The formation of social relationships via social interactions and memory are essential for one’s physical and mental health. To date, rodent studies have used the three-chamber social approach test to measure social approach, social novelty, and social memory. In recent years, techniques including optogenetics have been developed to acutely control the activity of genetically defined populations of neurons. Recent studies have even combined optogenetics with advanced temporal gene expression control systems to label certain populations of neurons during learning and subsequently reactivated for memory testing. We combined optogenetic targeting with the three-chamber social approach test to examine particular neural circuits of interest during social memory encoding or retrieval. First, we stereotaxically infected specific brain areas with viral-encoding opsins that acutely activate or inhibit the firing of the neurons. Next, we subjected the mice to the three-chamber behavioral paradigm while delivering light during social memory encoding or retrieval. Lastly, the mice were tested with the delivery of light in a counter-balanced manner which allows each subject to be its own internal control. Thus, the optogenetic stimulation coupled with the three-chamber social approach test is a well-validated paradigm to explore the contribution of diverse brain circuits in various social cognition processes.

Behavioural tests based on the spontaneous recognition paradigm have been used extensively for examining the memory capacity of rodents. By exploiting their innate preference to investigate novel stimuli, inferences can be drawn about the perceived familiarity of encountered objects. Olfaction is the dominant sense used by mice to navigate their environment, yet these tests are often conducted using visual objects. By employing odors, one can reduce the high level of variability commonly observed between subjects. In this paper, we describe a protocol for assessing context-dependent odor memory by probing spatial and temporal associations separately or in conjunction with each other. We also detail a context-independent novel odor recognition protocol. These tests offer a simple and effective method for measuring odor memory in rodents using cheap and easily obtained materials.