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Benevides RDDL, de-Lima SMV, Chagas CL, de Lima CF, Abadie-Guedes R, Guedes RCA. Lactation in large litters influences anxiety, memory, and spreading depression in adult male rats that were chronically subjected to a non-convulsive pilocarpine dose. Nutr Neurosci 2020; 25:846-856. [PMID: 32912080 DOI: 10.1080/1028415x.2020.1819103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Objectives: Unfavorable lactation influences brain excitability and behavioral reactions in adults. Administration early in life of the cholinergic agonist, pilocarpine, even at non-convulsive doses, alters the brain excitability-related phenomenon known as cortical spreading depression (CSD), and produce anxiogenic-like behavior. However, the influence of unfavorable lactation on the CSD- and memory-effects of pilocarpine administration late in life has not been investigated. Herein, we analyzed the ponderal, electrophysiological (CSD), and behavioral effects of chronic treatment with a non-convulsive dose of pilocarpine, in adult rats suckled under favorable and unfavorable conditions.Methods: Wistar rats were suckled in litters with 9 or 15 pups (groups L9 and L15, respectively). A very low dose of pilocarpine (45/mg/kg/day) was chronically administered in mature rats from postnatal day (PND) 69-90. Behavioral tests occurred at PND91 [elevated plus maze (EPM)], PND93 [open field (OF)], and PND94-95 [object recognition memory (ORM)]. CSD was recorded between PND96-120.Results: Pilocarpine-treated rats performed worse in the anxiety and memory tests, and displayed lower CSD propagation velocity when compared with saline-treated controls. In addition, L15 rats showed an increase in the distance traveled and a decrease in the immobility time in the EPM, impaired ORM, and accelerated CSD propagation when compared with L9 rats (p ≤ 0.05).Discussion: These data suggest that sub-convulsive pilocarpine treatment in adult rats can affect behavioral and excitability-related reactions. In addition, unfavorable lactation increases the ambulatory effects of pilocarpine. Further studies should investigate the possible cholinergic molecular mechanisms involved in these effects.
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Affiliation(s)
| | | | - Camila Lima Chagas
- Department of Nutrition, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Clara Farah de Lima
- Department of Nutrition, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Ricardo Abadie-Guedes
- Department of Physiology and Pharmacology, Universidade Federal de Pernambuco, Recife, PE, Brazil
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Liening AN, Epps SA. In Up to My Ears and Temporal Lobes: Effects of Early Life Stress on Epilepsy Development. Curr Top Behav Neurosci 2020; 55:17-40. [PMID: 33454921 DOI: 10.1007/7854_2020_190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Epilepsy and stress are each significant concerns in today's society, bearing heavy impacts on mental and physical health and overall quality of life. Unfortunately, the intersection between these is potentially even more concerning, as stress is a frequent trigger of seizures and may contribute to neural hyperexcitability. A growing body of research suggests a connection between early life stress (occurring in the prenatal or postnatal stage) and later development of epilepsy. While the larger part of this literature suggests that early life stress increases vulnerability for epilepsy development, there are a number of interacting factors influencing this relationship. These factors include developmental stage at which both stressor and seizure assessment occur, type of stressor, sex effects, and type of seizure (convulsive or non-convulsive). Additionally, a number of potential mechanisms have been identified, including activation of the hypothalamic-pituitary-adrenal axis, neuroinflammation, altered inhibitory/excitatory balance, and temporal lobe structures. Developing a clearer understanding of this relationship between early life stress and epilepsy, the factors that influence it, and underlying mechanisms that may serve as targets for intervention is crucial to improving quality of life for persons with epilepsy.
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Affiliation(s)
- Avery N Liening
- Department of Psychology, Whitworth University, Spokane, WA, USA
| | - S Alisha Epps
- Department of Psychology, Whitworth University, Spokane, WA, USA.
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Francisco EDS, Guedes RCA. Sub-Convulsing Dose Administration of Pilocarpine Reduces Glycemia, Increases Anxiety-Like Behavior and Decelerates Cortical Spreading Depression in Rats Suckled on Various Litter Sizes. Front Neurosci 2018; 12:897. [PMID: 30559645 PMCID: PMC6287009 DOI: 10.3389/fnins.2018.00897] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 11/16/2018] [Indexed: 12/22/2022] Open
Abstract
Epilepsy and malnutrition constitute two worldwide health problems affecting behavior and brain function. The cholinergic agonist pilocarpine (300-380 mg/kg; single administration) reproduces the human type of temporal lobe epilepsy in rats. Pilocarpine-induced epilepsy in rodents has been associated with glycemia, learning and memory and anxiety disturbances. Cortical spreading depression (CSD) is a neural response that has been linked to brain excitability disorders and its diseases, and has been shown to be antagonized by acute pilocarpine. This study aimed to further investigate the effect of chronic pilocarpine at a sub-convulsing dose on weight gain, blood glucose levels, anxiety-like behavior and CSD. In addition, we tested whether unfavorable lactation-induced malnutrition could modulate the pilocarpine effects. Wistar rats were suckled under normal size and large size litters (litters with 9 and 15 pups; groups L9 and L15, respectively). From postnatal days (PND) 35-55, these young animals received a daily intraperitoneal injection of pilocarpine (45 mg/kg/day), or vehicle (saline), or no treatment (naïve). On PND58, the animals were behaviorally tested in an open field apparatus. This was immediately followed by 6 h fasting and blood glucose measurement. At PND60-65, CSD was recorded, and its parameters (velocity of propagation, amplitude, and duration) were calculated. Compared to the control groups, pilocarpine-treated animals presented with reduced weight gain and lower glycemia, increased anxiety-like behavior and decelerated CSD propagation. CSD velocity was higher (p < 0.001) in the L15 groups in comparison to the corresponding groups in the L9 condition. The results demonstrate an influence of chronic (21-day) administration of a sub-convulsing, very low dose (45 mg/kg) of pilocarpine on CSD propagation, anxiety-like behavior, glycemia and body weight. Furthermore, data reinforce the hypothesis of a relationship between CSD and brain excitability. The lactation condition seems to differentially modulate these effects.
