Progesterone rapidly alters the use of place and response memory during spatial navigation in female rats

170-Estradiol (E2) and progesterone (P) influence place and response memory in female rats in spatial navigation tasks. Use of these memory systems is associated with the hippocampus and the dorsal striatum, respectively. Injections of E2 result in a well-established bias to use place memory, while much less is understood about the role of P. A total of 120 ovariectomized female rats were tested within a dual-solution T-maze task and treated with either low E2 (n = 24), high E2 (10 mu g/kg; n = 24), or high E2 in combination with P (500 mu g/kg) at three time points before testing: 15 min (n = 24), 1 h (n = 24), and 4 h (n = 24). Given alone, high E2 biases rats to the use of place memory, but this effect is reversed when P is given 1 h or 4 h before testing. This indicates that P may be playing an inhibitory role in the hippocampus during spatial tasks, which is consistent with past findings. Our findings show that P acts rapidly (within an hour) to affect performance during spatial tasks.

Automated summary

The study found that progesterone may play an inhibitory role in the hippocampus during spatial tasks, while estradiol shows a preference for place memory. However, this effect is reversed when progesterone is used in combination with estradiol, and progesterone can rapidly affect performance within an hour.