium ratio, blood urea nitrogen levels and total plasma cholesterol was measured for all groups. The results indicated that growth rate was higher for the SHR supplemented group. Supplementation also decreased diastolic blood pressure in both Wistar and SHR groups and increased red blood cell count and decreased total cholesterol in the SHR group. No adverse effects on the general health status of the animals were observed. MVMM supplementation may therefore be useful in aiding growth and delaying the onset of hypertension and its effects. It may also assist in the longevity of the breeding stock of SHR rats.
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Affiliation(s)
- Rosemarie U Höfler
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Westville Campus.
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Shih YH, Tsai SF, Huang SH, Chiang YT, Hughes MW, Wu SY, Lee CW, Yang TT, Kuo YM. Hypertension impairs hippocampus-related adult neurogenesis, CA1 neuron dendritic arborization and long-term memory. Neuroscience 2016; 322:346-57. [PMID: 26921651 DOI: 10.1016/j.neuroscience.2016.02.045] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/02/2016] [Accepted: 02/18/2016] [Indexed: 02/07/2023]
Abstract
Hypertension is associated with neurodegenerative diseases and cognitive impairment. Several studies using spontaneous hypertensive rats to study the effect of hypertension on memory performance and adult hippocampal neurogenesis have reached inconsistent conclusions. The contradictory findings may be related to the genetic variability of spontaneous hypertensive rats due to the conventional breeding practices. The objective of this study is to examine the effect of hypertension on hippocampal structure and function in isogenic mice. Hypertension was induced by the '2 kidneys, 1 clip' method (2K1C) which constricted one of the two renal arteries. The blood pressures of 2K1C mice were higher than the sham group on post-operation day 7 and remained high up to day 28. Mice with 2K1C-induced hypertension had impaired long-term, but not short-term, memory. Dendritic complexity of CA1 neurons and hippocampal neurogenesis were reduced by 2K1C-induced hypertension on post-operation day 28. Furthermore, 2K1C decreased the levels of hippocampal brain-derived neurotrophic factor, while blood vessel density and activation status of astrocytes and microglia were not affected. In conclusion, hypertension impairs hippocampus-associated long-term memory, dendritic arborization and neurogenesis, which may be caused by down-regulation of brain-derived neurotrophic factor signaling pathways.
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Affiliation(s)
- Y-H Shih
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - S-F Tsai
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - S-H Huang
- Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan
| | - Y-T Chiang
- Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan
| | - M W Hughes
- International Research Center of Wound Repair & Regeneration, Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan
| | - S-Y Wu
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - C-W Lee
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
| | - T-T Yang
- Department of Chinese Medicine for Post-Baccalaureate, I-Shou University, Kaohsiung, Taiwan
| | - Y-M Kuo
- Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan; Department of Cell Biology and Anatomy, National Cheng Kung University, Tainan, Taiwan.
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Phosphodiesterase-4 inhibitors ameliorates cognitive deficits in deoxycorticosterone acetate induced hypertensive rats via cAMP/CREB signaling system. Brain Res 2015; 1622:279-91. [PMID: 26168894 DOI: 10.1016/j.brainres.2015.07.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 07/02/2015] [Accepted: 07/03/2015] [Indexed: 12/17/2022]
Abstract
Phosphodiesterase-4 (PDE-4) inhibitors promote memory by blocking the degradation of cAMP. Existing evidence also shows that neuronal survival and plasticity are dependent on the phosphorylation of cAMP-response element-binding protein. In this regard, PDE-4 inhibitors have also been shown to reverse pharmacologically and genetically induced memory impairment in animal models. In the present study, the authors examined the effect of both rolipram and roflumilast (PDE-4 inhibitors) on the impairment of learning and memory observed in hypertensive rats. Deoxycorticosterone acetate (DOCA) salt hypertensive model was used to induce learning and memory deficits. The mRNA expression of different PDE-4 subtypes along with the protein levels of pCREB and BDNF in the hippocampus was quantified. Systolic blood pressure was significantly increased in DOCA salt hypertensive rats when compared to sham operated rats. This effect was reversed by clonidine, an α2 receptor agonist, while PDE-4 inhibitors did not. PDE-4 inhibitors significantly improved the time-induced memory deficits in object recognition task (ORT). In DOCA salt hypertensive rats, the gene expression of PDE-4B and PDE-4D was significantly increased. Furthermore, both pCREB and BDNF showed decreased levels of expression in hypertensive rats in comparison to sham operated rats. Repeated administration of PDE-4 inhibitors significantly decreased both PDE-4B and PDE-4D with an increase in the expression of pCREB and BDNF in hypersensitive rats. Also, rolipram, roflumilast and roflumilast N-oxide showed a linear increase in the plasma and brain concentrations after ORT. Our present findings suggested that PDE-4 inhibitors ameliorate hypertension-induced learning impairment via cAMP/CREB signaling that regulates BDNF expression downstream in the rat hippocampus.
