Project description:This experiment examined K63 polyubiquitin protein targets in the male and female hippocampus after contextual fear conditioning. Samples were the CA1 region of the dorsal hippocampus collected from male and female Sprague-Dawley rats that were 8-9 weeks old. Samples were collected 1 hour after contextual fear conditioning (Trained) or from non-stimulated controls (Naïve).
Project description:This experiment examined K63 polyubiquitin protein targets in the male and female hippocampus after contextual fear conditioning. Samples were the CA1 region of the dorsal hippocampus collected from male and female Sprague-Dawley rats that were 8-9 weeks old. Samples were collected 1 hour after contextual fear conditioning (Trained) or from non-stimulated controls (Naïve).
Project description:naïve and trained rats 24 hours after exposure to the contextual fear conditioning paradigm. Biological replicates: 4 naïve and 4 trained animals, independently conditioned and tissues were independently isolated. One replicate per array.
Project description:naïve and trained rats 24 hours after exposure to the contextual fear conditioning paradigm. Biological replicates: 3 independent pools of 3 animals each, 6 naïve and 6 trained animals, independently conditioned and tissues were independently isolated. One replicate per array.
Project description:Quantitative proteomic analysis was used to identify the proteins associated with a formation of fear memory in mice. The proteins from the hippocampal region were isolated from three groups of trained aminals representing aquisition, consolidation and retrieval of a contextual fear conditioning. The samples were digested by trypsin, analyzed by LC-MSMS followed by protein identification and label-free quantitation using MaxQuant 1.3.0.5. Each group consisted of three individuals and each sample was processed in two technical replicates.
Project description:Extinction learning refers to the phenomenon that a previously learned response to an environmental stimulus, for example the expression of an aversive behavior upon exposure to a specific context, is reduced when the stimulus is repeatedly presented in the absence of a previously paired aversive event. Extinction of fear memories has been implicated with the treatment of anxiety disease but the molecular processes that underlie fear extinctionare only beginning to emerge. Here we show that fear extinction initiates up-regulation of hippocampal insulin-growth factor 2 (Igf2) and down-regulation of insulin-growth factor binding protein 7 (Igfbp7). In line with this observation we demonstrate that IGF2 facilitates fear extinction, while IGFBP7 impairs fear extinction in an IGF2-dependent manner. Furthermore, we identify one cellular substrate of altered IGF2-signaling during fear extinction. To this end we show that fear extinction-induced IGF2/IGFBP7-signaling promotes the survival of 17-19 day-old newborn hippocampal neurons. In conclusion, our data suggests that therapeutic strategies that enhance IGF2-signaling and adult neurogenesis might be suitable to treat disease linked to excessive fear memory. We employed mice to investigate fear extinction in the hippocampus-dependent contextual fear conditioning paradigm. To this end, male C57BL/6J mice were exposed to the fear conditioning box (context) followed by an electric foot-shock which elicits the acquisition of conditioned contextual fear. For extinction training animals were repeatedly reexposed to the conditioned context on consecutive days (24h interval) without receiving the footshockagain (extinction trial, E). This procedure eventually results in the decline of the aversive freezing behavior. Mice that were exposed to the conditioning context without receiving fear conditioning training served as control groups. To gain a better understanding of the molecular processes underlying fear extinction we performed a genome-wide analysis of the hippocampal transcriptome during fear extinction. In the employed paradigm fear extinction is a gradual process. To capture the longitudinal course of fear extinction we decided to perform hippocampal microarray analysis at two time points: (1) After the first extinction trial (E1) when animals display high levels of aversive freezing behavior and (2) at the extinction trial on which the freezing behavior was significantly reduced when compared to E1. This extinction trial, in the case of this experiment E5, we termed “extinction trial low freezing” (ELF). Mice that were exposed to the conditioning context without receiving fear conditioning training served as control groups (3). For all three groups we hybridized 5 samples (biological replicates).
