Fluctuations in brain concentrations of neurosteroids are not associated to changes in gephyrin levels.
Fluctuations in the brain concentrations of neurosteroids are accompanied by changes in the expression of GABA(A) receptor subunits in the cerebral cortex and hippocampus. Here, we investigated the expression of the postsynaptic molecule gephyrin in the cerebral cortex and hippocampus of pregnant rats, as well as in rats treated chronically with contraceptive drugs. The amounts of gephyrin mRNA and protein did not change during pregnancy and after delivery, as well as in rats treated with ethynylestradiol (EE) and levonorgestrel (LNG) for 4 weeks. Similarly, using immunofluorescence and laser scanning confocal microscopy, we did not detect significant changes in the number and size of gephyrin-immunopositive clusters, which likely represent inhibitory postsynaptic sites. These findings indicate that the expression of gephyrin and the density of cortical inhibitory synapses are not influenced by endogenous neurosteroids.
Sassoè-Pognetto
Marco
M
Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, and Istituto Nazionale di Neuroscienze, Corso Massimo d'Azeglio 52, I-10126 Torino, Italy. marco.sassoe@unito.it
Follesa
Paolo
P
Panzanelli
Patrizia
P
Perazzini
Alice-Zaira
AZ
Porcu
Patrizia
P
Sogliano
Cristiana
C
Cherchi
Claudia
C
Concas
Alessandra
A
D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects / Q000502:physiology; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D016912:Levonorgestrel / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism; D013569:Synapses / Q000187:drug effects / Q000378:metabolism*; D013570:Synaptic Membranes / Q000187:drug effects / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D002352:Carrier Proteins; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D008565:Membrane Proteins; D012333:RNA, Messenger; D011963:Receptors, GABA-A; C073441:gephyrin; D004997:Ethinyl Estradiol; D011374:Progesterone; D004958:Estradiol; D016912:Levonorgestrel