GABA UPTAKE BY GAT1 MODULATES LONG-TERM OPTICAL CHANGES FOLLOWING ELECTRICAL STIMULATION OF THE PITUITARY GLAND NEUROINTERMEDIATE LOBE  

作　　者：P.KOSTERIN A.L.OBAID B.M.SALZBERG 

机构地区：[1]Department of Neuroscience Perelman School of Medicine University of Pennsylvania Philadelphia,PA 19104 [2]Department of Physiology Perelman School of Medicine University of Pennsylvania Philadelphia,PA 19104

出　　处：《Journal of Innovative Optical Health Sciences》2013年第3期46-57,共12页创新光学健康科学杂志（英文）

摘　　要：Intrinsic optical changes that follow infundibular stalk stimulation of the neurointermediate lobe of the mouse pituitary gland exhibit three different phases that reflect three distinct physiological events.The first(E-wave)is the rapid light-scattering increase that is associated with a nerve terminal volume increase(mechanical spike),and that accompanies excitation of the neurohy-pophysial terminals by the invading action potential;the second(S-wave)is the slower light-scattering decrease that is tightly corelated with the secretion of the peptide hormones oxytocin and arginine vasopressin,and the third is the long duration response(R-wave)that reflects cell volume changes in the pars interrmedia.We have studied the E-wave and the S-wave in earlier publications.The R-wave,considered here,is sensitive to chloride replacement as wel as to blockade of chloride channels.By blocking GABAA reeptors(which are ligand gated chloride channels)with pharrmacological agents,and by applying GABA directly into the bathing solution,or evoking its release from GABAergic inputs,we have demonstrated that this long-duration optical response is sensitive to chloride movements and reflects GABA-induced changes in the intrinsic optical propertis of the pars intermedia.The full time course of this optical response takes mimutes and,therefore,has to embody some other process(or processes)related to the restoration of resting physiological chloride concentrations,following the opening and closing of GABA A-reeptor channels.Here we demonstrate that the shape of the R wave,the longlasting light-scattering signal,is indeed affected by the activity of GAT1,one of the sodium-and.chloridedependent GA BA transporters.

关 键 词：Light scattering posterior pituitary pars nervosa NEUROHYPOPHYSIS volume changes pars intermedic GABAA receptors 

分 类 号：Q95[生物学—动物学]