Schedule of Events | Symposia

The Cerebello-Hippocampal Circuit: Sex Differences and Hormones in Aging

Poster Session D - Monday, March 31, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Tracey H. Hicks¹, Thamires N.C. Magalhaes¹, Jessica A. Bernard¹; ¹Texas A&M University

Function of the cerebellum and hippocampus predict neuropathology and cognitive decline in OA and direct cerebello-hippocampal (CB-HP) interactions have been observed in animal models. We examined the CB-HP circuit at rest (fcMRI) in OA and sex differences therein. We also quantified relationships between CB-HP connectivity and hormone levels.138 healthy adults (aged 35-86, 53% female) completed fcMRI and provided saliva samples to quantify 17β-estradiol and progesterone. We predicted: 1) lower CB-HP connectivity with increased age; 2) positive relationships between CB-HP and 17β estradiol levels; 3) lower CB-HP with greater progesterone levels; and 4) greater CB-HP connectivity in females as compared to males. Using ROI-to-ROI connectivity in the CONN toolbox and corrected for false discovery rate (FDR), we found lower CB-HP connectivity in several CB and HP nodes with increased age (F(3,134) = 8.68; pFDR <0.001), greater CB-HP connectivity with increased estradiol levels (F(3,124) = 6.81; pFDR = 0.003), and lower CB-HP connectivity with increased progesterone (F(3,134) = 8.68; pFDR <0.001). CB-HP did not demonstrate significant sex differences (pFDR > 0.05). These results suggest that progesterone and estradiol modulate CB-HP connectivity and that this circuit connectivity is lower in advanced age. Women experience up to a 90% decrease in ovarian estradiol production after the menopausal transition, implicating the CB-HP circuit as an area of vulnerability for postmenopausal women.

Topic Area: METHODS: Neuroimaging