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Mendes-da-Silva RF, Francisco EDS, Araújo Guedes RC. Pilocarpine/ascorbic acid interaction in the immature brain: Electrophysiological and oxidative effects in well-nourished and malnourished rats. Brain Res Bull 2018; 142:414-421. [PMID: 30232044 DOI: 10.1016/j.brainresbull.2018.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/24/2018] [Accepted: 09/11/2018] [Indexed: 01/29/2023]
Abstract
Ascorbic acid (AA) administration has been associated with neuroprotection against oxidative stress, although at high doses it can facilitate oxidation and acts like a proconvulsing drug. The pilocarpine-induced epilepsy model has been widely studied. However, less is known about the effects of sub-convulsive doses of pilocarpine on brain activity in immature animals under normal or deficient nutritional conditions. Herein, we investigated the effects of chronic pilocarpine administration in a sub-convulsive dose, with or without AA, on the excitability-related phenomenon denominated as cortical spreading depression (CSD) and levels of lipid peroxidation-induced malondialdehyde in well-nourished and malnourished rats. At postnatal days 7-28, rats received no gavage treatment (naïve group), saline (vehicle group), 45 mg/kg/d of pilocarpine and/or 120 mg/kg/d of AA. CSD propagation and malondialdehyde levels were analyzed at 34-40 days. The pilocarpine group presented with lower CSD velocities, while AA groups exhibited higher CSD velocities and augmented malondialdehyde levels compared with controls. The co-administration of AA partially antagonized the pilocarpine CSD effects, but did not revert it to control levels. Malnutrition increased CSD amplitude and velocity in comparison to the well-nourished condition. The electrocorticogram (ECoG) amplitude increased after CSD (ECoG potentiation) when compared with the baseline amplitude before CSD. However, no intergroup difference was observed in this CSD-related ECoG potentiation. The results support the hypothesis of a pilocarpine/ascorbic acid interaction in the immature rat brain and might help further the understanding of this interaction on neuronal electrical activity and oxidative stress.
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Medeiros LDB, Vitor-de-Lima SM, Lira Benevides RDD, do Egypto Queiroga RDCR, Araújo Guedes RC. Neonatal administration of goat whey modulates memory and cortical spreading depression in rats previously suckled under different litter sizes: Possible role of sialic acid. Nutr Neurosci 2016; 21:108-115. [DOI: 10.1080/1028415x.2016.1227762] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Koe AS, Salzberg MR, Morris MJ, O'Brien TJ, Jones NC. Early life maternal separation stress augmentation of limbic epileptogenesis: the role of corticosterone and HPA axis programming. Psychoneuroendocrinology 2014; 42:124-33. [PMID: 24636509 DOI: 10.1016/j.psyneuen.2014.01.009] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 10/25/2022]
Abstract
Early life stress causes long-lasting effects on the limbic system that may be relevant to the development of mesial temporal lobe epilepsy (MTLE) and its associated psychopathology. Recent studies in rats suggest that maternal separation (MS), a model of early life stress, confers enduring vulnerability to amygdala kindling limbic epileptogenesis. However, the mechanisms underlying this remain unknown. Here, we tested whether hypothalamic-pituitary-adrenal (HPA) axis hyper-reactivity induced by MS - specifically the excessive secretion of corticosterone following a seizure - was involved in this vulnerability. In adult female rats subjected to MS from postnatal days 2-14, seizure-induced corticosterone responses were significantly augmented and prolonged for at least two hours post-seizure, compared to control early-handled (EH) rats. This was accompanied by reduced seizure threshold (p<0.05) and increased vulnerability to the kindling-induced progression of seizure duration (p<0.05) in MS rats. Pre-seizure treatment with the corticosterone synthesis inhibitor, metyrapone (MET) (50mg/kgsc) effectively blocked seizure-induced corticosterone responses. When delivered throughout kindling, MET treatment also reversed the MS-induced reduction in seizure threshold and the lengthened seizure duration back to levels of EH rats. These observations suggest that adverse early life environments induce a vulnerability to kindling epileptogenesis mediated by HPA axis hyper-reactivity, which could have relevance for the pathogenesis of MTLE.
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Affiliation(s)
- Amelia S Koe
- Department of Medicine, Royal Melbourne Hospital, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Michael R Salzberg
- St Vincent's Mental Health Service, St Vincent's Hospital, Fitzroy, VIC, Australia; Department of Psychiatry, St Vincent's Hospital, University of Melbourne, Fitzroy, VIC, Australia
| | - Margaret J Morris
- Department of Pharmacology, University of New South Wales, Sydney, NSW, Australia
| | - Terence J O'Brien
- Department of Medicine, Royal Melbourne Hospital, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia; Department of Neurology, University of Melbourne, Parkville, VIC, Australia
| | - Nigel C Jones
- Department of Medicine, Royal Melbourne Hospital, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia.
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