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Effects of rolipram and roflumilast, phosphodiesterase-4 inhibitors, on hypertension-induced defects in memory function in rats. Eur J Pharmacol 2015; 746:138-47. [DOI: 10.1016/j.ejphar.2014.10.039] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 10/16/2014] [Accepted: 10/18/2014] [Indexed: 12/17/2022]
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Stanford SC. Psychostimulants, antidepressants and neurokinin-1 receptor antagonists ('motor disinhibitors') have overlapping, but distinct, effects on monoamine transmission: the involvement of L-type Ca2+ channels and implications for the treatment of ADHD. Neuropharmacology 2014; 87:9-18. [PMID: 24727210 DOI: 10.1016/j.neuropharm.2014.03.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/21/2014] [Accepted: 03/31/2014] [Indexed: 11/15/2022]
Abstract
Both psychostimulants and antidepressants target monoamine transporters and, as a consequence, augment monoamine transmission. These two groups of drugs also increase motor activity in preclinical behavioural screens for antidepressants. Substance P-preferring receptor (NK1R) antagonists similarly increase both motor activity in these tests and monoamine transmission in the brain. In this article, the neurochemical and behavioural responses to these three groups of drugs are compared. It becomes evident that NK1R antagonists represent a distinct class of compounds ('motor disinhibitors') that differ substantially from both psychostimulants and antidepressants, especially during states of heightened arousal or stress. Also, all three groups of drugs influence the activation of voltage-gated Ca(v)1.2 and Ca(v)1.3 L-type channels (LTCCs) in the brain, albeit in different ways. This article discusses evidence that points to disruption of these functional interactions between NK1R and LTCCs as a contributing factor in the cognitive and behavioural abnormalities that are prominent features of Attention Deficit Hyperactivity Disorder (ADHD). Arising from this is the interesting possibility that the hyperactivity and impulsivity (as in ADHD) and psychomotor retardation (as in depression) reflect opposite poles of a behavioural continuum. A better understanding of this pharmacological network could help explain why psychostimulants augment motor behaviour during stress (e.g., in preclinical screens for antidepressants) and yet reduce locomotor activity and impulsivity in ADHD. This article is part of the Special Issue entitled 'CNS Stimulants'.
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Affiliation(s)
- S Clare Stanford
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
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Dudley JA, Weir RK, Yan TC, Grabowska EM, Grimmé AJ, Amini S, Stephens DN, Hunt SP, Stanford SC. Antagonism of L-type Ca(v) channels with nifedipine differentially affects performance of wildtype and NK1R-/- mice in the 5-Choice Serial Reaction-Time Task. Neuropharmacology 2012; 64:329-36. [PMID: 22884624 DOI: 10.1016/j.neuropharm.2012.06.056] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 06/23/2012] [Accepted: 06/26/2012] [Indexed: 12/11/2022]
Abstract
Mice with functional ablation of the substance P-preferring receptor gene ('Nk1r' in mice ('NK1R-/-'), 'TACR1' in humans) display deficits in cognitive performance that resemble those seen in patients with Attention Deficit Hyperactivity Disorder (ADHD): namely, inattentiveness, impulsivity and perseveration. A recent report suggested that the L-type Ca(v) channel blocker, nifedipine, can ameliorate behavioral abnormalities of this type in humans. In light of evidence that NK1R antagonists modulate the opening of these L-type channels, we investigated whether nifedipine modifies %premature responses (impulsivity), perseveration or %omissions (inattentiveness) in the 5-Choice Serial Reaction-Time Task (5-CSRTT) and whether the response differs in NK1R-/- and wildtype mice. %Premature responses and perseveration were reduced in both genotypes, although wildtype mice were more sensitive to the effects of nifedipine than NK1R-/- mice. By contrast, nifedipine greatly increased %omissions but, again, was more potent in wildtypes. %Accuracy and locomotor activity were unaffected in either genotype. We infer that behavior of mice in the 5-CSRTT depends on the regulation of striato-cortical networks by L-type Ca(v) channels and NK1R. We further suggest that disruption of NK1R signaling in patients with ADHD, especially those with polymorphisms of the TACR1 gene, could lead to compensatory changes in the activity of L-type channels that underlie or exacerbate their problems. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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Affiliation(s)
- Julia A Dudley
- Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
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15
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Tayebati SK, Tomassoni D, Amenta F. Spontaneously hypertensive rat as a model of vascular brain disorder: microanatomy, neurochemistry and behavior. J Neurol Sci 2012; 322:241-9. [PMID: 22726353 DOI: 10.1016/j.jns.2012.05.047] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/23/2012] [Indexed: 11/28/2022]
Abstract
Arterial hypertension is the main risk factor for stroke and plays a role in the development of vascular cognitive impairment (VCI) and vascular dementia (VaD). An association between hypertension and reduced cerebral blood flow and VCI is documented and arterial hypertension in midlife is associated with a higher probability of cognitive impairment. These findings suggest that arterial hypertension is a main cause of vascular brain disorder (VBD). Spontaneously hypertensive rat (SHR) is the rat strain most extensively investigated and used for assessing hypertensive brain damage and treatment of it. They are normotensive at birth and at 6months they have a sustained hypertension. Time-dependent rise of arterial blood pressure, the occurrence of brain atrophy, loss of nerve cells and glial reaction are phenomena shared to some extent with hypertensive brain damage in humans. SHR present changes of some neurotransmitter systems that may have functional and behavioral relevance. An impaired cholinergic neurotransmission characterizes SHR, similarly as reported in patients affected by VaD. SHR are also characterized by a dopaminergic hypofunction and noradrenergic hyperactivity similarly as occurs in attention-deficit with hyperactivity disorder (ADHD). Microanatomical, neurochemical and behavioral data on SHR are in favor of the hypothesis that this strain is a suitable model of VBD. Changes in catecholaminergic transmission put forward SHR as a possible model of ADHD as well. Hence SHR could represent a multi-faced model of two important groups of pathologies, VBD and ADHD. As for most models, researchers should always consider that SHR offer some similarities with corresponding human pathologies, but they do not suffer from the same disease. This paper reviews the main microanatomical, neurochemical and behavioral characteristics of SHR with particular reference as an animal model of brain vascular injury.
