Social Investigation and Long-Term Recognition Memory Performance in 129S1/SvImJ and C57BL/6JOlaHsd Mice and Their Hybrids

Mario Engelmann,Jana Hädicke,Neil R Smalheiser

doi:10.1371/journal.pone.0054427

Mario Engelmann, Jana Hädicke + Show 1 more

Open Access

https://doi.org/10.1371/journal.pone.0054427

Copy DOI

Abstract

When tested for their behavioural performance, the mixed genetic background of transgenic mice is a critical, but often ignored, issue. Such issues can arise because of the significant differences in defined behavioural parameters between embryonic stem cell donor and recipient strains. In this context, the commonly used stem cell donor strain ‘129’ shows ‘deficits’ in different paradigms for learning and long-term memory. We investigated the long-term social recognition memory performance and the investigative behaviour in commercially available 129S1/SvImJ and C57BL/6JOlaHsd mice and two F1-hybrids (129S1/SvImJ×C57BL/6JOlaHsd) by using the social discrimination procedure and its modification, the volatile fraction cage (VFC). Our data revealed an unimpaired olfactory long-term recognition memory not only in female and male 129S1/SvImJ and C57BL/6JOlaHsd mice but also in the two hybrid lines (129S1/SvImJxC57BL/6JOlaHsd) when the full ‘olfactory signature’ of the ‘to-be-recognized’ conspecific was presented. Under these conditions we also failed to detect differences in the long-term recognition memory between male and female mice of the tested strains and revealed that the oestrus cycle did not affect the performance in this memory task. The performance in the VFC, based only on the volatile components of the ‘olfactory signature’ of the ‘to-be-recognized’ conspecific, was similar to that observed under direct exposure except that females of one F1 hybrid group failed to show an intact long-term memory. Thus, the social discrimination procedure allowing direct access between the experimental subject and the stimulus animal(s) is highly suitable to investigate the impact of genetic manipulations on long-term memory in male and female mice of the strain 129S1/SvImJ, C57BL/6JOlaHsd and 129S1/SvImJxC57BL/6JOlaHsd hybrids.

Highlights

There is increasing evidence that inbred mouse strains differ in their behavioural profile
The design of molecular tools for manipulating the mouse genome is continually progressing, the mixture of genetic material from different mouse strains remains critical [10,11,12,13]. To cope with these mouse strain-differences, guidelines were proposed to enable the use of mutant mice in tasks in which 129 mice show a very poor learning and memory performance and – very recently – a report suggested using animals of the C57BL/6N strain as stem cell donors [14]
We investigated the social investigation and olfactory cued social recognition memory of 129S1/SvImJ and C57BL/6JOlaHsd mice and two hybrid lines obtained from the parental strains

Summary

Introduction

There is increasing evidence that inbred mouse strains differ in their behavioural profile. The design of molecular tools for manipulating the mouse genome is continually progressing, the mixture of genetic material from different mouse strains remains critical [10,11,12,13] To cope with these mouse strain-differences, guidelines were proposed to enable the use of mutant mice in tasks in which 129 mice show a very poor learning and memory performance (e.g. numerous backcrosses to reduce the genetic material of the 129 strain) and – very recently – a report suggested using animals of the C57BL/6N strain as stem cell donors [14]. A recent study reports impaired social memories in 129P2 inbred mice [19] when tested in the ‘‘social recognition procedure’’ originally established in 1987 for testing social memory in rats [20]

Methods

Results

Conclusion