title: Long-term alcohol exposure elicits hippocampal nonsynaptic epileptiform activity changes associated with expression and functional changes in NKCC1, KCC2 co-transporters and Na+/K+-ATPase.
abstract: Nonsynaptic mechanism changes, particularly the enhancement of NKCC1 expression in the dentate gyrus (DG) after 4weeks of ethanol consumption, motivate the present work, in which rats were submitted to a period of chronic consumption (12weeks). Four groups of six animals (6-week-old male Wistar rats) were formed, including the control (C), ethanol 1 (E1), ethanol 2 (E2) and ethanol 3 (E3) groups. The rats in the E1, E2 and E3 groups were treated daily with a 30% v/v solution of ethanol, administered via oral gavage (1.0, 2.0 and 3.0g/kg, respectively). Nonsynaptic epileptiform activities (NEA) were induced by means of the zero-Ca2+and high-K+model using hippocampal slices and were recorded in the DG. The presence of NKCC1, KCC2, α1-Na+/K+-ATPase and GFAP immunoreactivity was analyzed. The results demonstrate that alcohol consumption changes NEA, and these changes are more prominent at the lower dosage. An increase in the DC shifts associated with epileptiform discharges was present with the low dose. This increase was correlated with the increment of NKCC1 expression. Confocal microscopy images indicate the NKCC1 increase was pronounced in the initial axonal segment of granule cells. The blockage of these cotransporters during NEA induction with bumetanide suppressed the DC shift increase and diminished all parameters of NEA that were quantified for all groups treated with ethanol. Therefore, the increase in NKCC1 expression and the effective activity of this cotransporter, which were observed in the treated groups, suggest that drugs that act for block NKCC1 represent promising strategies for diminishing the effects of alcohol damage on the brain.
authors.affiliation: Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, UFSJ, Brazil.
authors.forename: Luiz E C
authors.initials: LEC
authors.lastname: Santos
authors.affiliation: Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, UFSJ, Brazil.
authors.forename: Antônio M
authors.initials: AM
authors.lastname: Rodrigues
authors.affiliation: Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, UFSJ, Brazil.
authors.forename: Mariana R
authors.initials: MR
authors.lastname: Lopes
authors.affiliation: Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, UFSJ, Brazil.
authors.forename: Victor D C
authors.initials: VDC
authors.lastname: Costa
authors.affiliation: Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Unifesp, Brazil.
authors.forename: Carla A
authors.initials: CA
authors.lastname: Scorza
authors.affiliation: Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Unifesp, Brazil.
authors.forename: Fulvio A
authors.initials: FA
authors.lastname: Scorza
authors.affiliation: Disciplina de Neurologia Experimental, Escola Paulista de Medicina, Unifesp, Brazil.
authors.forename: Esper A
authors.initials: EA
authors.lastname: Cavalheiro
authors.affiliation: Laboratório de Neurociência Experimental e Computacional, Departamento de Engenharia de Biossistemas, UFSJ, Brazil. Electronic address: acga@ufsj.edu.br.
authors.forename: Antônio-Carlos G
authors.initials: AG
authors.lastname: Almeida
mesh_terms: D019973:Alcohol-Related Disorders / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D002034:Bumetanide / Q000494:pharmacology; D002492:Central Nervous System Depressants / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D004827:Epilepsy / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D000431:Ethanol / Q000633:toxicity; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D019636:Neurodegenerative Diseases / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D064506:Solute Carrier Family 12, Member 2 / Q000378:metabolism*; D027981:Symporters / Q000378:metabolism*; D046509:Tissue Culture Techniques; D000096922:K Cl- Cotransporters
chemical_list: D002034:Bumetanide; D002492:Central Nervous System Depressants; D000431:Ethanol; D011963:Receptors, GABA-A; D049994:Sodium Potassium Chloride Symporter Inhibitors; D000254:Sodium-Potassium-Exchanging ATPase; D064506:Solute Carrier Family 12, Member 2; D027981:Symporters; D000096922:K Cl- Cotransporters; C578879:Slc12a2 protein, rat
keywords: dentate gyrus; electrophysiology; epilepsy; ethanol; immunohistochemistry