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Affiliation(s)
- Seyed Khosrow Tayebati
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy.
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16
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Meneses A, Perez-Garcia G, Ponce-Lopez T, Tellez R, Gallegos-Cari A, Castillo C. Spontaneously hypertensive rat (SHR) as an animal model for ADHD: a short overview. Rev Neurosci 2011; 22:365-71. [DOI: 10.1515/rns.2011.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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17
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18
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Meneses A, Ponce-Lopez T, Tellez R, Gonzalez R, Castillo C, Gasbarri A. Effects of d-amphetamine on short- and long-term memory in spontaneously hypertensive, Wistar-Kyoto and Sprague-Dawley rats. Behav Brain Res 2010; 216:472-6. [PMID: 20813138 DOI: 10.1016/j.bbr.2010.08.035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 08/15/2010] [Accepted: 08/20/2010] [Indexed: 12/15/2022]
Abstract
Diverse studies indicate that the attention deficit hyperactivity disorder (ADHD) is associated with alterations in encoding processes, including working or short-term memory. Some ADHD dysfunctional domains are reflected in the spontaneously hypertensive rat (SHR). Here SHR-saline group showed significantly poor STM and LTM relative to SD and WKY saline rats. SD and WKY rats treated with d-amphetamine displayed better STM and LTM, compared to SD-vehicle, WKY-vehicle or SHR-d-amphetamine groups.
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Affiliation(s)
- A Meneses
- Department of Pharmacobiology, CINVESTAV, Mexico City, Mexico.
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19
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Seoane A, Massey PV, Keen H, Bashir ZI, Brown MW. L-type voltage-dependent calcium channel antagonists impair perirhinal long-term recognition memory and plasticity processes. J Neurosci 2009; 29:9534-44. [PMID: 19641116 PMCID: PMC6666523 DOI: 10.1523/jneurosci.5199-08.2009] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2008] [Revised: 06/05/2009] [Accepted: 06/08/2009] [Indexed: 01/22/2023] Open
Abstract
The perirhinal cortex of the temporal lobe is essential for the familiarity discrimination component of recognition memory. In view of the importance of changes in calcium ion concentration for synaptic plasticity, the present study examined the effects of L-type voltage-dependent calcium channel (VDCC) antagonism on rat perirhinal-based familiarity discrimination processes and plasticity including long-term depression (LTD), long-term potentiation (LTP), and depotentiation. Single doses of three different types of L-type VDCC antagonists, verapamil, diltiazem, and nifedipine, administered systemically, or verapamil administered locally into the perirhinal cortex, impaired acquisition of long-term (24 h) but not shorter-term (20 min) recognition memory. L-type VDCC antagonism also disrupted memory retrieval after 24 h but not 20 min. Differential neuronal activation produced by viewing novel or familiar visual stimuli was measured by Fos expression. L-type VDCC antagonism by verapamil in perirhinal cortex during memory acquisition disrupted the normal pattern of differential Fos expression, so paralleling the antagonist-induced memory impairment. In slices of perirhinal cortex maintained in vitro, verapamil was without effect on baseline excitability or LTP but blocked LTD and depotentiation. The consistency of effects across the behavioral and cellular levels of analysis provides strong evidence for the involvement of perirhinal L-type VDCCs in long-term recognition memory processes.
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Affiliation(s)
- Ana Seoane
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Peter V. Massey
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Hannah Keen
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Zafar I. Bashir
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Malcolm W. Brown
- Medical Research Council Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, Bristol BS8 1TD, United Kingdom
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Adenosine receptor antagonists improve short-term object-recognition ability of spontaneously hypertensive rats: a rodent model of attention-deficit hyperactivity disorder. Behav Pharmacol 2009; 20:134-45. [DOI: 10.1097/fbp.0b013e32832a80bf] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Klyueva NZ, Antonova OS, Petrova EI. Effect of exogenous calcium deficit on blood pressure and modification of brain proteins GAP-43 and BASP1 in SHR and WKY rats. Bull Exp Biol Med 2008; 145:277-9. [PMID: 19039922 DOI: 10.1007/s10517-008-0069-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We studied the effect of drinking of low mineralized water containing 8 mg/liter Ca2+ on blood pressure and content of brain proteins in synaptosomes of SHR and WKY rats. Blood pressure increased in WKY rats, but not in SHR rats. In SHR rats, Ca2+ deficit reduced the content of GAP-43 protein and induced the appearance of its fragment GAP-43-3 in brain synaptosomes. In WKY rats, the content of this protein did not change, and its fragment GAP-43-3 was absent. No structural changes in BASP1 protein were found.
