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

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.

Prenatal amphetamine exposure effects on dopaminergic receptors and transporter in postnatal rats.

We investigated the influence of prenatal amphetamine exposure (PAE) on dopamine (DA) receptors, and dopamine transporter (DAT) in various striatal and limbic subregions and locomotor activity induced by novel environmental conditions and amphetamine at two postnatal ages, 35 days old (prepubertal) and 60 days old (postpubertal). Experiments were carried out on pregnant female Sprague-Dawley rats, which were daily injected with either d-amphetamine sulfate (1 mg/kg) or saline solution (0.9%) for 11 days, from gestation day 11-21. In PAE rats compared to control we found the following: at pre-pubertal age, an enhancement of DA D1 in the dorsolateral area of the caudate-putamen (CPu), CPu-ventral and shell of the nucleus accumbens (NAcc) with a decrement of the DA D3 receptors in NAcc, olfactory tubercle (OT), and the islands of Calleja (IoC); whereas at postpubertal age, an increase in the levels of DAT in the NAcc and fundus of the CPu, and OT along with a decrease in the expression of DA D2 receptors only in the NAcc shell were found in PAE rats compared to control. In addition, amphetamine induces a marked decrease in locomotor activity at postpubertal age in rats with PAE. These results suggest a differential effect of amphetamines on the DAT mechanism of the nervous system during embryonic development of animals with implications in behavior and drug addictions at adulthood age.