Pregnancy improves cognitive deficit and neuronal morphology atrophy in the prefrontal cortex and hippocampus of aging spontaneously hypertensive rats

Abstract

It is well known that the survival is higher in women compared to men and women have a better survival prognosis than men in some pathologies such as vascular dementia (VD). Our previous reports showed that the spontaneously hypertensive (SH) rat, an animal model of VD, exhibited dendritic atrophy of pyramidal neurons of the dorsal hippocampus (DH) and the prefrontal cortex (PFC) at 8 months of age. Cerebrolysin (CBL), a neurotrophic peptide mixture, reduces dendritic atrophy and improves the memory process in aged rats. Here, we investigated whether one pregnancy or/and CBL was capable of improving cognitive behavior and neuronal alterations in old female SH rats. Diastolic and systolic blood pressure were assessed before pregnancy (3 months old) and CBL administration (6 months old), and after CBL administration (12 months old). Immediately after of 6 months of CBL treatment, locomotor activity in novel environments and memory and learning by the Morris Water Maze test were evaluated. By the Golgi-Cox staining method, dendritic parameters were assessed in PFC and DH. Our results suggest that rats with one pregnancy showed better memory with an enhancement in dendritic length and dendritic spine density in the aforementioned regions.

The neuropeptide‐12 improves recognition memory and neuronal plasticity of the limbic system in old rats

“…N‐PEP‐12 also increases SYP and BDNF and reduces reactive gliosis in elderly animals. However, it is suggested that this dietary supplement formed by different neuropeptides with trophic action increases BDNF levels in different brain regions such as the hippocampus and PFC (Cabrera‐Pedraza et al, ; Hutter‐Paier et al, ; Solis‐Gaspar, Vazquez‐Roque, De Jesús Gómez‐Villalobos, & Flores, ), similar to what was observed in our results, where a greater immunoreactivity was shown for this neurotrophin in the five brain areas studied in elderly animals treated with N‐PEP‐12. In this sense, the expression of BDNF activates mechanisms of cell survival and protection, promotes the stimulation of synaptic connections, and increases the number of dendritic spines, as well as the dendritic tree, as our results show (Harward et al, ; Ohta et al, ).…”

Juvenile stress causes reduced locomotor behavior and dendritic spine density in the prefrontal cortex and basolateral amygdala in Sprague–Dawley rats

“…In addition, by its characteristic conical shape, the ends of the dendrites must be positively identified to be included in the study. The pyramidal neurons were easily identified by the triangular form of their soma and by the extension of the apical dendrite toward the pial surface, apart from numerous dendritic spines (Cabrera‐Pedraza et al, ; Solís‐Gaspar et al, ; Tendilla‐Beltrán et al, ; Vidal et al, ). In the case of the PFC and CA1 region of DH and VH, the present analysis was performed on the basal dendrites, as they run parallel to the coronal plane.…”

“…Another assessment, the number of dendritic spines, was assessed by randomly selecting high‐magnification (1,000×) tracing of a 10‐µm‐long terminal segment of the distal branch exceeded 40 µm. Measurements of spine density were generated by counting the number of visible spines along the branch segment and expressing the data as number spines/10 µm (Cabrera‐Pedraza et al, ; Juarez et al, ; Juárez‐Méndez et al, ; Martinez‐Tellez., ; Monroy et al, ).…”

Pregnancies alters spine number in cortical and subcortical limbic brain regions of old rats

“…With puberty the female brain is exposed to hormonal variations, primarily, the hormones related to the estrous cycle and second, at adult age, with the placental trophic factors and hormones related to gestation (for review see Dhoable, ; Sahay, Sundrani, & Joshi, ; Sahay, Sundrani, Wagh, Mehendale, & Joshi, ). Our recent report showed that one pregnancy improves the memory and learning process in aged spontaneously hypertensive (SH) female rats (12 months) (Cabrera‐Pedraza et al, ). In addition, the aged SH rats are considered an animal model of vascular dementia (Flores, Flores‐Gómez, & de Jesús Gómez‐Villalobos, ).…”