Social recognition memory requires two stages of protein synthesis in mice

Abstract

Olfactory recognition memory was tested in adult male mice using a social discrimination task. The testing was conducted to begin to characterize the role of protein synthesis and the specific brain regions associated with activity in this task. Long-term olfactory recognition memory was blocked when the protein synthesis inhibitor anisomycin was injected 20 min before, immediately after, or 6 h after sampling. No effect was observed when anisomycin was administered 3 h or 18 h after sampling. Immunohistochemical analysis of Fos expression revealed that sampling-like exposure to a juvenile increased the activity of a subset of cells in the accessory olfactory bulb and the brain areas that are associated with it. Additionally, increased Fos expression was measured in the main olfactory bulb and the piriform cortex, whereas no signs of activation were seen in the cortical nucleus of the amygdala, all components of the main olfactory system. No increases in Fos immunoreactivity were observed after 4 h. Our data suggest that long-lasting olfactory recognition memory requires two stages of protein synthesis. The first stage takes place within 1–2 h and the second stage between 6–7 h after sampling. The first but not the second stage is paralleled by an increase in the number of Fos-immunoreactive cells in brain areas associated with both the main and accessory olfactory systems. It therefore appears that the role of the second stage of protein synthesis in recognition memory depends on the integrity of the first stage of protein synthesis

C-tactile afferents: Cutaneous mediators of oxytocin release during affiliative tactile interactions?

“…Perhaps reflecting the importance of these brain regions for regulating maternal behaviour, such as recognition of pup vocalisations & scents (Cohen et al, 2015;Richter et al, 2005), gender differences in oxytocin receptor expression have been reported. For example, denser receptor expression was found in the piriform cortex in female compared to male mice .…”

A Distributed Network for Social Cognition Enriched for Oxytocin Receptors

“…Scale bar, 100 m. p Ͻ 0.03, ANOVA with Bonferroni correction for multiple comparisons). Piriform cortex is an olfactory area believed to be important for learned odor associations and several forms of social behavior (Haberly and Bower, 1989;Richter et al, 2005;Cohen et al, 2015). Second, hippocampal CA2 in females had more OXTR-2ϩ cells than in other regions of the hippocampal formation (Fig.…”

Dissociation of within- and between-Session Extinction of Conditioned Fear

“…Brains were removed, postfixed in 4% formaldehyde diluted in PBS for 20 h and transferred to 1 M sucrose in PBS for another 20 h. The brains were shock frozen in isobutanol and stored at Ϫ80°C until cryosectioning. Floating frontal sections (40 m) were incubated with an antibody raised against a peptide mapping at the N terminus of human c-Fos p62 (identical to the corresponding mouse sequence; c-Fos sc-42; 1:20000; Santa Cruz Biotechnology) for 4 d. c-Fosimmunoreactive cells were visualized using a biotinylated goat antirabbit secondary antibody (1:2000, Jackson Laboratory) and the ABC method (Richter et al, 2005). The number of c-Fos-immunoreactive cells was determined using a Zeiss microscope (Axiophot) and a computer program (ImageJ; http://rsbweb.nih.gov/ij/).…”