Progesterone influences postischemic synaptogenesis in the CA1 region of the hippocampus in rats

Abstract

Synaptogenesis is considered necessary for learning and memory. Recently, it has been suggested that progesterone (PROG) effects synaptogenesis of the cerebellar Purkinje cell, helps alleviate symptoms of multiple sclerosis and helps arrest spinal cord neurodegeneration. However, it is unclear whether PROG influences synaptic plasticity in central nervous system neurons after global cerebral ischemia. The purpose of the present study was to reveal PROG's influence on postischemic synaptogenesis in the CA1 region of the hippocampus in rats. Global cerebral ischemia was induced in male Sprague-Dawley rats by the 4-vessel occlusion (4-VO) method. To determine the amount of synaptogenesis, growth-associated protein 43 (GAP-43) and synaptophysin (SYP) expression were examined by immunohistochemical, reverse transcription-polymerase chain reaction (RT-PCR) and western blot techniques. Histological and behavioral tests were used to indicate the effect of PROG on global cerebral ischemia. Recovery times were 3, 7, 14, 21, and 35 days after surgery. We found that PROG increased the expression of GAP-43 and SYP. In addition, there was a significant increase in neuronal cell density and improvement ability to remain on an accelerating rotarod observed in the 4-VO rats treated with PROG compared to vehicle. We propose that PROG helped enable synaptogenesis in the CA1 region of therat hippocampus after global cerebral ischemia in rats.

Efficacy of the selective progesterone receptor agonist Nestorone for chronic experimental autoimmune encephalomyelitis

“…A further enhancement of cell proliferation and DCX neuroblast staining was achieved in the EAE + Nestorone group. Positive effects of natural progesterone on hippocampal neurogenesis has been shown after brain trauma (Barha et al, 2011), brain ischemia (Zhao et al, 2011), aging (Frye, 2009) in normal adult mice (Zhang et al, 2010), but not in a neurodegeneration model (Meyer et al, 2013). Our data with Nestorone are in agreement with those reports showing a positive regulatory effect.…”

Regulation of object recognition and object placement by ovarian sex steroid hormones

“…However, like E 2 , P 4 can also enhance hippocampal LTP [84], neurogenesis [85; 86], ERK signaling, and mTOR-dependent local protein synthesis [87]. Nevertheless, understanding how P 4 influences memory is considerably more challenging than E 2 because P 4 serves as an obligatory precursor for the synthesis of other steroids including estrogens, androgens, and glucocorticoids.…”

Morphological Changes in the Suprachiasmatic Nucleus of Aging Female Marmosets (Callithrix jacchus)

“…Progesterone has been shown to exert significant protective effects in a variety of experimental model factors that mimic brain dysfunction seen with old age or neurodegenerative diseases related to age, such as in Alzheimer's disease [44]. Furthermore, it has been shown that progesterone decreases neuronal death resulting from global ischemic episode [45]; it may induce a remyelination of nerve fibers [46], and it increases hippocampal synapses [47]. …”