Numerous studies suggest an essential role for the intermediate (IRt) and parvocellular (PCRt) reticular formation (RF) in consummatory ingestive responses. Although the IRt and PCRt contain a large proportion of neurons with projections to the oromotor nuclei, these areas of the RF are heterogeneous with respect to neurotransmitter phenotypes. Glutamatergic, GABAergic, cholinergic, and nitrergic neurons are all found in the PCRt and IRt, but the projections of neurons with these phenotypes to the motor trigeminal (mV) and hypoglossal nucleus (mXII) has not been fully evaluated. In the present study, after small injections of Fluorogold (FG) into mV and mXII, sections were processed immunohistochemically to detect retrogradely labeled FG neurons in combination with the synthetic enzymes for nitric oxide (nitric oxide synthase) or acetylcholine (choline acetyltransferase) or in situ hybridization for the synthetic enzyme for GABA (GAD65/67) or the brainstem vesicular transporter for glutamate (VGLUT2). In three additional cases, FG injections were made into one motor nucleus and cholera toxin (subunit b) injected in the other to determine the presence of dual projection neurons. Premotor neurons to mXII (pre-mXII) were highly concentrated in the IRt. In contrast, there were nearly equal proportions of premotor-trigeminal neurons (pre-mV) in the IRt and PCRt. A high proportion of pre-oromotor neurons were positive for VGLUT2 (pre-mXII: 68%; pre-mV: 53%) but GABAergic projections were differentially distributed with a greater projection to mV (25%) compared to mXII (8%). Significant populations of cholinergic and nitrergic neurons overlapped pre-oromotor neurons, but there was sparse double-labeling (<10%). The IRt also contained a high proportion of neurons that projected to both mV and MXII. These different classes of premotor neurons in the IRt and PCRt provide a substrate for the rhythmic activation of lingual and masticatory muscles.

To investigate the association between visit-to-visit variability in blood pressure and the incidence of dementia and its subtypes in a general population, we conducted a population-based retrospective cohort study using the Korean National Health Insurance System database. We identified 7 844 814 subjects without a history of any dementia who underwent ≥3 health examinations from 2005 to 2012 in the Korean National Health Insurance System cohort. Blood pressure variability (BPV) was measured using the variability independent of the mean, coefficient of variation, and SD. During the median follow-up of 6.2 years, there were 200 574 cases of all-cause dementia (2.8%), 165 112 cases of Alzheimer’s disease (2.1%), and 27 443 cases of vascular dementia (0.3%). There was a linear association between higher BPV and outcome measures. In the multivariable adjusted model, the hazard ratios and 95% CIs of all-cause dementia were 1.06 (1.04–1.07) for the highest quartile of variability independent of the mean of diastolic blood pressure only, 1.09 (1.08–1.11) for that of systolic blood pressure only, and 1.18 (1.16–1.19) for that of both systolic and diastolic blood pressure compared with subjects having no highest quartile for BPV. Consistent results were noted for Alzheimer’s disease and vascular dementia using other indices of variability and in various sensitivity and subgroup analyses. BPV is an independent predictor for developing dementia and its subtypes. A dose-response relationship was noted between higher BPV and dementia incidence. Reducing BPV may be a target for preventing dementia in the general population.

Background and purpose The aim was to investigate whether female reproductive factors are associated with dementia. Methods In all, 4 696 633 post‐menopausal women without dementia were identified using the Korean National Health Insurance System database. Data on reproductive factors were collected using a self‐administered questionnaire. Dementia was determined using dementia diagnosis codes and anti‐dementia drug prescription. Cox proportional hazards regression was conducted to assess the hazard ratio (HR) for dementia according to reproductive factors. Results During a median follow‐up of 5.74 years, there were 212 227 new cases of all‐cause dementia (4.5%), 162 901 cases of Alzheimer’s disease (3.5%) and 24 029 cases of vascular dementia (0.5%). The HR of dementia was 1.15 [95% confidence interval (CI) 1.03–1.16] for menarcheal age ≥17 years compared with menarcheal age 13–14 years, 0.79 (0.77–0.81) for menopausal age ≥55 years compared with menopausal age <40 years, and 0.81 (0.79–0.82) for fertility duration ≥40 years compared with fertility duration <30 years. Whilst being of parity one (HR 0.89, 95% CI 0.85–0.94) and breastfeeding <6 months (HR 0.92, 95% CI 0.88–0.95) was associated with lower risk of dementia, being of parity two or more (HR 1.04, 95% CI 0.99–1.05) and breastfeeding ≥12 months (HR 1.14, 95% CI 1.01–1.07) was associated with a higher risk of dementia than women without parity or breastfeeding history. Use of hormone replacement therapy and oral contraceptives independently reduced the dementia risk by 15% and 10%, respectively. Conclusions Female reproductive factors are independent risk factors for dementia incidence, with higher risk associated with shorter lifetime endogenous estrogen exposure.

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IMPORTANCEAlthough estrogen level is positively associated with bone mineral density, there are limited data on the risk of fractures after menopause. OBJECTIVE To investigate whether female reproductive factors are associated with fractures among postmenopausal women. DESIGN, SETTING, AND PARTICIPANTS This population-based retrospective cohort study used data from the Korean National Health Insurance Service database on 1 272 115 postmenopausal women without previous fracture who underwent both cardiovascular and breast and/or cervical cancer screening from January 1 to December 31, 2009. Outcome data were obtained through December 31, 2018. EXPOSURES Information was obtained about reproductive factors (age at menarche, age at menopause, parity, breastfeeding, and exogenous hormone use) by self-administered questionnaire. MAIN OUTCOMES AND MEASURES Incidence of any fractures and site-specific fractures (vertebral, hip, and others). RESULTSAmong the 1 272 115 participants, mean (SD) age was 61.0 (8.1) years. Compared with earlier age at menarche (Յ12 years), later age at menarche (Ն17 years) was associated with a higher risk of any fracture (adjusted hazard ratio [aHR], 1.24; 95% CI, 1.17-1.31) and vertebral fracture (aHR, 1.42; 95% CI, 1.28-1.58). Compared with earlier age at menopause (<40 years), later age at menopause (Ն55 years) was associated with a lower risk of any fracture (aHR, 0.89; 95% CI, 0.86-0.93), vertebral fracture (aHR, 0.77; 95% CI, 0.73-0.81), and hip fracture (aHR, 0.88; 95% CI, 0.78-1.00). Longer reproductive span (Ն40 years) was associated with lower risk of fractures compared with shorter reproductive span (<30 years