Abstract
Ovarian hormones, such as estrogens and progesterone, are known to exert beneficial effects on cognition and some psychiatric disorders. The basis of these effects is not fully understood, but may involve altered cholinergic neurotransmission. This study aimed to investigate how a lack of ovarian hormones would impact muscarinic receptor-induced deficits in prepulse inhibition (PPI) and muscarinic receptor density in several brain regions. Adult female rats were either ovariectomized, to remove the source of ovarian hormones, or left intact (sham-operated). PPI is a measure of sensorimotor gating that is typically impaired in schizophrenia patients, and similar deficits can be induced in rats by administering scopolamine, a muscarinic receptor antagonist. Our results revealed no significant effects of ovariectomy on PPI after saline or scopolamine treatment. Autoradiography was performed to measure cholinergic muscarinic receptor binding density using [3H]-pirenzepine, [3H]-AF-DX, and [3H]-4-DAMP, to label M1, M2/M4, and M3 receptors, respectively. We examined the amygdala, caudate putamen, dorsal hippocampus, motor cortex, retrosplenial cortex, and ventromedial hypothalamus. There were no significant group differences in any region for any muscarinic receptor type. These results suggest that removing peripheral ovarian hormones does not influence the cholinergic muscarinic receptor system in the context of PPI or receptor binding density.
Highlights
Current data suggest that female ovarian hormones can improve cognitive function [1,2,3] and reduce symptom severity in neuropsychiatric disorders, such as schizophrenia [4]
The main effect of drug was observed (F(1,18) = 51.20, p < 0.001), reflecting the disruption of prepulse inhibition (PPI) caused by scopolamine treatment in intact rats (F(1,9) = 45.41, p < 0.001) and OVX rats (F(1,9) = 15.49, p =
We did not observe any effects of ovariectomy on scopolamine-induced impairments in PPI, nor did we detect any significant changes in the binding density of M1, M2 /M4, and M3 receptors in the amygdala, caudate putamen, dorsal hippocampus, motor cortex, retrosplenial cortex, or ventromedial hypothalamus of OVX rats relative to intact rats
Summary
Current data suggest that female ovarian hormones can improve cognitive function [1,2,3] and reduce symptom severity in neuropsychiatric disorders, such as schizophrenia [4]. Brain Sci. 2020, 10, 106; doi:10.3390/brainsci10020106 www.mdpi.com/journal/brainsci. There is evidence to suggest that the impact of ovarian hormones on the symptoms of schizophrenia varies across the reproductive lifespan of women, which is underscored by changing levels of hormones, including the main ovarian hormones, estrogen and progesterone [8,9,10]. Overall, these factors lead to a less severe course of illness, milder symptoms, and superior treatment outcomes in women.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
