Cyclic changes and actions of progesterone and allopregnanolone on cognition and hippocampal basal (stratum oriens) dendritic spines of female rats.

Cyclic changes and actions of progesterone and allopregnanolone on cognition and hippocampal basal (stratum oriens) dendritic spines of female rats.
Behav Brain Res. 2019 Nov 12;:112355
Authors: Barreto Cordero LM, Carrillo JR, Roldán-Roldán G, Rasia-Filho AA, Flores G, Bringas ME, Briones-Aranda A, Picazo O
Abstract
Ovarian steroids modulate the neuronal structure and function during the estrous cycle, contrasting peak effects during the proestrus cycle and low effects during the metestrus cycle. An ovariectomy (OVX) decreases gonadal hormones and tests the effects of substitutive therapies. We studied female rats with a normal estrous cycle and we also studied the effects of systemic progesterone (P4, 4.0 mg/kg) or its reduced metabolite allopregnanolone (ALLO, 4.0 mg/kg, both for 10 days) in females who had had an OVX 16.5 weeks prior to the study (long-term OVX) with the novel object recognition test (NORT) for associative memory. The dendritic shape and spine density in Golgi-impregnated basal dendrites (stratum oriens) of hippocampal pyramidal neurons was also studied. Proestrus females had a better performance than metestrus or OVX females in short-term memory (tested 1 h after the acquisition phase). Proestrus and metestrus females showed better results than OVX females for long-term memory (24 h after the initial phase). Both P4 and ALLO recovered the cognitive impairment induced by long-term OVX. Also, proestrus f...

Source: Behavioural Brain Research - November 11, 2019 Category: Neurology Authors: Barreto Cordero LM, Carrillo JR, Roldán-Roldán G, Rasia-Filho AA, Flores G, Bringas ME, Briones-Aranda A, Picazo O Tags: Behav Brain Res Source Type: research