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Affiliation(s)
- N Z Klyueva
- I. P. Paviov Institute of Physiology, Russian Academy of Sciences
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22
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Ferrari MFR, Reis EM, Matsumoto JPP, Fior-Chadi DR. Gene expression profiling of cultured cells from brainstem of newborn spontaneously hypertensive and Wistar Kyoto rats. Cell Mol Neurobiol 2008; 29:287-308. [PMID: 18949554 DOI: 10.1007/s10571-008-9321-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 09/26/2008] [Indexed: 02/07/2023]
Abstract
The spontaneously hypertensive rat (SHR) is a good model to study several diseases such as the attention-deficit hyperactivity disorder, cardiopulmonary impairment, nephropathy, as well as hypertension, which is a multifactor disease that possibly involves alterations in gene expression in hypertensive relative to normotensive subjects. In this study, we used high-density oligoarrays to compare gene expression profiles in cultured neurons and glia from brainstem of newborn normotensive Wistar Kyoto (WKY) and SHR rats. We found 376 genes differentially expressed between SHR and WKY brainstem cells that preferentially map to 17 metabolic/signaling pathways. Some of the pathways and regulated genes identified herein are obviously related to cardiovascular regulation; in addition there are several genes differentially expressed in SHR not yet associated to hypertension, which may be attributed to other differences between SHR and WKY strains. This constitute a rich resource for the identification and characterization of novel genes associated to phenotypic differences observed in SHR relative to WKY, including hypertension. In conclusion, this study describes for the first time the gene profiling pattern of brainstem cells from SHR and WKY rats, which opens up new possibilities and strategies of investigation and possible therapeutics to hypertension, as well as for the understanding of the brain contribution to phenotypic differences between SHR and WKY rats.
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Affiliation(s)
- Merari F R Ferrari
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, n.321 Cidade Universitária, Sao Paulo, SP, 05508-090, Brazil.
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23
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Loskutova LV, Dubrovina NI, Markel' AL. Comparative analysis of the persistence of a conditioned passive avoidance reflex in rats with different forms of inherited hypertension. ACTA ACUST UNITED AC 2007; 37:577-82. [PMID: 17657428 DOI: 10.1007/s11055-007-0055-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Revised: 11/16/2005] [Indexed: 02/02/2023]
Abstract
The characteristics of anxiety behavior and reproduction of a conditioned passive avoidance reflex acquired in response to a single combination with an unconditioned aversive stimulus were studied in NISAG rats with inherited stress-sensitive arterial hypertension and spontaneously hypertensive SHR rats. SHR rats were characterized by hyperactive behavior, very low levels of anxiety, and poor reproduction of the conditioned reflex as compared with NISAG and control Wistar and WAG rats. Intermediate-anxiety NISAG rats showed no difficulties in acquiring and subsequently retaining the conditioned reflex. These differences in the ability to undergo single-combination learning in rats with different forms of hypertension suggest that memory processes are independent of elevated arterial blood pressure. The effects of the genetic characteristics of behavior and emotional status of these animals on memory are discussed.
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Affiliation(s)
- L V Loskutova
- State Research Institute for Physiology, Siberian Division, Russian Academy of Medical Sciences, 4 Timakov Street, 630117, Novosibirsk, Russia
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Tomassoni D, Avola R, Mignini F, Parnetti L, Amenta F. Effect of treatment with choline alphoscerate on hippocampus microanatomy and glial reaction in spontaneously hypertensive rats. Brain Res 2006; 1120:183-90. [PMID: 16989788 DOI: 10.1016/j.brainres.2006.08.068] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 08/17/2006] [Accepted: 08/18/2006] [Indexed: 10/24/2022]
Abstract
The influence of long term treatment with choline alphoscerate on microanatomy of hippocampus and glial reaction was assessed in spontaneously hypertensive rats (SHR) used as an animal model of cerebrovascular disease. Choline alphoscerate is a cholinergic precursor, which has shown to be effective in countering cognitive symptoms in forms of dementia disorders of degenerative, vascular or combined origin. Male spontaneously hypertensive rats (SHR) aged 6 months and age-matched normotensive Wistar-Kyoto (WKY) rats were treated for 8 weeks with an oral daily dose of 100 mg/kg of choline alphoscerate, 285 mg/kg of phosphatidylcholine (lecithin) or vehicle. On the hippocampus of different animal groups, nerve cell number and GFAP-immunoreactive astrocytes were assessed by neuroanatomical, immunochemical and immunohistochemical techniques associated with quantitative analysis. Treatment with choline alphoscerate countered nerve cell loss and glial reaction primarily in the CA1 subfields and in the dentate gyrus of the hippocampus of SHR. Phosphatidylcholine did not affect hypertension-dependent changes in hippocampal microanatomy. Both compounds did not affect blood pressure values in SHR. These data suggest that choline alphoscerate may play a role in the countering hippocampal changes induced by cerebrovascular involvement. The observation that treatment with choline alphoscerate attenuates the extent of glial reaction in the hippocampus of SHR suggests also that the compound may afford neuroprotection in this animal model of vascular brain damage.
