Developmental exposure to intranasal vasopressin impacts adult prairie vole spatial memory.

Spatial memory is critical for many tasks necessary for survival (i.e., locating mates and food resources). The two mammalian nonapeptides arginine vasopressin (AVP) and oxytocin (OT) are mechanistically important in modulating memory ability, albeit in contrasting ways. In general, AVP facilitates memory consolidation and retrieval while OT is an amnesic. Although AVP and OT are known to have these memory effects, past work has focused on their impact in social memory with little research on their effects on spatial memory. In this experiment, we tested the impact of AVP and OT on spatial memory as determined by performance in the Morris water maze (MWM). We administered doses of AVP, OT, or saline (a control) intranasally to male prairie voles (Microtus ochrogaster), a species whose spatial memory is hypothesized to impact their mating tactics. We also investigated if acute doses (given immediately prior to the memory trial in the MWM) and chronic doses (given daily during adolescence) had differing impacts on spatial cognition. We found that chronic intranasal administration of AVP during post-wean development improved spatial memory performance. In contrast, both chronic and acute administration of OT and acute administration of AVP had no impact on spatial memory. These results together suggest that 1) chronic exposure to AVP has organizational effects on spatial memory in the prairie vole, and 2) acute administration of nonapeptides does not impact the retrieval of spatial memories.