TY - JOUR
T1 - Cyclic changes and actions of progesterone and allopregnanolone on cognition and hippocampal basal (stratum oriens) dendritic spines of female rats
AU - Barreto-Cordero, Lorna Marcela
AU - Ríos-Carrillo, Jorge
AU - Roldán-Roldán, Gabriel
AU - Rasia-Filho, Alberto A.
AU - Flores, Gonzalo
AU - Bringas, María Elena
AU - Briones-Aranda, Alfredo
AU - Picazo, Ofir
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/2/3
Y1 - 2020/2/3
N2 - 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 females had a higher density of dendritic spines than metestrus females, OVX reduced the density of spines when compared to intact females, whereas both P4 and ALLO treatments increased the dendritic spine density, number of dendritic branches along the dendritic length, and branching order compared to vehicle. These data add the dendrites of the stratum oriens as an additional site for naturally occurring changes in spine density during the estrous cycle and evidence the actions of progestins in both behavioral recovery and the structural dendritic rearrangement of hippocampal pyramidal neurons in long-term OVX female rats.
AB - 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 females had a higher density of dendritic spines than metestrus females, OVX reduced the density of spines when compared to intact females, whereas both P4 and ALLO treatments increased the dendritic spine density, number of dendritic branches along the dendritic length, and branching order compared to vehicle. These data add the dendrites of the stratum oriens as an additional site for naturally occurring changes in spine density during the estrous cycle and evidence the actions of progestins in both behavioral recovery and the structural dendritic rearrangement of hippocampal pyramidal neurons in long-term OVX female rats.
KW - Allopregnanolone
KW - CA1/CA2 subfields
KW - Dendritic morphology
KW - Estrous cycle
KW - Novel object test
KW - Progesterone
UR - http://www.scopus.com/inward/record.url?scp=85075540177&partnerID=8YFLogxK
U2 - 10.1016/j.bbr.2019.112355
DO - 10.1016/j.bbr.2019.112355
M3 - Artículo
C2 - 31730784
AN - SCOPUS:85075540177
SN - 0166-4328
VL - 379
JO - Behavioural Brain Research
JF - Behavioural Brain Research
M1 - 112355
ER -