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Affiliation(s)
- Daniele Tomassoni
- Sezione di Anatomia Umana, Dipartimento di Medicina Sperimentale e Sanità Pubblica,Università di Camerino, Camerino, Italy
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25
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Tayebati SK. Animal models of cognitive dysfunction. Mech Ageing Dev 2006; 127:100-8. [PMID: 16293295 DOI: 10.1016/j.mad.2005.09.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Revised: 02/04/2005] [Accepted: 09/15/2005] [Indexed: 10/25/2022]
Abstract
The increased life expectancy in industrialised countries in the last half century has also brought to a greater incidence of neurological disorders, including neurodegenerative diseases and developing in a rather long time. In this respect, Alzheimer's disease (AD), for the large incidence, and the dramatic loss of autonomy caused by its cognitive and behavioural symptoms represents one of the main challenges of modern medicine. Although AD is a typical human disease and probably includes several nosographic entities, the use of animal models may contribute to understand specific aspects of pathophysiology of the disease. The most widely used animal models are rodents and non-human primates. In this review different animal models characterised by impaired cognitive functions are analysed. None of the models available mimics exactly cognitive, behavioural, biochemical and histopathological abnormalities observed in neurological disorders characterised by cognitive impairment. However, partial reproduction of neuropathology and/or cognitive deficits of Alzheimer's disease (AD), vascular dementia and dementia occurring in Huntington's and Parkinson's diseases, or in other neurodegenerative disorders may represent a basis for understanding pathophysiological traits of these diseases and for contributing to their treatments.
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Affiliation(s)
- Seyed Khosrow Tayebati
- Anatomia Umana, Dipartimento di Medicina Sperimentale e Sanità Pubblica Università di Camerino, 62032 Camerino, Italy.
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26
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Prediger RDS, Fernandes D, Takahashi RN. Blockade of adenosine A2A receptors reverses short-term social memory impairments in spontaneously hypertensive rats. Behav Brain Res 2005; 159:197-205. [PMID: 15817183 DOI: 10.1016/j.bbr.2004.10.017] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Revised: 10/25/2004] [Accepted: 10/28/2004] [Indexed: 11/27/2022]
Abstract
Spontaneously hypertensive rats (SHR) exhibit impairment across several cognitive domains such as attention, short-term memory and spatial reference memory. These cognitive deficits have been variously attributed to disrupted dopaminergic, cholinergic and adenosinergic neurotransmitter function. However, social memory in SHR has not been investigated. In the present study, we therefore evaluated whether SHR exhibit altered short-term social memory abilities compared to normotensive Wistar rats (WIS) through two experimental paradigms (social recognition and habituation-dishabituation tests). We also compared the performance of SHR and WIS rats in the object recognition test. SHR exhibited significantly impaired performance in both models of social memory, but not in the object recognition test, demonstrating a selective deficit in the ability to recognize a juvenile rat after a short period of time. The administration of acute doses of the non-selective adenosine receptor antagonist caffeine (3.0 or 10.0 mg/kg, i.p.) and the adenosine A2A receptor antagonist 4-(2-[7-amino-2-[2-furyl][1,2,4]triazolo-[2,3-a][1,3,5]triazin-5-yl-amino]ethyl) phenol (ZM241385, 0.5 or 1.0 mg/kg, i.p.) but not the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX, 1.0 or 3.0 mg/kg, i.p.) reversed this social memory impairment in SHR, but these treatments did not alter the hypertension state. These results demonstrate an impairment of short-term social memory in SHR and the involvement of the adenosine A2A receptors in this alteration.
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Affiliation(s)
- Rui D S Prediger
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, UFSC, Campus Trindade, 88049-900 Florianópolis, SC, Brazil
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Meneses A, Manuel-Apolinar L, Rocha L, Castillo E, Castillo C. Expression of the 5-HT receptors in rat brain during memory consolidation. Behav Brain Res 2004; 152:425-36. [PMID: 15196811 DOI: 10.1016/j.bbr.2003.10.037] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 10/18/2003] [Accepted: 10/21/2003] [Indexed: 11/17/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) system displays more than 14 receptors subtypes on brain areas involved in learning and memory processes, and pharmacological manipulation of specific receptors selectively affects memory formation. In order to begin the search of 5-HT receptors expression during memory formation, in this work, we aimed to determine, by autoradiography (using 3H 5-HT as ligand, 2 nM, specific activity 123 Ci/mmol), 5-HT receptors (5-HTR) expression in passive (untrained) and autoshaping trained (3 sessions) adult (3 months) and old (9 months) male rats. Thus, trained adult rats had better retention than old animals. Raphe nuclei of adult and old trained rats expressed less receptors on medial and dorsal, respectively. Hippocampal CA1 area and dentate gyrus of adult trained rats expressed less 5-HTR, while dentate gyrus of old increased them. Basomedial amygdaloid nucleus in old trained rats expressed more 5-HTR; while in the basolateral amygdaloid nucleus they were augmented in both groups. Training decreased or did not change 5-HTR in caudate-putamen of adult or old animals. The above profile of 5-HTR expression is consistent with previous reports, and suggests that memory formation and aging modulates 5-HTR expression in brain areas relevant to memory systems.
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Affiliation(s)
- A Meneses
- Departamento de Farmacobiología, CINVESTAV-IPN, Tenorios 235, Granjas Coapa, Mexico City 14330, Mexico.
