, 2001a,b; Garcia-Osta et al., Bcl-2 pathway 2006; Nikitin, 2007), neuroinflammation
(Cardinaux et al., 2000; Ejarque-Ortiz et al., 2007; Straccia et al., 2011; Fields & Ghorpade, 2012), neurogenesis, and neuronal proliferation and differentiation (Cortés-Canteli et al., 2002; Calella et al., 2007; Aguilar-Morante et al., 2011), whereas its role in neuronal survival/apoptosis remains unclear. In fact, C/EBP β induces the expression of genes involved in brain injury and inflammatory processes; it is upregulated after ischemic injury and in a mouse model of hippocampal kainate excitotoxicity, as well as in adult hippocampal neurogenesis (Cortés-Canteli et al., 2004, 2008, 2011; Sandhir & Berman, 2010; Rininger et al., 2012). In cortical neurons, C/EBP β expression is induced after hypoxic stress, supporting neuronal survival by inhibiting p53 (Halterman et al., 2008). On the other hand, C/EBP β induces apoptosis in neuroblastoma through p53 activation (Cortés-Canteli et al., 2002). In primary cultures of rat cerebellar granule neurons (CGNs), high Ca2+ influx through N-methyl-d-aspartate (NMDA) receptors increases find more nuclear C/EBP β levels and induces excitotoxic neuronal death (Marshall et al., 2003). However, no studies so far have studied the expression of all C/EBP β isoforms in survival/apoptotic conditions. To fill this gap, we used neuronal primary cultures and induced apoptosis, in order
to study the role of C/EBP β isoforms in neuronal survival/death. Primary cultures of CGNs were prepared from 7-day-old Wistar Han Outbred Rat pups derived from a local animal house (Gallo et al., 1987). All animal experiments were authorized
by a local bioethical committee (Protocol no. 17-72-1212), and experiments were carried out in accordance with the European Communities Council Directive of 24 November 1986 (86/609/EEC). Animal health and comfort were veterinarily controlled. For all experiments presented here, a total number of 72 pups were used. Briefly, animals were rapidly anesthetized with an ice-cold treatment, and killed by decapitation; cerebella were removed and dissected from their meninges in Krebs’ buffer containing 0.3% bovine serum albumin (BSA). Cerebella were then dissociated with trypsin at 37 °C for 15 min, and triturated by use of a Pasteur pipette, in a 0.125 mg/mL Ergoloid DNaseI/0.52 mg/mL soybean trypsin inhibitor solution. Dissociated cells were collected by centrifugation, resuspended in Basal Medium Eagle (Invitrogen, DH Breda, NL, USA), supplemented with 2 mm glutamine, 100 μm gentamicin sulfate, 10% inactivated fetal bovine serum (Invitrogen), and 25 mm KCl, and plated in plastic dishes, previously coated with poly-l-lysine (0.01 mg/mL), at a density of 2.2 × 106 cells per 35-mm dish. After incubation for 16 h at 37 °C in a 95% air/5% CO2 (v/v) atmosphere, 10 μm cytosine arabinofuranoside was added to reduce proliferation of non-neuronal cells.