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Mignini F, Vitaioli L, Sabbatini M, Tomassoni D, Amenta F. The cerebral cortex of spontaneously hypertensive rats: a quantitative microanatomical study. Clin Exp Hypertens 2004; 26:287-303. [PMID: 15195685 DOI: 10.1081/ceh-120034135] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The morphology of cerebral cortex was investigated in male spontaneously hypertensive rats (SHR) aged 2, 4 and 6 months (pre-hypertensive, developing hypertension and established hypertension respectively) and in age-matched normotensive Wistar-Kyoto (WKY) rats using quantitative microanatomical techniques. Analysis included frontal and occipital cortex as a paradigm of motor and sensory cerebrocortical areas respectively. Values of systolic pressure were slightly higher in 2-month-old SHR compared to age-matched WKY rats and augmented progressively with increasing age in SHR. In frontal cortex of SHR a decrease of nerve cell number and of cortical volume was observed in layers V and VI of 4- and 6- month-old SHR, and in layers I-IV of 6- month-old SHR. In occipital cortex a decrease of the number of nerve cells and of cortical volume was observed in layers V and VI of 2-, 4-, 6- month-old SHR, and in layers I-IV of 6-month-old SHR. Numerical decrease of neurons in SHR affected to a greater extent occipital cortex than frontal cortex. An increase in the number of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes (hyperplasia) as well as in the mean immune reaction area (hypertrophy) was found in the two cerebrocortical areas investigated of 6-month-old SHR. The occurrence of apoptosis and/or necrosis identified using the terminal deoxyribo-nucleotidyl transferase (TdT)-mediated biotin-16-dUTP nick-end labeling (TUNEL) technique was also observed in frontal and occipital cortex of 6-month-old SHR, but not of younger cohorts. These findings indicate the development of microanatomical changes in the cerebral cortex of SHR, the extent of which increases parallel with the progression of hypertension. The occurrence of cerebrocortical apoptosis and/or necrosis as well as the obvious astrogliosis occurring in established hypertension may account for the increased risk of vascular dementia that represents a specific trait of complicated hypertension.
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Affiliation(s)
- Fiorenzo Mignini
- Sezione di Anatomia Umana, Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Camerino, Italy
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Meneses A. A pharmacological analysis of an associative learning task: 5-HT(1) to 5-HT(7) receptor subtypes function on a pavlovian/instrumental autoshaped memory. Learn Mem 2003; 10:363-72. [PMID: 14557609 PMCID: PMC218002 DOI: 10.1101/lm.60503] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Recent studies using both invertebrates and mammals have revealed that endogenous serotonin (5-hydroxytryptamine [5-HT]) modulates plasticity processes, including learning and memory. However, little is currently known about the mechanisms, loci, or time window of the actions of 5-HT. The aim of this review is to discuss some recent results on the effects of systemic administration of selective agonists and antagonists of 5-HT on associative learning in a Pavlovian/instrumental autoshaping (P/I-A) task in rats. The results indicate that pharmacological manipulation of 5-HT1-7 receptors or 5-HT reuptake sites might modulate memory consolidation, which is consistent with the emerging notion that 5-HT plays a key role in memory formation.
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Affiliation(s)
- Alfredo Meneses
- Depto De Farmacobiología, CINVESTAV-IPN, México City 14330, México.
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30
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De Bruin NMWJ, Kiliaan AJ, De Wilde MC, Broersen LM. Combined uridine and choline administration improves cognitive deficits in spontaneously hypertensive rats. Neurobiol Learn Mem 2003; 80:63-79. [PMID: 12737935 DOI: 10.1016/s1074-7427(03)00024-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rationale. Hypertension is considered a risk factor for the development of cognitive disorders, because of its negative effects on cerebral vasculature and blood flow. Genetically induced hypertension in rats has been associated with a range of cognitive impairments. Therefore, spontaneously hypertensive rats (SHR) can potentially be used as a model for cognitive deficits in human subjects. Consecutively, it can be determined whether certain food components can improve cognition in these rats. Objective. The present study aimed to determine whether SHR display specific deficits in attention, learning, and memory function. Additionally, effects of chronic uridine and choline administration were studied. Methods. 5-7 months old SHR were compared with normotensive Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. (a) The operant delayed non-matching-to-position (DNMTP) test was used to study short-term memory function. (b) The five-choice serial reaction time (5-CSRT) task was used to assess selective visual attention processes. (c) Finally, the Morris water maze (MWM) acquisition was used as a measure for spatial learning and mnemonic capabilities. Results. (1) SHR exhibited significantly impaired performance in the 5-CSRT test in comparison with the two other rat strains. Both the SHR and WKY showed deficits in spatial learning when compared with the SD rats. (2) Uridine and choline supplementation normalized performance of SHR in the 5-CSRT test. (3) In addition, uridine and choline treatment improved MWM acquisition in both WKY and SHR rats. Conclusion. The present results show that the SHR have a deficiency in visual selective attention and spatial learning. Therefore, the SHR may provide an interesting model in the screening of substances with therapeutic potential for treatment of cognitive disorders. A combination of uridine and choline administration improved selective attention and spatial learning in SHR.
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Affiliation(s)
- N M W J De Bruin
- Numico Research B.V., Department of Condition and Disease Specific Research/Neuroendocrinology section, Bosrandweg 20, 6704 PH Wageningen, PO Box 7005, 6700 CA Wageningen, The Netherlands.
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Meneses A. Tianeptine: 5-HT uptake sites and 5-HT(1-7) receptors modulate memory formation in an autoshaping Pavlovian/instrumental task. Neurosci Biobehav Rev 2002; 26:309-19. [PMID: 12034133 DOI: 10.1016/s0149-7634(02)00005-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent studies using invertebrate and mammal species have revealed that, endogenous serotonin (5-hydroxytryptamine, 5-HT) modulates cognitive processes, particularly learning and memory, though, at present, it is unclear the manner, where, and how long 5-HT systems are involved. Hence in this work, an attempt was made to study the effects of 5-HT endogenous on memory formation, using a 5-HT uptake facilitator (tianeptine) and, selective 5-HT(1-7) receptor antagonists to determine whether 5-HT uptake sites and which 5-HT receptors are involved, respectively. Results showed that post-training tianeptine injection enhanced memory consolidation in an autoshaping Pavlovian/instrumental learning task, which has been useful to detect changes on memory formation elicited by drugs or aging. On interaction experiments, ketanserin (5-HT(1D/2A/2C) antagonist) slightly enhanced tianeptine effects, while WAY 100635 (5-HT(1A) antagonist), SB-224289 (5-HT(1B) inverse agonist), SB-200646 (5-HT(2B/2C) antagonist), ondansetron (5-HT(3) antagonist), GR 127487 (5-HT(4) antagonist), Ro 04-6790 (5-HT(6) antagonist), DR 4004 (5-HT(7) antagonist), or fluoxetine (an inhibitor of 5-HT reuptake) blocked the facilitatory tianeptine effect. Notably, together tianeptine and Ro 04-6790 impaired learning consolidation. Moreover, 5-HT depletion completely reversed the tianeptine effect. Tianeptine also normalized an impaired memory elicited by scopolamine (an antimuscarinic) or dizocilpine (non-competitive glutamatergic antagonist), while partially reversed that induced by TFMPP (5-HT(1B/1D/2A-2C/7) agonist/antagonist). Finally, tianeptine-fluoxetine coadministration had no effect on learning consolidation; nevertheless, administration of an acetylcholinesterase inhibitor, phenserine, potentiated subeffective tianeptine or fluoxetine doses. Collectively, these data confirmed that endogenously 5-HT modulates, via uptake sites and 5-HT(1-7) receptors, memory consolidation, and are consistent with the emerging notion that 5-HT plays a key role on memory formation.
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Affiliation(s)
- Alfredo Meneses
- Departamento de Farmacobiología, CINVESTAV-IPN, Apdo Postal 22026, Mexico City 14000, Mexico.
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Thifault S, Lalonde R, Sanon N, Hamet P. Longitudinal analysis of motor activity and coordination, anxiety, and spatial learning in mice with altered blood pressure. Brain Res 2001; 910:99-105. [PMID: 11489259 DOI: 10.1016/s0006-8993(01)02658-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mice with either high or low blood pressure (BP) were compared to normotensive controls at 2 and 12 months of age for motor activity, equilibrium, anxiety, and spatial learning. Irrespective of age, high BP mice were more active in an open field than normotensive controls, whereas low BP mice were hypoactive at 2 months of age. High BP mice had a higher number of entries and a longer duration of visits in the open arms, a higher open arm/total arm ratio, a longer duration for the first visit into an open arm, and lower latencies before entering the first open arm than controls in the elevated +-maze, indicative of reduced anxiety. Reduced levels of anxiety were also displayed by low BP mice for the duration of the first open arm visit (both age groups) and for the time spent in the open arms (older group). In the motor coordination test (coat-hanger), high BP mice had higher two-paw movement time and reached the top of the apparatus on fewer occasions than controls. Both groups with abnormal BP values were deficient during visuomotor guidance in the water maze. These results indicate strain-, age-, and test-specific abnormalities in mice with uncontrolled hypertension or hypotension.
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Affiliation(s)
- S Thifault
- Centre hospitalier de l'Université de Montréal, CHUM Hôtel-Dieu, Centre de recherche, Laboratoire de pathophysiologie moléculaire de l'hypertension, 3840 rue St-Urbain, Québec, H2W 1T8, Montréal, Canada
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Kadish I, van Groen T, Wyss JM. Chronic, severe hypertension does not impair spatial learning and memory in Sprague-Dawley rats. Learn Mem 2001; 8:104-11. [PMID: 11274256 PMCID: PMC311361 DOI: 10.1101/lm.37301] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study tested the hypothesis that long-term hypertension impairs spatial learning and memory in rats. In 6-wk-old Sprague-Dawley rats, chronic hypertension was induced by placing one of three sizes of stainless steel clips around the descending aorta (above the renal artery), resulting in a 20-80-mm Hg increase of arterial pressure in all arteries above the clip, that is, the upper trunk and head. Ten months later, the rats were tested for 5 d in a repeated-acquisition water maze task, and on the fifth day, they were tested in a probe trial; that is, there was no escape platform present. At the end of the testing period, the nonsurgical and sham control groups had similar final escape latencies (16 +/- 4 sec and 23 +/- 9 sec, respectively) that were not significantly different from those of the three hypertensive groups. Rats with mild hypertension (140-160 mm Hg) had a final escape latency of 25 +/- 6 sec, whereas severely hypertensive rats (170-199 mm Hg) had a final escape latency of 21 +/- 7 sec and extremely hypertensive rats (>200 Hg) had a final escape latency of 19 +/- 5 sec. All five groups also displayed a similar preference for the correct quadrant in the probe trial. Together, these data suggest that sustained, severe hypertension for over 10 mo is not sufficient to impair spatial learning and memory deficits in otherwise normal rats.
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Affiliation(s)
- I Kadish
- Department of Neuroscience and Neurology, University of Kuopio, FIN 70211 Kuopio, Finland
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Abstract
Diverse evidence indicates that, the 5-HT system might play a role in learning and memory, since it occurs in brain areas mediating such processes and 5-HT drugs modulate them. Hence in this work, in order to explore further 5-HT involvement on learning and memory 5-HT1B receptors' role is investigated. Evidence indicates that SB-224289 (a 5-HT1B receptor inverse agonist) post-training injection facilitated learning consolidation in an associative autoshaping learning task, this effect was partially reversed by GR 127935 (a 5-HT1B/1D receptor antagonist), but unaffected by MDL 100907 (a 5-HT2A receptor antagonist) or ketanserin (a 5-HT1D/2A/7 receptor antagonist) at low doses. Moreover, SB-224289 antagonized the learning deficit produced by TFMPP (a 5-HT1A/1B/1D/2A/2C receptor agonist), GR 46611 (a 5-HT1A/1B/1D receptor agonist), mCPP (a 5-HT2A/2C/3/7 receptor agonist/antagonist) or GR 127935 (at low dose). SB-224289 did not alter the 8-OH-DPAT (a 5-HT1A/7 receptor agonist) learning facilitatory effect. SB-224289 eliminated the deficit learning produced by the anticholinergic muscarinic scopolamine or the glutamatergic antagonist dizocilpine. Administration of both, GR 127935 (5mg/kg) plus ketanserin (0.01 mg/kg) did not modify learning consolidation; nevertheless, when ketanserin dose was increased (0.1-1.0mg/kg) and SB-224289 dose was maintained constant, a learning facilitation effect was observed. Notably, SB-224289 at 1.0mg/kg potentiated a subeffective dose of the 5-HT1B/1D receptor agonist/antagonist mixed GR 127935, which facilitated learning consolidation and this effect was abolished by ketanserin at a higher dose. Collectively, the data confirm and extend the earlier findings with GR 127935 and the effects of non-selective 5-HT(1B) receptor agonists. Clearly 5-HT1B agonists induced a learning deficit which can be reversed with SB-224289. Perhaps more importantly, SB-224289 enhances learning consolidation when given alone and can reverse the deficits induced by both cholinergic and glutamatergic antagonist. Hence, 5-HT1B receptor inverse agonists or antagonists could represent drugs for the treatment of learning and memory dysfunctions.
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Affiliation(s)
- A Meneses
- Depto. de Farmacobiología, CINVESTAV-IPN., AP 22026 14000, Mexico City,
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Abstract
The 5-HT(6) receptor antagonist Ro-04-6790 or 8-OH-DPAT injection improved learning consolidation on an autoshaping task, while mCPP, scopolamine and dizocilpine decreased the performance. The effect induced by scopolamine, but not that induced by mCPP, was reversed completely by Ro-04-6790, while dizocilpine effect was antagonized partially. Nevertheless, ritanserin or WAY 100635, but not Ro 04-6790, antagonized the 8-OH-DPAT facilitatory effects on learning consolidation. As WAY 100635 did not modify the Ro 04-6790 facilitatory effect, hence 5-HT(1A), and/or 5-HT(7), but not 5-HT(6), receptors might mediate the 8-OH-DPAT facilitatory effect on learning consolidation. Since, the Ro 04-6790 facilitatory effect was unaffected by 5-HT(1A), 5-HT(2A)/(2B)/(2C), 5-HT(3) or 5-HT(4) receptor blockade, thereby, the facilitatory effect induced by Ro 04-6790 involved specifically 5-HT(6) receptors. Indeed, the present data provide further support to the notion that, 5-HT(6) receptors play a significant part in the learning consolidation under normal and dysfunctional memory conditions.
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Affiliation(s)
- A Meneses
- Depto. de Farmacología y Toxicologia, Terapeutica Experimental, CINVESTAV-IPN, AP 22026, 14000, DF, Mexico City, Mexico.
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Abstract
The study of 5-hydroxytryptamine (5-HT) system has benefited from the identification, classification and cloning of multiple 5-HT receptors (5-HT1 to 5-HT7). Growing evidence suggests that 5-HT is important in learning and memory and all its receptors might be implicated in this. Actually, 5-HT pathways, 5-HT reuptake site/transporter complex and 5-HT receptors show regional distribution in brain areas implicated in learning and memory. Likewise, the stimulation or blockade of presynaptic 5-HT1A, 5-HT1B, 5-HT(2A/2C) and 5-HT3 receptors, postsynaptic 5-HT(2B/2C) and 5-HT4 receptors and 5-HT uptake/transporter sites modulate these processes. Available evidence strongly suggests that the 5-HT system may be important in normal function, the treatment and/or pathogenesis of cognitive disorders. Further investigation will help to specify the 5-HT system nature involvement in cognitive processes, pharmacotherapies, their mechanisms and action sites and to determine under which conditions they could operate. In this regard, it is probable that selective drugs with agonists, neutral antagonist, agonists or inverse agonist properties for 5-HT1A, 5-HT(1B/1D), 5-HT(2A/2B/2C), 5-HT4 and 5-HT7 receptors could constitute a new therapeutic opportunity for learning and memory alterations.
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Affiliation(s)
- A Meneses
- Departamento de Farmacología y Toxicología, CINVESTAV-IPN, México D.F., Mexico.
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